Post-operative radiotherapy treats the operative bed and neck after resection of an oral cavity, oropharynx, larynx or hypopharynx cancer when the pathology shows features that raise the risk of recurrence. There is no gross tumor left to target, doses are lower than definitive treatment, and the pathology report decides both the dose levels and whether chemotherapy is added.
Setup, dose levels and organ limits follow Head & Neck Planning Essentials. After surgery, the planning problem changes:
Added to the standard mask setup.
Radio-opaque wire on the surgical scars; bolus considered where the target reaches the skin. More →
The scar and skin can be part of the operative bed, and wire makes them visible on the planning CT.
Image fusion aligns an outside scan with the planning CT so the target can be drawn using information the CT doesn't show. After surgery this means the diagnostic scans from before the operation — PET/CT, MRI or contrast CT — registered to the planning CT where possible.
They show where the tumor and involved nodes were, which defines the high-risk bed. Surgery and reconstruction change the anatomy, so registration is often approximate and read alongside the operative report.
Post-operative volumes are defined by risk rather than gross disease. Expansions come only from your protocol.
The surgical bed where a margin was microscopically positive, and the nodal bed where there was extracapsular extension.
These are the sites most likely to recur, so they receive the highest post-operative dose.
The primary tumor bed, including where the pre-operative tumor was, and the bed of the involved nodes.
Built from pre-operative imaging and the pathology report rather than visible disease.
The remaining operative bed at intermediate risk, and elective nodal levels at risk of microscopic disease.
Which levels are elective depends on the primary subsite and on what the neck dissection found.
Uses the shared head and neck constraint table — its oral cavity, lip and cervical esophagus goals come from RTOG 0920, a post-operative trial. What changes after surgery:
RTOG/Intergroup phase 3 trial of post-operative radiotherapy with or without concurrent cisplatin. Citation checked against Crossref; content not yet reviewed by DoseLab.
EORTC phase 3 trial of post-operative radiotherapy with or without concurrent cisplatin. Citation checked against Crossref; content not yet reviewed by DoseLab.
Comparative analysis of the EORTC 22931 and RTOG 9501 post-operative chemoradiation trials. Citation checked against Crossref; content not yet reviewed by DoseLab.
NRG Oncology's page for RTOG 0920, a phase 3 trial of post-operative IMRT with or without cetuximab for intermediate-risk resected head and neck cancer. The protocol prescribes 60 Gy in 2 Gy fractions (optional 66 Gy high-risk and 56 Gy at-risk levels) and lists IMRT planning goals for the cord and brainstem planning risk volumes, lips, oral cavity, parotids, pharynx, cervical esophagus, larynx and mandible, with a planning priority order. DoseLab read section 6.5.4 of the version dated 25 January 2016 (copy hosted by the University of Cincinnati) for the oral cavity, lip and cervical esophagus values in the head and neck table.
The 2013 update of the international consensus on the anatomical boundaries of the neck node levels. Citation checked against Crossref; content not yet reviewed by DoseLab.
Endorsed eviQ protocol for adjuvant radiotherapy after resection of squamous cell carcinoma of the oral cavity, oropharynx, larynx or hypopharynx. It covers the risk features that prompt post-operative treatment, the added very-high-dose level for positive margins and extracapsular extension, and timing after surgery.