Actively Recruiting
A Randomized Trial of Five-Fraction Partial Breast Irradiation (RAPID2)
Led by Ontario Clinical Oncology Group (OCOG) · Updated on 2026-05-22
910
Participants Needed
29
Research Sites
104 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating two radiation treatment methods for women with small, node-negative invasive breast cancer who have undergone breast-conserving surgery. This randomized, single-blind trial compares partial breast irradiation (PBI) to whole breast irradiation (WBI) to see if PBI is not worse than WBI in preventing local recurrence and if it results in better cosmetic outcomes. The study focuses on women aged 50 and older with tumors 3 cm or smaller and no metastatic disease. Participants will be randomly assigned to receive either PBI or WBI, each delivering a total radiation dose of 26 Gy in 5 daily fractions over 5 to 7 days. Treatments are given once per day, and care is taken to keep patients unaware of which treatment they receive to avoid bias in cosmetic assessments. The trial includes careful planning of radiation fields and uses tumor size, estrogen receptor status, and clinical center as factors for group assignment. Throughout the study, participants will be followed for up to 5 years to monitor local cancer recurrence and evaluate cosmetic results as reported by patients at 3 and 5 years after treatment. Additional assessments include disease-free survival, overall survival, radiation side effects, quality of life, and clinical evaluations of cosmetic outcomes. Safety and treatment effects will be closely monitored through scheduled visits and questionnaires during this period.
CONDITIONS
Brief Title
A Randomized Trial of Five Fraction Partial Breast Irradiation (RAPID2)
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Female with a new histological diagnosis of invasive breast cancer without metastatic disease
- Treated by breast-conserving surgery with microscopically clear resection margins of 1 mm or no residual disease on re-excision
- Negative axillary lymph node involvement confirmed by biopsy, dissection, or clinical and ultrasound assessment
- Unifocal tumors 2 cm or smaller with certain hormone receptor and HER2 status planning for endocrine therapy
You will not qualify if you...
- Age younger than 50 years
- Known BRCA 1 or BRCA 2 positive status
- Tumor size larger than 3 cm on pathology
- Extensive intraductal component (EIC) exceeding 25% and extending beyond invasive tumor, except smaller tumors with combined size 3 cm or less
- Ductal carcinoma in situ (DCIS) component larger than 3 cm
- Lobular carcinoma only
- More than one primary tumor in different breast quadrants
- Synchronous or previous contralateral breast cancer (except DCIS or LCIS)
- History of non-breast cancer within 5 years except treated non-melanoma skin cancer or in-situ carcinoma
- Known pregnancy or currently breastfeeding
- Inability to localize tumor bed on CT planning
- Inability to plan for the experimental radiation technique
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 5 to 7 days
Participants receive radiation treatment with either partial breast irradiation (PBI) or whole breast irradiation (WBI) once per day.
5 to 7 visits (in-person, daily)
Duration - Up to 5 years
Participants are monitored for recurrence, survival, radiation toxicity, cosmesis, and quality of life after treatment.
Annual visits for up to 5 years, plus visits at 2 weeks, 3 months, 3 years, and 5 years post-treatment
Trial Site Locations
Total: 29 locations
1
GenesisCare Darlinghurst
Darlinghurst, New South Wales, Australia, 2010
Actively Recruiting
2
GenesisCare Hurstville
Hurstville, New South Wales, Australia, 2220
Actively Recruiting
3
GenesisCare Mater Hospital
North Sydney, New South Wales, Australia, 2060
Actively Recruiting
4
GenesisCare Bundaberg
Bundaberg, Queensland, Australia, 4670
Actively Recruiting
5
GenesisCare Southport
Southport, Queensland, Australia, 4215
Actively Recruiting
6
GenesisCare Tugun
Tugun, Queensland, Australia, 4224
Actively Recruiting
7
GenesisCare Hervey Bay
Urraween, Queensland, Australia, 4655
Actively Recruiting
8
GenesisCare St Andrew's
Adelaide, South Australia, Australia, 5000
Actively Recruiting
9
GenesisCare Bedford Park
Bedford Park, South Australia, Australia, 5042
Not Yet Recruiting
10
GenesisCare Wembley
Wembley, Washington, Australia, 6014
Actively Recruiting
11
GenesisCare Fiona Stanley Hospital
Murdoch, Western Austrailia, Australia, 6150
Actively Recruiting
12
GenesisCare Hollywood
Nedlands, Western Australia, Australia, 6009
Actively Recruiting
13
Arthur J. E. Child Comprehensive Cancer Centre-Clinical Research Unit
Calgary, Alberta, Canada
Actively Recruiting
14
BCCA-Vancouver Island Cancer Centre
Victoria, British Columbia, Canada
Not Yet Recruiting
15
QEII HSC - Nova Scotia Cancer Centre
Halifax, Nova Scotia, Canada
Actively Recruiting
16
Royal Victoria Regional Health Centre
Barrie, Ontario, Canada
Actively Recruiting
17
Juravinski Cancer Centre
Hamilton, Ontario, Canada
Actively Recruiting
18
London Regional Cancer Centre
London, Ontario, Canada
Actively Recruiting
19
Stronach (Southlake) Regional Health Centre
Newmarket, Ontario, Canada
Actively Recruiting
20
Algoma District Cancer Program
Sault Ste. Marie, Ontario, Canada
Actively Recruiting
21
Princess Margaret Hospital
Toronto, Ontario, Canada
Actively Recruiting
22
Toronto-Sunnybrook Health Sciences Centre - Odette Cancer Centre
Toronto, Ontario, Canada
Actively Recruiting
23
Windsor Regional Cancer Centre
Windsor, Ontario, Canada, N8W2X3
Actively Recruiting
24
CSSS Champlain - Charles LeMoyne
Greenfield Park, Quebec, Canada
Actively Recruiting
25
CHUM - Centre Hospitalier de L'Université de Montréal
Montreal, Quebec, Canada, H2L 4M1
Actively Recruiting
26
McGill University Health Centre
Montreal, Quebec, Canada
Actively Recruiting
27
CHUQ-Pavillon Hotel-Dieu de Quebec
Québec, Quebec, Canada
Actively Recruiting
28
Centre Intégré Universitaire de Santé et de Services Sociaux de la Mauricie-Centre-du-Québec (CIUSSS MCQ)
Trois-Rivières, Quebec, Canada, G8Z 3R9
Actively Recruiting
29
Saskatoon Cancer Centre
Saskatoon, Saskatchewan, Canada, S7N 4H4
Actively Recruiting
Research Team
S
Shelley Chambers, MA
E
Erin McGean
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here