An analysis of intraoperative versus post-operative dosimetry with CT, CT-MRI fusion and XMR for the evaluation of permanent prostate brachytherapy implants

TY - JOUR

T1 - An analysis of intraoperative versus post-operative dosimetry with CT, CT-MRI fusion and XMR for the evaluation of permanent prostate brachytherapy implants

AU - Acher, Peter

AU - Puttagunta, Srikanth

AU - Rhode, Kawal

AU - Morris, Stephen

AU - Kinsella, Janette

AU - Gaya, Andrew

AU - Dasgupta, Prokar

AU - Deehan, Charles

AU - Beaney, Ronald

AU - Popert, Rick

AU - Keevil, Stephen

PY - 2010/8

Y1 - 2010/8

N2 - Background and purpose To assess the agreement between intraoperative and post-operative dosimetry and to identify factors that influence dose calculations of prostate brachytherapy implants Materials and methods Patients treated with prostate brachytherapy implants underwent post-operative CT and XMR (combined X-ray and MR) imaging Dose-volume histograms were calculated from Cl, XMR and CT-MR fusion data and compared with intraoperative values for two observers Multiple linear regression models assessed the influences of intraoperative D90, gland oedema, gland volume, source loss and migration, and implanted activity/volume prostate on post-operative D90 Results Forty-nine patients were studied The mean D90 differences (95% confidence limits) between intraoperative and post-operative CT, XMR and CT-MR fusion assessments were 11 Gy (-22, 45), 18 Gy (-13, 49) and 20 Gy (-17, 58) for Observer 1, and 15 Gy (-34, 63), 13 Gy (-29, 55) and 14 Gy (-27, 54) for Observer 2 Multiple linear regression modelling showed that the observed oedema and intraoperative D90 were significant independent variables for the prediction of post-operative D90 values for both observers using all modalities Conclusion This is the first study to report Bland-Altman agreement analysis between intraoperative and post-operative dosimetry Agreement is poor Post-operative dosimetry is dependent on the intraoperative D90 and the subjectively outlined gland volume (C) 2010 Elsevier Ireland Ltd All rights reserved Radiotherapy and Oncology 96 (2010) 166-171

AB - Background and purpose To assess the agreement between intraoperative and post-operative dosimetry and to identify factors that influence dose calculations of prostate brachytherapy implants Materials and methods Patients treated with prostate brachytherapy implants underwent post-operative CT and XMR (combined X-ray and MR) imaging Dose-volume histograms were calculated from Cl, XMR and CT-MR fusion data and compared with intraoperative values for two observers Multiple linear regression models assessed the influences of intraoperative D90, gland oedema, gland volume, source loss and migration, and implanted activity/volume prostate on post-operative D90 Results Forty-nine patients were studied The mean D90 differences (95% confidence limits) between intraoperative and post-operative CT, XMR and CT-MR fusion assessments were 11 Gy (-22, 45), 18 Gy (-13, 49) and 20 Gy (-17, 58) for Observer 1, and 15 Gy (-34, 63), 13 Gy (-29, 55) and 14 Gy (-27, 54) for Observer 2 Multiple linear regression modelling showed that the observed oedema and intraoperative D90 were significant independent variables for the prediction of post-operative D90 values for both observers using all modalities Conclusion This is the first study to report Bland-Altman agreement analysis between intraoperative and post-operative dosimetry Agreement is poor Post-operative dosimetry is dependent on the intraoperative D90 and the subjectively outlined gland volume (C) 2010 Elsevier Ireland Ltd All rights reserved Radiotherapy and Oncology 96 (2010) 166-171

U2 - 10.1016/j.radonc.2010.06.003

DO - 10.1016/j.radonc.2010.06.003

M3 - Article

VL - 96

SP - 166

EP - 171

JO - Radiotherapy and Oncology

JF - Radiotherapy and Oncology

IS - 2

ER -