RT dose/volume and Evidence Every Site Flashcards
Indications/Dose for gastric and gastroesophageal adenocarcinoma adjuvant EBRT chemoradiation:
Rationale and key studies.
Bonus if you can guess the chemo
Concurrent with cisplatin and capecitabine.
Indications
1) Stage:
T3 N+ OR
T3 N0 with positive margins OR
T4 OR N+
ECOG 0-2
2) Adequate nutritional intake
3) Suitable for combined therapy
TOPGEAR (ongoing) looking at NeoAdj 45/25
INT OS/PFS/DM benefit to adj CTRT
BUT CRITICS Trial Peri-op Epirubicin Etop Carboplatin (ECC) c4 then surg then c4 equivalent to ECC surg chemoRT
45/25 (INT Trial) + consider 5.4Gy/3# boost to GTV if can be visualised.
Notify surgeon if both ends of anastomosis likely to be in field.
Chemo
MAGIC (Epirubicin-Cisplatin-5FU), updated to FLOT-4 (5FU-leucovorin-oxaliplatin-docetaxel) (From Neoagis esophagus fame).
Thyroid RAI doses
Iodine 123 study = 2mCi
Ablative dose = 30mCi
ESMO guidelines (US tend to be less):
Adjuvant = 100mCi
micro residual = 150mCi
Metastatic = 200mCi
Retreatment can be considered up to cumulative 600mCi
Dose EBRT for thyroid cancer and indications:
60-70Gy 1.8-2Gy/#
It is optimally used in a small subset of pts w/aggressive locoregional disease.
A single randomized prospective trial failed to recruit adequate patients and only 26 received EBRT. However, a mounting retrospective data showing significant benefit for EBRT in select patients: with gross residual or unresectable locoregional disease, except for patients <45 years old with limited gross disease that is RAI-avid.
High risk prostate cancer: Definitive Brachy + EBRT dose:
Urinary function requirements?
Definitive radiotherapy:
HDR brachytherapy boost, 15Gy/1#
Or 18/2. There is no clear evidence on which dose/fraction schedule is superior, except RCT data suggests multifraction has better local control.
and
46Gy/23# EBRT
and ADT 18-36months (typically 2 years)
HDR brachytherapy can be given before, concurrent with or after the external beam radiation therapy.
The optimal dose, fractionation and brachytherapy scheduling has yet to be defined.
(15 and 15 is easier to remember and is recommended by EVIQ, in US they are way less picky/more aggressive).
IPSS < 15. If IPSS > 15, then formal flow studies
Caution:
Peak urinary flow r< 15 mL/sec or post void residual > 100 mL
Dose for SABR to spine met (e.g. prostate).
Some indications:
Which tumours are excluded?
24Gy/2 fractions (there are a very wide range including 27/3). Range: from 24/1 to 30/5.
Some indications:
Oligigomet disease as defined by COMET-SABR = 4-10
ESTRO ASTRO = 1-5
Oligoprogressive disease
Spinal metastases from the solid primary tumour (excluding haem seminoma and SCLC).
Life expectancy >3months
SINS score<12, >7 get consult.
For Int Risk Prostate Cancer: Conventional dose vs Hypo#
Evidence for Hypo# dose?
78Gy/39#
vs
60Gy/20#
60gy/20# supported by multiple Phase III trials: PROFIT, CHHiP, RTOG - these demonstrate non-inferiority (either with or without ADT, low or intermediate risk) and 2 studies demonstate no increased bladder or bowel toxity, one suggests more grd II/III late toxiciy.
Extensive stage SCLC dose?
Trial?
IF: Any response to systemic therapy and residual thoracic disease.
Limited extra-thoracic metastatic disease burden.
Consolidative dose: 30Gy/10#
CREST Trial:
CTRT improved 2-year overall survival (13% vs 3%) and 6-month progression free survival.
Limited stage SCLC dose?
Ideally concurrent with?
The alternative approach:
Give a little Hx of this dose:
(Concurrent chemotherapy is preferred - ideally with earlier cycles of chemotherapy. Eg cisplayin and Etoposide).
Currently Tiurrisi (INT0096) 45/25 BD remains the standard
66/33 CONVERT Trial found not superior (with trend favouring Turrisis.
Further escalation 70/35 not superior, and potentially more toxic.
Early trials demonstrated an OS benefit w/RT, subsequently confirmed on meta-analysis.
Turrisi 1999 - 45Gy/25# (1.8Gy/#) vs 45Gy BID (1.5Gy/#) (!!!These doses are not BED equivalent!!!) w/concurrent cisplatin etop.
IF Unlikely to tolerate full treatment: 40/15 to 50/25 +/-chemo
Extensive stage Small cell lung cancer PCI dose:
Discuss evidence.
Japanese RCT suggests for extensive stage pts PCI can be omitted in favour of close (3monthly MR) surveillance - original data suggesting benefit defined no cranial disease on CT (not MR) therefore a number of pts who truly had brain mets were included..
BUT Now! An NRG RCT has demonstrated that hippocampus sparing is safe and leads to less neuro cognitive SEs.
Complete responders: 25Gy/5#
Partial responders: 20Gy/5#s
Doses “partly” supported by metaanalysis. Original data (1999) supported OS benefit. RCT data suggests 25/5 as effective as 36/18…
Extensive stage Small cell lung cancer PCI dose:
20/5 or 25/5 both employed, or 25/10 with hippocampus sparing. RCT data = Slotman 2007 - better OS and less symptomatic brain mets at 1 year.
Japanese RCT suggests for extensive stage pts PCI can be omitted in favour of close (3monthly MR) surveillance - original data suggesting benefit defined no cranial disease on CT (not MR) therefore a number of pts who truly had brain mets were included..
Now NRG 25/10 hippocampus sparing minimal neuro cog tox (treated both limited and extensive).
Dose: Oligo mets to lung?
Criteria?
All evidence is at best phase II
48/4 near (<2cm) chest wall.
54/3 if not central. Less radio resistant Mets consider 28/1.
SABR to ultra central appears dangerous (increased haemorrhage). Recent SUNSET trial for NSCLC 60/8, no haemorrhage from 30 pts..
Oligometastatic/oligoprogressive/oligopersistent peripherally located (defined as at least 2 cm from the bifurcation of the lobar bronchi) lung metastases (0-3 metastases).
Tumour/s ≤5 cm in maximum diameter.
Supported by Phase II data:
30/1 or 54/3 - away from chest wall/not central
(phase II study, efficacy of a 30 Gy single fraction was found to have lower 2-year LC compared to multi-fraction SABR (74% vs 91% respectively).
48/4 within 1cm of chest wall - Saffron II TROG (phase II) suggests 48/4 not inferior to 30/1.
Indication for SABR for NSCLC and dose:
Target volume objectives!!!????!!
Key Study and finding!?
The below is from CHISEL which found OS and LC benefit compared with 66/33 or 50/20
1) Stage I-IIa non small cell lung cancer (NSCLC).
2) Tumour ≤5 cm in maximum diameter.
3) Peripherally located tumour defined as at least 2 cm from the bifurcation of the lobar bronchi.6
4) Medically inoperable or declining surgery.
IF tumour GTV <1 cm from chest wall, consider 48 Gy in 4 fractions (12 Gy/fx).
54/3 or 30/1
Target volume objectives!!!
iGTV = DMax 125-143% of PD
PTV= D99% ≥100% of PD.
Non-small cell lung cancer stereotactic EBRT central tumours?
Define central:
Define Ultra-Central:
Target volume objectives!!!????!!
For 1-2 (≤5 cm maximum diameter) N0 M0 non-small cell lung cancer (NSCLC). Centrally located tumour defined as ≤2 cm around the proximal bronchial tree (PBT) - NB not “ultra central”
Ultracentral defined as: PTV touching or overlapping the central bronchial tree, oesophagus, pulmonary vein, or pulmonary artery.
Dose for central 50/5
Dose for Ultracentral 60/8 SUNSET
iGTV should get DMax 125-140% of PD.
PTV should get D95-99% ≥100% of PD.
NSCLC adj dose in post op patients found to be node positive:
Its a bit of a trick: A meta-analysis demonstrates no clear evidence of an adverse or beneficial effect of PORT on survival in patients with pN2 disease. The applicability of this finding to current day practice is questionable. Data from four non-randomised studies suggest a survival benefit for PORT in pN2 disease.
N2 = mets in ipsilateral mediastinal/subcarinal nodes
N2 [R0] disease - 50/25
N2 R1 - 54/27
N2 R2 60/30
The non-SABR NSCLC curative intent dose:
Evidence?
60/30
Bradley (RCT) Trial 2015: for stage III dose escalation to 74Gy not supported. Better survival in 60gy arm
For node negative patients not suitable for SABR consider dose escalation e.g. 66Gy/33# or moderate hypofractionation
Definitive EBRT dose for FIGO stage IB-IVA squamous, adenosquamous or adenocarcinoma of the cervix.
SIB:
Pelvis and elective nodes: 45/25
Boost nodes 55/25
(CCCMAC)
A dose prescription of 40 Gy in 20 fractions is also in clinical use.
Chemoradiation therapy superior to radiation therapy alone.
Brachy boost dose for FIGO stage IB-IVA squamous, adenosquamous or adenocarcinoma of the cervix.
What do you prescribe to?
24/3 aim 1-2#s/week depending on timing of brachytherapy in relation to EBRT.
EBRT same as definitive: 45/25,
Prescribe to HR-CTVbrachy (D90)
= 90% of High risk CTV receives at least 100% of the dose.
Primary curative intent doses for Oral cavity SCC
70 to Gross + involved nodes (66/33 if superficial).
63 to High risk = BOT if tongue involved, equivocal nodes.
56 to elective nodes I, II, III, IV
Bilateral i close to midline or within 1cm of tip of tongue or >2 nodes
(Nothing lower than this)
T1 glottic/larynx
T2?
60/25
70/35
Doses and systemic Tx (where applicable) and key studies for esophagus RT (all the indications):
What is the alternative?
ESOPEC. CROSS vs perioperative FLOT. FLOT4 wins 3yr OS 57% vs CROSS 50%
ESOPEC confirms and improves on NeoAegis = Peri-operative MAGIC/FLOT 3yrs OS 56%.
Neoadj:
Neoadjuvant CROSS
- 41.4Gy/ 23#/5, 1.8Gy/#, 5#/week
CROSS (weekly x5 cycles) (CROSS better than FLOT/MAGIC):
- Carboplatin (AUC=2)
- Paclitaxel (50mg/m2)
Definitive RTOG94-05/ INT-0123
- 50.4Gy/28#/5, 1.8Gy/#, 5#/ week
RTOG94-05/ INT-0123 (week 1,5,8,11)
- Cisplatin (75mg/m2)
- 5FU (1000mg/m2/day D1-4)
Palliative 30-36Gy/ 10-12#/5 (36/12 if you can get away with it).
Preferred salvage option for locally recurrent esophagus Ca (POST multimodal therapy):
Esophagus HDR brachytherapy:
25/5 ti 5mm depth and 20mm above and below.
Supported by multple retrospective and institution reports
The standard of care for medulloblastoma is?
Key factors that decide treatment?
CTVs
VMAT Technique:
GTR (90% recur with GTR alone)
Followed by CSI 4 weeks post (evidence says longer time worse outcome).
Dose = 54Gy/30# 1.8Gy/#, with CSI dose determined by risk group:
Average Risk: CSI = 23.4/13, boost post fossa to 54Gy/30
High Risk: CSI 36/20, bring PF to 54.30.
Followed by x4c of CVP (cyclophos, Vincristin cisPlatinum)
All PTVs 3mm
CTVcranial = entire brain + optic nerves + cribiform plate
Boost = GTVpre-op + surgical cavity+gross residual
CTV54 = GTV+5mm, clipped to boundaries
CTV spine: thecal sac, including neural/intevertebral foramen to 1cm below sac (~S1/2)
VMAT: 3 PTVs Cranial, sup and inf spine.
Critical in plan review of a CSI peads plan:
3DCRT technique for CSI
Homogenous cover of the entire vertebrae to avoid scoliosis
Role of radiation and dose in:
Solitary plasmacytoma
Multiple Myeloma:
Plasmacytoma: Radiation is the mainstay, with surgery indicated only where stability is a concern - SINS score >8, Mirrels>8. Data is retrospective only.
Give 45/25 - ISRT - i.e whole involved vertebrae. Or 40/25 if <5cm.
For Extramedullary consider 45/25 to primary and 40/25 ENI
MM:
30/10
Rarely now (most given Mephalan) TBI prior to ASCT
Radiation dose and rationale for primary CNS lymphoma.
Evidence supports a PFS but not OS advantage to WBRT.
The critical treatment is Autologous Stem Cell transplant (if pt can get to that):
Fit young Pt: High-dose methotrexate, Ritux and alk agent - Progression = salvage 36/20. Partial 23.4/13 (These are the same as the CSI doses for medulloblastoma). complete may omit WBRT.
Elderly/not ASCT candidate: Chemo as above -> Partial/complete = 23.4/13, or watch and wait or maintenance e.g tmz
Progression = Individualised care, including WBRT up to salvage 36/20.
Unfit: Curative intent WBRT40/22
Palliative: E.g. 30/10
Marginal lymphoma doses:
Nodal, splenic, MALT (90%, GI 60%, 85% gastric):
Orbital (12% due to chlamydia psittaci - gross) 24/12 (same dose as??, Deb uses 4Gy/2 55% contol), CTV = whole bony orbit
Late tox: epiphora, cataracts,
Gastric MALT: If failure of triple therapy (Claire’s Amplified esophagus) of t(18,11): 30/10 entire stomach (GIJ to duodenal bulb) Fast 4hrs (commonly overnight).
Kaposi Sarcoma dose and evidence and broad Tx options available:
Key warning to patient about outcome after XRT?
Likely Outcome of RT
Surveillance can be considered but indolent progression highly likely (with a larger lesion the to be treated).
- Surgery: Excisional biopsy is an option for single symptomatic lesion. Can provide sustained local control
- Radiotherapy: Wide variation of dose (20Gy/10- 30Gy/15#) – higher dose has improved and
more durable response - Topical therapy – limited experience with imiquimod
- Cryotherapy – mainly cosmetic, no documentation of LC rate
- Intra-lesion therapy – painful, not generally recommended
Like other sarcomas can take 4 months to regress
XRT - 80-90% LCR but significant risk of progression outside of field.
A 63 year old man presents with extensive symptomatic Kaposi lesion on his right lower leg extending from just
below the knee anteriorly, involving the calf posteriorly as well as both dorsal and plantar surface of his foot.
c. Describe a suitable radiation therapy technique including a dose and fractionation schedule (4m)
I will offer this patient palliative radiotherapy to the right lower leg lesion to a total dose of 20Gy in 10 fractions, 2Gy/X, VMAT technique for local control
* An alternative technique is with water-bath technique, this is cumbersome, with less accurate dosimetry calculation, and on the assumption that the entire ‘water-bath’ (including the leg) is of homogenous
density
Sim
* Position: supine, arms on chest, leg towards gantry, left hip/ knee flex to move left leg out of treatment field
* Immobilisation: cradle under right leg
* Clinical mark-up the symptomatic lesion, or wire the most superior/ inferior/ lateral edge of lesion
* Bolus: 5mm bolus inside cradle, and 1cm bolus on skin anterior to the cradle
* Planning CT: 3mm slice from mid-thigh all the way down to cover the entire foot
Target volume
* CTV20 will be 1cm thickness from skin surface circumferentially from superior to inferior marker, clipped at
bone/ muscle fascia, and spare at least one strip of soft tissue
* PTV20 = CTV20 + 5mm expansion
Technique: partial arc VMAT with 6MV photon
Plan review:
* Ensure PTV well-covered by 95% isodose line
* Minimise hotspot outside of PTV
* Minimal OAR at risk of concern; important to ensure contralateral leg is not receiving any dose
Treatment verification: daily kV imaging, with 5mm tolerance
Dose, and rationale for adj XRT post node dissection for melanoma. Volumes:
For whom should you consider it?
Burmeister study: Improve LC from 60-80%
CTVprimary - 2cm margin around scar
CTVnodal - 3cm prox-distal (like esophagus) and 0.5cm axial.
EVIQ CTVs: Pre-operative disease + surgical bed (including scar) ± margin as appropriate for potential sub-clinical disease. Consider non-surgically perturbed at risk nodal basin
Dose 48/20
UNLESS H&N, Groin lymphoedema - 50/25
Burm’s criteria at least 1 RF:
1 or more parotids, 2 or more neck (pr>3cm), 3 or more groin (or >4cm), ENE
Dose technique for average risk meduloblastoma
Avg = age>3, GTR w<1.5cm, not mets
I will offer this patient cranio-spinal irradiation to a dose of 23.4Gy in 13 fraction followed by tumour bed boost to total dose of 54Gy/30#) (1.8Gy/#, 5#/ week). VMAT technique with 6MV photon- 3 isocentres (cranial, upper spinal, lower spinal), junction at 4cm depth, no feathering.
Pre-SIM
* Ensure recovery from surgery (but within 4 weeks!!)
SIM
* Positioning: supine, arms on side, head towards gantry
* Immobilisation: on vac bag/ body cradle, thermoplastic mask
* CT simulation: 3mm slice planning CT from vertex to mid-thigh
* Fusion: with pre-op MRI, post-op MRI
Target volume:
* Phase 1: CSI 23.4Gy/13# (entire intracranial/ spinal subarachnoid volume)
o CTVcranial = Entire brain, covering cribriform plate, and optic nerve
o CTVspine = Thecal sac expand laterally to intervertebral foramina; inferior level must be determined on
MRI (usually ~ S1-2)
o PTVcranial = CTVcranial + 3mm
o PTVspine = CTVspine + 5mm lat + 10mm AP + 10mm SI
* Phase 2: Tumour bed boost 30.6Gy/17#
o GTV: surgical cavity + post-op residual disease
o CTV30.6: GTV + 5mm
o PTV30.6: CTV30.6 + 3mm
Describe a suitable radiation therapy technique and dose fractionation schedule for 3cm Merkel cell carcinoma completely excised (R0) from the upper right lateral arm
(over the deltoid)
Give benefit, T1 vs. T2
SEER database suggests likely OS benefit to PORT. T2 = 2-5cm (consider PET even in T1 - 25% T1 and T2 get upstaged).
Definitive EBRT alone 54Gy in 27 fractions, 2Gy per fractions to the right deltoid primary and axillary node + supraclavicular fossa to improve local and distant control, and overall survival.
Pre-SIM:
- MDM discussion
Simulation:
- Position: supine, arms akimbo, head towards gantry
- Immobilisation: vac bag, knee fix, ankle support
- Addition: wire scar, bolus 3-5 cm around scar/ primary lesion
- Planning CT: 3mm slice planning CT from upper cervical to below diaphragm (cover the entire lung for DVH)
Fusion: pre-op MRI/ PET
Target volume:
- CTV54 = (pre-op GTV and scar) + 4cm radial margin, and 1.5cm DEEP to skin down to fascia, clipped at
anatomical boundaries
- CTV51.2 (50Gy EQD2) = CTV54 + at risk nodal group (level 1-3 axilla and supraclavicular fossa)
- PTV = CTV + 1cm margin for setup uncertainties
Technique: 5-7 field IMRT technique with 6MV photons
Plan review
- Target coverage, PTV D98>95%
- Minimise hotspot PTV D2<107%, ensure no hotspot outside of PTV or in OAR
- Ensure low dose (10%, 50%) reasonably distributed around PTV
- Try to spare a strip of skin/ subcutaneous tissue
- Review OAR DVH
o Brachial plexus Dmax< 54Gy
o Ipsilateral lung: V20Gy<30%, V30Gy<20%
Treatment verification: daily CBCT, matched to bone, soft tissue review
Describe a suitable radiation therapy technique and dose fractionation schedule for TBI. Justify your answer
DOSE PRESCRIPTION
* 12Gy in 6 fractions, 2 Gy per fraction, 2 fractions per day, over 3 days
* Prescribed to a single point at midline of the patient (usually umbilicus)
* (Other dose options: 2Gy/1#, 13.2Gy/11#, 4Gy/2#)
Pre-SIM
* MDM discussion
* Fertility preservation referral
SIMULATION
* Position: supine, upper arms on side resting on 4cm polystyrene (maximise lung shielding from lateral beam),
and hand resting on abdomen
* Planning CT: 3mm slice covering the entire body length (from vertex to mid-thigh)
TARGET VOLUME
* Entire body contour
TECHNIQUE
* 4-field equally weighted MV photons AP/PA and opposing lateral, with extended SSD (4m) and largest practical
field size
* 6/10/18 MV (avoid 18MV if possible)
Alternate APPA and oppose lateral for each fraction (e.g. APPA for fraction 1, 3, 5, lateral for fraction 2, 4, 6)
Lateral field Position:
* patient lie supine, small sponge under head, knee fix,
* Upper arm resting on 4cm polystyrene (to reduce lung dose)
* Hand resting on abdomen
* Trolley turn around for the opposing lateral field treatment
Compensator/ bolus (‘beam spoiler’) – (because of skin-sparing effect of photon)
* Super-flab – on lateral and anterior surface of neck + chest (to reduce dose to lung)
* Perspex – as head frame compensator, and from mid-thigh inferiorly (thicker from mid knee
inferiorly)
Doses and presim for pituitary adenomas:
SRS (non-functional) 14-16 Gy/ 1#
SRS (functional) 20 Gy/1# Functional needs higher dose
Fractionated SRT 25 Gy/ 5# (5 Gy/#)
(BED~ 11-13Gy / 1#)
(FSRT if: lesion >3cm size, or <3mm from optic
IMRT/ VMAT 40Gy/ 15# (1.8Gy/#)
50.4 Gy/ 28# (1.8Gy/#)
PRE-SIM
* Baseline ophthalmology, neurology, and endocrinology review
Bone SABR:
Rationale
Contraindications
Dose
Technique
24Gy/2#
Rationale - Compared to multi# EBRT, multiple RCTs demonstrate higher complete response rates at 3 months, BUT higher vert body collapse 17% vs 10%.
In oligomet setting - COMET SABR shows OS benefit,
Contras: Previous radiation at site!! (No evidence to support this), SIN Score > 11. >3 spinal mets (i.e. much higher risk of collapse)
Technique:
sim CT + MRI fusion
8-Field co-planar, non-opposed 6Mv photons
Prescribe to covering isodose
Volumes:
GTV on fusion
CTV = GTV + CTV defined by International Spin Radiation Consortium (ISRC) guidelines.
E.g Well lateralised Vert body then CTV = whole vert body + ipsi pedicle. e.g 2. Diffuse vert body, CTV whole v.body bilateral peds.
PTV = CTV +2mm, EXCEPT trimmed off spinal cord!!!
Verification daily 3D CBCT to bone.
Dose, volumes and rationale for RT in soft tissue sarcoma:
Key studies:
Key studies: O’sullivan = RCT of pre vs PORT
STRASS = retroperitoneal dont do RT unless relapse (if you have to to 50.4/28)
SEER database
Rationale: For higher-grade STS SEER multistudy reterospective analysis supports a benefit to RT in conjunction with surgical resection. Both pre and post have equivalent OS but differ in their toxicities - E.g higher wound complications (reversible) in pre vs higher fibrosis rates in PORT (not reversible). RCT supports Brachytherapy as approx equivalent LCR.
For reteroperitoneal tumours surgery alone (STRASS). PORT not recommended, consider if recurrence.
For extremities:
Pre-Op: 50.4/28 (Myxoid liposarcoma 36/12)
Some data demonstrating equivalent outcomes with 30/5!!
GTV as delineated on all imaging (MRI T1+C)
CTV = GTV + 1.5cm radial, 4cm (or 3cm) sup-inf
PTV= CTV +1cm
PORT:
CTV60= pre-op GTV/tumour bed +1.5cm radial (as above) + !2cm! sup inf
CTV50= CTV60+2cm sup-inf
PTV = CTV50+1cm
Definitive:
At least 70Gy required for local control
Dose and technique for Hodgkins (and rationale/evidence and clinical information used to decide dose).
Key Chemos?
(except for popcorn cell nodular lymph prodominant HL)
Relevant studies in order of disease severity: HD10/EORTC, HD11, RAPID, HD15 (Stag III/IV).
Risk = AMEEN = Age>50, Mediastinum>1/3rd, ESR elevated, Extra Nodal, Nodes>3. (1 or more = HR stg I/II).
ISRT: GTVp = residual, GTVpre = prechemo. CTV=GTVp+5mm axial, and cranio-caudal expansion to cover GTVpre. If no GTV pre then 1.5cm.
Stg I/II and low risk (H10):
1) x2ABDV then ISRT 20Gy (10yr PFS 10%) is standard
2) PET direct RAPID (fav or Unfav) x3ABVD no need for RT if PET-ve post c3.
IFF +ve then x1ABVD the 30Gy ISRT
Stg I/II and HR (AMEEN>0) H11 (10yr PFS 85% same as fav):
1) x4ABVD the 30Gy ISRT (i.e 10Gy more)
2) PET direct RAPID (fav or Unfav) x3ABVD no need for RT if PET-ve post c3.
IFF +ve then x1ABVD the 30Gy ISRT
Stg III/IV (HD15): BEACOPPx6 (dose escalation to x8 kills more ppl than it helps). IFF PET +ve or residual >2.5cm then 30Gy.
Exception: urgent debulking of initially bulky - 30/15.
ABVD = Adriamycin, Bleomycin, vinBLASTine, Dacarbazine - 1 month cycles, 2 infusions/mth
BEACOPP= Bleo, etoposide, Cyclophosphamise, Oncoven (vincristine), procarbazine, pred.
What are the subtypes of Hodgkins, give dose/approach for the exception to the group:
HL = RS cells (CD 15 and 30)
or Popcorn cells (CD 19,20 like NHL, and neg CD 15/30)
Classical has 4 types (2 are assoc w/EBV):
1) Nodular sclerosing (70%) often mediastinum M=F broad band of bifingent sclerosing collagen
2) Mixed Cellularity (20%) EBV associated, often abdo/Spleen, M>F, Diffuse effacement of node with mix of lympocytes/plasma/eosin and RS Cells. No sclerosis
3) Lymphocyte Rich (5%): best prognosis
4) Lymphocyte Depleted EBV associated.
Nodular Lymphocyte Predominant HL (5%) CD 19 and 20 (Ritux target). Frequently transform into DLBCL
Stage I/II get upfront ISRT 30Gy then R-CHOP if PET +ve
III/IV get R-CHOP +/I ISRT
Dose/schedule and rationale for bladder preservation approach.
Evidence for chemo?
Bladder preservation approach offers chance of preservation (66% at 8 years) with comparable OS to neoAdj chemo + surgery (both in order of 75%). Combined analysis of 2 trials favours hypofractionated approach for better LCR ~60%.
Concurrent chemo is supported by multiple phase II trials that demonstrate LC benefit, one trial had a trend for OS benefit
EBRT, Vmat technique 55Gy/20#, 5#s/week, to bladder and tumour volume (no clear evidence for ENI), 6MV photons, prescribed to D50. Concurrent with weekly cisplatin 35mg/m.sqr.
Dose, technique and volumes for bladder preservation approach.
EBRT, Vmat technique 55Gy/20#, 5#s/week, to bladder and tumour volume (no clear evidence for ENI), 6MV photons, prescribed to D50. Conc w/Day 1 MMC 12mg/msq, and D1 and D15 5-FU 2.5g/msq (DFS BENEFIT, trend to OS).
Pre sim: EMPTY BLADDER and Rectum. Maximal TURBT.
Sim: supine head, towards gantry, vac bag immobilisation, w/knee/ankle fix.
2mm Slice CT+contrast mid-abdomen to upper 1/3rd femur. Fuse w/pelvic MRI.
GTV: Gross tumour volume on imaging/cystoscopy, or is complete TURBT than pre TURBT volume.
CTV = GTV+5mm on gross extravesicular extension, whole bladder, IF: bladder neck/trigone, CIS, multi tumour do prostate, or females 2cm urethra. IF posterior tumours ant vag wall.
Broad Mx approach to germ-cell ball cancer
Name some factors in Stg 1 that may influence your choice.
(never Bx)
Orchidectomy with high spermatic cord ligation
The Mx based on seminoma vs NSGCT:
NSGCT: Any residual then resect. Lmited role for RT, LVI is critical (relapse 50 vs 15%), LVI = BEPx1, LVI neg = Surveillance.
Seminoma Mx based on Stg (Stg 1 = TanyN0, IIa=N<2cm = N1):
Stg 1 = Surveillance (15% Recurrence, but no OS risk) vs 1-2 cycles of carboplatin (unclear data for 1vs2) vs Para-aortic 20/10.
The TE19 study suggests Chemo is as effective as RT (relapse rate 5%), but less toxic.
Factors that may make surveillance bad = tumour>4cm, involves scrotum, raised markers post surg, poor compliance with follow up
Stg II - IIa (single node<2cm) consider dog-leg RT 20/10 (30/10 to dose).
Otherwise BEPx3 (or EPx4 if cant do B):
BEP = Bleomycin (pulmfibrosis risk) Etoposide
Mx post chemo residual ball cancer
<3cm do surveillance, >3cm do PET at 6 weeks. If neg surveillance, if+ resection (preferred) or RT
Suitable dose and broad techniques (and rationale) for Ball cancer:
1) Node -ve
2) Single small node (<2cm)
Rationale: Decrease relapse rate from 15% to 5%
1) EBRT VMAT technique treating para-ortic nodes to 20G/10#s, 6MV photons, prescribed to D50.
CTV20= IVC and aorta, from 2cm below renal apex to aortic bifurcation, expanded by 2cm and trimmed to anatomical boundaries. PTV = 0.5cm
2) Dogleg: As above but include common, internal, external and iliac vein to UPPER-BORDER of acetabulum
For pancreatic cancer give the: Benefit/evidence and doses of EBRT for each situation it may be used.
Inoperable panc cancer has 5yr OS of 5%, operable has 25%
One key role therefore is in borderline inoperable - where metananlysis suggests neoAdj ChemoRT may make 1/3rd operable. BUT the specific role of RT is unclear (PREOPANC 2), with 36/15+ gemcitabine -> surg ->x4cycle gem = x6FOLFIRINOX (both approaches are highly toxic w/50% Pt having “serious adverse events”).
Operable:
Resecection - if +ve margin metanalysis supports a LC benefit to 45/25.
Inoperable:
Very limited evidence of OS benefit to the addition of RT to Chemo - 50.4/28
MASTERPLAN trial is looking at 4 cycles mFOLFIRINOX SABR with chemo: 40/5
Target volumes for pre-op extremity soft tissue sarcoma:
Fusion: MRI and FDG PET
Target volume:
- GTV = visible disease based on planning CT, and fused MRI/ FDG PET (T1 and T2 sequence + contrast)
- CTV = GTV + 1.5cm radial expansion + 4cm sup-inf expansion (include all oedema on T2 sequence)
- PTV = CTV + 1cm expansion
Role and doses for Osteosarcoma?
Free knowledge: Histological Dx - characterised by osteoid production, and classified by site (central = within = conventional = 90% high grade, Juxta cortical most low grade, Extraskeletal is rare).
RT only if:
1) Cannot be resected - neoAdj Chemo->70Gy->Adj Chemo (3 agents including methotrexate)
2) Further resection not possible:
Roles and doses of radiation for mesothelioma:
Main role
Palliative 20Gy/5# low dose equivalent to HD
Other:
1) Neoadjuvant - investigational
2) Adjuvant:
NOT if Extra pleural pneumonectomy (EPP)! Consider but don’t for pneumonectomy and decortication. RO 50/25
R1 50/25 and boost to 56/28.
Phase 2 (MARS) says no benefit and may cause harm after EPP
May be tolerated, await IMPRINT trial to see if any benefit.
* SABR for oligo-mets
No role
Prophylactic RT to procedural tract
Partial breast: Who, dose, technique, rationale:
At least 7RCTs have shown non-inferiority to WBRT
IMPORT LOW: Unifocal. Age>50, IDC grd1 to 3, <=3cm, <3nodes (N1)
40/15, 5#/week, 3Dplanned tangents with FIF, Prescribed to ICRU83, 100% PTV>95%.
Sim: breath hold - all that shit
Volumes:
Tumour bed on imaging (clips, wired scar)
CTV=TB + 15mm, trimmed 5mm off skin and lung interface.
PTV=CTV+10mm.
For lung SABR define the doses in terms of tumour location:
Peripheral: >2cm from proximal bronchial tree = 54Gy/3#s UNLESS <2cm from chestwall - then 48Gy/4#s
Central: <=2cm around proximal bronchial tree, but not ultra central. 50Gy/5#
Ultracentral: PTV overlaps: proximal bronchial tree, pulmonary artery/vein, or esophagus. Controversial whether to treat with SABR - some reports of fatal pulmonary haemorrhage. SUNSET Trial 2024. Prospective phase 1 - 30Pts good LCR and no haemorrhage with 60Gy/8#s.
Curative approach (and rationale) to a pancoast tumour (AKA?):
Superior sulcus tumour: 2 phase II trials show pre-operative chemoRT has superior DFS and OS compared to historical controls. Approx 50% 5yrOS. But other phase II data suggests chemo alone may be sufficient…
DO ONLY if resectable (
Give a dose prescription for SABR (doesnt matter which dose, the main bits are prescribed to and aim):
Curative intent SABR 50Gy/5#s (using central tumour), 1#/day, prescribed to 100% isodose, 6MV photons, DCAT technique.
Aim Dmax within PTV 125-140% of prescribed dose, CI-100; 1.2-1.3, CI-50<5. PTV D98>100%PD.
CI-100 = Ratio of Volume getting 100% of prescribed dose to volume of PTV. Should be 1.2-1.3
CI-50 = Ratio of Volume getting 50% of prescribed dose to volume of PTV. Should be <5.
Technique options for SABR
For the moving target which may be better. Describe it in detail.
Technique options
- Fixed beam >7 beam – fixed beam angle, converging on one isocentre, with open field, mixed coplanar/ non- coplanar
- DCAT technique – modulated; open field; doesn’t allow MLC covering PTV at any stage; preferred for moving target
- VMAT technique – static target
DCAT (dynamic conformal arc therapy)
- MLC only modulate field edge, and doesn’t cover the PTV at all time (compared to VMAT where MLC can cover PTV at some)
- Avoid Interplay effect i.e. shielding of PTV with MLC during VMAT, leading to underdosage of PTV due to tumour motion
- VMAT is ok on apex
Primary Tx for a T2NOMO nasopharyngeal carcinoma:
What 2 factors may change volumes?
EBRT (VMAT partial arc 6MV photons) alone:
CTV_70Gy/35# = GTV+5mm
CTV_63/35 (EQD2 60Gy) = Entire nasopharynx +
Sup: Skull base w/ovale and rotundum, inf sphenoid sinus
if >=T3 - whole sphenoid and cavernous sinus
Inf: Soft palate
Ant: posterior 1/3 of max and nasal sinus
Post: Bilateral retropharynx nodes, ant 1/3 of clivus (whole clivus if involved - i.e. T3)
Lateral: Pterygoids and parapharyngeal space.
CTV 56 (EQD2 50): CTV 63+ Levels II-V.
If node +ve include 1B.
Treatment approaches for Primary CNS Lymphoma (with doses).
Divide into, young, elderly, and fit and unfit. Then response based (Autologous stem cell or WBRT or more chemo).
Evidence: post chemo WBT improves PFS but unclear OS benefit.
Unfit (for chemo): 40/20 WBRT or less
All fit (young n old) should get HDmethotrex + ritux + Alkylating agent (eg TMZ). +/- further chemo then:
If response: ASCT (preferred in young) or WBRT 23.4/13
No response/prog: Isofosphamide vs 23.4/13 then boost residual to 45/25
Fit elderly - 3 options:
WBRT
Maintenance TMZ
or Wait and Watch
The OARS of head and neck and Dmax
Brain stem/ optic chiasm = Dmax <54Gy
Optic nerve Spinal cord = Dmax <45Gy
Temporal lobe/Brain = Dmax< 60Gy, V40Gy<5cc
Brachial plexus= Dmax< 66Gy
Retina/ eye = Dmax< 50Gy
Lens = Dmax < 8Gy
Lacrima = Dmax < 30Gy
Manidble = Dmax < 70Gy
Carotid = Dmax <100Gy
Parodid is a mean dose = Dmean 26Gy
Describe suitable follow up regimes for Anal SCC, and some key principles.
Most recurrence is locoregional, so the role of CT CAP is unclear.
“Ass”ess at 8-12 weeks
* Clinical review at 6-8 weeks to ensure clinic complete response.
If incomplete continue as normal but at 26weeks residual/progression should be Bx and plan for APR.
* Clinical follow-up (DRE, and endoscopy surveillance) 3 monthly 1
st year, 6 monthly 2nd year, annually until 5
years
* 3-month MRI and PET
* Consider annual CT C/A/P if T3-4 or N+
Dose and volumes for Anal SSC, what is the chemo?
> T1, then chemo= MMC + (5-FU or Capecitabine) (MMC essential, substitute for cisplatin as last resort) for improved LC and CSS
SIB technique:
CTV50or54: primary + 2cm+ whole canal/sphincters
CTVnodes: inguinal, mesorectal, ischiorectal, pre-sacral, internal (inc obturator and external ilacs - do not do common.
Non bulky (<4cm = <=T2): 50.4Gy/28 and
42Gy/28
- COVID Dose 45/15
Bulky (T3): 54/30 and 45/30.
Describe suitable follow up regimes Post rectal (stg I to III) Ca Mx.
1st year:
3monthly: Physical exam/Hx
6monthly:
- CEA for 2 yrs then annually for 2 yrs
- DRE and sigmoidoscopy
CT CAP at 1 year.
2nd Year:
24month - Hx/Ex, DRE/Sigmoidoscopy
3rd-5th years:
Annual Hx/Ex
Coloscopy every 3-5year
Key anal cancer studies:
Key principles in the timing of anal SCC XRT:
Nigro (1974) Retrospective study 30/15 + CTx (MMC+5FU)
ACT1: Chemo improves LC and CSS compared w/RT alone. Other trial says cant omit MMC. No benefit to induction chemo.
ACT2: MMC+5FU = MMC+cis isoeffective/isotoxic
PLATO recruiting=ACT3 (T1 surg +/- adj), ACT4 (<4cm de-escalation 41.4Gy/ 23 = butt hole CROSS), ACT 5 (N+ and/or T>=3, boost to 61Gy).
OTT should be minimised (Not>6wks)
Treatment breaks are shit for tumour control avoided - BD or treat on weekend if any missed #.
Concurrent chemotherapy for butt SCC?
5FU/ MMC (MMC IV D1 12mg/m2 + 5FU infusion 1000mg/m2/day D1-4 week 1 and 5
Rationale for radiotherapy and chemoradiotherapy in dick cancers:
The goal is organ preservation.
Benefit of concurrent chemo is extrapolated from vulva/anal.
For adj Pelvis RT retrospective data is mixed. Some suggests DSS and OS benefit, especially where multiple nodes. Therefore, adjuvant RT is recommended following a PLND with +ve nodes.
Doses and volumes for penile cancers:
And benefit for each.
Also, indications for concurrent chemo
Use 2gy/# cisplatin 40mg.
1) Definitive local:
- Primary <4cm and does not involve cavernosum local +/- cisplatin - 60Gy/30#s CTV = GTV+2cm (alternative is brachy 60/5). Surgery seems about equivalent for local - 5yr OS 75%, 80% LCR.
2) Definitive advanced (surg is the standard approach):
>4cm, or >=T3 (meaning cavernosus invasion or worse): 50/25 whole penis and inguinal/pelvis, boost primary (+ve nodes, or ece and dissection) to 66/33Gy. This supported by UK RCR.
(PORT is the same but adds 60/30 to micro)
> 4cm or >T2 should always get concurrent chemo:
E.g. cisplatin or cisplain + MMC
3)PORT: 66/33 to residual, 60/30 to R1and ECE, then 50/25 to everything else. Chemo is R1, ECE or very advanced. Benefit extrapolated from anal/cervix. RT added to CT may increase PFS to 30% from 15% (multi-institutional anaylsis).
4) NeoAdj is investigational InPACT (45/25).
Broad statement on penile SCC node status, general Mx of penile Ca and evidence.
Indications for treating nodes with RT:
Approximately 20–30% of patients with positive inguinal nodes have positive pelvic nodes. Lymph node status is a major prognostic factor for penile cancer.
Surgery is the mainstay of locoregional treatment.
There is a lack of high-level evidence to guide management.
ECE or >2 nodes
What does Adj RT add to chemo for dick cancer after inguinal surgery?
A multi-institutional retrospective analysis was carried out to review the benefit of adj RT to Adj Ctx after inguinal surgery for penile cancer. Found longer cancer-specific survival with ChemoRT (29%) compared with adj chemoalone (16%)
Role of chemo in dick cancer:
What is the trigger point for neoAdj and the level of evidence.
NeoAdj:
1) Bulky: resectable disease rarely cured with a single modality; therefore, consider NACTx prior to Iliac LND.
2) >2 nodes or bilateral nodes - Phase 2 support OS benefit to TIP (paclitaxel, ifosfamide, and cisplatin) or “TIP PIC”.
Adj:
No diff bet adjuvant versus neoadjuvant chemotherapy or adjuvant versus no intervention, OS was higher with neoadjuvant chemotherapy compared to no intervention and PFS was higher with adjuvant compared to neoadjuvant chemotherapy.
Types of vaginal brachy applicators (and role of each):
Vaginal cylinder (often segmented) - best for symmetric brachy
Multichannel cylinder - For asymmetric dose (also e.g. to avoid bowel loop 80Gy)
Tandem and ovoid or ring applicator (or tandem or ring): Cervix cancer
Combined interstitial intracavity devices.
Rotte applicator (a 2 channel tandem thing where both channels can go into the uterine cavity) - in rare case of intact uterus.
In general terms, list the steps in treatment planning LDR prostate implant (3 marks)
Planning:
- Based on TRUS volume
- Contouring
o CTV = prostate; PTV = CTV + 3mm (except 0mm posterior)
o Urethra and rectum
- Placement of seed ~ 100 through the prostates
- Review DVH
o PTV: V100>98%, V150% ~50%, V200%~ 13-18% , D100%>95Gy
o Urethra: D10<210Gy, no 150% isodose line encircling/ in urethra
o Rectum: V100<1cc, 70% isodose line away from anterior rectal wall
- Seed ordered from overseas
In general terms, list the steps in treatment that are involved with delivering an LDR prostate implant (3 marks)
- GA, lithotomy position
- Prep and drape
- IDC and injection of ~120mL mixed normal saline/ contrast
- TRUS probe per-rectum, ensure image closely resembles volume study
- Interstitial needle inserted using template and under ultrasound guidance, and position
checked - Stylet (with radioactive seed) deployed
- Interstitial needles removed, leaving stylet (with radioactive seed) in situ
- TRUS probe removed
- Cystoscopy – to check bladder and urethra of any seed, trauma, obstruction
For Ewing’s give the indications for PORT and approach (dose/volumes). How does the PORT differ from definitive?
PORT dose = definitive (post chemo) dose. Post operative volumes based on degree of necrosis (<90% necrosis = bigger volume = pre chemo GTV).
Indications for PORT:
* Positive (R1/R2) or close margin <1cm
* poor response to chemotherapy (<90% necrosis)
* tumour spill
* For tumour spill, boost pre-chemo volume
45Gy/25# to pre-chemo volume then boost to 54/30 as below (I.e the only thing that changes is bigger volume if worse/less necrosis):
IF post CTx NECROSIS >90%, then boost 9Gy/5# (1.8Gy/#) to post-chemo GTV (smaller volume)
IF NECROSIS <90%, then boost 9Gy/5# (1.8Gy/#) to pre-chemo GTV (bigger volume)
For Ewing’s XRT (PORT or curative), what are the planning considerations?
- Do not treat across a joint/ encompass an extremity circumferentially (i.e. need to spare a strip), unless absolutely necessary for tumour coverage
- Reduce margins if there is no extension beyond joint space, but adjacent epiphysis is in volume
- For diaphyseal lesion, exclude one epiphysis of the affected bone, if possible
- If CR to chemo, boost post-chemo volume
- If incomplete response then boost pre-chemo volume
For Ewings, what is the chemo, and timing of chemo in relation to XRT in the following settings:
Definitive
Adjuvant
VDCA-IE – VDCA+IE better than VDCA alone in CCG-7881 trial (5yr OS 72% vs 61%)
Induction chemotherapy 6 cycles Q2W (=12 weeks)
o Chemotherapy break for surgery (week 13)
o Adjuvant chemotherapy (restarted as soon as possible) to 48 weeks (i.e. total of 24 cycles)
o If definitive/ adjuvant RT, start with cycle continue chemotherapy (withhold doxorubicin during RT)
Not a dose/technique question. But very high yield.
For each tumour marker, state which tumours can elevate it (i.e. not all of these are routine by any means).
1) CEA
2) CA15.3
3) CA 125
4) CA19.9
5) AFP. Give half-life
6)Beta or just hCG. Give half-life
7) LDH
8) Calcitonin
9) NSE
10) S100
1) CEA: Colorectal Ca, colangiocarcinoma, medullary thyroid
2) CA15.3: Breast
3) CA 125: Ovarian
4) CA19.9: Pancreatic Ca
5) AFP: NSGCTs = yolk sac and embryonal, Liver HCC
6)Beta or just hCG: choriocarcinoma, some mixed NSGCTs, and approx 10%seminomas that express it.
7) LDH: Melanoma, Myeloma, Folicular lymphoma, DLBCL
8) Calcitonin: Medullary thyroid ca
9) NSE: can be a marker of SCLC
10) S100: melanoma - not routine at Dx/or ever
Another high yield non Dose/technique question:
Relate radiation (maximum) doses to fertility and ovarian/testes function:
Males:
- Infertility if >6Gy
- Reduced sperm count (and North Queensland quality sperm) 0.15-0.5Gy
- Azoospermia 0.5-6Gy
- Leydig dysfunction 10-15Gy
Ladies:
- Permanent: >12Gy prepubertal, >2Gy near menopause
- Hormone insufficiency 10-15Gy (same as Leydig)
Timing of adjuvant breast radiotherapy after chemo
4-6 weeks
Dose/approach to endometrial Ca:
State benefit and study
All get TAH+BSO+lymph node sampling + washings (peritoneal sampling if serous carcinoma).
Stages:
1A = Observation (includes 1AmPOLEmut)
1B = VBT 28/4 (GOG99) consider ommitting
1C= Pelvic RT alone (45/25, SIB 55 to nodes) GOG249. VBT may be reasonable (PORTEC2)
2-IVa = ChemoRT (cisplatin 5mg D1 and D20) 45/25 pelvis and bed + VBT 10Gy/2#s (PORTEC 3)
Definitive: EBRT 45/25 pelvis,SIB nodes 55Gy, VBT 21/3.+ Chemo.
Or for IA definitive brachy: 27/3
Salvage (if no previous Rad): 45/25 (55 to nodes), 21/3 VBT - Observational data only. + Chemo.
Whole abdo RT for IIIC/V 30/20 is shit compared to chemo alone.
Broadly, staging (which determines dose) in endometrial ca is based on?
Stgs based on: Invasion, extensive LVI, fav (grd I-III) vs aggressive (III, serous, clear cell), local (stg III) regional (III) systemic. POLEmut, p53abn.
In the setting of endometrial cancer - For VAGINAL BRACHYTHERAPY: Give doses and origin of dose:
Definitive: For IA in-operable:
27/3
PORTEC 2 - VBT adj alone. Stage IB
21Gy/ 3, 7Gy/ , 1-2 #/ week
* Prescribed to 5mm from surface of cylinder
* Dose to 5mm cranial from vaginal vault along the axis of cylinder should not vary more than 10% of prescribed dose
PORTEC 3 - ChemoPelvis and VBT if stroma involved.
* 10Gy/ 2, 5Gy/#, 1-2 #/ week
* Prescribed to 5mm from surface of cylinder
Stg II endometrial Ca what get brachy? outline the technique.
Stromal involvement:
Vaginal vault brachytherapy
* Position: supine, use largest vaginal cylinder that will fit comfortably to minimise air pocket
* Target volume: upper half of vagina
* Dose/fractionation: 10Gy/ 2#, 5Gy/#, 2#/ week
* Technique: HDR brachytherapy with Iridium-192 radioactive source, prescribed to 5mm from surface.
Approach to cranipharyngioma (and dose).
If GTR then >90% dont come back = observation.
STR = 70% recurrence = Adj RT = 54/30.
Indication for adjuvant therapy for heterotopic ossification?
Timing?
Dose/fraction?
Benefit?
Alternate treatment?
If recurrent.
<24hrs pre-op, <72hrs post.
Dose fractionation - 7Gy/1# , AP/PA dose to midline, spare a strip of soft tissue.
Reduces risk of recurrence to 10%.
Alternative - Surgery followed by NSAID (indomethacin 75-100mg/day) for 7-14 days post-op
For pineal tumours what are the indications for CSI
After induction carbo-etop (4-6 cycles):
Germinoma (always 1.5Gy#s): Mets = CSI (1.5Gy/#) 18/12 + GTV boost to total 45Gy/30#.
NGGCT (always 1.8Gy#s): Mets or No response to induction CSI (1.8Gy/#) 36Gy/20# (1.8Gy/#) + 18Gy/10# boost to GTV (total dose of 54Gy/30#)
Approach to pineal tumours (not ependymomas)
Always aim GTR.
Pineal parancymal tumours if GTR then obs, if STR consider RT.
Germ cell: InductionCT (carbo etop) x4 if germinoma, x6 NGGCT:
Radiation based on class, and induction response (CT/PR/none) and mets.
1) Germinoma (always 1.5Gy/#, total 30 or 36Gy):
CR: 30Gy total. WVRT 18Gy/12# + GTV boost 12Gy/8#
PR: 36Gy total. WVRT 24Gy/16# + GTV boost 12Gy/8#
Mets: 45Gy. CSI 24Gy/16# + GTV boost to 45Gy/30#
2)NGGCT (always 1.8Gy, total 54Gy)
CR/PR: WVRT 30.6Gy/17# + GTV boost 23.4Gy/13# = 54Gy
No-response or mets:
36Gy/20# (1.8Gy/#) CSI + 18Gy/10# boost to GTV (total dose of 54Gy/30#) + 9Gy/5# to bulky spinal met (total dose of 45Gy/25#)
Brief epidemiology and associated risks for AVM. How are they graded?
Indication for XRT? Relate to treatment options:
1/2000 people. 2-4% chance of bleed/year, At each bleed - 30%chance of morbidity, 10%chance of death. Biggest risk for bleed is a previous bleed. Present from birth, average age become clinically apparent is in 30s.
Graded (Spetzler-Martin) score 1-5: based on Size (<3cm, 3-6,>6cm), location (eloquent/non-eloquent), Presence of deep venous drainage.
Size >4cm attempt emobilisation to facilitate surgery/SRS
Surgery Tx of choice where possible. Improves seizures indicated in S-M score 1-2 (may not be possible in eloquent brain or deep venous drainage).
SRS - tumours <3cm
Observation: may be only option, if previous, aneurysm or deep location should be avoided if possible.
For AVM give indications dose and expected outcome.
SRS for tumours <3cm. with dose 16-20Gy/1# (GTV on angiogram).
Outcome 80-90% at 3years (requires endothelial proliferation to cause obliteration), in latent period risk of bleeding is unchanged.
Epidemiology of acoustic neuromas:
Preferred approach and why?
XRT dose and outcome:
8% Brain tumours, 96% of NF2 get them (often bilateral), 5%NF1 (also oft bilateral). M=F.
Merlin is a Schwan cell tumour suppressor protein (gene on chromo 22), dsPyfunction ->proliferation.
Preferred Mx = surgery, especially in younger Pt - allows debulking and reduction of BS compression (but signif risk hearing loss if tumour >2cm)
Observation=6-12month MR, if growth>2.5mm/year or hearing loss/worsening Sx need Tx.
SRS: 12.5Gy/1# for tumours <3cm and PTV not on BS. Otherwise…..
SRT: 25/5
Outcomes growth arrest (=LC) 85%@3yrs.
It’s possible some crazy big tumours need VMAT 50/25.
Gamma Knife based brain SRS, ???% is usually chosen as the prescription (marginal) dose.
Typical prescription point for SRS
Gamma Knife based brain SRS, 50% is usually chosen as the prescription (marginal) dose.
We (Hamilton) prescribe to 100%, other places prescribe to 60-80%, it’s apparently not an arbitrary choice.
Dose and technique for adjuvant SRS post resction of a brain met:
Evidence?
You could do WBRT (e.g 30/10) isoefective control - but more neurotoxicity and time toxicity (2 phase 3 trials). Neither SRS or WBRT is better than observation in terms of OS.
SRS 12-20Gy ALIANCE Trial
SRT if <30cc 27Gy/3#
If > 30cc 25Gy/5#s
Adj SRT to the surgical cavity, VMAT technique, 6mV photons,
Prescribed to 100% isodose line.
Sim: patient supine, head towards gantry, arms by side, knee rests, comfort measures. Imo: thermoplastic mask.
Contrast CT 1mm fine slice - vertex to C4. Planning MRI T1+C.
HighRiskTumourVolume=HRTV=Surgical cavity
CTV = HRCTV + any GTV + 2mm (may include tract and/or dural margin).
PTV: =GTV +3mm
OARS: in 2Gy/# (I would convert for SRT): Brain stem <45Gy, Brain Dmax<60Gy, V40Gy<5cc.
Verification: daily CBCT matched to bone
Volumes for adj cavity/brain SRT:
Dose?
When should you be cautious when using SRT?
As an aside what should be done about asymtomatic brain mets (if possible)
GTV if any (though if residual present is technically post operative SRS)
High Risk Tumour Volume=HRTV=Surgical cavity
CTV = HRCTV + any GTV + 2mm (may include tract and/or dural margin).
PTV: = CTV +2mm (1-3mm)
DOSE:
30/5 (if >3cm).
OR
27/3 IF<2cm
Caution >5cm, Change to WBRT at about 5.5cm.
Osimertinib only if Exon 19/21 EGFR mutations.
Options for Liver HCC? SABR dose?
No RT or TACE if Childs C (caution in B)
1) Surgery:
-Solitary tumour<2cm do Partial/hemihepatectomy
-2-3 lesions or a single lesion <5cm (Milan criteria) aim liver transplant with bridging therapies while waiting (see below). 5yr OS70% (best chance survival)
2) Ablation:
- Thermal = RFA if <3cm 90%CR, 2-5cm 50-70%, Microwave improved CR for tumours up to 5cm.
- Non Thermal = Irreversible Electroporation: preserves structural integrity of. bile ducts and vessels (used more in pancreas).
3) Trans Arterial Embolisation - +Chemo (TACE) Yttium-90 microsphere (TARE). Local response 50% (TARE up to 70%)
- For lesions too large for TACE (>5cm)
- 85% post-embolisation syndrome 3-4days, 15% irrevesible liver injury.
4) XRT - preferred in patients w/vascular invasion, portal vein thrombosis: SABR 30 or 50 in 5# (LC up to 90%). Conventional 66/33 (French), Palliative whole liver 10/2 for 60%response rate
5) Systemic - no chemo, but Sorafenib increases OS 2-3 months
6) Sorafinib + SABR for disease unsuited to other treatments.
Role and doses for XRT for HCC:
Can be used in bridging prior to transplant.
In combination with other therapies (e.g. TACE+RT reduces recurrence in tumours>3cm).
Preferred in patients w/vascular invasion, portal vein thrombosis. Some retrospective data suggests better LC with SABR compared to RFA,
SABR 30 or 50 in 5# (LC up to 90%).
Conventional 66/33 (French),
Palliative whole liver 10/2 for 60%response rate
In patients unsuitable or refractory to TACE
Sorafinib OS + SABR for disease unsuited to other treatments. SABR adds 3-5 Months OS = 16months.
SABR doses and volumes for liver HCC
Rationale: Equivalent local control to historic RFA (90%<3cm, with better control than RFA for tumours >3cm).
SABR: 30/5 to 50/5 1#/day 5#s week, prescribed to 100% isodose.
4DCT Contrast CT 1mm slice (HCC enhances on arterial phase only). + MRI
Volumes contoured on MIP and checked across all phases of respiratory cycle.
iGTV= All parenchymal (iGTVp) + vascular (iGTVv) on imaging.
CTV=GTV
PTV=CTV+5mm
Motion management system.
Mean liver dose <28Gy
In what curative setting would you use RT for cholangiocarcinoma? What is the benefit?
Dose?
Phase 2 SWOG trial for T2-T4 node positive resected Ro or R1:
Adjuvant RT increases OS compared to historic data (Median OS=3yrs).
45/25 nodes
54/30 to bed
59/33 to R1.
Approach to Inflammatory breast cancer:
5yr OS
NeoAdj chemo -> Mastectomy +ALND -> Adj RT + Receptor targeted therapy
You need pre-treatment clinical photos.
There will never be an RCT, but large retrospective studies demonstrate control benefit of escalation>60Gy.
MDACC (largest study): 66/44, 1.5Gy/#BD, CTV 3cm beyond scar + Bolus until skin rxn too significant. Do this for age<45 or residual post chemo, otherwise can de-escalate - e.g. 60Gy.
5yr OS =40%
If no residual post
28F w/ Left inflammatory breast cancer, has neoAdj Chemo, mastectomy and ALND. 2cm CW residual, and 14/16 nodes.
What do you do (dose, volume)?
MDACC suports dose escalation in this patient (up to 66Gy).
I would treat chestwall and undissected nodes including IMC to 50Gy/25, then boost chest wall to 16Gy. VMAT, DIBH.
Bolus as long as tolerated.
CTV50= GTV+1cm (trimmed to boundaries) + whole chest wall and nodes (level III, SCF, IMC)
PTV=CTV+5mm
CTVboost= GTV+1cm (trimmed to boundaries) + whole chest wall
