onc brain

Practical contouring guideline from a multi-institution author group, built on V1/V2/V3 radio-anatomy, PNI spread routes, and published imaging series. No outcome endpoint.

Primary RT: GTV = post-contrast enhancement along the nerve; CTV-P1 = GTV + 5 mm along the nerve path; CTV-P2 ≥30 mm along the nerve, skull base often recommended. Post-op R1: CTV-P1 = margin + 5 mm along the nerve path plus PNI in the whole tumor bed. Skull base involvement extends CTV-P2 to the brainstem.

High-risk spread is defined by histology (ACC; cutaneous or non-cutaneous SCC with extensive PNI) or site (pterygopalatine fossa or masticator space invasion, nasopharyngeal or maxillary sinus primaries). Non-lateralized tumors get bilateral nerve-path consideration.

Imaging guidance: MRI is the modality of choice, CT complements for foraminal bony change, and 18FDG-PET-CT is often inferior to MRI for macroscopic PNI. MRI co-registration in treatment position is recommended whenever possible.

EORTC 22931 included pts with PNI and showed concurrent cisplatin improved locoregional control over post-op RT alone. The Zukauskaite primary-RT series placed most recurrences in the GTV but excluded the PNI-prone sites this guideline targets.

No dosimetric or failure-pattern validation of the margins is reported. Large CTV-P2 extensions near brainstem and optic pathway force OAR compromises the guideline leaves to case-by-case judgment.

The document standardizes nerve-path delineation where IMRT planning on axial CT routinely misses retrograde spread. It does not settle how far elective coverage must go, or whether skull base extension improves control enough to justify the added OAR dose.

Expert consensus from DAHANCA, EORTC, HKNPCSG, NCIC CTG, NCRI, RTOG and TROG: radiation oncologists, a head and neck surgeon and an anatomist. Boundaries are defined on axial CT and illustrated on sample slices, with a 110-slice DICOM-RT teaching set.

Defines levels Ia through Xb, including parotid (VIII), bucco-facial (IX) and retroauricular/occipital (Xa/Xb) groups for skin and salivary primaries. Landmarks assume a neutral neck position. Hyperextension to flatten skin folds shifts the Ib/II relationship, and the upper edge of C1 may then mark the cranial retropharyngeal limit better than the hard palate.

Nomenclature is modified from Robbins and cross-walked to the TNM atlas neck node groups. The source flags the cross-walk table as having uncertain row alignment, so no level-to-group pairing is reproduced here.

Boundaries only hold in a neutral position; adapting them to hyperextension is left to clinical judgment. No interobserver or patterns-of-failure validation is reported in the source.

The panel's stated aim is to reduce delineation variation between patients and institutions and to make multi-institutional trials easier to run. It pairs naturally with separate guidance on which levels to treat for each primary site.

Multi-society consensus guideline for primary-tumour CTV (CTV-P) delineation, illustrated with endoscopic and planning-CT cases by subsite and T stage (UICC 8th edition).

CTV-P1 = GTV-P + 5 mm (high dose, typically 70 Gy in 2 Gy fx). CTV-P2 = GTV-P + 10 mm (50 Gy prophylactic with 2 levels, or 60 Gy intermediate with 3 levels, adding a 50 Gy CTV-P3). Delineate CTV-P2 first, then CTV-P1 inside it.

The margins rest on surgical evidence: Zanoni et al. found a 2.2 mm margin optimal for loco-regional recurrence-free survival, and laser microsurgery with 2-3 mm mucosal margins gave 85-95% local control without PORT. Tonsillar TORS/laser series with at least 2-3 mm margins report local control above 90%.

Margin data come mostly from T1-T2 tumours in selected high-volume surgical series, and the HPV effect on required margin is unknown. Infiltrative-border tumours and tumour budding are acknowledged as sources of GTV uncertainty the 5 + 5 mm concept does not resolve.

The main gain is a shared nomenclature tying CTV-P1/P2/P3 to dose level plus stage-specific editing rules. It does not settle margin adequacy under RT, and PTV expansion is explicitly left to each centre.

Narrative review of international consensus guidelines for nodal level selection, node-level delineation and primary-tumor CTV, by authors from the guideline groups. No new patient data.

Primary RT for SCC of the oral cavity, oropharynx, hypopharynx and larynx, p16-negative and p16-positive oropharynx alike. Not valid for the postoperative setting or adenoid cystic carcinoma. After induction chemo, contour from pre-chemotherapy information.

SIB: elective nodal PTV 54-56 Gy in 33-35 fx over 6.5-7 weeks. Therapeutic nodal CTV (nodal GTV + 5 mm) gets 70 Gy in 33-35 fx of 2.12-2.0 Gy. GTV + 10 mm anatomically edited becomes the low-dose CTV-P2, on 2 mm contrast-enhanced planning CT.

The consensus sits between the anatomic school (whole compartments, 2-3 cm where no barrier) and the DAHANCA geometric 5 + 5 mm rims. The authors expect consensus volumes to be smaller than anatomic volumes in all directions, and smaller than DAHANCA volumes mainly axially for T1-T2 tumors.

Support for margin reduction rests on one three-center Danish series and transoral resections in mainly T1-T2 tumors. The volume comparisons are single illustrative cases, and no systematic comparison of the three approaches had been done.

Nodal selection follows long-standing drainage-pattern data and changes little for most centers. The real shift is the smaller geometric primary CTV. Its safety depends on the geographic-miss analysis the authors describe as ongoing.

ESTRO ACROP committee consensus: structured questionnaire, then consensus discussion and voting, then literature-referenced writing and committee review. Each item graded Mandatory, Recommended, Optional or Discouraged.

CTV primary = GTV + 5–8 mm, manually edited at natural barriers such as bone or heart (M). Nodal CTV is either the whole involved station or a 5–8 mm geometric expansion (M). Elective hilum or adjacent stations are optional; further elective nodal CTV is discouraged.

Motion handling follows ICRU 62 (ITV) or the van Herk margin recipe; nodal stations follow the TNM Atlas 8th edition. Station-based nodal CTV is justified by large multicentre trials with acceptable out-field mediastinal recurrence, which the excerpt does not name.

Departments must quantify their own residual setup error, so PTV size is not standardised across centres. Leaving nodal CTV option 1 vs 2 open signals the committee could not settle it.

The guideline sets the threshold for including a node at inclusion when in doubt, accepting larger volumes over geographic miss. It does not quantify what elective coverage of the hilum adds, which is why that is left optional.