onc brain

International expert contouring exercise: 8 radiation oncologists and 1 neurosurgeon from 9 academic centres independently contoured GTV, CTV and neural elements on 10 sacral metastasis cases previously treated with SBRT. Agreement by STAPLE at 80% confidence with kappa statistics; acceptance of the modified consensus contour voted per case (consensus defined as >75% of experts).

Cases chosen to represent a range of tumour sizes and locations across S1 to S5, from midline VB lesions to ala disease with foraminal or epidural extension. Planning CT fused with T1, T2 and T1 post-gadolinium MRI per SPINO guidelines.

Compartmental CTV: the involved compartment plus adjacent marrow at risk, mapped to an eight-segment sacral classification system. S1 ala exception: any S1 ala GTV starts the CTV at the superior S1 ala. Thecal sac contoured to the inferior S5 VB as cauda equina surrogate; lumbosacral nerve roots per Yi et al., typically restricted to no hot spots.

GTV kappa 0.73 (range 0.59-0.83), CTV kappa 0.59 (range 0.41-0.70), P < .001 for all cases. Modified STAPLE CTV reached consensus acceptance in 9 of 10 cases; Case 5 was predominant (6 of 9, 67%).

Mirrors the compartmental logic of the Cox et al. (intact) and Redmond et al. (postoperative) mobile-spine guidelines, which left out the sacrum. A cited imaging-based sacral SBRT series reported cumulative LC 86.5% at 1 year and 78.7% at 2 years, median time to local recurrence 4.7 months.

Three experts preferred a 0-5 mm isotropic margin over the compartmental approach, citing nerve root and bowel toxicity and sacral insufficiency fracture risk. Dose and fractionation are not specified in the main text, and OAR constraints sit in the supplement.

The sacral classification system is the durable product: it gives a common language for reporting sacral volumes and failures. Whether compartmental expansion improves sacral LC, or only adds toxicity, remains untested.

Expert contouring consensus from 10 cases and 9 experts; agreement measures panel coherence, not outcomes. No sacral pattern-of-failure or external validation.

ESTRO clinical practice guideline built on a PRISMA systematic review of PubMed, Embase and Cochrane (Jan 2005-Sep 2021), with RTOG 0631 added Apr 2023. ASTRO methodology graded evidence and recommendation strength; ≥75% agreement defined consensus.

Vertebral metastases from solid malignancies, painful or oligometastatic, previously unirradiated. Re-irradiation and symptomatic MSCC excluded from scope.

Dose above 1x18Gy (BED10=50Gy10) for durable LC; 2x12Gy conditionally preferred palliative schedule. PTV margin ≤3mm (minimum 1mm), intensity-modulated delivery, daily IGRT, cord PRV prioritized over coverage.

VCF is the most frequent AE (6-14% in two multicenter analyses); single fractions >20Gy raise VCF risk (high-level evidence). Myelopathy 0.4% in a pooled de novo series of >1,000 pts; routine prophylactic steroids for pain flare not recommended.

The pain recommendation leans on SC.24 (24Gy/2fx vs 20Gy/5fx: CR 35% vs 14%, p=0.0002). RTOG 0631 (16 or 18Gy x1 vs 8Gy x1) showed no pain gain, which the panel reads as a dose-floor problem rather than a failure of technique.

Search closed Sep 2021 apart from RTOG 0631; ROBOMET is abstract-only and the TwiCs trial was underpowered with non-standardized dosing. Panel is radonc-weighted with one spine surgeon and no medical oncologist, yet addresses concurrent targeted/IO toxicity.

Dose, not technique, organizes the document: low single-fraction SBRT matched or trailed 8Gy, while higher doses improved CR and LC at a fracture cost. 2-5 fraction schedules are the hedge where fracture management capacity is limited.

ESTRO practice guideline from a PRISMA systematic review with ≥75% panel consensus; most recommendations rest on moderate or expert-opinion evidence, not new outcome data.

Three-round international Delphi; Round 1 opened 27/10/2020, Round 3 closed 22/03/2021. 44 statements after Round 1, 29 reached consensus in Round 2, 15 re-presented in Round 3.

Panel of radiation/clinical oncologists who had published on pelvic SABR re-irradiation or were judged international experts; one per research group. 23 of 41 invited joined Round 1; median 10 cases/yr per participant (range 10-100). Subspecialty interest GU 19 (83%), lower GI 11 (48%), gyn 8 (35%).

Agreed schedules: 30-37.5 Gy in 5-6 fx or 21-27 Gy in 3 fx, alternate days. Agreement also covered IMRT-level conformity and daily online volumetric or fiducial verification. The 140% PTV point-max cap reached only 73%; 1 participant favoured 115-125%.

66% of statements reached consensus, covering definition, patient selection, set-up, delineation, planning and delivery. No consensus on minimum interval since prior RT (43% for 12 mo), maximum lesion number/size, or cumulative OAR constraints.

Sits beside the ESTRO ACROP Delphi on salvage SBRT for intraprostatic relapse, which addresses a narrower prostate-only scenario. A thoracic re-irradiation Delphi hit the same wall: no agreed quantified dose overlap to define re-irradiation.

The panel is GU-dominant, so transfer to gyn and rectal recurrences rests on fewer voices. Optimal OAR constraints were borrowed from de novo AAPM TG-101 limits used cumulatively, not from re-irradiation outcome data.

The selection and technique framework is usable now. The unresolved items (interval, lesion count/size, cumulative constraints with recovery) are the ones that set the dose actually deliverable, so the core dosimetric decision remains case-by-case.

Delphi panel output: agreement percentages measure expert opinion, not outcomes. Frames practice where no randomised re-irradiation data exist; key dosimetric questions explicitly unresolved.

ASTRO task force guideline addressing 4 key questions, built on an AHRQ systematic review of 97 studies. Consensus by modified Delphi: ≥75% agreement threshold (≥90% for expert opinion recommendations).

Intact and resected brain metastases from nonhematologic solid tumors in adults. Small cell lung cancer excluded from the KQ1 RCT evidence base.

SF SRS 2000-2400 cGy for <2 cm; SF 1800 cGy or MF 2700 cGy/3 fx or 3000 cGy/5 fx for ≥2 to <3 cm; multifraction for ≥3 to 4 cm. WBRT example 3000 cGy in 10 fractions, with hippocampal avoidance for favorable prognosis.

Outcomes weighed: intracranial control, PFS, OS, neurocognitive function and patient-reported outcomes; symptomatic radionecrosis for KQ4.

SRS-alone rows rest on five RCTs of local therapy with or without WBRT in 1 to 3 mets (one allowing 4), where WBRT improved intracranial control without a survival gain; N0574 showed worse neurocognition and QoL with SRS plus WBRT. The 5-10 row rests on JLGK0901, an observational count-stratum comparison, not a WBRT comparison.

Literature cutoff Sept 2020 predates NCT01592968, CCTG CE.7 and the DFCI SRS vs HA-WBRT plus memantine trials. The panel overrode AHRQ conclusions it deemed incongruent with practice by adding neurocognitive and QoL outcomes AHRQ had excluded.

Deferral of local therapy for asymptomatic pts on CNS-active systemic therapy has no randomized evidence; cited response rates of approximately 30% to 75% come from trials that largely excluded symptomatic or steroid-requiring pts, and up to 40% show early progression without response.

Society guideline graded by modified Delphi over an AHRQ review; no new outcome data. Dose-fractionation and 5-10 met SRS rows rest on Low QoE.

PRISMA systematic review by the GEC-ESTRO H&N and Skin Working Group, PubMed search through 31 May 2019, plus a theoretical TG-43 planning exercise (Oncentra Brachy, Ir-192 HDR) on 6×6 and 10×10 cm² CTVs.

Clinical studies of NMSC superficial HDR Ir-192 BT with flaps or custom moulds; conference papers, surveys, case reports and reviews included, English only.

Planning model used parallel catheters at 1 cm spacing, 2 mm source step, prescription depths of 3, 5, 10 and 20 mm crossed with bolus of 3, 5, 10 and 20 mm. ACROP-listed mould/flap schedules range from 17-18 × 3 Gy to 8 × 5 Gy twice daily.

Thicker bolus lowers surface Dmax at the cost of a shallower gradient; the bolus × Dmax × R100-R50 trade is tabulated above for the 5 mm depth case.

GEC-ESTRO ACROP, ABS, AAPM and GEB guidance converge on a 5 mm prescription ceiling and ABS/GEB on 125% (flaps) / 140% (moulds) surface Dmax. The ABS Dmax limit was modelled on its APBI consensus, where skin is an OAR rather than the target. Zaorsky's meta-analysis (EBRT 9965 vs BT 553 pts) favoured BT cosmesis but carried no bolus or Dmax data.

Dosimetry is TG-43 without scatter correction, with MC deviations up to 5% for flaps. Skin toxicity shows a volume and layer effect that a single surface Dmax point cannot capture, and telangiectasia needs 2-3 yr follow-up to assess.

The 5 mm and 125-140% limits are not tied to PROMs in any published series, and deviating centres report similar results. The group calls for standardized dosimetry reporting and homogeneous multicentre data via the COBRA project before revising thresholds.

Working-group critical review of retrospective series and surveys; no trial data, and the group declines to propose any new PROM-based Dmax or depth threshold.