Pediatric Radiation Oncology - Board Review Summary

PLANNING AND LATE-EFFECT GUARDRAILS

Normal-Tissue / Late-Effect Dose Anchors

Domain	Seconds-glance planning reminder
Growth and asymmetry	Partial irradiation of vertebrae, ribs, limbs, breast buds, or facial bones can produce asymmetric growth. If a growing vertebral body is meaningfully irradiated, symmetric coverage may be safer than a sharp partial-body gradient.
Neurocognition	Risk rises with younger age, higher cranial dose, and larger brain volume. Counsel on processing speed, attention, short-term memory, school accommodations, and repeat testing through school age.
Endocrine axis	Hypothalamic-pituitary dose can cause GH deficiency, thyroid/adrenal/gonadal axis dysfunction, or puberty changes; baseline and long-term endocrine follow-up are part of the plan.
Hearing / vision	Actively spare cochleae, lenses, lacrimal glands, retina, optic nerves/chiasm, and brainstem. Practical anchors: cochlea mean ideally <35 Gy and max <45 Gy when feasible; optic pathway usually kept <54 Gy with conventional fractionation.
Second malignancy & fertility	Children have decades for late toxicity. Minimize integral dose. Infertility dose-threshold ranges from 2-12 Gy (prepubertal ovaries are more resistant). Aim <10 Gy to prepubertal ovaries. Alkylating chemotherapy increases risk. Use ALARA and advanced techniques (e.g., protons).

Pediatric RT Mindset

Default trend: pediatric RT is moving toward smaller fields, lower doses, later RT, or omission only when the disease risk group and systemic therapy context support it.
Before contouring: fuse initial diagnostic imaging, post-chemo imaging, and post-op imaging. Many pediatric volumes are based on the initial disease footprint, even after dramatic response.
PENTEC: pediatric-specific normal-tissue evidence is the current framework; age, dose, volume, and chemotherapy exposure all matter. Do not blindly port adult QUANTEC constraints into children.
Modality: protons, IMRT/VMAT/tomo, electrons, and conventional 3D fields are tools. Choose the modality that best respects target volumes and late-effect priorities.
Survivorship lens: even low pediatric doses can leave decades of risk: cardiac, renal, pulmonary, hepatic, endocrine/thyroid, fertility, growth/asymmetry, neurocognitive decline, hearing loss, cataracts, dry eye, vascular events, radiation necrosis/myelitis, and second malignancy.

Planning checkpoint	Board-facing reminder
Baseline before cranial/CSI RT	Ophthalmology, audiology, endocrine labs, and neurocognitive baseline are useful before RT and for long-term surveillance.
CSI in skeletally immature patients	Cover the thecal sac to about S2/S3 and nerve roots laterally to the vertebral-body edge; consider whole/bony spine low-dose coverage when the approach requires it to reduce asymmetric growth.
CSI OAR check	Review cochleae, heart/left ventricle, brainstem, lacrimal glands, lenses, pituitary, liver, kidneys, thyroid, and esophagus.
Wilms overlapping fields	In selected favorable-histology patients with lung metastases, moving all RT after induction can avoid flank/whole-lung field overlap; protocol timing controls.
Clinical trials	Open-study schemas are not default standards. WNT medulloblastoma 18 Gy CSI remains study-only until mature published results support routine use.

PART I - NON-CNS MALIGNANCIES

Management Paradigm + Dose Anchors

Entity	Default management frame	RT / dose anchor
Wilms tumor	COG-style surgery first when classic presentation; do not biopsy unless diagnosis is unclear. RT for FH stage III-V and unfavorable histology all stages.	Flank 10.8 Gy / 6 fx for FH stage III; diffuse anaplasia stage III 19.8 Gy; WAI 10.5 Gy / 7 fx; WLI 12 Gy / 8 fx or 10.5 Gy / 7 fx if <1 year.
Neuroblastoma	Low/intermediate risk usually no RT. High-risk sequence: induction, surgery, ASCT, RT, then anti-GD2 immunotherapy.	Primary site and selected persistent metastatic sites 21.6 Gy / 12 fx; no routine boost for gross residual after surgery.
Rhabdomyosarcoma	Group and FOXO1 status drive RT. Local therapy is usually after induction chemo; delayed primary excision helps only if all gross disease can be removed with acceptable morbidity.	Group I FOXO1+ 36 Gy; Group II margin+ 36 Gy; node+ 41.4 Gy; orbit Group III 45 Gy; non-orbit Group III 50.4 Gy; WLI 15 Gy / 10 fx (>6 years) or 12 Gy / 10 fx (<7 years).
Ewing sarcoma	Systemic therapy is essential; local control is surgery, RT, or both. Surgery favored for expendable bones; RT favored for unresectable or morbid surgical sites.	Definitive/gross residual 55.8 Gy; postop microscopic positive margin 50.4 Gy; preop RT 36 Gy; WLI 15 Gy / 10 fx or 12 Gy / 8 fx if <6 years.

Wilms Tumor

Most common abdominal tumor of childhood; median age just under 4 years; painless mass that moves with the kidney on ultrasound.

Syndromes: WAGR, Denys-Drash, Beckwith-Wiedemann. Associated findings include aniridia, GU anomalies, and hemihypertrophy.
Histology: triphasic embryonal tumor. Unfavorable histology: anaplastic Wilms, clear cell sarcoma of kidney, and rhabdoid tumor of kidney.
Prognosis worse: higher stage, unfavorable histology, age >24 months, and LOH 1p and/or 16q.
Do not biopsy if you suspect Wilms because favorable histology is upstaged to stage III via spill risk. COG approach is surgery first, then chemotherapy.
RT indications: favorable histology stage III-V and unfavorable histology all stages. Start RT within 10-14 days of surgery.

Scenario	Dose / fractionation
Flank, stage III favorable histology	10.8 Gy / 6 fx
Flank, stage III diffuse anaplasia	19.8 Gy
Whole abdomen, positive cytology / spill / peritoneal seeding	10.5 Gy / 7 fx
Boost to gross residual nodes or abdomen	+10.5-19.8 Gy
Whole lung irradiation	12 Gy / 8 fx (10.5 Gy / 7 fx if <1 year)
Whole brain	21.6 Gy / 12 fx
Focal liver	19.8 Gy / 11 fx
Bone metastases	25.2 Gy (<16 years) / 30.6 Gy (>=16 years)
Lymph nodes	10.8 Gy resected / 19.8 Gy unresected

AREN0533: favorable-histology Wilms with lung metastases and no LOH could omit whole-lung RT if lung nodules had complete response after induction chemotherapy. EFS was borderline lower than expected, but OS was preserved.

Flank field rules: pre-resection tumor plus 1 cm; avoid splitting vertebral bodies; do not cross more than 1 cm into the contralateral kidney; if LN+ include para-aortics from crus of diaphragm to L5/S1.

Neuroblastoma

Second most common abdominal tumor of childhood; neural crest origin; often acutely ill appearance, periorbital ecchymoses, and mass moving separately from kidney.

Workup: urine catecholamines, CT C/A/P, MIBG (PET if not MIBG-avid), bone marrow biopsy, echo/MUGA, and audiogram/BAERS.
Do not resect at diagnosis in typical neuroblastoma because that commits to larger RT fields; this contrasts with Wilms.
Histologic / molecular risk factors: MYCN amplification, diploidy, age >17 months, LOH 1p or 11q, and poor differentiation.
INRG staging drives risk stratification; low/intermediate risk rarely get RT, while high-risk patients generally receive RT.
High-risk sequence: induction chemo, surgery, ASCT, RT, then anti-GD2 immunotherapy.

Site	Dose / target
Primary site after induction/surgery	21.6 Gy / 12 fx
Persistent metastatic sites at ASCT	21.6 Gy / 12 fx
GTV1 definition	Extent of disease at time of surgery, after induction, including involved nodes. CTV1 = GTV1 + 1 cm, anatomically confined.

ANBL0532: radiation dose escalation (adding a 14.4 Gy boost on top of 21.6 Gy) to gross residual primary tumor did not improve local control compared to historical A3973 data; do not reflexively boost residual postoperative disease.

Vertebral-body growth pearl: if a vertebral body touches the 10 Gy line, protocol logic may include it in the 18 Gy target to reduce asymmetric growth.

Rhabdomyosarcoma

Most common pediatric soft tissue sarcoma; radiosensitive. FOXO1 fusion status now dominates over the old embryonal/alveolar shorthand.

Favorable: FOXO1-negative embryonal/botryoid/spindle cell and FOXO1-negative alveolar-like biology.
Unfavorable: FOXO1-positive disease, usually alveolar, older age, and worse EFS.
Nodal risk by site: orbit 0-1%, extremity 10-15%, paratesticular 25-30%. LN sampling is required for all extremity primaries and males >10 years with paratesticular RMS.
Parameningeal workup: CSF cytology + neuraxis MRI; for H&N/PM planning, T1+Gad and T2 are needed to distinguish tumor from mucus.
Group, not stage, drives RT decisions. Group is defined before chemotherapy.

Group	Definition	RT dose
I	Localized, completely resected	0 Gy if FOXO1-negative; 36 Gy if FOXO1-positive
IIA	Gross resection, microscopic positive margin	36 Gy
IIB/C	Resection with involved nodes	41.4 Gy
III orbit	Gross residual orbital primary	45 Gy
III non-orbit	Gross residual disease	50.4 Gy
Whole lung	Metastatic disease	15 Gy / 10 fx (>6 years); 12 Gy / 10 fx (<7 years)

ARST0531 / ARST1431: dose escalation from 50.4 Gy to 59.4 Gy did not solve local control for tumors >5 cm. Delayed primary excision can reduce local failure when feasible without unacceptable morbidity.

Target volumes: GTV1 = visible pre-therapy disease, cut back for pushing margins but not infiltrating margins. CTV1 = GTV1 + 1 cm, anatomically confined. Local therapy usually begins around week 13.

Cyclophosphamide dose matters: later trials with reduced cyclophosphamide had higher local recurrence despite similar RT dose; RT cannot fully compensate for reduced systemic intensity.

Ewing Sarcoma

Bone or soft tissue small round blue cell tumor; classic t(11;22) EWS-FLI1; radiosensitive but systemic disease dominates outcomes.

Chemo: VAC/IE, with vincristine/doxorubicin/cyclophosphamide alternating with ifosfamide/etoposide. Drop doxorubicin during RT.
Local therapy: surgery, RT, or both. Surgery is preferred for expendable bones; RT is favored for unresectable or morbid surgical sites.
High-risk local features: pelvis and large primaries, especially >200 mL, have worse local control and EFS.
Even localized disease fails distantly most often: adequate systemic therapy remains central.

Scenario	Dose
Definitive RT or postop gross residual	55.8 Gy
Post-op microscopic positive margin	50.4 Gy
R0 resection, no tumor at ink	0 Gy
Pre-op RT	36 Gy
Large tumor dose escalation	Up to 63 Gy, trial only
Lung metastases	15 Gy / 10 fx (12 Gy / 8 fx if <6 years)

AEWS1031: adding vincristine/topotecan/cyclophosphamide to interval-compressed chemotherapy did not improve outcomes in nonmetastatic Ewing sarcoma. Pre-op RT AEWS1031 report: protocolized preoperative RT is feasible for selected localized Ewing cases.

AEWS1221: metastatic Ewing outcomes remain poor despite intensification; local control decisions do not replace systemic-risk reality.

Target volumes: GTV1 = pre-chemo soft tissue and bone disease. CTV1 = GTV1 + 1 cm. GTV2 = pre-chemo bone + post-chemo soft tissue; CTV2 = GTV2 + 1 cm. Cone down after 45 Gy. Give RT with IE, not doxorubicin.

PART II - CNS MALIGNANCIES

Management Paradigm + Dose Anchors

Entity	Default management frame	RT / dose anchor
Average-risk medulloblastoma	Age >=3, M0, residual <1.5 cm2. Max safe resection, CSI + boost, then adjuvant chemo.	CSI 23.4 Gy then tumor-bed boost to 54 Gy. Do not drop to 18 Gy outside a study-defined approach.
High-risk medulloblastoma	M+ disease, residual >=1.5 cm2, or diffuse anaplasia.	CSI 36 Gy then boost 54-55.8 Gy; metastatic boost by site.
Ependymoma	Extent of resection is the key prognostic factor. Most intracranial ependymomas receive focal adjuvant RT; CSI only for metastatic disease.	Focal 54 Gy + boost to 59.4 Gy when age/target allows; CTV often only 0.5 cm.
Localized germinoma	Chemo-response-adapted whole-ventricle RT + boost; bifocal pineal/suprasellar disease is localized if no other dissemination.	If CR after chemo: WV 18 Gy + boost 12 Gy, total 30 Gy; higher if less than CR.
NGGCT	Chemo + second-look surgery if residual; spine coverage is back in the modern field strategy because WVI-only had spine failures.	WV + spine 30.6 Gy then primary boost to 54 Gy.
Craniopharyngioma	Biopsy/STR + RT often gives disease control comparable to aggressive GTR with less catastrophic hypothalamic/visual morbidity.	52.2-54 Gy; re-image during RT because cysts can change.
Diffuse midline glioma / DIPG	RT is the only proven life-extending therapy; systemic/biologic approaches remain study-driven.	54 Gy / 30 fx standard; recurrence re-RT often 20-30 Gy if performance status permits.

Medulloblastoma

Posterior fossa embryonal tumor with high CSF dissemination potential. Molecular subtypes: WNT, SHH, Group 3, Group 4.

Posterior fossa syndrome: mutism, dysphagia, truncal ataxia, hypotonia, mood lability, gaze palsy, and rare respiratory failure after resection.
Workup: MRI brain and spine pre-op, max safe resection, post-op MRI brain, LP 10-14 days after surgery, and methylation profiling.
M staging: M0 none; M1 CSF+; M2 intracranial beyond primary; M3 gross spinal seeding; M4 beyond CNS.
Start RT: usually within 31-35 days of surgery, followed by 6-9 months of adjuvant chemotherapy.

Risk group	Criteria	RT regimen
Average risk	>=3 years, M0, residual <1.5 cm2	CSI 23.4 Gy -> boost to 54 Gy
High risk	M+ or residual >=1.5 cm2 or diffuse anaplasia	CSI 36 Gy -> boost to 54-55.8 Gy
Infant	<3 years	Typically chemotherapy-focused with delayed/risk-adapted RT.

Boost/mets doses: primary tumor bed to 54 Gy with CTV = tumor bed + 1 cm. Diffuse posterior fossa metastases about 54-55.8 Gy; diffuse spine metastases about 39.6 Gy; focal spinal drops often 45 Gy at cord level and 50.4 Gy below cord.

ACNS0331: CSI dose reduction from 23.4 Gy to 18 Gy was inferior in average-risk medulloblastoma. Tumor-bed boost was acceptable compared with whole posterior fossa boost.

ACNS0332: high-risk medulloblastoma intensification showed molecularly dependent benefit from carboplatin; isotretinoin did not become a broad standard.

WNT caution: WNT medulloblastoma is favorable, but upfront CSI omission caused unacceptable neuraxial failures in a prospective low-risk WNT study. Do not omit CSI or routinely use 18 Gy CSI outside a study-defined approach.

CSI contouring: inferior thecal sac usually S2-S3, about 1.5 cm below the sac on sagittal MRI. Cover nerve roots to the lateral edge of vertebral bodies. In skeletally immature patients, consider whole vertebral body / bony spine coverage to reduce asymmetric growth.

Ependymoma

Often infratentorial in children; low CSF dissemination risk. Extent of resection is the dominant prognostic factor.

#1 prognostic factor: extent of resection. 1q gain is adverse.
Workup: MRI brain + spine pre-op, max safe resection, post-op brain MRI, and LP 10-14 days later.
Target review: look for extension through foramen of Magendie/Luschka, IAC, jugular foramen, and cavernous sinus.

Target	Definition / dose
GTV	Residual disease + resection bed.
CTV1	GTV + 0.5 cm; limit to about 3 mm into brainstem unless invaded.
Dose, CTV1	54 Gy / 30 fx
Boost to GTV	+5.4 Gy, total 59.4 Gy; omit in very young patients as protocol/institution dictates.
Metastatic disease, age >=3	CSI 36 Gy

ACNS0121: adjuvant RT improved outcomes compared with observation for completely resected supratentorial grade II ependymoma. Most intracranial ependymoma gets local RT, not CSI, unless disseminated.

CNS Germ Cell Tumors

Pineal and suprasellar are classic sites. Bifocal pineal + suprasellar disease is treated as localized if there is no other dissemination.

Presentation: suprasellar -> DI, endocrine, visual deficits. Pineal -> hydrocephalus and Parinaud syndrome.
Tumor markers: CSF is more sensitive than serum. Germinoma may have mild beta-hCG elevation, but AFP should be normal. AFP elevation means not pure germinoma.
Diagnosis: prefer tumor markers when diagnostic; surgery/biopsy is morbid in these regions.

Entity	Regimen
Localized germinoma	Carbo/etop x 4 -> if CR: WV 18 Gy + boost 12 Gy, total 30 Gy. If less than CR: WV 24 Gy + boost to 36 Gy. Further de-escalation is study-only.
Metastatic germinoma	CSI 36 Gy-style approach; cure rate remains high.
NGGCT	Chemo, second-look surgery if less than CR, then WV + spine 30.6 Gy -> primary boost to 54 Gy.

ACNS1123B: localized germinoma can be treated with response-adapted whole-ventricle RT and boost after chemotherapy. NGGCT field evolution: WVI-only strategies had spine failures, so modern approaches add spine coverage back while avoiding whole brain.

Growing teratoma: markers may normalize while mass grows from teratomatous component. Resection is needed for mass effect and to exclude viable malignant progression.

Craniopharyngioma

Rathke pouch remnant tumor with cysts and calcifications; anatomically benign-looking but morbidity-prone because of hypothalamic/optic proximity.

Management tradeoff: aggressive GTR can control disease but carries major DI, vision, and hypothalamic risk. Biopsy/STR + RT gives similar control with a different morbidity profile.
Targets: GTV = residual disease including cysts. CTV = GTV + 3-5 mm. PTV = CTV + 3-5 mm.
Dose: 52.2-54 Gy at 1.8 Gy/fx.
Re-image during treatment because cyst/tumor swelling can threaten target coverage and vision.

Diffuse Midline Glioma / DIPG

Diffuse midline glioma, H3 K27-altered biology. Classic DIPG is pontine and often diagnosed radiographically; median survival remains about 9-12 months.

RT is the only proven life-extending therapy. Start quickly because patients can progress rapidly.
Dose: 54 Gy / 30 fx to MRI extent + 1 cm CTV, anatomically confined, + 0.3-0.5 cm PTV. Hypofractionated 39 Gy / 13 fx is used in some settings.
Patients often clinically improve before later progression.
At recurrence: clinical trial versus re-irradiation 20-30 Gy for selected patients with adequate performance status.
Do not mistake DIPG for low-grade glioma; the treatment paradigms are entirely different.

Re-irradiation literature: re-RT can palliate selected recurrent DIPG/DMG patients, but it is not curative.

ADDITIONAL PEDIATRIC QUICK HITS

Selected Additional Entities

Entity	Board-review hook / RT role
Retinoblastoma	Modern management is usually chemotherapy + non-irradiative focal therapy or enucleation when vision is absent. Plaque brachy can salvage selected focal failures. Avoid EBRT when possible because of second malignancy and facial-growth risks; orbital RT is now rare and mainly for extra-scleral/extraocular extension, positive optic nerve cut margin, or CNS-risk scenarios after chemotherapy.
Low-grade glioma	R0/R1 or near-complete resection -> observation. R2/unresectable -> observation vs systemic/targeted therapy vs RT. Younger children and NF1 patients usually favor observation, surgery, systemic therapy, or targeted therapy before RT when feasible. Older children needing RT: 50.4-54 Gy at 1.8 Gy/fx, typical CTV about 0.5 cm.
Pediatric ALL / leukemia RT	Cranial RT is increasingly restricted to overt/high-risk CNS disease and is protocol-specific: CNS3 commonly 18 Gy; selected T-ALL prophylaxis in older protocols used 12 Gy. Residual testicular leukemia after induction: testicular RT 24 Gy. HSCT conditioning TBI commonly 12-13.2 Gy and up to about 14.4 Gy by regimen.
Pediatric Hodgkin / NHL	RT is response-adapted and volume-reduced: use ISRT/INRT concepts, not historical mantle/TNI fields. Contemporary protocols avoid RT when PET response and risk group allow. Common anchors include 15-21 Gy for pediatric HL and 20-30 Gy for selected NHL or residual sites. AHOD 1331 (High-Risk HL): Brentuximab + AVE-PC improved outcomes. Requires consolidative RT to initial mediastinal bulky disease to 21 Gy, with a 9 Gy boost if incomplete metabolic response (Deauville 3-5).
Osteosarcoma / NRSTS	Surgery and systemic therapy dominate. RT is reserved for unresectable disease, high-risk anatomic sites, residual/positive-margin disease, or regimen-defined multimodality care. Definitive/salvage dosing is often 50-70 Gy when normal tissues allow.
Pediatric nasopharyngeal carcinoma	Rare, usually EBV-associated/WHO type III. Pediatric regimens use induction chemotherapy followed by concurrent cisplatin-based chemoRT with comprehensive head-and-neck volumes. Gross primary/nodal disease commonly receives about 66-70 Gy.

CROSS-CUTTING HIGH-YIELD POINTS

Most pediatric RT targets are defined from the initial disease footprint, then anatomically edited after surgery/chemo; dramatic response does not automatically mean tiny fields.
Wilms vs neuroblastoma bedside differentiation: Wilms -> well appearing, mass moves with kidney, resect upfront. Neuroblastoma -> acutely ill, periorbital ecchymoses, mass moves separately, biopsy/chemo first.
RMS stage vs group: stage = site + TNM before treatment; group = surgical result / residual disease. Group drives RT.
Do-not-biopsy memory list: classic Wilms, retinoblastoma, optic pathway glioma/meningioma, classic DIPG/DMG, marker-positive CNS GCT, and many medulloblastoma presentations.
LP timing post-op: always 10-14 days for embryonal tumors, ependymoma, and CNS GCT; too early risks blood contamination and false-positive cytology.
CSI doses: average-risk medulloblastoma 23.4 Gy; high-risk medulloblastoma / metastatic ependymoma / metastatic germinoma 36 Gy; NGGCT WV + spine 30.6 Gy.
PENTEC: the pediatric normal-tissue framework; adult QUANTEC is not enough.
Growth-preserving technique: if a vertebral body touches the 10 Gy isodose, include it in the 18 Gy target when protocol logic requires it to prevent asymmetric growth.

CONSOLIDATED DOSE TABLE

Setting	Dose / regimen	Board anchor
Wilms flank, FH stage III	10.8 Gy / 6 fx	Start within 10-14 days after surgery.
Wilms diffuse anaplasia stage III	19.8 Gy	Higher-risk histology.
Wilms WAI	10.5 Gy / 7 fx	Spill, positive cytology, peritoneal seeding.
Wilms WLI	12 Gy / 8 fx	10.5 Gy / 7 fx if <1 year.
High-risk neuroblastoma primary / persistent mets	21.6 Gy / 12 fx	No routine gross residual boost.
RMS group II margin+	36 Gy	Also group I FOXO1+.
RMS node+	41.4 Gy	Group IIB/C.
RMS group III orbit / non-orbit	45 Gy / 50.4 Gy	Gross residual disease.
Ewing definitive / gross residual	55.8 Gy	Local control anchor.
Ewing microscopic positive margin	50.4 Gy	Post-op microscopic residual.
Ewing pre-op RT	36 Gy	Selected protocolized approach.
Average-risk medulloblastoma	CSI 23.4 Gy -> boost 54 Gy	18 Gy CSI not routine.
High-risk medulloblastoma	CSI 36 Gy -> boost 54-55.8 Gy	Metastatic/residual/diffuse anaplasia.
Ependymoma focal RT	54 Gy + boost to 59.4 Gy	Local RT, not CSI, unless metastatic.
Localized germinoma CR after chemo	WV 18 Gy + boost 12 Gy	Total 30 Gy.
NGGCT	WV + spine 30.6 Gy -> boost 54 Gy	Spine coverage back in modern strategy.
Craniopharyngioma	52.2-54 Gy	Re-image during RT.
DIPG / DMG	54 Gy / 30 fx	Only proven life-extending therapy.
Pediatric ALL CNS3	18 Gy	Protocol-specific, increasingly restricted.
Testicular leukemia residual	24 Gy	After induction if persistent.
High-Risk Pediatric HL (AHOD 1331)	21 Gy +/- 9 Gy boost	21 Gy to initial bulk; 9 Gy boost if incomplete metabolic response (Deauville 3-5).

KEY LANDMARK TRIALS (memorize)

Trial	Disease	One-line takeaway
AREN0533	Wilms FH + lung mets	Omit WLI if complete response to induction in selected patients; OS preserved.
CCG-3891	High-risk neuroblastoma	TBI conditioning reduced local failure historically; modern practice uses focal post-ASCT RT.
ANBL0532	High-risk neuroblastoma	Do not boost gross residual post-op.
ARST0531	Intermediate-risk RMS	Local failure increased; dose escalation alone did not fix large tumors.
ARST1431	RMS	Escalation to 59.4 Gy failed to improve LC for >5 cm tumors; DPE remains important when feasible.
AEWS1031	Localized Ewing	Adding VTC did not improve outcomes with interval-compressed chemotherapy.
AEWS1031 pre-op RT	Localized Ewing	Protocolized pre-op RT is feasible in selected cases.
AEWS1221	Metastatic Ewing	Metastatic Ewing remains systemic-risk dominated.
ACNS0331	Average-risk medulloblastoma	18 Gy CSI inferior to 23.4 Gy; tumor-bed boost OK.
ACNS0332	High-risk medulloblastoma	Molecularly dependent carboplatin benefit; isotretinoin not broadly useful.
ACNS1123B	Localized germinoma	Chemo + WV 18 Gy + 12 Gy boost if CR.
ACNS1123A	Localized NGGCT	WVI-only de-escalation had spine failures; spine coverage has returned.
ACNS0121	Ependymoma	Adjuvant focal RT is better than observation after GTR in supratentorial grade II disease.
ACNS0831	Intracranial ependymoma	Adjuvant chemotherapy role remains interpreted variably; RT is the local backbone.
DIPG re-irradiation series	DIPG / DMG	Re-RT can palliate selected recurrence.
PENTEC	Normal tissue	Pediatric-specific dose-volume toxicity framework.
AHOD 1331	High-Risk Pediatric HL	Brentuximab + chemo improves EFS; RT uses 21 Gy to bulk + 9 Gy boost for incomplete response.