Robyn Banerjee1, Sang-June Park2, Erik Anderson2, D Jeffrey Demanes2, Jason Wang2, Mitchell Kamrava3. 1. Department of Oncology, University of Calgary, Calgary, Alberta T2N 4N2, Canada. 2. Department of Radiation Oncology, University of California Los Angeles (UCLA), Los Angeles, CA 90095, USA. 3. Department of Radiation Oncology, University of California Los Angeles (UCLA), Los Angeles, CA 90095, USA. Electronic address: mkamrava@mednet.ucla.edu.
Abstract
PURPOSE: To assess the magnitude of dosimetric reductions of a focal and ultra-focal high-dose-rate (HDR) prostate brachytherapy treatment strategy relative to standard whole gland (WG) treatment. METHODS AND MATERIALS: HDR brachytherapy plans for five patients treated with WG HDR monotherapy were optimized to assess different treatment strategies. Plans were generated to treat the hemigland (HG), one-third gland (1/3G), and one-sixth gland (1/6G), as well as to assess treating the WG with a boost to one of those sub-volumes (WG + HG, WG + 1/3G, WG + 1/6G). Dosimetric parameters analyzed included Target D90%, V100%, V150%, Bladder (B), Rectal (R), Urethral (U) D0.1, 1 and 2cc, Urethral V75%, and the V50% to the contralateral HG. Two-tailed t tests were used for comparison of means, and p-values less than 0.05 were considered statistically significant. RESULTS: Target objectives (D90 > 100% and V100 > 97%) were met in all cases. Significant organs at risk dose reductions were achieved for all approaches compared with WG plans. 1/6G vs WG plans resulted in the greatest reduction in dose with a mean bladder D2cc 24.7 vs 64.8%, rectal D2cc 32.8 vs 65.3%, urethral D1cc 52.1 vs 103.8%, and V75 14.5 vs 75% (p < 0.05 for all comparisons). CONCLUSION: Significant dose reductions to organs at risk can be achieved using HDR focal brachytherapy. The magnitude of the reductions achievable with treating progressively smaller sub-volumes suggests the potential to reduce morbidity, but the clinical impact on morbidity and tumor control remain to be investigated.
PURPOSE: To assess the magnitude of dosimetric reductions of a focal and ultra-focal high-dose-rate (HDR) prostate brachytherapy treatment strategy relative to standard whole gland (WG) treatment. METHODS AND MATERIALS: HDR brachytherapy plans for five patients treated with WG HDR monotherapy were optimized to assess different treatment strategies. Plans were generated to treat the hemigland (HG), one-third gland (1/3G), and one-sixth gland (1/6G), as well as to assess treating the WG with a boost to one of those sub-volumes (WG + HG, WG + 1/3G, WG + 1/6G). Dosimetric parameters analyzed included Target D90%, V100%, V150%, Bladder (B), Rectal (R), Urethral (U) D0.1, 1 and 2cc, Urethral V75%, and the V50% to the contralateral HG. Two-tailed t tests were used for comparison of means, and p-values less than 0.05 were considered statistically significant. RESULTS: Target objectives (D90 > 100% and V100 > 97%) were met in all cases. Significant organs at risk dose reductions were achieved for all approaches compared with WG plans. 1/6G vs WG plans resulted in the greatest reduction in dose with a mean bladder D2cc 24.7 vs 64.8%, rectal D2cc 32.8 vs 65.3%, urethral D1cc 52.1 vs 103.8%, and V75 14.5 vs 75% (p < 0.05 for all comparisons). CONCLUSION: Significant dose reductions to organs at risk can be achieved using HDR focal brachytherapy. The magnitude of the reductions achievable with treating progressively smaller sub-volumes suggests the potential to reduce morbidity, but the clinical impact on morbidity and tumor control remain to be investigated.
Authors: Amar U Kishan; Sang J Park; Christopher R King; Kristofer Roberts; Patrick A Kupelian; Michael L Steinberg; Mitchell Kamrava Journal: Br J Radiol Date: 2015-10-14 Impact factor: 3.039
Authors: Rafael R Tourinho-Barbosa; Lucas Teixeira Batista; Xavier Cathelineau; Javier Sanchez-Macias; Rafael Sanchez-Salas Journal: Turk J Urol Date: 2020-10-09