Single‑session targeted partial breast radiation with a simultaneous boost for early-stage favorable‑subtype breast cancer
Accelerated Partial Breast Irradiation in One Fraction for Patients With Early-stage Disease and Favorable Histological Subtypes (Breast-1F).
This trial will test whether a single high‑dose, targeted radiation session with a built‑in boost works as well as a five‑fraction schedule for women 40 and older with early, node‑negative luminal A or B HER2‑negative breast cancer after surgery.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 311 (estimated) |
| Ages | 40 Years and up |
| Sex | Female |
| Sponsor | IRCCS San Raffaele Academic / other |
| Locations | 1 site (Milan) |
| Trial ID | NCT06946238 on ClinicalTrials.gov |
What this trial studies
This is a randomized, monocentric, non‑inferiority trial comparing a single‑fraction stereotactic accelerated partial breast irradiation (APBI) of 15.5 Gy with a simultaneous integrated boost to 21 Gy versus the department's standard APBI of 30 Gy delivered in five consecutive fractions (Florence protocol). Eligible patients are those with pathological stage pTis–pT2 (≤3 cm), node‑negative status, negative surgical margins, and luminal A or B HER2‑negative histology following breast‑conserving surgery. Treatments target the planning target volume (PTV) of the tumor bed with stereotactic techniques and the boost is directed to the gross tumor volume (GTV) representing the tumor bed. The trial will track local control, acute and late toxicity, and cosmetic outcomes over follow‑up to determine whether the single‑fraction approach is non‑inferior to the multifraction standard.
Who should consider this trial
Good fit: Ideal candidates are women aged 40 or older who had breast‑conserving surgery for a luminal A or B HER2‑negative tumor ≤3 cm with clear surgical margins and no lymph node involvement.
Not a fit: Patients with larger tumors, positive lymph nodes, high‑risk histologies (HER2‑positive or triple‑negative), positive margins, prior thoracic radiotherapy, or those under 40 are unlikely to be appropriate or to benefit from this single‑fraction approach.
Why it matters
Potential benefit: If non‑inferior, this approach could offer equivalent cancer control with a single treatment visit instead of multiple sessions, improving patient convenience and reducing overall treatment time.
How similar studies have performed: Early‑phase and institutional reports of stereotactic or single‑fraction partial breast irradiation have shown promising local control and acceptable toxicity, but data remain more limited than for multifraction regimens.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: 1. Histological diagnosis of breast cancer 2. Patients aged ≥40 years 3. Signed informed consent 4. Stage pTis-T2, up to 3 cm in the greatest diameter 5. Luminal A and Luminal B HER2-negative histological subtypes 6. Negative surgical margins (≥ 0.2 cm) 7. Negative lymph nodes at sentinel lymph node biopsy, or alternatively with imaging tests (Positron Emission Tomography (PET)/Computed Tomography (CT) and/or axillary ultrasound, and/or breast Magnetic Resonance Imaging (MRI) with and without contrast), or, in rare cases, where still performed, with axillary dissection 8. Clinical M0 (PET/CT and/or bone scintigraphy and/or abdomen-pelvis CT with and without contrast in suspected patients), within the previous 3 months. 9. Performance Status (PS) Eastern Cooperative Oncology Group (ECOG) ≤2 10. No prior thoracic radiotherapy 11. Fertile women using contraception methods initiated during oncological treatment. Exclusion Criteria: 1. Patients aged \< 40 years 2. Tumors \> 3 cm 3. Multicentric tumors 4. Positive or close surgical margins (\<0.2 cm) 5. Lobular carcinoma 6. Negative hormone receptors 7. HER2-positive 8. BReast CAncer (BRCA) genes BRCA1 and/or BRCA2 positive (only if known) 9. Severe systemic diseases 10. Psychiatric or other disorders that may prevent the patient from signing informed consent 11. Previous invasive cancer, except for skin cancer (excluding melanoma) unless the patient has been disease-free for at least 3 years (e.g., carcinoma in situ of the oral cavity or bladder) 12. Collagen or autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjogren's syndrome) 13. Lymph node disease (N1) 14. Evidence of distant metastasis (M1) 15. Contraindication to systemic treatment 16. Pregnant women 17. Non-compliance with the dose limits established in the treatment plan
Where this trial is running
Milan
- IRCCS San Raffaele Scientific Institute — Milan, Italy (Recruiting)
Study contacts
- Principal investigator: Andrei Fodor, MD — IRCCS San Raffaele Scientific Institute
- Study coordinator: Andrei Fodor, MD
- Email: fodor.andrei@hsr.it
- Phone: +390226437634
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.