Raj Selvaraj MS, Presenter: Nothing to Disclose

Ajay Bhatnagar MD, Abstract Co-Author: Nothing to Disclose

Debbie Sonnik, Abstract Co-Author: Nothing to Disclose

Edward Brandner, Abstract Co-Author: Nothing to Disclose

Robert Surgent, Abstract Co-Author: Nothing to Disclose

Robert Mogus, Abstract Co-Author: Nothing to Disclose

Melvin Deutsch MD, Abstract Co-Author: Nothing to Disclose

Kristina Gerszten, Abstract Co-Author: Nothing to Disclose

Cheng B Saw, Abstract Co-Author: Nothing to Disclose

Andrew Wu, Abstract Co-Author: Nothing to Disclose

Shalom Kalnicki, Abstract Co-Author: Nothing to Disclose

Dwight E Heron, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Purpose/Objective: To determine the dose received by the skin during breast irradiation using balloon catheter-based high dose rate (HDR) brachytherapy compared to Intensity Modulated Radiation Therapy (IMRT) and conventional radiation techniques. Materials/Methods: Between June 2002 and January 2004 at University of Pittsburgh Cancer Institute, 39 patients with early stage breast cancer (15 with left breast cancer) underwent a lumpectomy followed by high dose rate brachytherapy using the MammoSite® (Proxima Therapeutics, Inc.) applicator. Between March 2003 and January 2004, 65 patients with breast carcinoma were treated using 6, 10, or mixed 6/18MV photons (52 with tangential IMRT and 13 with 2-dimensional techniques using tangential fields with wedges) to the primary breast irradiation following breast conserving surgery. Paired thermoluminescent dosimeters (TLDs) were placed on each patient’s skin just above the balloon catheter for MammoSite®) and 4cm inside the treatment borders for IMRT and 2D. The TLDs were left on the patient during a single fraction of radiation and then measured 24 hours afterwards using the Harshaw model 5500 TLD reader (Thermo Electron Corporation, Santa Fe, New Mexico). The paired TLDs were averaged for each patient. Using SPSS software, a two tailed T-test was used to compare the skin dose for patients treated with MammoSite® versus IMRT and conventional 2D techniques. Results: The dose delivered with MammoSite® was 3400cGy in 10 fractions given BID whereas the dose with IMRT and 2D was 5000cGy in 25 fractions. The mean percent of the prescribed dose to skin was 57.55% (SD=21.4) for the patients treated with MammoSite®, 69.05 (SD=6.7) for patients treated with IMRT and 70.73% (SD=5.9) for the patients treated with conventional 2D techniques. This represented a 16.7% reduction in the mean dose to the skin using mammoSite® compared to IMRT and 18.6% reduction compared to conventional 2D. The reductions were statistically significant (p<0.001). Conclusions: This preliminary study suggests that patients treated for breast cancer with MammoSite® technique significantly reduces the dose to the skin compared to IMRT and 2D standard radiation techniques.

Selvaraj, R, Bhatnagar, A, Sonnik, D, Brandner, E, Surgent, R, Mogus, R, Deutsch, M, Gerszten, K, Saw, C, Wu, A, Kalnicki, S, Heron, D, et al, , Balloon Catheter-based High-Dose Rate (HDR) Breast Brachytherapy Reduces the Dose to the Skin When Compared to Intensity Modulated Radiation Therapy (IMRT) and Conventional Tangential Field for Breast Irradiation.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4417905.html