Gutíerrez Alonso N, Deveau Michael, Forrest Lisa J, Tomé Wolfgang A, Mackie Thomas R
Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53792, USA.
Vet Radiol Ultrasound. 2007 Nov-Dec;48(6):594-602. doi: 10.1111/j.1740-8261.2007.00304.x.
Feasibility of delivering a simultaneously integrated boost to canine nasal tumors using helical tomotherapy to improve tumor control probability (TCP) via an increase in total biological equivalent uniform dose (EUD) was evaluated. Eight dogs with varying size nasal tumors (5.8-110.9 cc) were replanned to 42 Gy to the nasal cavity and integrated dose boosts to gross disease of 45.2, 48.3, and 51.3 Gy in 10 fractions. EUD values were calculated for tumors and mean normalized total doses (NTD(mean)) for organs at risk (OAR). Normal Tissue Complication Probability (NTCP) values were obtained for OARs, and estimated TCP values were computed using a logistic dose-response model and based on deliverable EUD boost doses. Significant increases in estimated TCP to 54%, 74%, and 86% can be achieved with 10%, 23%, and 37% mean relative EUD boosts to the gross disease, respectively. NTCP values for blindness of either eye and for brain necrosis were < 0.01% for all boosts. Values for cataract development were 31%, 42%, and 46% for studied boost schemas, respectively. Average NTD(mean) to eyes and brain for mean EUD boosts were 10.2, 11.3, and 12.1 Gy3, and 7.5, 7.2, and 7.9 Gy2, respectively. Using helical tomotherapy, simultaneously integrated dose boosts can be delivered to increase the estimated TCP at 1-year without significantly increasing the NTD(mean) to eyes and brain. Delivery of these treatments in a prospective trial may allow quantification of a dose-response relationship in canine nasal tumors.
评估了使用螺旋断层放射治疗同时对犬鼻肿瘤进行整合加量，以通过增加总生物等效均匀剂量（EUD）来提高肿瘤控制概率（TCP）的可行性。八只患有不同大小鼻肿瘤（5.8 - 110.9立方厘米）的犬被重新计划给予鼻腔42 Gy的剂量，并对大体病变进行10次分割的45.2、48.3和51.3 Gy的整合剂量加量。计算了肿瘤的EUD值以及危及器官（OAR）的平均归一化总剂量（NTD(mean)）。获得了OAR的正常组织并发症概率（NTCP）值，并使用逻辑剂量反应模型并基于可交付的EUD加量剂量计算了估计的TCP值。分别对大体病变进行10%、23%和37%的平均相对EUD加量时，估计的TCP可显著提高至54%、74%和86%。所有加量方案中，单眼失明和脑坏死的NTCP值均<0.01%。所研究的加量方案中，白内障形成的值分别为31%、42%和46%。平均EUD加量时，眼睛和大脑的平均NTD(mean)分别为10.2、11.3和12.1 Gy3，以及7.5、7.2和7.9 Gy2。使用螺旋断层放射治疗，可以同时进行整合剂量加量，以在1年时增加估计的TCP，而不会显著增加眼睛和大脑的NTD(mean)。在前瞻性试验中进行这些治疗可能有助于量化犬鼻肿瘤的剂量反应关系。
