F Böckelmann1, M Hammon2, S Lettmaier1, R Fietkau1, C Bert3, F Putz1. 1. Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany. 2. Department of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Maximiliansplatz 1, 91054, Erlangen, Germany. 3. Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054, Erlangen, Germany. christoph.bert@uk-erlangen.de.
Abstract
OBJECTIVE: This study aimed to assess the reduction in dose to the penile bulb (PB) achieved by MRI-based contouring following drinking and endorectal balloon (ERB) instructions. PATIENTS AND METHODS: A total of 17 prostate cancer patients were treated with intensity-modulated radiation therapy (IMRT) and interstitial brachytherapy (IBT). CT and MRI datasets were acquired back-to-back based on a 65 cm3 air-filled ERB and drinking instructions. After rigid co-registration of the imaging data, the CT-based planning target volume (PTV) used for treatment planning was retrospectively compared to an MRI-based adaptive PTV and the dose to the PB was determined in each case. The adapted PTV encompassed a caudally cropped CT-based PTV which was defined on the basis of the MRI-based prostate contour plus an additional 5 mm safety margin. RESULTS: In the seven-field IMRT treatment plans, the MRI-based adapted PTV achieved mean (Dmean) and maximum (Dmax) doses to the PB which were significantly lower (by 7.6 Gy and 10.9 Gy, respectively; p <0.05) than those of the CT-contoured PTV. For 6 patients, the estimated PB Dmax (seven-field IMRT and IBT) for the adapted PTV was <70 Gy, whereas only 1 patient fulfilled this criterium with the CT-based PTV. CONCLUSION: MRI-based contouring and seven-field IMRT-based treatment planning achieved dose sparing to the PB. Whereas the comparison of MRI and CT contouring only relates to external beam radiotherapy (EBRT) sparing, considering EBRT and IBT shows the improvement in PB sparing for the total treatment.
OBJECTIVE: This study aimed to assess the reduction in dose to the penile bulb (PB) achieved by MRI-based contouring following drinking and endorectal balloon (ERB) instructions. PATIENTS AND METHODS: A total of 17 prostate cancerpatients were treated with intensity-modulated radiation therapy (IMRT) and interstitial brachytherapy (IBT). CT and MRI datasets were acquired back-to-back based on a 65 cm3 air-filled ERB and drinking instructions. After rigid co-registration of the imaging data, the CT-based planning target volume (PTV) used for treatment planning was retrospectively compared to an MRI-based adaptive PTV and the dose to the PB was determined in each case. The adapted PTV encompassed a caudally cropped CT-based PTV which was defined on the basis of the MRI-based prostate contour plus an additional 5 mm safety margin. RESULTS: In the seven-field IMRT treatment plans, the MRI-based adapted PTV achieved mean (Dmean) and maximum (Dmax) doses to the PB which were significantly lower (by 7.6 Gy and 10.9 Gy, respectively; p <0.05) than those of the CT-contoured PTV. For 6 patients, the estimated PB Dmax (seven-field IMRT and IBT) for the adapted PTV was <70 Gy, whereas only 1 patient fulfilled this criterium with the CT-based PTV. CONCLUSION: MRI-based contouring and seven-field IMRT-based treatment planning achieved dose sparing to the PB. Whereas the comparison of MRI and CT contouring only relates to external beam radiotherapy (EBRT) sparing, considering EBRT and IBT shows the improvement in PB sparing for the total treatment.
Authors: A V D'Amico; J Manola; M Loffredo; L Lopes; K Nissen; D A O'Farrell; L Gordon; C M Tempany; R A Cormack Journal: Int J Radiat Oncol Biol Phys Date: 2001-12-01 Impact factor: 7.038
Authors: Kent E Wallner; Gregory S Merrick; Mark L Benson; Wayne M Butler; Jeffrey Maki; Bryan G Tollenaar Journal: Int J Radiat Oncol Biol Phys Date: 2002-07-15 Impact factor: 7.038
Authors: Mark K Buyyounouski; Eric M Horwitz; Robert G Uzzo; Robert A Price; Shawn W McNeeley; Daniel Azizi; Alexandra L Hanlon; Bart N Milestone; Alan Pollack Journal: Int J Radiat Oncol Biol Phys Date: 2004-08-01 Impact factor: 7.038
Authors: Bin S Teh; Shiao Y Woo; Wei-Yuan Mai; John E Mcgary; L Steven Carpenter; Hsin H Lu; J Kam Chiu; Maria T Vlachaki; Walter H Grant; E Brian Butler Journal: Med Dosim Date: 2002 Impact factor: 1.482
Authors: Ugur Selek; Rex Cheung; Mingfwu Lii; Pamela Allen; Roy E Steadham; Terry R Vantreese; Darren J Little; Isaac I Rosen; Deborah Kuban Journal: Int J Radiat Oncol Biol Phys Date: 2004-07-15 Impact factor: 7.038
Authors: Mark K Buyyounouski; Eric M Horwitz; Robert A Price; Alexandra L Hanlon; Robert G Uzzo; Alan Pollack Journal: Int J Radiat Oncol Biol Phys Date: 2004-03-01 Impact factor: 7.038
Authors: Lucian Beer; Stephan H Polanec; Pascal A T Baltzer; Georg Schatzl; Dietmar Georg; Christian Schestak; Anja Dutschke; Harald Herrmann; Peter Mazal; Alexander K Brendel; Shahrokh F Shariat; Helmut Ringl; Thomas H Helbich; Paul Apfaltrer Journal: PLoS One Date: 2019-12-19 Impact factor: 3.240