Viva Prep Flashcards
Work up
WORK-UP or FURTHER ASSESSMENT
ABC + urgent bloods + oxygen if required.
Detailed history:
Symptoms.
-Eg pain and manage these
Baseline organ function (important ones).
Risk factors:
PMHx/ Social Hx + Performance status (that may impact on fitness for radical treatment), Meds (use of radiosensitisers, antigoags) + CI to RT (previous RT/PPM/connective tissue disorder).
Exam
Focused and system review.
Investigations
Bloods (FBC UEC CMP LFTs) + related to the prompt cancer (+ tumour markers (LDH, CEA, Ca19.9, AFP, bHCG etc)+/- haem bloods)
Imaging—USS, CT, MRI, FDG PET.
Procedure (EUA, cystoscopy, colonoscopy/endoscopy, bronchoscopy, surgery upfront for certain ca)/biopsy and important markers/IHC/cytogenetics
Discuss in MDT
In a [complex] case [insert clinical prompt/situation], I would discuss this patient in an MDT to discuss curative and palliative options of treatment. Curative management option in this setting is [insert] and palliative management option would be [insert].
Treatment
I would treat this patient with curative/palliative intent with (concurrent) radiotherapy to a dose of XXXX
Pre-sim (HN, young fertility, stop smoking, stop driving, pregnancy test, baseline blood🡪 Sim (position, immobilisation, wire/bolus/preparation, 2mm 3D/4D CT XXXX, fuse🡪 dose prescription and TECHNIQUE🡪 target volumes🡪 OAR🡪 “during treatment” my target verification would be.
Planning
CB CHOP– contours, beam arrangements/fields, coverage, heterogeneity/hotspots, OARs, prescription.
PLANNING
This is a planning CT scan through (….at the level of…) with overlaying isodose lines.
Dose prescription is… so this is like a curative/palliative intent treatment for XX (thorax/abdominal/etc) malignancy.
Technique:
VMAT—number of arcs, energy.
IMRT—number of fields, energy
3DCRT—number of fields, directions, energy, field weighting, use of beam modifying devices (e.g. wedge, lead shields, etc).
SBRT—energy, FFF or normal MV
Target volumes (GTV, CTV, PTV likely represented by X colours) or field borders
Coverage of the PTV by 95% isodose + Dose homogeneity + conformity→ (not conformed/generous, adequately/inadequately covered, heterogeneity/homogenous).
If hereterogenous– state location & size of heterogeneity (i.e excess dose)
DMax (ensure less than 107%) and cold spot within PTV
Hot spot outside PTV, location, by what isodose.
Coverage of OARs by isodose lines
Any high dose isodose covering the OARs? “OARs (named structure) is unnecessarily covered by the high dose”, “Doses to OARs appears to be safe from this image, but i would like to review other slices and DVH”
Need for PRV
Check DVH
Ensure 95% of PTV is covered 95% of prescribed dose.
OARs
Critical OARS first and secondary OARS
Primary and secondary endpoints
In summary, would this be an acceptable/ unacceptable plan and why or why not according to the above.
If not, how could it be improved.
Change beam energy.
Change beam arrangement: add more fields, change beam entry points or angle, add arcs/ arc, change Arc angles, change weighting, change technique (IMRT, two phases with phase 2 to a smaller volume), add wedges, add shielding.
Change target volume: reduce CTV or PTV margin, Add PRV to OAR, Add avoidance structure, remove elective nodal irradiation, consider non-coplanar beam arrangement
Use motion management e.g. abdominal compression or gating, or plan adaptation (e.g. re-sim and reduce target volume for second half of the treatment).
Change dose prescription: fractionation schedules e.g. hyper or hypo#, change TD, or change treatment intent (cure to high dose palliative). Compromise dose or volume coverage to 95%
OR any combination of the above.
Check correct set up, immobilisation and motion management.
Review target volumes to ensure accurate delineation of GTV/CTV/PTV and OARs.
Review dose coverage, homogeneity and conformity.
Review dose prescription (59.4Gy/33# or 54Gy/30 for LG glioma).
Review technique.
IMRT/3DCRT
Adding more fields/beam, change beam arrangements (entry/exit), angle and weighting.
Change energy.
Beam modifiers– Add wedges, shielding, blocks, tissue compensator.
Change treatment technique (2 phases with smaller phase 2 volume, VMAT).
VMAT
Modifying number of arcs, arcs length, arc placement, restrict arc entry/exit angle, collimator angle.
Changing OAR priority on the TPS.
Creating avoidance structure over OARs (or watever organ in the prompt).
Change target volume:
Reduce CTV or PTV margin.
Add PRV to OAR.
Add avoidance structure.
Remove unnecessary elective nodal irradiation.
Consider non-coplanar beam arrangement
Change technique.
Use motion management e.g. abdominal compression or gating), or plan adaptation (e.g. re-sim and reduce target volume for second half of the treatment).
Change dose prescription and compromise on coverage–
Fractionation schedules e.g. hyper or hypo#, change total dose, or change treatment intent (cure to high dose palliative). Compromise dose or volume coverage to 95%
Accept lower dose/undercoverage in the PTV immediately adjacent to the brainstem/OAR (e.g. 90% dose coverage vs 95%)
If high risk of recurrence– accept minor violations and avoid compromise to the target coverage.
In the setting of major violations, open discussion with patient regarding balancing act between tumour control and toxicity
OR any combination of the above.
Consider alternative treatment– e.g. surgery, chemo, pall care.
Regular patient review post treatment to monitor for recovery and late toxicity.
+ lifestyle modification if required.
Planning for SABR
Check and describe dose fall-off (steep for SBRT) and low dose wash (i.e. no unnecessary splay of dose).
Check conformality Index (<1.2)
To assess dose conformity of the PTV coverage (CI 100% closest to 1= better conformity).
High dose spillage= cumulative volume of tissue outside PTV receiving dose >105% PD should be no more than 15% of PTV.
Intermediate dose spillage= CI50% is dependent on tumour volume, shape and proximity to OAR.
Gradient Index
Dmax in PTV 125-143% PD→ To assess dose (in)homogeneity.
Breast nodal volumes
Breast nodal volumes
Level 1
Inf– 4/5th mid axillary line→ sup– subclavian artery behind pec minor.
Ant– line lat dorsi to pec → post– line lat dorsi to intercostal.
Level 2
Inf– beginning of pec minor→ sup– suclavian artery cross medial to pec minor.
Level 3
Inf– 5mm caudal to the subclavian vein→ sup– cranial extent of subclavian artery.
Med– subclavian vein junction int jugular.
Level 4
Inf– 5mm caudal to the subclavian vein→ sup– cranial extent of subclavian artery.
Med– medial aspect of jugular vein (excld CCA and thyroid)
Post– scalenes
IMC
5mm from IMC vessels from SCF to the top of the 4th rib.
Head and neck nodal volumes
Pelvis nodal volumes
Pelvis nodal volumes
Nodes: Start covering CTV LN at L4/L5 at the level of distal CI and proximal presacral nodes.
Zaorsky: [Prostate cancer failure patterns after RP]
Use 7 mm vessel expansion for nodes, cropped at muscle, bowel, and bone.
Cover presacrals from S1-S3. The posterior border along ant sacrum and ant border ~10mm ant to ant sacral bone carving out the bowel, bladder bone.
Stop EI CTV at the top of femoral heads.
Per NRG atlas (Fig 3k-l; see summary box above): “EI contours should typically end when vessels are completely lateral to the most medial aspect of acetabulum”
Stop contours of obturator CTV at the top of pubic symphysis (see nuances in NRG prostate atlas Summary Box above).
PTV = CTV + 7 mm.
Prophylactic node CTV as per NRG
5-7mm expansion around the arterial and venous vessels from the bifurcation of the aorta into common iliac arteries at L4-L5, external iliac, internal iliac, presacral
Include prevertebral, presacral and posterior mesorectal nodes to the bottom of S3
Posterior aspect of internal iliac CTV limited to the anterior edge of piriformis muscle and after pudendal artery and inferior gluteal artery
External iliac CTV end inferiorly when vessels are medial to t he acetabulum or femoral head pr when vessels enter the inguinal canal
Obturator node 1-2cm width extending 1cm anterior to the obturator internus to the posterior edge oft he muscle, end inferiorly when fat plane between the muscle and prostate dissapears or when SV joins the prostate
Note:
Exclude bone, bowel, bladder and muscle formt eh nodal CTV
If node pos, use post ADT nodal tumour volume for boosting
No CTV expansion gtom GTVn. Only PTV expansion from GTV (as per EVIQ)
If possible, elective should be contoured at least 1-2 cm above the highest node.
Inferiorly extend to S1-S3, or lower depending on location of involved nodes.
Contouring prostate bed
Prostate bed FROGG volume borders
CTV
Inferior
5mm below vesicourethral anastomosis
Superior
Horizontal trajectory of vas deferens
Anterior
Lower 3cm of CTV should extend to pubic bone
Remainder extends 1.5cm into bladder
Posterior
Anterior rectal wall should be included (no circumferential inclusion)
Lateral
Levator ani muscle
PTV
CTV + anisotropic margin
Posterior = 8mm
Based on FROGAll others = 10mm
Side effects of ADT
Side Effects (overall)
· Osteoporosis, clinical fractures (21 – 54% relative incr facture risk)
· Hot flashes, vasomotor instability
· Loss of libido, erectile dysfunction
· Shrinkage of penis, testicles
· Loss muscle mass and strength
· Fatigue
· Gynacomastia
· Depression, mood swings
· Hair loss
· Obesity, insulin resistance, alteration in lipids, risk of DM
· Cardiovascular disease - esp if pre-exisiting CVD
Dose constraints for conventional prostate RT
Bladder
- V40 < 50%
- V65 < 35%
Rectum
- V40 < 40%
- V60 < 20%
Femoral Heads
- V50<5
- V40<50
- Dmax < 50Gy
Small Bowel
- ALARA (avoid hotspots)
- D1cc<54Gy
- V45 < 195cc (peritoneal cavity)
- V15Gy < 120cc (loops)
Urethra -Dmax 61.8Gy EQD2
Penile bulb
- Mean ≤52.5Gy
Spinal Cord/Cauda Equina
- Dmax < 45Gy
Dose constraints for hypofractionated prostate RT
Bladder
- V40 < 50%
- V60 < 5%
Rectum
- V30 < 60%
- V40 < 40%
- V50 < 30%
Femoral Heads
- V50<5
- V40<50
- Dmax < 50Gy
Small Bowel
- ALARA (avoid hotspots)
Spinal Cord/Cauda Equina
- Dmax < 45Gy
Avoid urethral hot spots
Side effects of prostate RT
Acute
Skin: 15% Gr 1-2
Fatigue
GU
· Resolves w/in 3wks
· 65% Gr 1-2
· 25% gr 2
· ½ : freq, dysuria, urgency, hem, cystitis, incont, spasm, retention
· 1/3: symp are mod/severe
GI
· 30% gr 2
· return to baseline 3-8wks
· Rad’n proctitis 2-40% (↑ w/ ↑ bowel dose & ↑ dose)
· Rad’n proctitis for ≥ 74Gy = 40%
· Abdo cramping
· Tenesmus
· Urgency/frequency of defecation/diarrhea
Late
GI: 15% (proctitis, diarrhea, blood PR)
· SBO/stricture: 1%
· Diarrhea
· Tenesmus
· Rectal urgency
· Hematochezia 5-10% (dose escalation)
· Rectal/anal strictures, ulcers, perf rare
GU: <15% (retent’n, incont, LUTS, stricture, hematuria)
· Urinary incont 0.3%
· Urethral stricture
· Cystits
· Hematuria
· Bladder contracture
· Grade 3+: 8% (1/2 = urethral stricture)
ED: up to 50% - ↑ w/ time, ↓ w/ spare of corpus spongiosum
· Impotence, dry/painful ejaculation
· hematospermia
≥74Gy: 20% mod/severe late effects (3-10% ≥70Gy)
