Every head and neck plan — whatever the subsite — is built the same way: a mask for daily reproducibility, targets at two or three dose levels delivered together with a simultaneous integrated boost or in phases with a sequential boost, and the same crowded set of organs at risk. This page covers that shared foundation once. The subsite pages build on it and describe only what changes.
The same for nearly every subsite. Subsite pages note only what they add.
Supine with the head neutral in a thermoplastic mask, a neck support or vacuum bag, and the shoulders pulled down as far as possible.
Treatment runs for six to seven weeks with millimeter-scale margins around the cord and brainstem, so the head and neck must return to the same position every day. Low shoulders keep them out of the lower-neck beams and arcs.
A device held in the mouth during simulation and treatment. A cheek spacer is wax placed against the inside of the cheek.
It moves normal tissue — the tongue, palate or cheek — away from the target, and it makes the mouth position reproducible. Mostly used for oral cavity and some oropharynx targets.
Radio-opaque wire on scars or skin involvement; tissue-equivalent bolus over targets near the skin.
Wire shows the scar or skin disease on the planning CT. Megavoltage beams under-dose the surface, so bolus is considered when the target reaches the skin.
A CT with slices of 2 mm or less, commonly from the vertex to 1 cm below the carina, with IV contrast when appropriate.
Contrast separates nodes from vessels. Dental fillings cause streak artifact, so metal artifact reduction may be needed.
Image fusion aligns an outside scan with the planning CT so the target can be drawn using information the CT doesn't show. For head and neck this is the staging PET/CT, MRI and diagnostic CT. MRI matters most near the skull base or when perineural spread is suspected; it is ideally taken as close to the treatment position as possible, with distortion correction applied.
MRI shows soft-tissue and skull-base spread; PET helps define gross disease and involved nodes, and nodes that are equivocal on PET are often still included in an intermediate-risk volume. Diagnostic scans are taken without the mask, so head and neck position can differ — check the registration at the primary and at the involved nodes rather than relying on one overall match. When IV contrast can't be given, one template recommends fusing PET/CT and MRI for tumor and organ definition.
Daily cone-beam CT matched to bone, with a check of soft tissue and the body outline.
Weight loss and tumor or node shrinkage change the anatomy over the course and loosen the mask fit. Departments need a way to spot those changes and decide whether their dose effect needs a new plan.
How head and neck schedules are built. The schedules quoted on the subsite pages are SIB schedules from published protocols; sequential-boost schedules use different dose levels, set by your protocol.
One plan that delivers a different dose per fraction to each target level in the same session — for example 2.0, 1.8 and 1.6 Gy per fraction, giving 70, 63 and 56 Gy over 35 fractions.
The gross disease, the high-risk tissue around it and the elective neck all receive their prescriptions in one plan over the same number of fractions, instead of sequential phases. The steep dose steps between levels are where coverage and organ sparing compete.
Treating in phases: a first plan takes every target level to the lower (elective) dose, then one or more boost plans — sometimes called cone-downs — take the higher-risk volumes up to their full dose.
Also a common approach. Every phase uses a standard dose per fraction, so the elective neck is not treated with smaller fractions as it is in an SIB. The trade-off is several plans instead of one: dose from all phases must be summed, and organ limits apply to the composite.
Levels are named by risk (high, intermediate and low dose — HD, ID and LD) or by dose (for example PTV_7000, PTV_6300, PTV_5600). More →
The naming differs between protocols; what matters is knowing which structure carries which prescription. AAPM TG-263 gives standard naming conventions.
The number of days from the first to the last fraction.
Longer overall time can reduce locoregional control and survival, so missed days — holidays, machine service, treatment breaks — are usually made up, for example with two fractions in a day or an extra treatment day.
Six fractions a week instead of five, so the same total dose finishes in about six weeks. The sixth fraction is a second daily fraction at least six hours apart, or a weekend treatment. More →
Shortening overall time can improve tumor control. It may be considered for radiotherapy alone and was used with chemotherapy in trials such as RTOG 1016.
The volumes every subsite uses. What goes into each one changes by subsite — see the subsite pages. Expansions come only from your protocol.
All gross disease seen on imaging, examination and endoscopy — the primary (GTVp) and the involved nodes (GTVn).
Endoscopy findings and fused MRI and PET often show mucosal or soft-tissue disease that is hard to see on CT alone, so the physician's examination notes matter as much as the images.
The gross disease expanded to cover nearby microscopic spread, then edited back from anatomical barriers such as bone, air and fascia that the tumor has not crossed.
Editing to anatomy keeps the high dose out of tissue the tumor cannot reach — often the difference between sparing and overdosing a nearby organ.
Areas at higher risk of microscopic disease: routes of contiguous spread from the primary, equivocal nodes, and whole subsites when the protocol calls for them.
Some protocols treat this volume to the low-dose level instead, so not every plan has three dose levels.
Uninvolved nodal levels at risk of microscopic spread, contoured using the neck level definitions.
Which levels are included — and whether one side or both — is one of the biggest differences between subsites and nodal stages, and it largely decides how much of the salivary glands and swallowing structures can be spared.
Each CTV expanded for setup uncertainty. Coverage is often judged on a copy cropped back from the skin.
Near the skin, build-up means the PTV cannot be fully covered without bolus. For example, RTOG 0920 evaluates coverage on PTVs that exclude the tissue within 8 mm of the skin.
One table for every subsite. Click an organ for its anatomy, why it matters and contouring resources. Superscripts link to the study behind each value.
| Organ | Conventional fractionation70 Gy / 35 fx definitive · 60–66 Gy / 30–33 fx post-op |
|---|---|
| Spinal Cord | |
| BrainstemHigher doses may be appropriate depending on the clinical situation. | |
| Optic Chiasm & Optic Nerves | |
| Temporal Lobes | |
| Pituitary GlandGiven for nasopharynx cancer. |
|
| CochleaKeep as low as possible to reduce hearing loss. | |
| Lens |
|
| Globes (Eyes) | |
| Parotid GlandsReduce the mean dose to both glands as much as possible. | |
| Submandibular Glands |
|
| Oral CavityFor oral cavity cancers, evaluated outside the PTV. Avoid hotspots above 60 Gy. | |
| Lips | |
| MandibleLimiting intermediate-dose volumes may reduce osteoradionecrosis risk. | |
| Pharyngeal Constrictors | |
| LarynxGlottic and supraglottic larynx, when it is not part of the target. |
|
| Cervical EsophagusFor oral cavity and oropharynx cancers; higher doses are expected with larynx cancer. |
|
| Carotid ArteriesEspecially when the neck is not treated, such as early glottic cancer. |
|
| Brachial PlexusTarget coverage takes priority. |
|
Values quoted from eviQ 5049 (first approved 30 April 2026; review due 30 June 2030) and RTOG 0920, checked by DoseLab on 2026-09-24. Verify against your protocol, institutional policy and physician directive before clinical use.
Search all head & neck constraints in the Constraint Finder →
Consensus CT delineation guidelines for head and neck organs at risk from eight cooperative groups, with anatomical descriptions and example images. Citation checked against Crossref; content not yet reviewed by DoseLab.
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.
Updated consensus on selecting elective nodal levels for definitive radiotherapy of oral cavity, oropharynx, hypopharynx, larynx, nasopharynx, sinonasal and unknown-primary cancers. Citation checked against Crossref; content not yet reviewed by DoseLab.
Consensus guidelines from multiple international groups for delineating the primary-tumor CTV in definitive radiotherapy of squamous cell carcinoma of the larynx, hypopharynx, oropharynx and oral cavity. Citation checked against Crossref; content not yet reviewed by DoseLab.
CT-based guidelines for delineating the organs at risk involved in swallowing. Citation checked against Crossref; content not yet reviewed by DoseLab.
The 2025 update of the DAHANCA radiotherapy quality-assurance guidelines, with new chapters on planning complex targets and hypofractionation. 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.
An international expert guideline that ranks targets and organs at risk for nasopharyngeal carcinoma planning and gives ideal and acceptable dose criteria, including D0.03 cc near-maximum doses. A correction was published later in 2019. Citation checked against Crossref; content not yet reviewed by DoseLab.
Randomized trial of five versus six fractions per week of conventionally fractionated radiotherapy for head and neck squamous cell carcinoma. Citation checked against Crossref; content not yet reviewed by DoseLab.
Individual-patient-data meta-analysis of chemotherapy added to locoregional treatment for head and neck squamous cell carcinoma. Citation checked against Crossref; content not yet reviewed by DoseLab.
Endorsed eviQ protocol for definitive radiotherapy of oropharyngeal squamous cell carcinoma, with or without concurrent chemotherapy. It replaces the earlier separate radiotherapy-alone (740) and chemoradiation (3362) protocols. DoseLab's head and neck constraint table reproduces selected values from its organs-at-risk table, keeping eviQ's citation for each. The same organ table appears in eviQ's oral cavity, larynx/hypopharynx, early glottic, nasopharynx and post-operative head and neck protocols.
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.