PURPOSE: To develop and optimize a technique for inverse treatment planning based solely on magnetic resonance imaging (MRI) during high-dose-rate brachytherapy for prostate cancer. METHODS AND MATERIALS: Phantom studies were performed to verify the spatial integrity of treatment planning based on MRI. Data were evaluated from 10 patients with clinically localized prostate cancer who had undergone two high-dose-rate prostate brachytherapy boosts under MRI guidance before and after pelvic radiotherapy. Treatment planning MRI scans were systematically evaluated to derive a class solution for inverse planning constraints that would reproducibly result in acceptable target and normal tissue dosimetry. RESULTS: We verified the spatial integrity of MRI for treatment planning. MRI anatomic evaluation revealed no significant displacement of the prostate in the left lateral decubitus position, a mean distance of 14.47 mm from the prostatic apex to the penile bulb, and clear demarcation of the neurovascular bundles on postcontrast imaging. Derivation of a class solution for inverse planning constraints resulted in a mean target volume receiving 100% of the prescribed dose of 95.69%, while maintaining a rectal volume receiving 75% of the prescribed dose of <5% (mean 1.36%) and urethral volume receiving 125% of the prescribed dose of <2% (mean 0.54%). CONCLUSION: Systematic evaluation of image spatial integrity, delineation uncertainty, and inverse planning constraints in our procedure reduced uncertainty in planning and treatment.
PURPOSE: To develop and optimize a technique for inverse treatment planning based solely on magnetic resonance imaging (MRI) during high-dose-rate brachytherapy for prostate cancer. METHODS AND MATERIALS: Phantom studies were performed to verify the spatial integrity of treatment planning based on MRI. Data were evaluated from 10 patients with clinically localized prostate cancer who had undergone two high-dose-rate prostate brachytherapy boosts under MRI guidance before and after pelvic radiotherapy. Treatment planning MRI scans were systematically evaluated to derive a class solution for inverse planning constraints that would reproducibly result in acceptable target and normal tissue dosimetry. RESULTS: We verified the spatial integrity of MRI for treatment planning. MRI anatomic evaluation revealed no significant displacement of the prostate in the left lateral decubitus position, a mean distance of 14.47 mm from the prostatic apex to the penile bulb, and clear demarcation of the neurovascular bundles on postcontrast imaging. Derivation of a class solution for inverse planning constraints resulted in a mean target volume receiving 100% of the prescribed dose of 95.69%, while maintaining a rectal volume receiving 75% of the prescribed dose of <5% (mean 1.36%) and urethral volume receiving 125% of the prescribed dose of <2% (mean 0.54%). CONCLUSION: Systematic evaluation of image spatial integrity, delineation uncertainty, and inverse planning constraints in our procedure reduced uncertainty in planning and treatment.
Authors: Georgina Fröhlich; Péter Agoston; József Lövey; András Somogyi; János Fodor; Csaba Polgár; Tibor Major Journal: Strahlenther Onkol Date: 2010-06-24 Impact factor: 3.621
Authors: Anurag K Singh; Peter Guion; Robert C Susil; Deborah E Citrin; Holly Ning; Robert W Miller; Karen Ullman; Sharon Smith; Nancy Sears Crouse; Denise J Godette; Bronwyn R Stall; C Norman Coleman; Kevin Camphausen; Cynthia Ménard Journal: Radiat Oncol Date: 2006-08-16 Impact factor: 3.481
Authors: Ima Paydar; Brian S Kim; Robyn A Cyr; Harriss Rashid; Amna Anjum; Thomas M Yung; Siyuan Lei; Brian T Collins; Simeng Suy; Anatoly Dritschilo; John H Lynch; Sean P Collins Journal: Front Oncol Date: 2015-09-01 Impact factor: 6.244