SRS eligibility brain mets
Dose/#
Volume <20cc
Ps 0-1
Prognosis > 6 months
Other disease controlled or controllable
(Post neuro-surgery - can consider for residual or recurrent disease.)
Single fraction
* <20 mm – 21–24 Gy single dose (Grade B)
* 21–30 mm – 18 Gy single dose (Grade B)
Hypofractionated SRS:
* 24–27 Gy in 3 daily fractions (Grade B)
* 30 Gy in 5 daily fractions (Grade B)
Fractionated/Staged SRS if: larger than 2–3 cm in diameter, close proximity to a critical OAR or if V12 Gy >10 cm3.
Management of medulloblastoma, CNS embryonal tumour and pineoblastoma?
Complete surgical resection.
Adjuvant craniospinal radiotherapy.
Adjuvant Chemo.
CSRT:
Medulloblastoma, CNS embryonal tumours and pineoblastoma:
Standard-risk craniospinal:
* 23.4 Gy /13#/2.5 weeks followed by boost of 30.6 Gy in 17 fractions of 1.8 Gy daily in 3.5 weeks to tumour bed or whole posterior fossa to a total dose of 54 Gy/30#/6weeks (Level B)
High-risk craniospinal:
* 36.0 Gy in 20 fractions of 1.8 Gy daily over 4 weeks (Level B)
* 39.6 Gy in 22 fractions of 1.8 Gy daily over 4.5 weeks (St Jude’s regimen for M2–3)
(Level B)
* Followed by boost to primary site to a total of 54.0–55.8 Gy in fractions of 1.8 Gy daily i.e. 54Gy/30#/6weeks.
(Level B)
* Boost to sites of metastases to a total of 45–50.4 Gy (spinal) and 54–55.8 Gy
(intracranial) fractions of 1.8 Gy daily (Level B)
Adjuvant chemo = 6-8 cycles of packer chemotherapy.
= cisplatin (or carboplatin), lomustine (CCNU), and vincristine
Medulloblastoma is an embryonal tumour of the CNS, which arises in the cerebellum. It
is notable for its propensity for metastatic spread via the craniospinal fluid (CSF) and its
radiosensitivity. Embryonal tumours can arise elsewhere in the CNS and are now referred to as
CNS embryonal tumours, with those arising in the pineal area defined as pineoblastoma.
Medullo volumes:
Phase 1:
CTV: Should include the entire craniospinal axis and spinal meninges including the thecal sac and dural tails on nerve roots. The cranial CTV is determined with the scan window set to bony thresholds and is the inner table of the skull including the cribriform plate. The CTV should extend to inferior limit of the thecal sac, determined on spine MRI - it is helpful to have input from a radiologist with this, especially if paediatric case. Laterally, include the entire subarachnoid space including extensions along nerve roots as far as intervertebral foramina.
PTV: CTV + 1 cm.
Phase 2: posterior fossa tumours
CTV: Superiorly: tentorium
Inferiorly: at least 2 cm below the lower limit of the tumour on the pre-op scan, it should at least include the outer table of the skull at the foramen magnum.
Anteriorly: anterior edge of brain stem
Posteriorly: the posterior extension of the meninges as far as inner table of skull. The CTV does not need to include any herniation of meninges though craniotomy defect.
Laterally: lateral extension of the meninges around the cerebellum
PTV: CTV + 0.5 - 1 cm margin.
Phase 2: supratentorial tumours
CTV: GTV + 1 - 2.5 cm margin
PTV: CTV + 0.5 - 1 cm margin
Treatment technique
6 MV photons are used for all treatments. Detailed planning instructions are given in TP/182.
Phase 1: The cranium is treated by two parallel opposed lateral fields, appropriately shielded by MLC’s. These cover the whole skull and upper neck to include C2 or C3 although the lower edge should be altered where possible to prevent the exit beam of the spinal field passing through the teeth or lower jaw.
The spine is treated by posteriorly applied direct field/s. Where possible, a single fixed-SSD field should be used. Depending on the length to be treated, a second field may be required. One or more boost fields may be required to compensate for any spine curvature that may be present.
The inferior edges of the lateral cranial fields are matched to the superior edge of the direct posterior spinal field. In order to follow beam divergence of the spinal field, the collimator is twisted approximately 10 degrees for the cranial fields. (The angle collimator is 7-8 degrees if the length of spine necessitates use of the two spinal fields).
Phase 2: Typically this involves a boost within the cranium, delivered via RapidArc utilising 2 full arcs with avoidance sectors anteriorly (to reduce the low dose splash to facial tissues), although this does depend on the site that is being boosted.
Sometimes a spinal boost is required; this is generally achieved via a direct posterior field.
Management of localised intracranial germ cell tumours?
Kids protocol RCR*****
Localised disease for both germinoma (non-secretory) and non-germinoma GCT (80% secrete AFP, BHCG) refers to unifocal or bifocal disease involving only the pineal and/or the pituitary/suprasellar region.
Mx: Chemo (PIE x 4 - cisP, ifos, etoposide).
Whole ventricular RT + boost to either residual disease (Germinoma) or primary (NGGCT).
RCR guidance:
Germinoma, post-chemotherapy, localised disease – whole-ventricular radiotherapy:
*24 Gy in 15 fractions of 1.6 Gy daily over 3 weeks
*Bifocal tumours, and those localised to suprasellar or pineal regions not achieving complete radiological response (CR) with induction chemotherapy, should receive a further boost to residual disease of 16 Gy in 10 fractions of 1.6 Gy daily over 2 weeks, delivering a total dose of 40 Gy (Level B)
Non-germinomatous GCT, localised disease – whole-ventricular radiotherapy:
*24 Gy in 15 fractions of 1.6 Gy daily over 3 weeks followed by a boost to primary tumour to a total dose of 54 Gy, in fractions not exceeding 1.8 Gy daily (Level B) - can also consider surgery to residual disease.
*A simultaneous integrated boost approach can be used to treat the primary site(s) to 27 Gy in 15 fractions (1.8 Gy daily) concurrently with the whole ventricles receiving 24 Gy in 15 fractions (1.6 Gy daily). This is followed by a boost of 27 Gy in 15 fractions to the primary site(s) only, with a total dose to the primary site(s) of 54 Gy in 30 fractions of 1.8 Gy daily over 6 weeks.
QART copied below:
Germinoma
Non- surgical treatment with craniospinal RT 24Gy in 15 fractions with boost (with 5mm margin on gross disease) to primary of 16Gy in 10 fractions and boost to metastases. Whole ventricular radiotherapy + boost may be sufficient. Chemotherapy should not be used outside of a clinical trial.
=Total of 40Gy/25#/5 weeks.
Non-Germinomatous Germ Cell Tumour (NGGCT):
Usually receive PEI chemotherapy (Cisplatin, Etoposide, Ifosfamide), followed by surgery if appropriate and localised disease RT with 54Gy in 29-30 fractions of 1.8 fractions over 6 weeks.
For metastatic disease, craniospinal 30Gy in 20 fractions, followed by boost 24Gy in 15 fractions in 1.6Gy per fraction.
Management of metastatic intracranial germ cell tumours?
Localised disease for both germinoma and non-germinoma GCT refers to unifocal or bifocal disease involving only the pineal and/or the pituitary/suprasellar region.
Mets 1L SACT:
Seminoma and NSGCT
BEP x 3 if good prognosis, x 4 if intermediate prognosis.
Carboplatin alone an option if can’t have cisP
QART states: Non germinomatous GCT
For metastatic disease, craniospinal 30Gy in 20 fractions, followed by boost 24Gy in 15 fractions in 1.6Gy per fraction.
Management of ependymoma?
Arise within ventricular wall, metastasise within CSF.
Mx = surgery - to primary + mets if feasible.
Post-op RT for all G3 tumours or incomplete resection (SP says not G1)
Consider Adj RT completely resected G2.
QART dose/# = They are treated to a dose of 60Gy in 30# after maximal resection. Spinal lesions have a dose of 50Gy/30#.
RCR below
Intracranial ependymoma:
*59.4 Gy in 33 fractions of 1.8 Gy daily over 6.5 weeks (Level B)
*54 Gy in 30 fractions of 1.8 Gy daily over 6 weeks in very young children <18 months, poor neurological status or multiple surgeries.
Volumes as per HGG.
Spinal ependymoma:
*50.4–54 Gy in 28–30 fractions of 1.8 Gy daily over 5.5–6 weeks (Level B
Do consider re-irradiation for relapse.
Volumes:
Grade 3 tumours are treated as per high grade glioma with the same margins (copied below), involved fields only.
GTV (or resection cavity) Drawn using T1 gadolinium scans. GTV does not include any tumour oedema.
CTV = GTV + 2.0cm margin (trimmed off bone & tentorium). The CTV can follow CSF spaces, and should include tumour oedema (T2 Flair signal abnormality).
PTV = CTV + 0.5cm margin
Management of vestibular schwanoma?
Initial management = active surveillance.
Koos 1-3, if enlarging, for SRS 12-13Gy.
Koos IV (compressing brainstem) = consider surgery.
If unfit for surgery can consider hypofractionated or conventionally fractionated RT for Koos IV.
Management of pituitary adenoma?
RT indications and dose/#.
Primary tx = surgery.
Consider RT if: not fit for surgery, recurrent or progressive following excision, residual disease and threat to vision, adverse oath e.g. ki67 >3%, secretory with peristent raised hormones despite max blockade.
45Gy/25#/5weeks.
Lagre of marked invasion = 50.4Gy/28#/5.5 weeks - 54Gy/30##6 weeks.
Volumes GTV (pre-op), NO CTV, PTV =GTV +0.5cm.
Management of craniopharyngioma?
Cystic hypothalamic tumour arising from rathke’s pouch.
RT if residual disease.
50.4Gy/28#/5.5 weeks (QART) - 54Gy/30##6 weeks (alternative option on RCR).
Volumes GTV (pre-op), CTV = GTV +0.5cm, PTV =CTV +0.5cm.
Management of meningioma?
Indications for tc and dose/#.
Dural based, include the dural tail in the GTV.
G1 if inoperable, incomplete resection or recurrance.
QART says G2 +G3 and meningeal sarcomas = consider RT, balance of risks and benefits.
RCR dose/#
Grade 1:
* VMAT 50–54 Gy in 25–30 fractions over 5–6 weeks (Grade C)
* SRS 13–15 Gy in a single fraction (Grade C) = small volume (<7.5-10cc and >5mm from OARs)
* SRS 25 Gy in 5 fractions (Grade D) (small <3cm, clsoder to OARs
Grade 2 (atypical):
* VMAT 54–60 Gy in 30 fractions over 6 weeks (Grade B)
Grade 3 (anaplastic) (also meningeal sarcomas):
* VMAT 60 Gy in 30 fractions over 6 weeks (Grade B)
Volumes as per HG Glioma
GTV Include dural tail
CTV = GTV + 1 - 2.0cm margin
However, for some tumours (skull base or post orbit) may require smaller margins (0.5cm – 1.0cm) due to anatomical differences.
PTV = CTV + 0.5cm margin
Management of grade 4 glioma?
IL SACT
Glioblastoma, IDH wildtype:
Good performance status (KPS 80–100) and aged <70 with minimal residual tumour:
* 60 Gy in 30 daily fractions over 6 weeks ± temozolomide 75mg/m2 OD during RT with PCP prophylaxis. (Grade A)
Moderate performance status (KPS 60–70) PS 2, or aged over 70:
* 40 Gy in 15 fractions over 3 weeks ± temozolomide if MGMT methylated (Grade A)
Followed by 6 cycles of 4 weekly temozolamide 150 mg/m2 (cycle 1)
then 200mg/m2 (cycle 2 onwards) OD PO D1-5.
Poor performance (KPS 50–60 = PS 3) may be considered for shorter-course:
30 Gy in 6 fractions on alternate days/2 weeks (Grade C))
Diffuse Midline glioma (H3K27M mutant)
V.poor prognosis - for upfront RT.
54Gy/30#/6weeks.
1L palliative SACT:
TMZ (don’t re-challenge if <6m since TMZ).
PCV
Lomustine alone
Alternative: carboplatin
Volumes:
GTV (or resection cavity) Drawn using T1 gadolinium scans. GTV does not include any tumour oedema.
CTV = GTV + 2.0cm margin (trimmed off bone & tentorium). The CTV can follow CSF spaces, and should include tumour oedema (T2 Flair signal abnormality).
PTV = CTV + 0.5cm margin
Re-irradiation for HGG?
Diffuse midline Glioma of brainstem - consider 20Gy/10# if >6m post RT.
Brioche inclusion criteria: First recurrence (incl. if had surg for recurrence + residual or new lesion), >/= 6m post primary RT, Small - max diameter </=6cm for single or combines multifocal lesions, received at least 2 weeks TMZ previously.
Brioche dose/#: 35Gy/10#/2weeks
SRS re-treat eligibility?
New lesions - can consider if >3m since last treatment.
Treated lesions, could consider if >6m post initial treatment.
Management of grade 3 glioma?
Adjuvant radiotherapy 59.4Gy/33#/6.5 weeks with adjuvant:
1p19q co-deleted oligo = PCV x 6 cycles.
Procarbazine PO D1-10, Lomustine (CCNU) 100mg/m2 PO D1, Vincristine 1.5mg/m2 IV D1, 42 day cycle.
1p19q NON co-deleted = 12 x adjuvant temozolamide 4 weekly temozolamide 150 mg/m2 (cycle 1) then 200mg/m2 (cycle 2 onwards) OD PO D1-5.
Volumes:
GTV (or resection cavity) Drawn using T1 gadolinium scans. GTV does not include any tumour oedema.
CTV = GTV + 2.0cm margin (trimmed off bone & tentorium). The CTV can follow CSF spaces, and should include tumour oedema (T2 Flair signal abnormality).
PTV = CTV + 0.5cm margin
Management of Grade 2 Glioma
RT if >40 or incomplete resection.
Pignatti score for LGG = SLASH. 3 or more features = definitely needs treatment.
Size >/=6cm, location = midline, age >40, nonSeizure = non-seizure pre-op neuro deficit, histology = astrocytic.
Adjuvant radiotherapy 50.4Gy/28#/5.5 weeks followed by adjuvant PCV chemo.
GTV (or resection cavity) Drawn using T1 gadolinium scans. GTV does not include any tumour oedema.
CTV = GTV + 1.5cm margin (trimmed off bone & tentorium). The CTV can follow CSF spaces, and should include tumour oedema (T2 Flair signal abnormality).
PTV = CTV + 0.5cm margin
Radiotherapy for spinal glioma dose/#?
Low or high grade (biopsy recommended) = same dose/#
54Gy/30#/6weeks.
Same for paeds or can go lower to 50.4Gy/28#/5.5weeks.
Pineal tumour work up
Initial evaluation
• MRI brain + spine
• CSF cytology
• Tumour markers:
• AFP
• β-hCG
• Biopsy if markers are not diagnostic
Surgery is usually limited to biopsy, not full resection in seminoma
