Breast CancerPhase 2MAPBINCT03936478
Real-Time MRI-Guided 3-Fraction Accelerated Partial Breast Irradiation in Early Breast Cancer
A Phase 2 study testing MRIdian Radiation Treatment Unit in people with Breast Cancer and DCIS, run by University of Wisconsin, Madison at 1 site in United States.
Trial summary
This trial will investigate a novel 3-fraction radiation regimen for participants undergoing breast-conserving therapy (BCT) for early breast cancer that will: 1) significantly reduce the duration of treatment and can be completed in one-week (5 working days) and 2) MRI-guided radiotherapy (MRIdian) would limit the… Read more about this study
- Who is it for?
- Ages 40 years and older, women only
- Conditions the study is for
- Breast Cancer, DCIS, LCIS
- What is being tested?
- MRIdian Radiation Treatment Unit
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 16 May 2022to Jan 2031
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- For all participants
- Participants should have no contraindications to undergo MRI scan as part of radiotherapy planning and treatment.
- Lumpectomy cavity must be clearly visible on CT and MRI scan at radiotherapy simulation.
- Pregnancy test negative in women of child bearing potential (WOCBP).
- The participant must consent to be in the study and must have signed an approved consent form conforming with institutional guidelines.
- Participants with a history of non-breast malignancies are eligible if they have been disease-free for 5 or more years prior and are deemed by their physician to be at low risk for recurrence. Participants with the following cancers are eligible if diagnosed and treated within the past 5 years: carcinoma in situ of the cervix, carcinoma in situ of the colon, melanoma in situ, and basal cell and squamous cell carcinoma of the skin.
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- For participants with Invasive Carcinoma
- Suitable:
- Age: >=50 years
- Margins: Negative by at least 2 mm
- T Stage: Tis or T1
- Cautionary:
- Age: 40-49 years
- Margins: Negative by at least 2 mm
- T Stage: Tis or T1 OR
- Age: >=50 years IF participant has at least 1 of the pathologic factors below and does not have any "unsuitable" factors (below)
- Pathologic Factors:
- Size 2.1-3.0 cm (size of the invasive component)
- T2
- Close margins (<2 mm)
- Limited/focal Lymphovascular Space Invasion (LVSI)
- ER (-)
- Clinically unifocal with total size 2.1-3.0 cm (Microscopic multifocality allowed, provided the lesion is clinically unifocal (a single discrete lesion by physical examination and ultrasonography/mammography) and the total lesion size (including foci of multifocality and intervening normal breast parenchyma) falls between 2.1 and 3.0 cm).
- Invasive lobular histology
- Extensive Intraductal Component (EIC) <=3 cm
- For participants with DCIS
- Suitable Criteria, DCIS allowed if all of the following are met:
- Screen-detected
- Low to intermediate nuclear grade
- Size <=2.5 cm
- Resected with margins negative at >=3mm OR
- Cautionary Criteria:
- Pure DCIS <=3 cm if "suitable" criteria not fully met
Who cannot join
- Men are not eligible for this study.
- BRCA1/2 mutation positivity.
- Age < 40 years (American Society for Radiation Oncology (ASTRO) Unsuitable Criteria).
- Positive resection margins on post operative pathology(ASTRO Unsuitable Criteria).
- Palpable or radiographically suspicious ipsilateral or contralateral axillary, supraclavicular, infraclavicular, or internal mammary nodes, unless there is histologic confirmation that these nodes are negative for tumor.
- Suspicious micro calcifications, densities, or palpable abnormalities (in the ipsilateral or contralateral breast) unless biopsied and found to be benign.
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- Non-epithelial breast malignancies such as sarcoma or lymphoma.
- Proven multicentric carcinoma (invasive cancer or DCIS) (ASTRO Unsuitable Criteria).
- Pure DCIS >3 cm in size (ASTRO Unsuitable Criteria).
- Presence of extensive intraductal component >30mm (ASTRO Unsuitable Criteria).
- Paget's disease of the nipple.
- History of previous invasive breast cancer, DCIS, synchronous bilateral invasive or non-invasive breast cancer. (Participants with a history of LCIS treated by surgery alone are eligible.)
- Surgical margins that cannot be microscopically assessed or are positive at pathologic evaluation.
- Concurrent therapy with any hormonal agents such as raloxifene (Evista®), tamoxifen, Aromatase Inhibitors or other selective estrogen receptor modulators (SERMs), either for osteoporosis or breast cancer prevention or neoadjuvant therapy.
- Breast implants.
- Prior breast or thoracic radiotherapy for any condition or treatment plan that includes regional nodal irradiation.
- Collagen vascular disease, specifically dermatomyositis with a creatinine phosphokinase level above normal or with an active skin rash, systemic lupus erythematosus, or scleroderma.
- Pregnancy or lactation at the time of treatment. Women of reproductive potential must agree to use an effective non-hormonal method of contraception during therapy.
- Psychiatric or addictive disorders or other conditions that, in the opinion of the investigator, would preclude the participant from meeting the study requirements.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Wisconsin Carbone Cancer Center
Madison, Wisconsin, 53705
Cancer Connect, 800-622-8922, clinicaltrials@cancer.wisc.edu
Bethany Anderson, MD
About this study
Official title: A Phase II Study of Real-Time MRI-Guided 3-Fraction Accelerated Partial Breast Irradiation in Early Breast Cancer (MAPBI)
This trial will investigate a novel 3-fraction radiation regimen for participants undergoing breast-conserving therapy (BCT) for early breast cancer that will: 1) significantly reduce the duration of treatment and can be completed in one-week (5 working days) and 2) MRI-guided radiotherapy (MRIdian) would limit the volume of normal tissue radiated and therefore resultant toxicity. The hypothesis is that 3-fraction radiation therapy can be delivered safely without compromising the therapeutic ratio. Participants can expect to be on study for follow up up to 5 years.
- Conditions
- Breast Cancer, DCIS, LCIS
- Being tested
- MRIdian Radiation Treatment Unit
- Keywords
- cosmesis, cosmetic, breast-conserving therapy
- Medical subject headings
- Breast Neoplasms, Carcinoma, Intraductal, Noninfiltrating
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MRIdian Radiation Treatment UnitRadiation
partial breast irradiation using 3 x 8.2 Gy to the lumpectomy cavity with a 3mm planning tumor volume (PTV) margin
| Study group | Role | What they receive |
|---|---|---|
| 8.2 Gy Radiation Therapy | Experimental | Accelerated partial breast irradiation using 3 x 8.2 Gy to the lumpectomy cavity with a 3mm PTV margin. Treatment duration will be 5-6 days and treatments will be on alternative weekdays, with a minimum interval of 40 hours between subsequent fractions. Receives: Radiation: MRIdian Radiation Treatment Unit |
What is being measured
The primary outcome is the main question the study is designed to answer.
Physician Reported Cosmesis: 1-year
The Harvard Cosmesis Scale will be used to report cosmesis at 1 year post treatment. The physician will report how the breast looks relative to original appearance or untreated breast (excellent, good, fair, poor). The physician answers 9 questions on a scale of 0-2 where 0 is none, 1 is present but does not affect cosmesis, 2 is present and affects cosmesis. Scoring is objective with lower scores indicating improved conditions.
Measured: up to 1-year
Secondary outcomes (11)
Participant Quality of Life: BCTOS Survey
Participant Quality of Life will be assessed prior to starting treatment, at end of radiotherapy (RT), 4 weeks post RT, 6 months post RT, 12 months post RT and yearly through 5 years by collecting measures from three scales.The Breast Cancer Treatment Outcomes Scale (BCTOS) is a 22-item scale scored 1-4 where 1 is none, 2 is slight, 3 is moderate, and 4 is large. Total score ranges from 22-88 where lower scores indicated better outcomes.
Measured: up to 5 years
Participant Quality of Life: Convenience of Care Scale
Participant Quality of Life will be assessed prior to starting treatment, at end of radiotherapy (RT), 4 weeks post RT, 6 months post RT, 12 months post RT and yearly through 5 years by collecting measures from three scales. The Convenience of Care scale is an 8-item scale scored 0 (not at all) to 10 (a lot). The total score ranges from 0-80 where lower scores indicate less disruptive interventions.
Measured: up to 5 years
Participant Quality of Life: MOS SF-36 Survey
Participant Quality of Life will be assessed prior to starting treatment, at end of radiotherapy (RT), 4 weeks post RT, 6 months post RT, 12 months post RT and yearly through 5 years by collecting measures from three scales.The Medical Outcomes Study Short Form - 36 (MOS SF-36) Vitality scale measures how a participant has felt in the last 4 weeks. 4-items are scored from 1-5 where 1 is all of the time and 5 is none of the time. 4-items are scored from 0 (no pain) to 10 (pain as bad as you can imagine). Total score ranges from 4-60 where lower scores indicate increased vitality.
Measured: up to 5 years
Physician Reported Cosmesis: 3-year
The Harvard Cosmesis Scale will be used to report cosmesis at 1 year post treatment. The physician will report how the breast looks relative to original appearance or untreated breast (excellent, good, fair, poor). The physician answers 9 questions on a scale of 0-2 where 0 is none, 1 is present but does not affect cosmesis, 2 is present and affects cosmesis. Scoring is objective with lower scores indicating improved conditions.
Measured: up to 3 years
Physician Evaluated Fat Necrosis
Fat necrosis will be assessed prior to treatment, at 6 months post RT, at 12 months post RT, and yearly through 5 years, graded as follows: Grade 0 is no fat necrosis, Grade 1 is Asymptomatic fat necrosis (only radiologic and/or cytologic findings), Grade 2 is Symptomatic fat necrosis not requiring medication (palpable mass with or without mild pain), Grade 3 is Symptomatic fat necrosis requiring medication (palpable mass with significant pain), Grade 4 is Symptomatic fat necrosis requiring surgical intervention.
Measured: up to 5 years
Acute Radiation Toxicity
The NCI's Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 will be used to identify the type and to grade the severity of acute toxicities. Acute toxicities will be scored from the start of radiation to 90 days after completion of radiotherapy and late toxicities will be scored > 90 days from completion of radiation therapy.
Measured: up to 90 days from completion of radiation therapy
Late Radiation Toxicity
The NCI's Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 will be used to identify the type and to grade the severity of late toxicities.
Measured: up to 5 years
Ipsilateral Breast Tumor Recurrence (IBTR)
Defined as evidence of invasive or in situ breast cancer (except LCIS) in the ipsilateral breast. Participants who develop clinical evidence of tumor recurrence in the remainder of the ipsilateral breast must have a biopsy of the suspicious lesion to confirm the diagnosis with documentation of the location.
Measured: up to 5 years
Ipsilateral Regional Nodal Recurrence
Defined as the development of tumor in the ipsilateral internal mammary, ipsilateral supraclavicular, ipsilateral infraclavicular and/or ipsilateral axillary nodes, as well as the soft tissue of the ipsilateral axilla, after operation.
Measured: up to 5 years
Disease Free Survival (DFS)
Disease free survival (DFS) defined as the time from start of radiation to the time of documented recurrent disease in the ipsilateral breast or regional nodes (supraclavicular, axillary or internal mammary) or distant sites (e.g. bone, liver, lung or brain).
Measured: up to 5 years
Overall Survival (OS)
Overall survival (OS) defined as the time from start of radiation to death from any cause.
Measured: up to 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 May 2019
- Study start16 May 2022
- Primary completionJan 2027 (estimated)
- Study completionJan 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- More trials run by University of Wisconsin, MadisonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This study will have a lead-in phase consisting of 10 patients, followed for 6-months from the date of completion of radiotherapy for the tenth patient. The second phase of accrual (20 patients) will commence only if three or fewer patients (3/10=30%) have CTCAE v 5.0 grade 3 or higher skin toxicity (radiation dermatitis) or Lövey et al. grade 3 or higher fat necrosis.
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Wisconsin, Madison
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Bethany Anderson, MD, Principal investigator, University of Wisconsin, Madison
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03936478
- Sponsor's protocol ID
- 2019-0322
- Other IDs
- NCI-2019-03111, UW18099, SMPH\HUMAN ONCO\HUMAN ONCO, A533300, Protocol Version 5/24/2024
- Acronym
- MAPBI
- Status last verified
- Jun 2026
- First submitted
- 1 May 2019
- Last updated
- 11 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase II Study of Real-Time MRI-Guided 3-Fraction Accelerated Partial Breast Irradiation in Early Breast Cancer (MAPBI)
- ClinicalTrials.gov ID
- NCT03936478
- Acronym / sponsor ID
- MAPBI / 2019-0322
- Conditions
- Breast Cancer, DCIS, LCIS
- Keywords
- cosmesis, cosmetic, breast-conserving therapy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- University of Wisconsin, MadisonUniversity, hospital or other
- Study start
- 16 May 2022 (actual)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- Jan 2031 (estimated)
- First posted
- 3 May 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This trial will investigate a novel 3-fraction radiation regimen for participants undergoing breast-conserving therapy (BCT) for early breast cancer that will: 1) significantly reduce the duration of treatment and can be completed in one-week (5 working days) and 2) MRI-guided radiotherapy (MRIdian) would limit the volume of normal tissue radiated and therefore resultant toxicity. The hypothesis is that 3-fraction radiation therapy can be delivered safely without compromising the therapeutic ratio. Participants can expect to be on study for follow up up to 5 years.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This study will have a lead-in phase consisting of 10 patients, followed for 6-months from the date of completion of radiotherapy for the tenth patient. The second phase of accrual (20 patients) will commence only if three or fewer patients (3/10=30%) have CTCAE v 5.0 grade 3 or higher skin toxicity (radiation dermatitis) or Lövey et al. grade 3 or higher fat necrosis.
| Arm | Type | Receives |
|---|---|---|
| 8.2 Gy Radiation Therapy | Experimental | Radiation: MRIdian Radiation Treatment UnitAccelerated partial breast irradiation using 3 x 8.2 Gy to the lumpectomy cavity with a 3mm PTV margin. Treatment duration will be 5-6 days and treatments will be on alternative weekdays, with a minimum interval of 40 hours between subsequent fractions. |
Who may qualify
- Ages
- 40 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (33 listed)
- For all participants
- Participants should have no contraindications to undergo MRI scan as part of radiotherapy planning and treatment.
- Lumpectomy cavity must be clearly visible on CT and MRI scan at radiotherapy simulation.
- Pregnancy test negative in women of child bearing potential (WOCBP).
- The participant must consent to be in the study and must have signed an approved consent form conforming with institutional guidelines.
Key exclusion criteria (19 listed)
- Men are not eligible for this study.
- BRCA1/2 mutation positivity.
- Age < 40 years (American Society for Radiation Oncology (ASTRO) Unsuitable Criteria).
- Positive resection margins on post operative pathology(ASTRO Unsuitable Criteria).
- Palpable or radiographically suspicious ipsilateral or contralateral axillary, supraclavicular, infraclavicular, or internal mammary nodes, unless there is histologic confirmation that these nodes are negative for tumor.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MRIdian Radiation Treatment Unitpartial breast irradiation using 3 x 8.2 Gy to the lumpectomy cavity with a 3mm planning tumor volume (PTV) margin | Radiation | 8.2 Gy Radiation Therapy |
Primary outcome
Physician Reported Cosmesis: 1-year
Time frame: up to 1-year
The Harvard Cosmesis Scale will be used to report cosmesis at 1 year post treatment. The physician will report how the breast looks relative to original appearance or untreated breast (excellent, good, fair, poor). The physician answers 9 questions on a scale of 0-2 where 0 is none, 1 is present but does not affect cosmesis, 2 is present and affects cosmesis. Scoring is objective with lower scores indicating improved conditions.
11 secondary outcomes
Participant Quality of Life: BCTOS Survey
Time frame: up to 5 years
Participant Quality of Life: Convenience of Care Scale
Time frame: up to 5 years
Participant Quality of Life: MOS SF-36 Survey
Time frame: up to 5 years
Physician Reported Cosmesis: 3-year
Time frame: up to 3 years
Physician Evaluated Fat Necrosis
Time frame: up to 5 years
Acute Radiation Toxicity
Time frame: up to 90 days from completion of radiation therapy
Late Radiation Toxicity
Time frame: up to 5 years
Ipsilateral Breast Tumor Recurrence (IBTR)
Time frame: up to 5 years
Ipsilateral Regional Nodal Recurrence
Time frame: up to 5 years
Disease Free Survival (DFS)
Time frame: up to 5 years
Overall Survival (OS)
Time frame: up to 5 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Bethany Anderson, MD principal investigator
University of Wisconsin, Madison
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing MRIdian Radiation Treatment Unit in people with Breast Cancer and DCIS, run by University of Wisconsin, Madison at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 33 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Cancer Connect (800-622-8922, clinicaltrials@cancer.wisc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Physician Reported Cosmesis: 1-year (time frame: up to 1-year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jun 2026; AzTrials last refreshed its copy on 6 Nov 2026.