2026-05-22

digest generated 2026-06-27

DBCG IMN2: 15y OS 65.0 vs 60.8% with internal mammary nodal RT (HR 0.85, p=0.0016), no cardiac penalty in the modern systemic era.

TL;DR

Nodal RT volume carried the day across two sites: DBCG IMN2 sustains an internal-mammary OS gain (HR 0.85) into the taxane/AI/trastuzumab era with no cardiac excess, while PEACE V–STORM is the first RCT favouring whole-pelvis ENRT over focal MDT in nodal oligorecurrence (4yr MFS 76 vs 63%, p=0.063). Lymphoma adds an EORTC per-entity low-dose algorithm.

Lymphoma

EORTC Cutaneous Lymphoma RT Recommendations

TL;DR≥92% 1yr local control with low-dose RT (8-12 Gy) in MF; EORTC consensus algorithm standardizes per-entity dosing absent RCTs.

Why it mattersRadiation oncology

The actionable read is dose: 8-12 Gy in 2-3 fx clears ≥92% 1yr local control in MF, while 4 Gy underperforms, so ultra-low-dose trades control for fewer visits. The EORTC algorithm sets a per-entity dose floor where no RCT exists, reserving 24 Gy for bulky lesions or pre-transplant remission.

vs leading data

Folliculotropic MF: RT more effective than other modalities (Dutch registry, n=203, retrospective)

Radiation Consensus / guideline

6 details 5 trials watching

Methods

💊 Sézary syndrome: TSEBT controversial, rarely durable; systemic effect lowers circulating Sézary cells
🔍 Expert consensus / literature review; no completed RCTs defining standard dose per entity
🔍 EORTC algorithm (Figs 2A/2B) standardizes per-entity dose recommendations across centres

Results

📊 Low-dose RT in MF: 1yr local control ≥92%

📊 Recommended RT dose by cutaneous lymphoma entity

Entity	RT dose / fractionation
MF, localized plaques/tumours	8-12 Gy in 2-3 fx
MF, >10% BSA (TSEBT)	8-12 Gy palliative; up to 24 Gy pre-autologous SCT
Cutaneous DLBCL, leg type	16-45 Gy (4 Gy/wk up to 40 Gy)

Critique

⚠️ 4 Gy (1-2 fx) gave inferior local control vs 8-12 Gy in MF

Open questions

Standard radiation dose per cutaneous lymphoma entity (no completed RCT)

active Low Dose Radiotherapy in Primary Indolent Cutaneous B-cell Lymphoma

n=52 · primary completion 2025-12 · 4 Gy low-dose RT in cutaneous B-cell entity

recruiting Low-Dose Total Skin Electron Therapy in Treating Patients With Refractory or Relapsed Stage IB-IIIA Mycosis Fungoides

n=60 · primary completion 2026-09 · low-dose total skin electron therapy in MF

recruiting Ultra Low Dose Radiation Therapy in Treating Patients With Mycosis Fungoides Phase 2

n=50 · primary completion 2027-12 · phase 2 ultra-low-dose RT in MF
Factors predicting outcome after different radiation doses
Optimal low-dose RT combined with immunomodulatory/systemic agents

recruiting Effectiveness of Concurrent Ultra-Low-Dose Total-Skin Electron Beam Therapy and Brentuximab Vedotin Given Quarterly Over 12 Months for Patients With Mycosis Fungoides Phase 2

n=30 · primary completion 2027-01 · ULD-TSEBT + brentuximab vedotin

recruiting Combining Topical Imiquimod With Local Radiotherapy for Treatment of Mycosis Fungoides Phase Early 1

n=25 · primary completion 2027-06 · concurrent imiquimod + RT, both doses studied

Sourced from Khaled Elsayad et al.

📚 Sources · 📄 1 paper

📄 PAPER Khaled Elsayad; Emmanuella Guenova; Chalid Assaf et al. · European Journal of Cancer (2024)

Radiotherapy in cutaneous lymphomas: Recommendations from the EORTC cutaneous lymphoma tumour group

doi

Breast

DBCG IMN2 NCT06549920

ForNode-positive breast cancer, incl 1-3 positive nodes, modern systemic therapy

TL;DR15y OS 65.0% vs 60.8% with IMNI, adjusted HR 0.85 (0.76-0.94) p=0.0016, in node-positive breast, modern-systemic era.

Why it mattersRadiation oncology

Moves the IMN-coverage decision in 1-3 node disease, where guidelines split: benefit held in the lowest-burden subgroup, no omission group identified. Cardiac safety is the additive read: 15y ischemic/valvular death 0.2% with IMNI (right) vs 0.7% without, so modern 3D IMNI carried no excess cardiac death.

vs leading data

vs DBCG IMN1 (n=3089, treated 2003-07): absolute OS gain 4.7% at 14.8y; IMN2 sustains a similar 65.0 vs 60.8% spread in the modern era
vs EBCTCG regional-node-RT meta-analysis: 3% absolute 15y survival gain; IMN2 consistent. Contrasts the negative Korean KROG 06-08 IMNI study

Radiation Curative Real-world evidence Confirmatory

7 details 4 trials watching

Methods

🔍 Nationwide population-based prospective cohort, N=4541, treated 2007-14; right-sided → IMNI, left-sided → no IMNI (laterality allocation to limit cardiac confounding)
🔍 Median f/u 13.7y; systemic backbone was taxane chemo, aromatase inhibitors, trastuzumab (modern era), with 3D-based RT

Results

📊 IMNI vs no IMNI across endpoints (adjusted HRs)

Endpoint Adjusted HR (95% CI) p

Overall survival 0.85 (0.76-0.94) 0.0016
Breast cancer mortality 0.84 (0.74-0.95) 0.0077
Distant metastasis 0.87 (0.78-0.98) 0.026
📊 Benefit held in 1-3 positive node subgroup; no subgroup identified for IMNI omission; authors advocate guideline IMNI for 1-3 nodes
📊 15y ischemic/valvular heart death 0.2% (0.0-0.5) right-sided/IMNI vs 0.7% (0.4-1.2) left-sided/no IMNI — no excess cardiac death with modern 3D IMNI

Endpoint	Adjusted HR (95% CI)	p
Overall survival	0.85 (0.76-0.94)	0.0016
Breast cancer mortality	0.84 (0.74-0.95)	0.0077
Distant metastasis	0.87 (0.78-0.98)	0.026

Critique

⚠️ Not randomised: laterality-based allocation, residual confounding possible; cancer outcomes reported balanced right vs left, but this is a cohort, not an RCT
⚠️ Cardiac comparison confounded: left-sided chest-wall RT carries cardiac dose regardless of IMNI, so the 0.2 vs 0.7% gap is not purely IMNI-attributable

Open questions

Confirmatory RCT for IMNI benefit in 1-3 positive nodes

active Postmastecomy Internal Mammary Nodal Irradiation for High-risk Breast Cancer Patients Phase 3

n=2400 · primary completion 2025-11 · phase 3 IMNI vs no-IMNI, primary endpoint DFS

recruiting The Postoperative Radiotherapy in N1 Breast Cancer Patients Phase 3

n=1106 · primary completion 2026-12 · phase 3 regional RT vs no RT in pN1
Optimal IMNI technique (proton vs photon) to limit cardiac and lung dose

not yet Proton vs Photon IMRT Toxicity in Breast Cancer

n=750 · primary completion 2027-12 · IMPT vs photon IMRT, heart/lung toxicity endpoint

recruiting Safety and Efficacy of IMPT or IMRT for Breast Cancer

n=500 · primary completion 2029-11 · IMPT vs IMRT toxicity, incl regional nodes
IMNI benefit by molecular subtype with current systemic therapy

Sourced from Anders W. Mølby Nielsen et al.

📚 Sources · 📄 1 paper

📄 PAPER Anders W. Mølby Nielsen; Lise B. J. Thorsen; Demet Özcan et al. · The Lancet Regional Health - Europe (2025-02)

Internal mammary node irradiation in 4541 node-positive breast cancer patients treated with newer systemic therapies and 3D-based radiotherapy (DBCG IMN2): a prospective, nationwide, population-based cohort study

doi

Prostate

PEACE V–STORM NCT03569241

ForPelvic nodal oligorecurrent prostate ca (≤5 nodes), post radical Rx

TL;DR4yr MFS 76% vs 63% favouring whole-pelvis ENRT over MDT, HR 0·62 (80% CI 0·44–0·86), p=0·063, in nodal oligorecurrence.

Why it mattersRadiation oncology

Target volume is the decision: whole-pelvis ENRT beat focal MDT on 4-yr MFS (76% vs 63%, HR 0·62), arguing microscopic nodal disease extends beyond the PET-visible node. The cost was modest, G3 urinary incontinence 10% vs 6%. Reason to elect pelvic nodal coverage over node-only SBRT, pending phase 3.

vs leading data

First RCT in this setting; STOMP/ORIOLE tested MDT vs surveillance, not wider ENRT vs focal MDT

Radiation Curative Phase 2 trial Challenges SOC

8 details

Methods

🔍 Phase 2, open-label, randomised 1:1, N=196 (MDT 99 / ENRT 97), 190 evaluable; 21 sites, 6 countries
🔍 Population: PET-detected pelvic nodal oligorecurrence (≤5 nodes) post radical local Rx, WHO PS 0–1
🔍 ENRT arm: 45 Gy/25 fx to pelvis + SIB 65 Gy to PET-positive nodes (or salvage LND), + 6mo ADT
🔍 MDT arm: SBRT 30 Gy/3 fx every other day (or salvage LND), + 6mo ADT

CONSORT flow

Assessed / enrolled 198

↓ 2 excluded

Randomized 196

↓

MDT

allocated 99

analyzed 97

ENRT

allocated 97

analyzed 93

Results

📊 1° EP metastasis-free survival, ENRT vs MDT

Endpoint MDT ENRT HR (ENRT vs MDT)

4-yr MFS 63% (80% CI 56–69) 76% (80% CI 69–81) 0·62 (80% CI 0·44–0·86), p=0·063
📊 Most common grade 3 AEs, MDT vs ENRT — comparison values omitted (cell value "9" not verified in source)

Endpoint	MDT	ENRT	HR (ENRT vs MDT)
4-yr MFS	63% (80% CI 56–69)	76% (80% CI 69–81)	0·62 (80% CI 0·44–0·86), p=0·063

Critique

⚠️ p=0·063 by conventional two-sided test; positive only under the trial's phase-2 80% CI design. Authors await phase 3
⚠️ Both arms permitted salvage LND as the local option, folding surgery into the RT comparison and blurring a clean ENRT-vs-MDT contrast

Open questions

Phase 3 confirmation of ENRT MFS benefit over MDT
OS and long-term QoL of whole-pelvis ENRT vs MDT
Does PSMA-PET selection change the ENRT vs MDT result

Sourced from Piet Ost et al.

📚 Sources · 📄 1 paper

📄 PAPER Piet Ost; Shankar Siva; Sigmund Brabrand et al. · The Lancet Oncology (2025-05)

Salvage metastasis-directed therapy versus elective nodal radiotherapy for oligorecurrent nodal prostate cancer metastases (PEACE V–STORM): a phase 2, open-label, randomised controlled trial

doi

🌐 Lymphoma

EORTC Cutaneous Lymphoma RT Recommendations

🎀 Breast

DBCG IMN2 NCT06549920

🌰 Prostate

PEACE V–STORM NCT03569241

Lymphoma

Breast

Prostate