PURPOSE: To compare the results of intraoperative ultrasound (US)-based dosimetry with those of postimplant computed tomography (CT)-based dosimetry after (125)I prostate brachytherapy. METHODS AND MATERIALS: Subjects comprised 160 patients who underwent prostate brachytherapy using (125)I seed implants. Prescribed dose was set as 145 Gy to the periphery of the prostate. Implantation was performed using an intraoperative interactive technique. Postimplant dosimetry was performed on Days 1 and 30 after implantation using CT. Dosimetric results for the prostate, urethra, and rectum were compared among intraoperative US and CT on Day 1 (CT(1)) and Day 30 (CT(30)). RESULTS: Mean minimal dose received by 90% of prostate volume was 133.7%, 115.6%, and 125.8% of the prescribed dose on US, CT(1), and CT(30), respectively: This value temporarily decreased on Day 1 and increased on Day 30. Other parameters for the prostate and urethra showed similar trends. Conversely, mean rectal volume receiving 100% of the prescribed dose was 0.69, 0.46, and 1.02 mL on US, CT(1), and CT(30), respectively. Rectal parameters tended to be underestimated on US relative to CT(30)-based dosimetry. A positive linear relationship was identified between US and CT observations for every prostate parameter and the dose covering 30% of the urethra. CONCLUSIONS: Our results demonstrate significant differences between dosimetric parameters obtained by US, CT(1), and CT(30). However, significant correlations also exist between US and CT, at least in prostate and urethral parameters. Clarification of the degrees of difference might make US planning more feasible. (c) 2010 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
PURPOSE: To compare the results of intraoperative ultrasound (US)-based dosimetry with those of postimplant computed tomography (CT)-based dosimetry after (125)I prostate brachytherapy. METHODS AND MATERIALS: Subjects comprised 160 patients who underwent prostate brachytherapy using (125)I seed implants. Prescribed dose was set as 145 Gy to the periphery of the prostate. Implantation was performed using an intraoperative interactive technique. Postimplant dosimetry was performed on Days 1 and 30 after implantation using CT. Dosimetric results for the prostate, urethra, and rectum were compared among intraoperative US and CT on Day 1 (CT(1)) and Day 30 (CT(30)). RESULTS: Mean minimal dose received by 90% of prostate volume was 133.7%, 115.6%, and 125.8% of the prescribed dose on US, CT(1), and CT(30), respectively: This value temporarily decreased on Day 1 and increased on Day 30. Other parameters for the prostate and urethra showed similar trends. Conversely, mean rectal volume receiving 100% of the prescribed dose was 0.69, 0.46, and 1.02 mL on US, CT(1), and CT(30), respectively. Rectal parameters tended to be underestimated on US relative to CT(30)-based dosimetry. A positive linear relationship was identified between US and CT observations for every prostate parameter and the dose covering 30% of the urethra. CONCLUSIONS: Our results demonstrate significant differences between dosimetric parameters obtained by US, CT(1), and CT(30). However, significant correlations also exist between US and CT, at least in prostate and urethral parameters. Clarification of the degrees of difference might make US planning more feasible. (c) 2010 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
Authors: Rajat J Kudchadker; Thomas J Pugh; David A Swanson; Teresa L Bruno; Yasemin Bolukbasi; Steven J Frank Journal: Med Dosim Date: 2012-05-03 Impact factor: 1.482
Authors: Hyeli Park; Ja Young Kim; Bo Mi Lee; Sei Kyung Chang; Seung Young Ko; Sung Jun Kim; Dong Soo Park; Hyun Soo Shin Journal: Radiat Oncol J Date: 2011-09-30