A dosimetric comparison of MammoSite and ClearPath high-dose-rate breast brachytherapy devices

Abstract Purpose A new form of partial breast irradiation (PBI), ClearPath (CP) breast brachytherapy, has been introduced. We present our results of a dosimetric comparison of MammoSite ® (MS) and CP PBI. Methods and Materials The dimensions of the CP device were reconstructed onto the MS planning CT scans for 15 previously treated patients. The mean % V 100 , % V 150 , % V 200 (percent of the PTV that received 100%, 150%, and 200% of the prescription dose, respectively), ipsilateral breast % V 50 (percent of the ipsilateral normal breast that received 50% of the prescription dose), ipsilateral lung % V 30 (percent of the ipsilateral lung that received 30% of the prescription dose), the heart % V 5 (percent of the heart that received 5% of the prescription dose), and the maximum skin point dose per fraction were then determined for each patient using the two methods of balloon-based PBI. Results The mean % V 100 was 96.5% vs. 96.5%, the mean % V 150 was 42.1% vs. 42.9% ( p  = ns), and the mean V 200 was 11.4% vs. 15.2% ( p V 50 was 19.8% vs.18.0% ( p V 30 was 3.7% vs. 2.8% ( p V 5 was 57.0% vs. 54.3% ( p p Conclusions The MS and CP methods of PBI offer comparable target volume coverage; however, the CP device achieves increased normal tissue sparing.