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Updated: Apr 11, 2026
Clinical Imaging of Microwave Mammography
Published on: November 14, 2025
MR Imaging for Selection of Patients for Partial Breast Irradiation: A Systematic Review and Meta-Analysis
Giovanni Di Leo1, Rubina Manuela Trimboli1, Adrienn Benedek1
1From the Radiology Unit, IRCCS Policlinico San Donato, via Morandi 30, 20097 San Donato Milanese, Italy (G.D.L., R.M.T., A.B., L.A.C., F.S.); Department of Radiation Oncology, European Institute of Oncology, Università degli Studi di Milano, Milan, Italy (B.A.J.F., P.F., M.C.L., R.O.); CNAO, Pavia, Italy (P.F., R.O.); and Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy (F.S.).
Purpose:
To systematically review articles that estimated the ineligibility for partial breast irradiation (PBI) after magnetic resonance (MR) imaging.
Materials And Methods:
No ethics committee approval was needed. A systematic search was performed by using MEDLINE and EMBASE. The rate of patients eligible at standard assessment (ie, clinical examination, mammography, and/or ultrasonography) but ineligible after MR imaging was a study outcome. Odds ratios (ORs) were calculated to identify predictors. Quality was appraised by using the Strengthening Reporting of Observational Studies in Epidemiology checklist.
Results:
Of 93 retrieved articles, six were included (total, 3136 patients). For PBI eligibility, all studies applied National Surgical Adjuvant Breast and Bowel Project B-39 criteria. Ineligibility at standard assessment varied from 21% to 80%; MR imaging prompted ineligibility for PBI in 6%-25% of patients who were initially deemed eligible or in 2%-20% if calculated on the overall number of patients initially screened. Meta-regression showed a negative correlation between ineligibility at standard assessment and ineligibility after MR imaging (P < .001). The pooled percentage of patients eligible at standard assessment but ineligible after MR imaging was 11% (95% confidence interval [CI]: 6%, 19%). Predictors for ineligibility after MR imaging were cancers stage pT2 or greater versus less than stage pT2 (OR, 8.8 [95% CI: 4.7, 16.7]; P < .001), invasive lobular histopathologic results versus invasive ductal pathologic results (OR, 3.0 [95% CI: 1.6, 6.6]; P = .007), pre- versus postmenopausal status (OR, 1.9 [95% CI: 1.3, 2.6]; P < .001), invasive cancer versus ductal carcinoma in situ (OR, 1.6 [95% CI: 1.0, 2.4]; P = .031). Study quality ranged from 17 to 20 (maximum quality, 22). The risk of publication bias was moderate.
Conclusion:
One of nine women (11%), who on the sole basis of standard assessment were candidates to undergo PBI, was found to be ineligible after undergoing MR imaging. Breast MR imaging should be used to select patients for PBI.
Insights
Magnetic resonance (MR) imaging identifies women ineligible for partial breast irradiation (PBI) who initially seemed candidates. Breast MR imaging is crucial for accurate PBI patient selection.
Area of Science:
- Oncology
- Radiology
- Surgical Oncology
Background:
- Partial breast irradiation (PBI) is a treatment option for early-stage breast cancer.
- Patient selection is critical for PBI efficacy and safety.
- Magnetic resonance (MR) imaging may reveal findings not detected by standard assessments, impacting PBI eligibility.
Purpose of the Study:
- To systematically review studies evaluating patient ineligibility for PBI after MR imaging.
- To determine the rate of patients initially eligible but later deemed ineligible for PBI based on MR imaging findings.
Main Methods:
- A systematic literature search was conducted using MEDLINE and EMBASE.
- Studies estimating the rate of ineligibility for PBI after MR imaging were included.
- Predictors of ineligibility were identified using meta-regression analysis.
Main Results:
- Eleven percent (95% CI: 6%, 19%) of patients eligible by standard assessment were found ineligible for PBI after MR imaging.
- Predictors of ineligibility included larger tumor size (pT2+), invasive lobular histology, and premenopausal status.
- MR imaging prompted ineligibility in 6%-25% of initially eligible patients.
Conclusions:
- A significant proportion of patients initially considered candidates for PBI become ineligible after MR imaging.
- Breast MR imaging plays a vital role in refining patient selection for PBI.
- Utilizing MR imaging improves the accuracy of identifying suitable candidates for PBI.
