Rubina Manuela Trimboli, Abstract Co-Author: Nothing to Disclose

Gianni Di Leo, Presenter: Nothing to Disclose

Barbara Jereczek-Fossa MD, Abstract Co-Author: Nothing to Disclose

Alessandro Poloni, Abstract Co-Author: Nothing to Disclose

Ileana Ioan, Abstract Co-Author: Nothing to Disclose

Francesco Sardanelli MD, Abstract Co-Author: Speakers Bureau, Bracco Group Research Grant, Bracco Group Speakers Bureau, Bayer AG Research Grant, Bayer AG Research Grant, IMS International Medical Scientific

There is no consensus regarding magnetic resonance imaging (MRI) when selecting patients for partial breast irradiation (PBI). This meta-analysis examines the effect of pre-treatment MRI on eligibility of women initially candidate for PBI on the basis of conventional imaging, mammography and US.

A literature cross-referencing search, limited to articles written in English with no time limits, was performed on MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews. Heterogeneity (I2) was evaluated using the Cochrane Q statistics: P-value <.100 were considered significant. Using random-effects model, we estimated the pooled proportion of women deemed not eligible for PBI given the MRI results. We also investigated the association between pre-treatment variables and ineligibility for PBI, reported as odds ratio.  

Ninety-three citations were initially retrieved and finally 7 studies including 3369 cases met the eligibility criteria and entered the analysis. Heterogeneity was low, overall and for all subgroup analyses (I2<40%). 245/1432 women were found to be ineligible for PBI with a pooled overall ineligibility rate of 14% (95%CI 8‒23%); invasive lobular carcinomas had a higher rate of ineligibility than invasive ductal carcinomas (OR 2.16; 95%CI 1.36‒3.44) while rate of ineligibility was lower for DCIS (OR 0.64; 95%CI 0.42‒0.97). Preoperative variables significantly associated to ineligibility for PBI included pT stage ≥2 (OR 7.0), premenopausal status (OR 2.7), palpable lesions (OR 2.2), Her2 amplification (OR 1.6), first degree relative with a history of breast cancer (OR 1.4) and dense breasts (OR 1.2).  

This meta-analysis supports the evidence that breast MRI alters the PBI recommendations for 14% of women candidate based on standard assessment, with higher rates for invasive lobular carcinomas. Factors associated with ineligibility were found to be pT stage ≥2, premenopausal status, palpable lesions, Her2 amplification, first degree relative with a history of breast cancer and dense breasts.

Women who are candidate for PBI on the basis of conventional imaging should undergo a pre-treatment MRI, revealing 14% to be not eligible to. This is especially true for women with invasive lobular carcinoma, pT stage ≥2, premenopausal status, palpable lesions, Her2 amplification, first degree relative with a history of breast cancer and dense breasts.

Trimboli, R, Di Leo, G, Jereczek-Fossa, B, Poloni, A, Ioan, I, Sardanelli, F, The Role of Magnetic Resonance Imaging (MRI) in Selecting Patients Candidate for Partial Breast Irradiation (PBI). A Meta-analysis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14018801.html