Program Information
Permanent Breast Seed Implant as Partial Breast Radiation Therapy for Early Stage Patients Using Yb-169
S Awan1*, M Shah2 , A S. Meigooni3 , (1) Mt. Carmel Regional Cancer Center, Pittsburg, KS,KU Medical Center, Kansas City, Kansas (2) NV-Comprehensive CC of Nevada, Henderson, NV, (3) 4Department of Radiation Therapy, Comprehensive Cancer centers of Nevada, Nevada, Las Vegas
Presentations
SU-I-GPD-T-28 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: Majority of women with breast cancer are diagnosed at an early stage due to mammography screening. Breast conserving surgery followed by adjuvant irradiation for local regional control is a treatment option. In this project we explored a technique of delivering partial breast irradiation using permanent breast seed implants (PBSI) using Yb-169 seeds.
Methods: Whole breast external beam radiation therapy achieves the best results but is inconvenient and carries risk of painful skin reactions. Patients with life expectancy of at least ten years with in situ ductal adenocarcinoma of the breast, Stage 0 or I with Tumor size < 2 cm can benefit from this treatment option. Ytterbium-169(Yb-169) radioactive seeds have been manufactured for possible application to brachytherapy. Ytterbium-169 emits photons with an average energy of 93 keV and decays with a half-life of 32 days. TG-43U1 recommended dosimetric parameters of Yb-169 sources were entered in VariSeedTM treatment planning system. Target volume was drawn 19.0cc and was extended to 1.0cm uniformly all around the tumor bed. A total of 36 seeds were placed inside the PTV volume of 72.0cc to deliver 45.0Gy to PTV.
Results: Excellent target coverage was achieved by using Yb-169 seeds. Target volume received 100% coverage whereas; PTV100 received 95.64% of Rx dose. Dose uniformity indicators, PTV150 and PTV200 were17.95% and 5.62% respectively indicating high uniformity implant achievability. Similar results were achieved for other target volumes.
Conclusion: A number of methods for delivering partial breast irradiation have been developed to offer improved convenience. Permanent breast seeds implants using Yb-169 is safe and convenient treatment option for early stage breast cancer patients. Patients can be released to go home following NCRP released criteria of public dose below 5 mSv
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