Overview

Regional nodal irradiation adds the axillary, supraclavicular and sometimes internal mammary nodes to breast or chest wall treatment. The volumes are larger and closer to the lung, heart and neck, so organ limits are different from breast-only treatment.

How It Differs From Breast or Chest Wall Alone

Adding the regional nodes extends the target up into the lower neck and, for the internal mammary chain, medially along the sternum. Randomized trials including MA.20 and EORTC 22922 underpin modern nodal treatment.

Common schedules include 45–50 Gy at 1.8–2 Gy per fraction and 40 Gy in 15 fractions for the nodes; hypofractionated nodal treatment is being studied in trials such as SKAGEN Trial 1.

What changes for the planner:

  • More lung and heart in the field. Lung limits are looser than for breast alone, and internal mammary treatment can increase heart and lung dose — breath hold is worth considering.
  • Several targets that meet. Breast or chest wall, supraclavicular, axillary and internal mammary volumes have to be covered without gaps or overlaps.
  • New organs in play. The spinal cord, thyroid and esophagus sit near the supraclavicular volume.

Simulation & Daily Setup

As for breast or chest wall treatment, with the neck included.

Setup, breath hold and planning CT
The breast-board setup with a scan long enough to cover the supraclavicular region; breath hold weighs more when the internal mammary nodes are treated.

What is it?

Supine on a breast board with the arm above the head, scanned from the neck to below the diaphragm with the whole lungs included. More →

Why does it matter?

The scan has to cover the supraclavicular region; breath hold matters more when the internal mammary nodes are treated.

Arm and head position
Arm and shoulder position move the axilla and supraclavicular nodes, so the setup has to be the same every day.

What is it?

A reproducible arm-up position, with the head position set by the immobilization device.

Why does it matter?

Arm and shoulder position move the axilla and supraclavicular region, so small changes shift the nodal targets relative to the beams.

Image fusion — PET/CT and pre-operative imaging
Staging PET/CT and pre-operative imaging show which nodes were involved; arm position decides whether a fusion lines up.

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 nodal treatment this means any staging PET/CT, MRI or CT, plus the mammogram and ultrasound, from before surgery.

Why does it matter?

They show which axillary, supraclavicular or internal mammary nodes were involved, which affects the nodal volumes. The axilla and supraclavicular region move with arm and shoulder position, so a diagnostic scan taken in a different arm position won't line up with the planning CT — check the registration at the nodes themselves.

Target Delineation

Which nodal regions are treated, and where each starts and stops, come from your protocol and the consensus atlases.

Supraclavicular CTV — Lower neck

Definition

The nodes above the clavicle, drawn around the vessels in the lower neck.

Why it matters

Its upper border and how far it extends toward the thyroid and trachea differ between atlases, which changes thyroid, esophagus and cord dose.

Contouring resources

Organ contouring guides →

Axillary CTV — Levels I–III

Definition

The axillary nodes, divided into levels by their relation to the pectoralis minor muscle.

Why it matters

Which levels are treated depends on surgery and risk; the atlases define each level's borders.

Contouring resources

Organ contouring guides →

Internal mammary CTV — Along the sternum

Definition

The internal mammary nodes, drawn around the internal mammary vessels in the upper intercostal spaces.

Why it matters

A small target right next to the heart and lung. Including it is one of the biggest drivers of heart dose in breast planning.

Contouring resources

Organ contouring guides →

Breast or chest wall CTV — With the nodes

Definition

The breast or chest wall volume treated together with the nodes. More →

Why it matters

Planned as on the whole-breast or post-mastectomy pages, but it has to join the nodal volumes cleanly.

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.

Organ45–50 Gy / 25 fx1.8–2 Gy per fraction40 Gy / 15 fx
Ipsilateral Lung15 fx: dose from the breast or chest wall and nodal plans combined.
  • V20 Gy <30%1
  • V5 Gy <70%2
  • V17 Gy <35% (combined plans)3
Contralateral Lung
  • V5 Gy <10%4
—
Heart / PericardiumMean <5 Gy may be hard to achieve; keep as low as reasonably achievable. Consider breath hold.
  • V25 Gy <10%5
  • Mean <5 Gy4
  • V17 Gy <10%4
LAD (Left Anterior Descending Artery)Left-sided treatment. May not be achievable when the internal mammary nodes are treated.
  • Mean <10 Gy6
  • Mean <10 Gy6
Contralateral BreastKeep as low as reasonably achievable, especially with VMAT or fields crossing the midline.
  • V3 Gy <10% (ideal)2
  • V5 Gy <10% (acceptable)2
—
Spinal CordNot expected to come near this limit.
  • Max ≤45 Gy EQD2 (acceptable)4
  • Max ≤40 Gy (ideal)4
—
  • Internal mammary node treatment can increase heart and lung dose.
References (6)
  1. Yim 2015 — Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index. J Med Radiat Sci. 2015;62(3):184–191 Source
  2. NSABP B-51 — NSABP B-51 / RTOG 1304 protocol — A Randomized Phase III Clinical Trial Evaluating Post-Mastectomy Chestwall and Regional Nodal XRT and Post-Lumpectomy Regional Nodal XRT in Patients with Positive Axillary Nodes Before Neoadjuvant Chemotherapy Who Convert to Pathologically Negative Axillary Nodes After Neoadjuvant Chemotherapy. Protocol document, NSABP B-51 Source
  3. SKAGEN Trial 1 — The SKAGEN Trial 1 (DBCG HYPO II; TROG 17.07) — Moderately hypofractionated loco-regional adjuvant radiation therapy of early breast cancer combined with a simultaneous integrated boost. Trial protocol Source
  4. eviQ 1924 — Breast invasive cancer adjuvant nodal irradiation EBRT (eviQ ID 1924). eviQ Radiation Oncology protocol 1924 Source
  5. QUANTEC heart — Radiation dose–volume effects in the heart (QUANTEC). Int J Radiat Oncol Biol Phys. 2010;76(3 Suppl):S77–S85 Source
  6. DEGRO 2019 — Heart toxicity from breast cancer radiotherapy: Current findings, assessment, and prevention. Strahlenther Onkol. 2019;195(1):1–12 (online 11 October 2018) Source

Values quoted from eviQ 1924 (last reviewed 28 March 2024; review due 30 June 2026) and DEGRO 2019, checked by DoseLab on 2026-09-23. Verify against your protocol, institutional policy and physician directive before clinical use.

Search all breast constraints in the Constraint Finder →

Protocols & Literature

Clinical protocolSource Verified

Randomized trial of 40 Gy in 15 fractions versus 50 Gy in 25 fractions for loco-regional breast radiotherapy. The protocol lists the DBCG organ limits used in the trial (Table 7) and quotes the DBCG guideline LAD maximum of 17 Gy (hypofractionated) and 20 Gy (normofractionated), noting that heart limits were under review because of the benefit of treating the internal mammary nodes — so the trial asked centers to delineate the LAD and report its dose rather than enforce a limit.

Clinical protocolUnder Review

NRG Oncology's protocol page for NSABP B-51 / RTOG 1304, a phase 3 trial of regional nodal irradiation after neoadjuvant chemotherapy. The protocol document holds the trial's normal-tissue requirements.

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.

Planning studyUnder Review

Planning study comparing IMRT with 3D-conformal whole-breast radiotherapy and proposing a normal tissue index for plan evaluation. Citation as given in the eviQ reference list; not yet checked against the journal.

Clinical resourceSource Verified

Endorsed eviQ protocol for regional nodal irradiation (axilla, supraclavicular fossa and internal mammary chain). DoseLab's regional nodal constraint table reproduces selected values from its organs-at-risk table, keeping eviQ's citation for each. The review date eviQ lists had passed when DoseLab checked this page — check the live page for the current version.

All breast literature →