IMPACT OF POST-IMPLANT EDEMA ON DOSE COVERAGE
IN PROSTATE BRACHYTHERAPY: CAN IMPLANT QUALITY BE ASSESSED ON DAY 0?
Frank M. Waterman and Adam P. Dicker
Supported in part by P30 CA 56036-03 (NCI)
Department of Radiation Oncology,
Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University Hospital,
Philadelphia, PA 19107
Methods and Materials:
A pre-implant CT scan and 2 post-implant CT scans were obtained on 50 patients who
received monotherapy I-125 prostate seed implants. These implants were peripherally loaded
using an average seed strength of 0.70 mCi/seed and planned such that the prescribed
isodose line (150 Gy-TG 43) was typically 5 mm outside the gland. The first post-implant
CT scan was obtained on the day of the implant; the second typically 34 to 48 days later
(mean: 46 + 23 days; range 27–135 days). A dose-volume-histogram (DVH) of the
prostate was compiled from each CT study. Mean values of D90 (the dose which encompasses
90% of the prostate volume), D80, D50, and D25 were computed and used to define mean DVHs
for day 0 and day 46. A mean DVH was similarly compiled from the pre-plan DVHs for
comparison.
Purpose
| Materials and Methods | Results | Conclusions
Medical Physics Home |
