An interventional study of Intraoperative Radiation Therapy and Laboratory Biomarker Analysis in Stage IA Breast Cancer and Stage IIA Breast Cancer, sponsored by University of California, San Francisco. Active, not recruiting at 25 sites in United States. Open to female participants aged 45 Years and older. Per ClinicalTrials.gov, last updated 2026-03-18.
Sponsored by University of California, San Francisco · Not applicable, Interventional, and Treatment
This phase IV trial studies the side effects of intraoperative radiation therapy and how well it works in treating patients with breast cancer undergoing breast-conserving surgery. Delivering radiation one time to the area where the tumor was removed while the patient is still in the operating room may kill any residual tumor cells and may be as effective as standard radiation therapy in patients with early stage breast cancer.
PRIMARY OBJECTIVES:
I. To establish eligibility criteria based on previously published trials and studies in order to allow women who meet these criteria to receive intraoperative radiation therapy (IORT) on an Institutional Review Board (IRB)-approved protocol.
II. To systematically collect and assess acute and long-term toxicity and outcomes in larger cohort of patients.
III. To study the efficacy and toxicity of breast radiotherapy given intra-operatively as a single fraction after breast conserving surgery, with or without whole breast radiation, as indicated by pathologic risk factors, in women with early stage breast cancer.
IV. In-breast local failure and patterns of in-breast failure. V. Ipsilateral regional nodal failure. VI. Toxicity and morbidity. VII. Relapse-free survival. VIII. Overall survival.
OUTLINE:
Patients undergo IORT in a single fraction over 15-40 minutes at the time of standard of care lumpectomy.
After completion of study treatment, patients are followed up within 6 weeks and then every 6 months for 3 years and yearly for 2 years.
12,544 studies on the registry are indexed under Breast Neoplasms; 2,892 are open to participants now.
This study's enrollment of 1,259 is above the median of 72 across 9,303 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →University of California, San Francisco is the lead sponsor of 2,132 studies on the registry; 375 are open to participants now.
Of its 262 completed or terminated interventional studies of FDA-regulated products, 196 (75%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Additional exclusion criteria for University of California San Francisco (UCSF) (as laid out in the Treatment Policy):
Patients undergo IORT in a single fraction over 15-40 minutes at the time of standard of care lumpectomy.
Radiation: Intraoperative Radiation Therapy · Other: Laboratory Biomarker Analysis
Undergo IORT
Also known as: Intraoperative Radiotherapy, IORT, radiotherapy, intraoperative
Correlative studies
Incidence of local recurrence
Local tumor control is defined as no recurrent tumor in the ipsilateral breast. Patients will be regularly monitored as per the individual center's policy provided this meets the minimum trial criteria for follow-up with physical examination at least every 6 months for 3 years and yearly at 4 and 5 years post-treatment. Confirmation of recurrence will follow clinical examination and cytology or biopsy. The two patient cohorts will not be separated for the analysis regarding local control.
Time frame: Up to 5 years
Frequency of site of relapse within the breast
Site of relapse within the breast will be recorded in order to assess whether the recurrence is at the site of initial tumor or at a new site and whether it has occurred within the treated field (IORT).
Time frame: Up to 5 years
Percentage of participants with treatment-related adverse events
Local toxicity and morbidity will be recorded as adverse events related to the primary treatment of the breast cancer. These were recorded in the randomized trial and outcomes showed no significant difference in clinical complications for the IORT as compared to standard external beam radiation. However, all expected toxicities of hematoma, seroma, wound infection, wound breakdown and delayed wound healing will be assessed according to Radiation Therapy Oncology Group (RTOG) criteria. Late skin reactions, rash, telangiectasia and pain due to radiation and all other toxicities will be recorded and graded according to standard NCI-CTCAE V. 4 criteria
Time frame: Up to 5 years
Median Relapse-free survival
Relapse-free survival will be recorded as the time interval between trial entry and the date of confirmation of any recurrence. The actual date to be used is the clinic day on which the investigations that led to a confirmed diagnosis of the recurrence were requested. Relapse-free survival would include any recurrence of breast cancer (local, regional or distant) or death without prior report a relapse. All patients will be analyzed under an "Intent to Treat" policy
Time frame: Up to 5 years
Median Overall Survival
Overall survival will be the time interval between enrollment and death.
Time frame: Up to 5 years
Documents are hosted by the registry — open the source record to download them.
Plan to share: No
This study is active, not recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
Get 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.
University of California, San Francisco