2026-11-14

Oligometastatic / Mets

Liver SBRT dose selection tracks BED and OAR distance; the evidence base stays single-arm and retrospective.

SBRT for liver metastases (Seminars in Radiation Oncology review)

TL;DRBED ≥100 Gy10 tied to 3-year LC 93% vs 65% in liver mets; review maps fractionation to OAR distance and liver dose constraints.

Trials discussed

MAESTRO

Why it mattersRadiation oncology

The dose argument rests on one pooled analysis: BED above 100 Gy10 tracked with 3-year LC 93% vs 65% in mets, while primary liver tumors showed no gain above 100 Gy10. That separates the dose target for liver mets from HCC practice. For lesions near bowel or the central biliary tree, the review protracts fractionation rather than lowering BED.

Monday clinic

In a non-cirrhotic pt with a liver metastasis abutting bowel or the central biliary tree, this supports protracted fractionation over a 3-fraction ablative course; it does not extend to cirrhotic livers, where the cited limits are tighter. The longer read

11 details 3 trials watching

Design

Narrative topic review of liver SBRT for metastases. It covers prospective series, pooled analyses, prognostic scores, QOL, dose and fractionation, OAR tolerance and motion management. No search strategy or inclusion criteria are stated in the source.

Radiotherapy

Most series use 3-5 fractions (range 1-6). When maximizing LC is the priority the review recommends BED ≥100 Gy10 to the PTV. Fractionation is chosen to respect OARs in priority order: luminal GI, central biliary tree, chest wall, then liver. An SIB with PRV is suggested for tumors 1-2 cm from OARs.

Safety

QUANTEC: MLD limits of 15 Gy in 3 fractions and 20 Gy in 6 fractions keep the risk of G3 liver enzyme toxicity under 20%. In 6-fraction SBRT, G3 liver enzyme risk was 0% at MLD ≤15Gy but 6-18% at MLD ≤21Gy, depending on D800cc, so MLD alone is insufficient.

vs leading data

Against RFA, a 2238-pt meta-analysis showed 2-year LC 84% vs 60% favoring SBRT in liver mets studies, with no OS difference and G3+ toxicity <5% for both. MAESTRO, a randomized phase II trial of MR-guided adaptive vs ITV-based SBRT, is cited as the randomized technique question.

Applies to

liver oligometastases, mostly non-cirrhotic, including unresectable colorectal liver metastases

Does not represent cirrhotic livers or HCC, for which the review cites tighter constraints and a different dose response.

Limitations

The BED >100 Gy10 threshold comes from a pooled analysis of published series, open to selection by lesion size and location. Several cited constraints are borrowed from the ASTRO guideline for liver primaries, not derived in metastases.

Discussion

The review positions SBRT for lesions percutaneous ablation handles poorly: periampullary, perihilar, subcapsular, perivascular or large tumors. Optimal dose and fractionation remain unknown, with no consensus guideline. Whether CRC histology is radioresistant at sufficiently high dose is unresolved.

Results

Distance to OAR	Dose range	Fractions
>2 cm from all OARs	45-75 Gy	3
1-2 cm from any OAR	50-60 Gy	5-6
<1 cm from luminal GI or central biliary tree	60-67.5 Gy	10-15

Metric	3 fractions	5 fractions
Mean liver dose	<12-15 Gy	<15-18 Gy
Critical volume ≥700cc	<19 Gy	<21 Gy

Open questions

Optimal dose and fractionation for liver metastases

recruiting Standard Versus Radiobiologically-Guided Dose Selected SBRT in Liver Cancer Phase NA

n=110 · primary completion 2026-04 · standard vs radiobiologically-guided SBRT dose

recruiting Ultra-high Dose Radiation for Liver Metastasis Using MR-guided TReatment With Stereotactic Ablative Single-fraction Phase 3

n=114 · primary completion 2031-09 · phase 3 RCT, ultra-high vs high single-fraction dose
Randomized comparison of SBRT vs RFA for liver metastases
Benefit of MR-guided adaptive SBRT over ITV-based planning

recruiting Magnetic Resonance-guided Adaptive Stereotactic Body Radiotherapy for Hepatic Metastases Phase 2

n=90 · primary completion 2029-01 · MRgSBRT vs ITV-based SBRT, 1-3 hepatic mets

Sourced from Lee, Sangjune Laurence et al.

📚 Sources · 📄 1 paper

📄 PAPER Lee, Sangjune Laurence; Bassetti, Michael F.; Rusthoven, Chad G. · Seminars in Radiation Oncology (2023-04)

The Role of Stereotactic Body Radiation Therapy in the Management of Liver Metastases

doi

Radiation

Breast

Three reviews (2012-2018) span the nodal RT decision chain: ALND omission, RNI field extent, PMRT after NAC; post-NAC guidance predates Alliance A011202 and NSABP B-51 results.

Surgery and radiotherapy for regional nodes in breast cancer

TL;DR10-yr LRR 6.2% ALND vs 5.3% SLNB alone (P = .36) in Z0011 anchors this review of ALND omission and nodal RT field choice.

Trials discussed

Z0011AMAROS

Why it mattersRadiation oncology

For RT, the decision here is field design. Z0011 used WBRT with no mandated nodal fields, and the review credits incidental axillary dose for its low failure rate. AMAROS required coverage of the undissected axilla plus the supraclavicular region. The source titles a field-design figure and PMRT algorithms, but their content is not in the captured text.

Monday clinic

In T1-T2 cN0 pts with one or two positive SLNs having BCS with conventionally fractionated WBRT, the cited 2016 ASCO guideline supports omitting ALND. That does not extend to tumors larger than 5 cm or gross extranodal extension.

10 details 5 trials watching

Population & inclusion

Focus on T1-T2/N1mi-N1 breast cancer with positive SLN(s) after clinically node-negative staging. Isolated tumor cells (pN0(i+), pN0(mol+)) are handled as node-negative.

Radiotherapy

Z0011 used WBRT, and the review credits incidental axillary irradiation for some of its control. AMAROS required fields covering the undissected axilla and the supraclavicular region. Field-design and PMRT recommendations are titled in the source but not captured in its text.

vs leading data

ALND omission rests on Z0011, IBCSG 23-01 and AMAROS, with NSABP B-04 as the historical rationale: about 40% predicted nodal disease, but regional recurrence in only 20% without dissection.

Applies to

T1-T2 cN0 pts with one or two positive SLNs or micrometastases undergoing BCS with WBRT

Does not represent tumors larger than 5 cm, gross extranodal extension, or clinically involved axillary nodes.

Limitations

The review dates to 2018, before later axillary trials such as SENOMAC and NSABP B-51. The excerpt cuts off at the mastectomy section, so PMRT and post-NACT recommendations are not captured.

Discussion

The review sets out two linked decisions after a positive SLN. The first is further axillary treatment (none vs ALND vs axillary RT). The second is the extent of RT, including regional nodes and chest wall.

Results

Feature	Z0011	IBCSG 23-01	AMAROS
N	891	931	Not stated in source
SLN burden	One or two positive SLNs	Micrometastases (N1mi)	Positive SLNB
Breast surgery / RT	BCS + WBRT	91% BCS + WBRT; mastectomy allowed	RT fields: undissected axilla + supraclavicular
Comparison	Completion ALND vs SLNB alone	Completion ALND vs SLNB alone	Completion dissection vs no further surgery
Outcome	Similar 5-yr OS/DFS; 10-yr LRR 6.2% vs 5.3%, P = .36	No DFS/OS difference	No surgical benefit for LC, DFS or OS

Open questions

Role of SLNB in T3-T4 clinically node-negative disease
Nodal RT extent by nodal response to neoadjuvant chemotherapy

active Standard or Comprehensive Radiation Therapy in Treating Patients With Early-Stage Breast Cancer Previously Treated With Chemotherapy and Surgery Phase NA

n=1636 · primary completion 2023-09 · phase 3 RNI vs no RNI after chemo and surgery

not yet De-escalation of RNI in Breast Cancer Patients With pN0 After Neoadjuvant Therapy Phase NA

n=100 · primary completion 2028-06 · RNI de-escalation in cN1 → ypN0 after NAT

recruiting Axillary Management in Breast Cancer Patients With Needle Biopsy Proven Nodal Metastases After Neoadjuvant Chemotherapy Phase NA

n=1900 · primary completion 2030-02 · omit ALND + axillary RT if ypN0 on SLNB post-NACT

recruiting Response-Adapted Omission of Nodal Boost In N3 Breast Cancer After Neoadjuvant Systemic Therapy Phase NA

n=534 · primary completion 2030-09 · nodal boost omission in cN3 with cCR after NST

not yet Internal Mammary Node Irradiation After Neoadjuvant Systemic Therapy for Breast Cancer Phase 3

n=1760 · primary completion 2032-07 · phase 3 ± IMNI for residual ypN+ after NST
ALND omission with tumors larger than 5 cm or gross ENE

Sourced from Melissa P. Mitchell et al.

📚 Sources · 📄 1 paper

📄 PAPER Melissa P. Mitchell; Priyanka Sharma · Oncology (Williston Park) (2018-06)

The Use of Surgery and Radiotherapy as Treatment of Regional Nodes in Breast Cancer Patients

Curative

Clinical perspective on regional nodal irradiation for breast cancer

TL;DR10-yr DFS 82% vs 77% (MA.20) and 72.1% vs 69.1% (EORTC 22922) with RNI, no OS gain in either trial alone.

Trials discussed

NCIC MA.20EORTC 22922AMAROSACOSOG Z0011Alliance A011202NSABP-B51

Why it mattersRadiation oncology

The transferable detail is target volume: MA.20 treated IMC, SCV and level III axilla after BCS in a cohort roughly 85% 1-3 node-positive, while EORTC 22922 treated IMC plus medial SCV with 44.4% node-negative in the RNI arm. Both DFS gains (82% vs 77%; 72.1% vs 69.1%) support nodal fields in higher-risk pN1, with IMC coverage planned against cardiac dose. The longer read

9 details 5 trials watching

Radiotherapy

Target volumes differ by trial: MA.20 treated the undissected axilla, IMC (first 3 intercostal spaces) and SCV; EORTC 22922 treated IMC and medial SCV. Z0011-era high tangents cover most of level I/II but not level III or SCV.

Safety

RNI adds cardiopulmonary toxicity and lymphedema risk, worst after complete ALND. Coronary events rose 7.4% per Gy mean heart dose in a 1958-2001 series, and a retrospective series showed CAD 18% vs 7% with vs without IMC fields (P=0.01).

vs leading data

EBCTCG PMRT data in 1-3 node disease frame the debate; MA.20 and EORTC 22922 test it with CT-era RT. AMAROS and ACOSOG Z0011 recast the axilla as an RT target after limited SLN disease.

Applies to

stage II, pN1 or high-risk pN0 breast cancer after BCS or mastectomy

Does not represent cT1-3N1 disease converting to ypT0N0 after neoadjuvant chemotherapy, which the authors route to NSABP-B51.

Limitations

Narrative, not systematic; cardiac evidence mixes pre-CT-era and retrospective series. Trial-era pN1 differs from today's microsectioned, SLN-staged pN1, so absolute gains may not transfer.

Discussion

Authors favor RNI for advanced and high-risk stage II disease and ask that grade, subtype, nodal burden and extent of axillary surgery guide stage I-II decisions. Recurrence-score-guided RNI is proposed but untested prospectively.

Results

Characteristic	NCIC MA.20	EORTC 22922
Accrual	2000-2007	1996-2004
N	1832	4004
BCS	100%	76.1%
RNI targets	IMC + SCV + level III axilla	IMC + medial SCV
Median age (yr)	53-54	54
0 ALN+ (RNI vs control)	9.6% vs 9.7%	44.4% vs 44.5%
1-3 ALN+ (RNI vs control)	84.9% vs 85.1%	42.9% vs 43.3%
>3 ALN+ (RNI vs control)	5.5% vs 5.1%	12.2% vs 12.2%
Chemotherapy (RNI vs control)	90.7% vs 90.5%	54.6% vs 55.1%

Endpoint	NCIC MA.20	EORTC 22922
10-yr DFS	82% vs 77%, P=0.01	72.1% vs 69.1%, P=0.04
10-yr distant DFS	Not stated in source text	78% vs 75.5%, P=0.02
10-yr BC mortality	Not stated in source text	12.5% vs 14.4%, P=0.02
10-yr OS	No long-term benefit	No long-term benefit

Open questions

Does RNI benefit favorable stage II or luminal pN1 disease?

recruiting The T-REX Trial: Tailored Regional External Beam Radiotherapy in Clinically Node-negative Breast Cancer Patients With 1-2 Sentinel Node Macrometastases. Phase NA

n=1350 · primary completion 2028-12 · RCT omitting regional RT in ER+/HER2- 1-2 SN macromets

recruiting Hypofractionated Postoperative Regional Nodal Irradiation for Patients With Intermediate-risk Breast Cancer Phase 3

n=3142 · primary completion 2029-11 · phase 3 RNI in pT1-2N1 intermediate-risk disease
Is RNI needed after nodal pCR following neoadjuvant chemotherapy?

active Standard or Comprehensive Radiation Therapy in Treating Patients With Early-Stage Breast Cancer Previously Treated With Chemotherapy and Surgery Phase NA

n=1636 · primary completion 2023-09 · randomized phase 3 regional nodal XRT after chemo + surgery

not yet De-escalation of RNI in Breast Cancer Patients With pN0 After Neoadjuvant Therapy Phase NA

n=100 · primary completion 2028-06 · RNI de-escalation in cN1→ypN0 after neoadjuvant therapy

recruiting Axillary Management in Breast Cancer Patients With Needle Biopsy Proven Nodal Metastases After Neoadjuvant Chemotherapy Phase NA

n=1900 · primary completion 2030-02 · omits axillary RT if SNB node-negative after NACT; DFS
Can recurrence score select pts for RNI?

Sourced from Moreno, Amy C. et al.

📚 Sources · 📄 1 paper

📄 PAPER Moreno, Amy C.; Shaitelman, Simona F.; Buchholz, Thomas A. · The Breast (2017-08)

A clinical perspective on regional nodal irradiation for breast cancer

doi

Radiation Curative

Radiation decisions after neoadjuvant chemotherapy and mastectomy

TL;DRNo randomised post-NAC PMRT data: retrospective MDACC/NSABP series put ypN+ LRR without RT at ≥15%, cT1–T2 ypN0 <10%, supporting response-adapted PMRT.

Trials discussed

NSABP B-18NSABP B-27RAPCHEM

Why it mattersRadiation oncology

The omission case rests on small denominators: NSABP pCR + ypN0 (n=68) had 5.9% 8-yr LRF without PMRT, MDACC cT1–2 ypN0 (n=19) 5%. Clinical T3N0 converting to ypN0 is the contested cell (MDACC 14% vs 2%, p=0.06; NSABP 6.2% and 11.8%), so chest wall and nodal RT stay individualized there.

Monday clinic

In clinical T1–T2 disease that is ypN0 after NAC and mastectomy, these data support discussing PMRT omission; they do not extend to clinical T3–T4, N2–N3, or ypN+ disease, where retrospective series favor PMRT. The longer read

12 details 2 trials watching

Design

Lancet Oncol 2012 Personal View from MD Anderson radiation and surgical oncology authors. Medline and Embase searched to October 2011; inflammatory breast cancer excluded.

vs leading data

Upfront-mastectomy PMRT benefit comes from the Danish and Canadian randomised trials and the EBCTCG meta-analysis, all predating routine NAC. Pathological extent after NAC carries higher risk: with ≥4 involved nodes, MDACC 5-yr LRR was 53% vs 23% neoadjuvant vs upfront surgery (p<0.001).

Applies to

non-inflammatory, non-metastatic breast cancer treated with NAC and mastectomy

Does not represent inflammatory breast cancer or breast-conserving surgery.

Limitations

MDACC series overlap across publications and span eras of evolving staging, imaging, chemo and surgery. NSABP pts were earlier stage than MDACC pts: only 35% had clinical nodal involvement at diagnosis.

Discussion

Authors propose response-adapted PMRT: LRR at least 15% without RT in ypN+ supports PMRT, <10% in cT1–T2 ypN0 supports omission. Clinical stage III with pCR is unsettled, with MDACC and Le Scodan pointing in opposite directions.

Results

Subgroup	No PMRT	PMRT	p
Clinical T3	22%	8%	0.002
Clinical T4	46%	15%	<0.0001
Clinical N2–3	40%	12%	<0.0001
Clinical N1	14%	9%	0.062
Clinical N0	23%	10%	0.014
Path tumour 2.1–5.0 cm	31%	14%	0.002
Path tumour >5.0 cm	52%	13%	0.001
≥4 nodes at resection	59%	16%	<0.0001

Stratum	n	5-yr LRR
T1–2, ypN0	19	5%
T3–4, ypN0	23	34%
T1–2, ypN+	42	13%
T3–4, ypN+	64	36%

Cohort	Endpoint	No PMRT	PMRT	p
MDACC cStage III + pCR	10-yr LRR	33%	7.3%	0.04
Le Scodan stage II, ypN0	5-yr LR-RFS	92.9%	97.4%	>0.4
Le Scodan stage III, ypN0	5-yr LR-RFS	94.7%	90.9%	>0.2

Open questions

Can PMRT be safely omitted in cT1–T2 cN+ converting to ypN0?

active Standard or Comprehensive Radiation Therapy in Treating Patients With Early-Stage Breast Cancer Previously Treated With Chemotherapy and Surgery Phase NA

n=1636 · primary completion 2023-09 · phase 3 randomised chest wall/nodal RT after NAC + surgery

not yet De-escalation of RNI in Breast Cancer Patients With pN0 After Neoadjuvant Therapy Phase NA

n=100 · primary completion 2028-06 · response-adapted RNI de-escalation, cT1-3 N1 to pN0 post-NAT
PMRT benefit in clinical T3N0 that is ypN0 after NAC
Does PMRT benefit clinical stage III with pCR?

Sourced from Karen E Hoffman et al.

📚 Sources · 📄 1 paper

📄 PAPER Karen E Hoffman; Elizabeth A Mittendorf; Thomas A Buchholz · Lancet Oncol (2012)

Optimising radiation treatment decisions for patients who receive neoadjuvant chemotherapy and mastectomy

Radiation Curative

Prostate

Urethral dose constraints are the main lever on late GU toxicity, most of all for SBRT.

Urinary toxicity from prostate radiotherapy: mechanisms, mitigation, management

TL;DRNarrative review: urethral dose steering (FLAME-derived D0.1 cm³ <105% Rx; SBRT Dmax <107% → est. 7.7% late moderate GU) is the main mitigation lever.

Trials discussed

PROTECTASCENDE-RTFLAMEHEATNRG GU005

Why it mattersRadiation oncology

The planning numbers are the transferable part: urethra D0.1 cm³ <105% of prescription from the FLAME dosimetric analysis, and Dmax <107% at 40 Gy/5 fx tied to an estimated 7.7% late moderate GU rate. Sparing below prescription stays conditional on MRI or PSMA PET localisation with tumor clear of the urethra.

Monday clinic

In men with moderate-to-high IPSS or obstructive urodynamics before prostate RT, this supports weighing pre-emptive TURP; it argues against TURP early after RT for persistent obstructive symptoms, where incontinence reached 18% (7 of 38) and 27% (30 of 111) in two series. The longer read

13 details 1 trial watching

Design

Narrative review (Lancet Oncol, December 2022) from an Australian radiation oncology and urology group. PubMed search 1995 to April 2022 plus the authors' files; English only, no quantitative synthesis.

Radiotherapy

FLAME-derived constraint: urethra D0.1 cm³ <105% of the prostate prescription. For 40 Gy/5 fx SBRT, urethral Dmax <107% was estimated to give late moderate GU toxicity of 7.7%. HDR brachytherapy has no urethral consensus; one ABS guideline lists 11 different constraints.

Safety

Acute irritative symptoms in ~50%, resolving within 4–6 weeks. Stricture risk rises with brachytherapy boost and salvage post-RP RT; 4-yr G3+ bleeding was 15.5% on anticoagulants vs 3.6% without.

vs leading data

FLAME showed a DIL boost improved bDFS (HR 0.45, 95% CI 0.28–0.71) without an overall rise in moderate-to-severe GU toxicity. ASCENDE-RT is the counterpart for brachytherapy dose escalation, with stricture 18.4% vs 5.2%. PROTECT showed RT-related QoL detriment regressing over 12 months.

Discussion

The thesis is that cure and urinary function need not trade off if urethral dose, image guidance, ADT cytoreduction and early salvage over adjuvant RT are used. Urethral sparing below prescription stays conditional on reliable MRI or PSMA PET localisation with tumor away from the urethra.

Limitations

Most toxicity series are retrospective and physician-graded, and CTCAE/RTOG scales under-capture chronic urgency. The reassurance on relapse with urethral sparing is qualitative, with no event counts given.

Applies to

men receiving definitive or post-prostatectomy RT for localized prostate cancer

Does not represent anorectal or cervical pelvic RT, which the review mentions but does not address.

Results

Series	N	Dose	Urethral constraint	GU toxicity
LDR brachy	2693	I-125 144 Gy or Pd-103 130 Gy (median)	Max <217 Gy; D30% <125%	Late G2 19%, G3 4%
HDR boost	110	EBRT 35.75 Gy/13 fx + HDR 2 × 8.5 Gy	Max <120% Rx; D10% <120 Gy EQD2	Late G2 31% at 7 yr
Virtual HDR boost	135	19 or 20 Gy/2 fx + EBRT 46 Gy/23 fx	Urethra PRV Dmax 0.1 cc <110%	Acute G2 26.6%; late G≥2 6.3% at 36 mo
SBRT	48	36.25 Gy/5 fx	Urethra PRV max D0.1 cm³ ≤38.78 Gy	Late G2 4%
SBRT	101	36.25 Gy/5 fx	PTVurethra relatively spared to 32.5 Gy	Acute G2 23.8%; late G2 4%
SBRT	52	35 or 37.5 Gy/5 fx	Max urethral dose ≤35 Gy	Acute G2 10%; late G2 4%
SBRT	36	38 Gy/4 fx	80–90% of Rx	Acute G2 16.7%; late G2 8.3%

Trial	N	Control	Experimental	Status
NINJA	472	40 Gy/5 fx	Virtual HDR boost 20 Gy/2 fx + EBRT 36 Gy/12 fx	Recruiting
PACE-B	874	78 Gy/39 fx or 62 Gy/20 fx	SBRT 36.25 Gy/5 fx	Not stated in source
HEAT (NCT01794403)	456	70.2 Gy/26 fx	36.25 Gy/5 fx	Recruiting
NRG GU005 (NCT03367702)	692	70 Gy/28 fx	36.25 Gy/5 fx	Closed to accrual June 2022

Open questions

Does urethral sparing below prescription compromise local control for periurethral tumor?

not yet MRI-guided Ultrahypofractionated SBRT Prostate Program Phase NA

n=40 · primary completion 2030-06 · urethral-sparing 2-fx MRgSBRT, local control vs 5-fx
Which urethral dose constraint best predicts late GU toxicity after HDR brachytherapy?
Does urethral steering reduce patient-reported late urgency in randomised SBRT trials?

Sourced from Jarad M Martin et al.

📚 Sources · 📄 1 paper

📄 PAPER Jarad M Martin; Matthew Richardson; Shankar Siva et al. · The Lancet Oncology (2022-12)

Mechanisms, mitigation, and management of urinary toxicity from prostate radiotherapy

Radiation

🎯 Oligometastatic / Mets

SBRT for liver metastases (Seminars in Radiation Oncology review)

🎀 Breast

Surgery and radiotherapy for regional nodes in breast cancer

Clinical perspective on regional nodal irradiation for breast cancer

Radiation decisions after neoadjuvant chemotherapy and mastectomy

🌰 Prostate

Urinary toxicity from prostate radiotherapy: mechanisms, mitigation, management

Oligometastatic / Mets

Breast

Prostate