A Contura catheter offers dosimetric advantages over a MammoSite catheter that increase the applicability of accelerated partial breast irradiation

Abstract 

Purpose

The purpose of this study was to determine whether a Contura catheter (SenoRx, Inc, Aliso Viejo, CA) can increase the applicability of accelerated partial breast irradiation.

Methods and Materials

One hundred eighty-two women with early stage breast carcinomas were treated with postlumpectomy brachytherapy using a Contura multilumen catheter (n=45) or a MammoSite single-lumen catheter (Cytyc Corp, Marlborough, MA) (n=137). Hypothetical MammoSite catheter treatment plans were created for the Contura patients. Treatment planning goals were to (1) avoid a radiation “hot spot” in the skin and (2) have only a small air/fluid pocket next to the balloon.

Results

The median followup was 16 months. Eighty-nine percent (40 of 45) of Contura plans satisfied both treatment planning goals vs. only 36% (16 of 45) of MammoSite plans (p<0.0001). A Contura catheter did not require explantation in 16% (7 of 45) of patients where balloon-to-skin spacing was only 3–6mm and 11% (5 of 45) of patients where there was an air/fluid pocket >10% of the planning target volume for plan evaluation (PTV_EVAL). A MammoSite catheter was explanted in 10% of cases where the minimum balloon-to-skin distance was <7mm and in 13% of cases where there was a large air/fluid pocket next to the balloon. Our incidence rates of acute toxicity with a Contura catheter were similar to those with a MammoSite catheter.

Conclusions

A Contura catheter provides important dosimetric advantages over a MammoSite catheter and does not require explantation in cases where balloon-to-skin spacing is only 3–6mm or an air/fluid pocket next to the balloon is >10% of PTV_EVAL.

Keywords: Contura, MammoSite, Accelerated, Partial, Breast, Irradiation