An interventional study of moderate hypofractionated proton radiotherapy and ultra-hypofractionated proton radiotherapy in Breast Cancer and Proton Therapy, sponsored by Shanghai Proton and Heavy Ion Center. Recruiting at 1 site in China. Open to female participants aged 40 Years and older. Per ClinicalTrials.gov, last updated 2025-08-22.
Sponsored by Shanghai Proton and Heavy Ion Center · Not applicable, Interventional, and Treatment
Breast-conserving surgery (BCS) followed by whole-breast irradiation (WBI) remains the standard therapeutic approach for early-stage breast cancer. Long-term follow-up data from the FAST trial (10-year analysis) demonstrated that the 28.5 Gy/5-fraction regimen exhibited comparable adverse effects to the conventional 50 Gy/25-fraction regimen, with no statistically significant differences in photographic cosmetic assessments at 2 and 5 years post-treatment. The FAST-Forward trial demonstrated comparable 5-year ipsilateral breast tumor recurrence rates (IBTR) and incidence of radiation-related toxicities between ultra-hypofractionated whole-breast irradiation (UH-WBI; 26 Gy in 5 fractions over 1 week) and moderately hypofractionated whole-breast irradiation (MH-WBI; 40 Gy in 15 fractions over 3 weeks). Additionally, no statistically significant difference in cosmetic outcomes was observed between the two regimens at the 2-year follow-up.
Proton radiotherapy enables precise dose delivery to tumor targets while minimizing radiation exposure to surrounding normal tissues, thereby reducing treatment-related toxicities. However, current clinical protocols predominantly employ conventional fractionation for proton therapy, with a paucity of robust evidence evaluating the efficacy and safety of ultra-hypofractionated proton radiotherapy in breast cancer patients. This prospective randomized controlled trial aims to establish high-level scientific evidence for the clinical application of ultra-hypofractionated proton radiotherapy following BCS, ensuring non-inferiority in oncologic control, toxicity profiles, and cosmetic preservation compared to standard regimens.
Exclusion Criteria:
Whole Breast Irradiation, at 40 Gy(RBE) in 15 fractions, tumor bed SIB to 48Gy(RBE)
Radiation: moderate hypofractionated proton radiotherapy
Whole breast radiotherapy, 26 Gy(RBE) in 5 fractions，tumor bed boost with 10Gy(RBE) in 2 fractions.
Radiation: ultra-hypofractionated proton radiotherapy
moderate hypofractionated proton radiotherapy: Whole Breast Irradiation, at 40 Gy(RBE) in 15 fractions, tumor bed SIB to 48Gy(RBE)
Ultra-hypofractionated proton radiotherapy:Whole breast radiotherapy, 26 Gy(RBE) in 5 fractions，tumor bed boost with 10Gy(RBE) in 2 fractions.
Cosmetic Outcomes
Cosmetic outcomes will be assessed at 2 years after radiotherapy. Changes in breast appearance compared to baseline will be evaluated using the Breast Cancer Treatment Outcome Scale (BCTOS), independently completed by the patient, the treating physician, and a trained research assistant at each follow-up visit. Standardized photographs of the treated breast will be taken at each assessment time point and analyzed using BCCT.core software for objective cosmetic scoring.
Time frame: 2 years
Acute and late toxicities
Acute radiation-induced toxicities will be assessed from the start of radiotherapy to three months after its completion. Evaluations will be performed weekly during radiotherapy and at 1 and 3 months after treatment. Late radiation-induced toxicities will be assessed every 3 months for first 2 years, every 6 months from the 3rd to the 4th year, and annually thereafter. The toxicities will be graded using Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 and radiation Therapy Oncology Group (RTOG) and the European Organization for Research and Treatment of Cancer (EORTC).
Time frame: 5 years
Locoregional recurrence (LRR)
Any first recurrence confirmed by histology or cytology within the ipsilateral breast and/or regional nodes area (including supraclavicular, infraclavicular, axillary, or internal mammary lymph nodes)
Time frame: 5 years
Disease-free survival (DFS)
The duration from the date of enrollment to the first occurrence of local recurrence, distant metastases, tumor-related death, death without prior progression, or end of follow-up.
Time frame: 5 years
Overall survival (OS)
The duration from the date of enrollment to the date of death from any cause or the last follow-up.
Time frame: 5 years
Quality of Life, as measured by EORTC QLQ-BR23 questionnaire
To compare quality of life at 1 year after radiotherapy measured by the EORTC QLQ-BR45. Raw scores are linearly converted to a 0-100 scale with higher symptom scales reflecting increased levels of symptom burden.
Time frame: 1 years
Plan to share: Undecided
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Shanghai Proton and Heavy Ion Center