Conventional / Hypofractionated Lung RT

LungConventional fractionationHypofractionationChemoradiationPlan Evaluation
Overview

Most lung cancers that are too large, too central or too advanced for SBRT are treated with conventionally fractionated radiation — frequently alongside chemotherapy — or with a moderately hypofractionated course. The planning challenge shifts from sculpting a tiny, steep dose cloud to covering larger targets, including lymph nodes, while keeping the dose to the lungs, heart and esophagus as low as the plan allows.

How It Differs From SBRT

Conventionally fractionated treatment (around 2 Gy per fraction over several weeks, often with concurrent chemotherapy) and moderately hypofractionated courses are used for tumors that are too large, too central or too extensive for SBRT — most often locally advanced disease involving the mediastinal lymph nodes.

That changes the planning problem:

  • Targets are larger and more irregular, often including nodal stations, so plans are judged more on coverage and homogeneity than on the extreme conformity and steep gradient that define SBRT.
  • Parallel organs dominate. Volume-based metrics — mean dose and Vx values for the lungs, heart and esophagus — carry more weight than single point doses.
  • Fraction size changes tolerance. Limits written for SBRT cannot be used for a 30-fraction plan, and vice versa. When comparing schedules, BED and EQD2 are the tools; published tables for each fraction count are the reference.

Simulation & Motion Management

The same motion principles as SBRT apply; see the Lung SBRT page for fuller explanations.

4DCT and motion
Motion is assessed for each target, since the primary tumor and nodes can move differently.

What is it?

Measuring how the primary tumor and nodes move with breathing. More →

Why does it matter?

Primary tumors and nodes can move by different amounts and in different directions, so motion is assessed for each target.

Whether an ITV, gating or breath hold is used — and for which targets — is set by your department's motion-management policy.

Image fusion — PET/CT
The staging PET/CT, fused with the planning CT, shows involved nodes and helps separate tumor from collapsed lung.

What is it?

Image fusion aligns an outside scan with the planning CT so the target can be drawn using information the CT doesn't show. For conventionally fractionated lung treatment this is the staging PET/CT, which protocols recommend for staging; MRI can also be used. The final contours are confirmed on the planning CT.

Why does it matter?

PET shows which nodes are involved — read together with endobronchial ultrasound and biopsy results — and helps separate tumor from atelectasis. IV contrast on the planning CT helps too, because collapsed lung does not enhance. Check the registration at the primary tumor and at each involved node, since they can sit and move differently.

Immobilization
The setup has to stay reproducible over several weeks while weight and tumor size change.

What is it?

Positioning that stays reproducible across several weeks of treatment.

Why does it matter?

Setup has to hold across many fractions, and patients' weight and tumor size can change during that time.

Arm position is a trade-off between beam access and comfort; supraclavicular targets and the brachial plexus are affected by it.

Adaptive considerations
Re-imaging during the course catches tumor shrinkage or lung re-expansion that moves the target.

What is it?

Re-imaging during the course of treatment to catch anatomical change.

Why does it matter?

Tumors can shrink, and collapsed lung can re-expand, over a multi-week course — moving the target and changing the dose to normal lung.

Many departments review cone-beam CTs for these changes and re-simulate when needed; the trigger is an institutional decision.

Target Delineation

Definitions of each volume. Nodal target definition and all margins are protocol- and institution-specific.

GTV — Primary and nodal

Definition

Visible primary tumor and involved lymph nodes, delineated separately.

Why it matters

PET/CT, endobronchial ultrasound and mediastinoscopy findings are commonly used to decide which nodes are involved; contours should reflect what was found.

Contouring resources

Organ contouring guides →

CTV — Clinical Target Volume

Definition

GTV plus a margin for microscopic extension, and — depending on the approach — nodal regions at risk.

Why it matters

Whether uninvolved nodal stations are treated electively or only involved nodes are targeted is a key protocol decision that changes target size substantially.

Contouring resources

Organ contouring guides →

ITV — Internal Target Volume

Definition

A volume accounting for internal motion of the target. Concept page →

Why it matters

Built for moving targets when motion is managed with a motion-encompassing approach.

Contouring resources

Organ contouring guides →

PTV — Planning Target Volume

Definition

An expansion for setup and delivery uncertainty.

Why it matters

In large lung targets, the PTV often overlaps the esophagus, heart or lung; how those overlaps are handled is part of the plan's design.

Contouring resources

Organ contouring guides →

Organs at Risk & Dose Constraints

Click an organ for its anatomy, why it matters and contouring resources. Superscripts link to the study behind each value.

Organ60 Gy / 30 fx± concurrent chemotherapy
LungsBoth lungs minus iGTV (4DCT) or GTV (3DCT). Targets ≤20% risk of grade 2+ pneumonitis.
  • Mean lung dose ≤20 Gy1
  • V20Gy ≤35%1
Spinal CordApplied to the bony spinal canal.
  • Max dose <50 Gy2
EsophagusMean <34 Gy: 5–20% risk of grade 3+ acute esophagitis. Chemo limits target ≤10–15%.
  • Mean dose <34 Gy3
  • Mean dose ≤28 Gy (concurrent chemo)4
  • V60Gy ≤17% (concurrent chemo)5
Heart / PericardiumNever at the expense of target coverage.
  • Mean heart dose ≤20 Gy6
  • V50 ≤25%7
Brachial Plexus
  • Max dose ≤66 Gy (EQD2)8
  • QUANTEC organ chapters are the evidence reviews behind the lung and spinal cord values; the RTOG 0617 protocol gives trial-specific limits for concurrent chemoradiation.
References (8)
  1. QUANTEC lung — Radiation dose–volume effects in the lung (QUANTEC). Int J Radiat Oncol Biol Phys. 2010;76(3 Suppl):S70–S76 Source
  2. QUANTEC spinal cord — Radiation dose–volume effects in the spinal cord (QUANTEC). Int J Radiat Oncol Biol Phys. 2010;76(3 Suppl):S42–S49 Source
  3. QUANTEC summary — Use of normal tissue complication probability models in the clinic. Int J Radiat Oncol Biol Phys. 2010;76(3 Suppl):S10–S19 Source
  4. Wei 2006 — Risk factors for acute esophagitis in non-small-cell lung cancer patients treated with concurrent chemotherapy and three-dimensional conformal radiotherapy. Int J Radiat Oncol Biol Phys. 2006;66(1):100–107 Source
  5. Palma 2013 — Predicting esophagitis after chemoradiation therapy for non-small cell lung cancer: an individual patient data meta-analysis. Int J Radiat Oncol Biol Phys. 2013;87(4):690–696 Source
  6. Wang 2017 — Cardiac Toxicity After Radiotherapy for Stage III Non-Small-Cell Lung Cancer: Pooled Analysis of Dose-Escalation Trials Delivering 70 to 90 Gy. J Clin Oncol. 2017;35(13):1387–1394 Source
  7. Speirs 2017 — Heart Dose Is an Independent Dosimetric Predictor of Overall Survival in Locally Advanced Non-Small Cell Lung Cancer. J Thorac Oncol. 2017;12(2):293–301 Source
  8. eviQ 1871 — Respiratory non-small cell lung cancer definitive EBRT with or without chemotherapy (eviQ ID 1871). eviQ Radiation Oncology protocol 1871 Source

Values quoted from eviQ 1871 (last reviewed 16 March 2023; review due 30 June 2027) and QUANTEC summary, checked by DoseLab on 2026-09-22. Verify against your protocol, institutional policy and physician directive before clinical use.

Search all lung constraints in the Constraint Finder →

Protocols & Literature

Landmark trialUnder Review

Randomized two-by-two factorial phase 3 trial of standard- versus high-dose chemoradiation (with or without cetuximab) for stage III non-small cell lung cancer. The high-dose arm did not improve survival.

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Consensus guidelineUnder Review
Radiation dose–volume effects in the lung (QUANTEC)
Marks LB, Bentzen SM, Deasy JO, et al. · QUANTEC · 2010

The lung chapter of the 2010 QUANTEC supplement. It reviews the relationship between lung dose–volume parameters and radiation pneumonitis and emphasizes that no single threshold cleanly separates safe from unsafe plans.

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Consensus guidelineUnder Review
Radiation dose–volume effects in the heart (QUANTEC)
Gagliardi G, Constine LS, Moiseenko V, et al. · QUANTEC · 2010

The heart chapter of the 2010 QUANTEC supplement, covering pericarditis and long-term cardiac effects and the dose–volume relationships reported for them. A later letter in the same journal comments on its breast-cancer conclusions.

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AAPM reportSource Verified

AAPM task group report on respiratory motion in thoracic, abdominal and pelvic treatment. It groups management approaches into motion-encompassing methods, respiratory gating, breath-hold techniques, forced shallow breathing (such as abdominal compression) and respiration-synchronized (tracking) techniques. Read in the AAPM report PDF (Report No. 91, July 2006): using ICRU Report 62 nomenclature, the PTV adds margins to the CTV for respiratory (intrafraction) motion, interfraction motion and set-up error; without a respiratory management device the entire range of motion should be considered in the internal margin; and for lung tumors a maximum intensity projection (MIP) can give the motion-encompassing volume, provided there is no mediastinal involvement.

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All lung literature →