BACKGROUND AND PURPOSE: Variations in organ position, shape, and volume cause uncertainties in dose assessment for brachytherapy (BT) in cervix cancer. The purpose of this study was to evaluate uncertainties associated with bladder dose accumulation based on DVH parameter addition (previously called "the worst case assumption") in fractionated BT. MATERIALS AND METHODS: Forty-seven patients treated for locally advanced cervical cancer were included. All patients received EBRT combined with two individually planned 3D image-guided adaptive BT fractions. D(2cm(3)) and D(0.1cm(3)) were estimated by DVH parameter addition and compared to dose accumulations based on an in-house developed biomechanical deformable image registration (DIR) algorithm. RESULTS: DIR-based DVH analysis was possible in 42/47 patients. DVH parameter addition resulted in mean dose deviations relative to DIR of 0.4±0.3 Gy(αβ3) (1.5±1.8%) and 1.9±1.6 Gy(αβ3) (5.2±4.2%) for D(2cm(3)) and D(0.1cm(3)), respectively. Dose deviations greater than 5% occurred in 2% and 38% of the patients for D(2cm(3)) and D(0.1cm(3)), respectively. Visual inspection of the dose distributions showed that hotspots were located in the same region of the bladder during both BT fractions for the majority of patients. CONCLUSION: DVH parameter addition provides a good estimate for D(2cm(3)), whereas D(0.1cm(3)) is less robust to this approximation.
BACKGROUND AND PURPOSE: Variations in organ position, shape, and volume cause uncertainties in dose assessment for brachytherapy (BT) in cervix cancer. The purpose of this study was to evaluate uncertainties associated with bladder dose accumulation based on DVH parameter addition (previously called "the worst case assumption") in fractionated BT. MATERIALS AND METHODS: Forty-seven patients treated for locally advanced cervical cancer were included. All patients received EBRT combined with two individually planned 3D image-guided adaptive BT fractions. D(2cm(3)) and D(0.1cm(3)) were estimated by DVH parameter addition and compared to dose accumulations based on an in-house developed biomechanical deformable image registration (DIR) algorithm. RESULTS: DIR-based DVH analysis was possible in 42/47 patients. DVH parameter addition resulted in mean dose deviations relative to DIR of 0.4±0.3 Gy(αβ3) (1.5±1.8%) and 1.9±1.6 Gy(αβ3) (5.2±4.2%) for D(2cm(3)) and D(0.1cm(3)), respectively. Dose deviations greater than 5% occurred in 2% and 38% of the patients for D(2cm(3)) and D(0.1cm(3)), respectively. Visual inspection of the dose distributions showed that hotspots were located in the same region of the bladder during both BT fractions for the majority of patients. CONCLUSION: DVH parameter addition provides a good estimate for D(2cm(3)), whereas D(0.1cm(3)) is less robust to this approximation.
Authors: Joshua S Niedzielski; Yufei Liu; Sylvia S W Ng; Rachael M Martin; Luis A Perles; Sam Beddar; Neal Rebueno; Eugene J Koay; Cullen Taniguchi; Emma B Holliday; Prajnan Das; Grace L Smith; Bruce D Minsky; Ethan B Ludmir; Joseph M Herman; Albert Koong; Gabriel O Sawakuchi Journal: Int J Radiat Oncol Biol Phys Date: 2021-08-13 Impact factor: 7.038
Authors: Hayeon Kim; Yongsook C Lee; Stanley H Benedict; Brandon Dyer; Michael Price; Yi Rong; Ananth Ravi; Eric Leung; Sushil Beriwal; Mark E Bernard; Jyoti Mayadev; Jessica R L Leif; Ying Xiao Journal: Int J Radiat Oncol Biol Phys Date: 2021-06-17 Impact factor: 7.038
Authors: Christian Kirisits; Mark J Rivard; Dimos Baltas; Facundo Ballester; Marisol De Brabandere; Rob van der Laarse; Yury Niatsetski; Panagiotis Papagiannis; Taran Paulsen Hellebust; Jose Perez-Calatayud; Kari Tanderup; Jack L M Venselaar; Frank-André Siebert Journal: Radiother Oncol Date: 2013-11-30 Impact factor: 6.280