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Rad Onc Oral Boards > CNS > Flashcards

CNS Flashcards

1
Q

CNS Lymphoma presentation and workup

A

Older patient with neuro symptoms

1 or multiple enhancing periventricular masses with FLAIR, crosses corpus callosum

MRI Brain/Spine, PET

LP
Slit Lamp
Testicular Exam

LDH/HIV/EBV

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2
Q

CNS Lymphoma management

A

All are stage IE:
R-MPV x 6 -> auto SCT or consolidation WBRT -> High dose cytarabine

rdWBRT CR 23.4, full dose 36 for PR + boost residual to 45 Gy, include posterior globe, if eye involved entire eye, down to C2

High neuro toxicity

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3
Q

Pathologic Grading

A 
AMEN
Atypia (Nuclear)
Mitotic index
Endothelial proliferation
Necrosis
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4
Q

MRI sequences

A

T1: longitudinal relaxation images. Good for soft tissue
– white matter brighter than dark matter; fat bright; blood bright

T2: transverse relaxation images. Good for fluid

FLAIR (fluid attenuated inversion recovery): T2 with CSF signal subtracted out
– dark matter brighter than white matter; fluid/CSF bright

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5
Q

Supratentorial Ddx
Suprasellar
Central
Peripheral

A

Suprasellar (COP GEM):

  1. Craniopharyngioma
  2. Optic glioma
  3. Pituitary adenoma
  4. Germ cell tumor (3rd vent)
  5. Ependymoma (3rd vent)
  6. Meningioma

Central/thalamic/pineal (GG PP M):

  1. Germ cell
  2. Glioma
  3. Pineocytoma
  4. Pineoblastoma
  5. Mets

Cerebral/peripheral (MAGLAV):

  1. Mets
  2. Astrocytoma
  3. Glioma
  4. Lymphoma
  5. Abscess
  6. Vascular
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6
Q

Infratentorial Differential

A

Infratentorial Differential

Posterior fossa (MEGa JAMA):

  1. Medulloblastoma
  2. Ependymoma
  3. Glioma
  4. JPA
  5. cerebellar Astrocytoma
  6. Mets
  7. ATRT

Brainstem:

  1. Glioma
  2. AVM
  3. Encephalitis
  4. Abscess
CSI
Medulloblastoma
Supratentorial PNET
Pineoblastoma
NGGCT

CSI if M+ only
Germinoma
Ependymoma
ATRT

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7
Q

CSF Connections

A

CSF Connections

  • Aqueduct of Sylvius – connects 3rd to 4th ventricle
  • Foramen of Magendie – connects 4th ventricle to cisterna magna
  • Foramina of Luschka – connects 4th ventricle to cerebellopontine angle
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8
Q

Termination of Cord

A

Termination of Cord

  • Adults: L1/L2
  • Newborn: L3/4
  • Thecal sac: S2
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9
Q

Astrocytoma histology

A

Astro- neural glial fibrils GFAP positive
IDH mutant, 1p19q intact, ATRX loss, p53 mut

*picture

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10
Q

Oilgo histology

A

Oligo
Fried egg- nuclear halo

IDH mutant, 1p19q co-deleted, ATRX retained, p53 wt
*picture

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11
Q

GBM histology

A

GBM – grade IV - PPMM

  • pseudo-palisading necrosis
  • pleomorphic nuclei
  • microvascular proliferation
  • mitotic rate increased
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12
Q

GBM on MRI

A

MRI brain - enhancing, irregular mass with surrounding edema (FLAIR) causing mass effect with midline shift. Often rim-enhancing signifying central necrosis

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13
Q

GBM workup

A

Neurosurg consult:
Resection if possible; If not, biopsy
Decadron/PPI, Keppra

  • MGMT methylation status (MGMT is DNA repair enzyme. If promotor is methylated, gene product down-regulated, less methylation of guanine, inc alkylation by TMZ). Prognostic.

Temozolamide alyklates DNA directly, MGMT produces a compound that undos this damage

Post-op MRI w/in 48-72 hrs after surgery

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14
Q

RPA class

A
  • I - AA, age<50, KPS>70
  • II - AA, age >50, KPS>70
  • III: GBM <50 yrs KPS>90 MS 18mo
  • IV: GBM <50 yrs KPS<90 MS 11mo
  • V: GBM >50 yrs KPS>70, MS 9 mo
  • VI: GBM >50 yr, neuro deficit, KPS<70, MS 5 mo
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15
Q

GBM treatment

A

Clinical trial
Max safe resection -> RT 60/2 Gy with concurrent TMZ -> adjuvant TMZ starting 1 month after RT
-concurrent TMZ dose: 75mg/m2/day x 7 days/wk
-adj dose starting 1 month after RT: 150mg/m2/day x 5 days/28 days x 6 mo

(Zofran and Bactrim MWF PPX w/ TMZ)
-take TMZ night before per Stupp

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16
Q

GBM elderly

A

<70 yrs KPS high -> Stupp regimen

> 70 yr wih KPS good -> TMZ + 40 Gy/15 fx – concurrent and adjuvant TMZ. (mMGMT was predictive) >65 and ECOG 0-2

KPS fair -> TMZ alone if MGMT methylated
-> RT alone if MGMT unmethylated (40/15 or 25/5 [Roa])

KPS very poor -> supportive care only

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17
Q

GBM MS MGMT vs not

A

MGMT methylated – 22 vs. 15 months

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18
Q

GBM Volumes

A

Use post-op imaging: RTOG
GTV_46= any T1 enhancement + tumor bed + T2 FLAIR
CTV_46=GTV + 2 cm (cropped to 5 mm at natural barriers)
PTV_46=CTV + 0.3 cm w/ daily kV imaging and weekly CBCT

GTV_60=T1 enhancement + tumor bed (no FLAIR)
CTV_60=GTV + 2 cm
PTV_60=CTV + 0.3 cm

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19
Q

GBM planning objectives and constraints

A

> 95% of PTV receives 100% of dose
Min dose to PTV 90%

Brainstem < 54 Gy (max 60 to <10 cc)
Optic chiasm/nerve < 54 Gy
Spinal cord/Retina < 45 Gy
Cochlea Dmean < 45 Gy
Lens < 10 Gy
Lacrimals < 26 Gy
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20
Q

GBM acute side effects

A

Fatigue 25% (mod-severe)

TMZ – low platelets (check labs q 2 wks), need to use Bactrim for PCP prophy

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21
Q

Followup GBM

A

Follow-up:

  • MRI at 4 wks post RT
  • Then q 2-3 mo x 3 yrs

Radiographic progression occurs on first MRI in 40%

  • 1/2 true progression
  • 1/2 pseudoprogression
  • do NOT change tx after first scan
  • pseudoprogression stabilizes or improves within 3 months of TMZ/RT
  • RANO: cannot call first post-trreatment scan progressioin, unless clearly progressive (such as out of field 80% ISL and path confirmation). >12 wks increase in T2/flair on angiogenic tx (angiogenic cause pseudo-response)

MacDonald criteria (T1 post) vs. RANO criteria (T2/FLAIR) for progression

Consider adj TTF s/p CRT (start with adj TMZ), need to wear 18 hours daily
Med OS with TTF 16 vs. 21 mo (Stupp JAMA 2017)

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22
Q

GII-III IDH wildtype treatment

A

treat like GBM

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23
Q

G2 Astro treatment and OS

A

MSR ->

Low risk -> observe

High risk -> 54 Gy (T2/T1gad/cavity + 1cm) -> PCV

6y

LR: <=40y and GTR

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24
Q

G3 Astro treatment and OS

A

MSR -> 59.4 Gy (T2/T1gad/cavity + 1.5cm) -> TMZ

5y

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25
Q

G2 Oligo treatment and OS

A

MSR ->

Low risk -> observe

High risk -> 54 Gy (T2/T1gad/cavity + 1cm) -> PCV

14y

LR: <=40y and GTR

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26
Q

G3 Oligo treatment and OS

A

MSR -> 54 Gy (T2/T1gad/cavity + 1cm) -> PCV

14y

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27
Q

JPA histology

A

Rosenthal fibers

28
Q

RT benefit for LGG

A

Summary

  1. RT improves PFS 35 -> 55% (mPFS 3 -> 5 yrs) but has not been shown to improve OS (MS 7 yrs) (Nonbelievers)*
  2. Chemo improves OS for high risk LGG (>40 years or STR) per RTOG 9802
    - 1. Sequential PCV  RT better than RT alone
    - 2. Unknown if TMZ vs PCV matters
    - 3. Optimal timing not known
  3. Low dose = high dose (use 54 Gy)
  4. Chemo monotherapy should not be used (CODEL, NOA-04, EORTC)
  5. Observation vs. immediate post-op RT:
    - Observation: young (<40 years) s/p GTR, oligo component (50% PFS on RTOG 9802)
29
Q

LGG poor prognostic factors

A

“SATAN” (from Believer’s and Non-Believers)

1) size > 6 cm
2) age > 40
3) tumor crosses midline
4) astrocytic component
5) neuro deficit

0-2 low risk: 7.7yr MS
3-5 high risk: 3.2yr MS

30
Q

Gemistocytic management

A

Gemistocytic – more aggressive, treat to 60 Gy and give concurrent temodar

31
Q

JPA management

A

JPA: max safe surgery

  • RT only if multiply recurrence or bx only
  • RT dose 50.4
32
Q

Meningioma risk factors

A

Risk factors: NF II, prior cranial RT, HRT

33
Q

Cavernous Sinus contents

A

Cavernous sinus III, IV, V1, V2, VI

Internal Carotid

34
Q

Dural tail sign differential:

A 
Dural tail sign differential: 
(“CLSM” – cats like spilled milk)
Chloroma
Lymphoma
Sarcoid
Meningioma
35
Q

Meningioma pathology

A

psammoma bodies

  • Benign (75-85%) – Grade I: <4 mitoses / 10 HPF
  • Atypical (5-10%) – Grade II: 4-19 mitoses/ 10 HPF, or Brain invasion
  • Anaplastic (<5%) – Grade III: >=20 mitoses / 10 HPF
36
Q

Grade 1 Meningioma Man

A

Grade 1 (benign):
Asx and < 3 cm: observe
-median growth 4 mm/yr

Sx, large, high risk area, progressing

  1. Surgery – consider post-op RT if STR (but mostly observe)
  2. Definitive RT to 54 Gy
  3. Definitive SRS to 12 Gy

CTV is 1 cm along dura for Grade 1, 2-3 cm for Grade 2/3

37
Q

Grade 2 Meningioma Man

A

Grade II (atypical):
Surgery -> RT
If GTR, RT to 54 Gy (could observe if good surg salvage option)
If STR, RT to 60 Gy (RTOG 0593)

CTV is 1 cm along dura for Grade 1, 2-3 cm for Grade 2/3

38
Q

Grade 3 Meningioma Man

A 
Grade III (anaplastic):
Surgery -> RT to 60 Gy

No SRS for G2-3

CTV is 1 cm along dura for Grade 1, 2-3 cm for Grade 2/3

39
Q

Simpson grade resection

A

Simpson grade resection (1-3 is GTR, 4-5 is STR)
I – GTR removal bone/dura
II – GTR dural coag
III – GTR no dural coag/removal
IV – STR
V – Decompression only
**new addition of a grade 0- stripping of 2-4 cm of dura

40
Q

SRS constraints

A 
SRS: 
Optic chiasm: 8 Gy need 3mm to do this
Whole brain – GTV V12 < 5-10cc
Brainstem < 12 Gy
Eye/retina: 8 Gy
Cochlea: 4 Gy
41
Q

Meningioma LR

A

LR10 after Simpson I-III: 20%
LR10 after Simpson IV: 60%

Grade 1: 90% LC regardless of tx

Grade 2:
40% LR after GTR alone
30% LR after surgery + RT

Grade 3:
OS5 50%

42
Q

Sella boundries

A 
Anatomy:
Ant – clinoids
Sup – ant cerebral arteries, optic chiasm
Inf – sphenoid
Lat – cavernous sinus
43
Q

Adenoma hormone production

A

Microadenoma < 1 cm
Macroadenoma > 1 cm

Functioning 75%, non-functioning 25%

Hormone type: prolactinoma (30%), GH (25%), ACTH (15%)

Post lobe: ADH, oxytocin
Ant lobe: everything else

MEN1 (3 P’s): Parathyroid, Pituitary,
endocrine Pancreas

44
Q

Pituitary adenoma presentation

A

History: visual field deficits (bitemporal homonomous hemianopsia), headaches, endocrine changes

  • Prolactinoma: amenorrhea, infertility, galactorrhea, gynecomastia
  • Cushing’s Disease (ACTH): central obesity, HTN, DM, hirsutism, skin changes, osteoporosis.
  • Acromegaly (GH): changes in bones, HA, cardiac disease, colonic polyps, large squishy hands, frontal bossing (skull)
45
Q

Pit Adenoma Workup

A

Imaging: thin cut MRI; CT scan

Labs:
Prolactin
Serum IGF-1 (or GH level after oral glucose) 
Cortisol, ACTH, 24-urine cortisol
TSH/fT4/T3
FSH, LH
46
Q

Pit Adenoma Treatment

Non-functioning:

A

No role for UPFRONT RT unless inoperable!!

Non-functioning:
Trans-sphenoidal surg (TSS)
-adj RT at 6 wks if STR or growth

EBRT 45 Gy
SRS: 15 Gy

47
Q

Pit Adenoma Treatment

ACTH or GH

A

No role for UPFRONT RT unless inoperable!!

ACTH or GH: TSS
-adj RT for persistent hormone secretion post-op or STR

EBRT 50.4 Gy
SRS: 25 Gy

48
Q

Pit Adenoma Treatment

TSH-secreting

A

No role for UPFRONT RT unless inoperable!!

TSH-secreting:
TSS -> post-op RT always (54 Gy)

49
Q

Pit Adenoma Treatment

Prolactinoma:

A

No role for UPFRONT RT unless inoperable!!

Prolactinoma: medical management (bromocriptine) first even if visual sx. Surgery for failure of medical tx.

Inoperable: RT
Recurrence after surgery: RT

50
Q

Pit adenoma control, hormone normalization, toxicity

A

LC > 90%
Hormone normalization:
Surgery – 50-80% (depends on size, hormone)
Def RT – 30-50% (note TSH has worst outcome)

RT hormone normalization takes 12-18 months

Toxicity:
Hypopit (50%): GH first
Vision loss

Follow-up:

  • MRI q 6 mo x 1 yr, then annual
  • Endo lab panel
  • Annual visual field testing
51
Q

AN presentation

A

75% present with hearing loss

CPA angle
Vestibular part of CN VIII
Bilateral AN is pathognomonic feature of NF2

52
Q

AN workup

A

Audiometry
MRI – usually homogeneous. Enhancing (dif=meningioma)
No biopsy needed
NF2 testing if bilateral

53
Q

AN treatment

A

1) EBRT or SRS
both offer > 90% LC
60-70% hearing preservation (may be lower w/ SRS)

EBRT dose: 50.4/1.8 Gy (>3 cm, useful hearing, malignant (54 Gy), NF2, pressing on brainstem)

SRS dose: 12 Gy

SRT doses:
7 Gy x 3 (Stanford)
5 Gy x 4-5 (Slotman)

2) Microsurgery (translabyrinthine or middle cranial fossa or subocipital)
50% useful hearing

3) Observation: tumors grow 1-2 mm/year, so observation is always an option in someone who has already lost their hearing

54
Q

AN success and side effects

A

LC > 90% after w/ SRS

<5% risk of CN VII or V damage w/ RT

20-30% transient tumor enlargement after RT

Surgery side effects:
CSF leak, damage to adjacent CN VII, infection (all < 5%)
-higher rates of facial and trigeminal neuropathy than RT

55
Q

AVM classification

A

Classification system
I: isolated malformation without peripheral drainage;
II: malformation draining into normal veins
III: malformation draining into dilated veins
IV: malformation representing dysplastic venous ectasia

56
Q

AVM dose and success

A

< 3 cm: 20 Gy to 50% IDL
> 3 cm: 16 Gy to 50% IDL

Target is nidus, not feeding arteries or draining veins

For tumors >15 cc, consider staged SRS 6 months apart

Obliteration rate 80-90% with SRS (especially if <10cc)
Median time 1-3 yrs for complete obliteration
Risk dec by 50% during latency period

57
Q

Trigeminal Neuralgia dose

A

80 Gy max; target is trigeminal nerve root; single 4 mm isocenter; brainstem edge at 20-30% IDL

58
Q

Chordoma dose

A

Max safe resection -> RT

Dose: 70 Gy (refer for protons for BOS location)

59
Q

RPA class and GPA Brain mets

A

RPA class:
I – KPS >70, age <65, primary controlled/brain mets only
II – all others
III – KPS <70

RPA I – 7 months
RPA II – 4 months
RPA III – 2 months

GPA:
0, 0.5, or 1 pt for each risk factor (site specific)
-varies by diagnosis (breast, lung, etc)
- KPS, age, extracranial mets, # brain mets

60
Q

HA- WBRT

A

HA-WBRT: 3 Gy x 10

  • brain target: brain – hippocampus + 5mm, no PTV
  • contour all mets – not required
  • contour hippocampus + 5 mm margin
  • hippocampus is grey matter
  • RCT CC001 – iimproved cognitive outccomes with HA-WBRT over traditiional WBRT – ineligible if SCLC, mets within 5 mm of hippocampus, lepto
  • hippocampus: max < 16 Gy, D100%<9Gy
  • optics <37.5
  • *who gets this?

HA-WBRT+memantine:
Phase III trial of WBRT+memantine +/- HA
*HR for NCF 0.74, lower risk exec function at 4 month, encoding and consolidation at 6, pt reported faigue, speaking, and memory improved 6 months.

61
Q

SRS dose

A

≤2cm: 24 Gy (20 Gy)

  1. 1-3 cm: 18 Gy
  2. 1-4 cm: 15 Gy (or 6 Gy x 5)
62
Q

SRS cavity

A

SRT (cavity):
CTV: 2 mm
PTV: 1 mm
Dose resection > SRS vs WBRT

6 Gy x 5 fine I think but…

  • < 4.2 cc 􀃆20 Gy : 1cm
  • 4.2-7.9 cc􀃆18 Gy
  • 8.0-14.3 cc􀃆17 Gy
  • 14.4-19.9 cc􀃆15 Gy
  • 20.0-29.9 cc􀃆14 Gy
  • ≥30 cc􀃆12 Gy : 2cm
63
Q

SRS side effects

A 
NECROSIS:
SRS necrosis rate: 20-30%
Symptomatic: 10-15%
*dual phase PET- Tracer increase = tumor
* perfusion: relative cerebral blood volume (more in tumor).necrosis looks feathery swiss cheese and worse than patient feels

Asymptomatic: observe
Symptomatic or progression
1. High dose steroids: 4 mg BID x 4-6 wks then taper  re-MRI
2. Avastin (IJROBP 2011): 7.5 mg/kg q 3 wk x 2; durable; high rate of clinical and radiographic response – need to be sure it’s not progression, after Avastin cannot do surgery
3. Hyperbaric oxygen
4. Surgery/laser coagulation: can be diagnostic and therapeutic; high complication

64
Q

SRS LC

A

SRS alone LC:
< 2 cm: > 90%
2-3 cm: 80-90%
3-4 cm: 60-70%

65
Q

Present with seizure good or bad

A

positive prognostic sign

Rad Onc Oral Boards (11 decks)

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