School of Veterinary Science, Massey University, Palmerston North, New Zealand.
Department of clinical studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
J Vet Intern Med. 2021 Mar;35(2):1062-1072. doi: 10.1111/jvim.16076. Epub 2021 Mar 4.
Most dogs with sinonasal tumors (SNT) treated with radiation therapy (RT) died because of local disease progression.
HYPOTHESIS/OBJECTIVES: Our hypothesis is that the majority of local failure and residual disease would occur within the radiation field.
Twenty-two dogs with SNT treated with RT.
Retrospective cohort study.
dogs with SNT receiving 10 daily fractions of 4.2 Gy with intensity modulated radiation therapy (IMRT)/image guided radiation therapy (IGRT) and follow-up cone beam computed tomography (CBCT). Each CBCT was registered with the original radiation planning CT and the gross tumor volume (GTV) contoured. The GTV was classified as residual (GTVr) or a failure (GTVf). The dose statistic for each GTV was calculated with the original IMRT plan. For GTVf, failures were classified as "in-field," "marginal," or "out-field" if at least 95, 20-95, or less than 20% of the volume of failure was within 95% (D95) of the total prescription dose, respectively.
There were 52 follow-up CBCT/CTs. Overall there was a GTVr for 20 dogs and GTVf for 16 dogs. The majority of GTVr volume was within the original GTV. GTVf analysis showed that 75% (12/16) were "in-field," 19% (3/16) were "marginal" and 6% (1/16) were "out-field."
In-field failures are the main pattern for local recurrence, and there is evidence of radioresistant subvolumes within the GTV.
大多数接受放射治疗（RT）的鼻窦肿瘤（SNT）犬因局部疾病进展而死亡。
假设/目的：我们的假设是，大多数局部失败和残留疾病将发生在放射野内。
22 只接受 RT 治疗的 SNT 犬。
回顾性队列研究。
接受 10 次 4.2Gy 每日分割的 SNT 犬，采用调强放射治疗（IMRT）/图像引导放射治疗（IGRT）和随访锥形束 CT（CBCT）。每次 CBCT 均与原始放射治疗计划 CT 进行配准，并对大体肿瘤体积（GTV）进行轮廓勾画。GTV 分为残留（GTVr）或失败（GTVf）。使用原始的 IMRT 计划计算每个 GTV 的剂量统计数据。对于 GTVf，如果失败区域的至少 95%、20-95%或小于 20%的体积位于 95%处方剂量（D95）内，则分别将失败分类为“场内”、“边缘”或“场外”。
共进行了 52 次随访 CBCT/CT。总体上，有 20 只犬存在 GTVr，16 只犬存在 GTVf。大多数 GTVr 体积位于原始 GTV 内。GTVf 分析显示，75%（12/16）为“场内”，19%（3/16）为“边缘”，6%（1/16）为“场外”。
场内失败是局部复发的主要模式，并且 GTV 内存在放射抵抗的亚体积。
