Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.
Carolina Veterinary Specialists, Matthews, North Carolina, USA.
Vet Comp Oncol. 2022 Sep;20(3):623-631. doi: 10.1111/vco.12815. Epub 2022 Apr 3.
One radiotherapy (RT) protocol used for canine oral melanoma (OM) gives 36 Gy total, in six weekly or biweekly fractions (6 Gy × 6). This retrospective study characterizes oncologic outcomes for a relatively large group of dogs treated with this protocol and determines whether radiation dose intensity (weekly vs. biweekly) affected either progression-free or overall survival (PFS and OS). Dogs were included if 6 Gy × 6 was used to treat grossly evident OM, or if RT was used postoperatively in the subclinical disease setting. Kaplan-Meier statistics and Cox regression modelling were used to determine the predictive or prognostic value of mitotic count, bony lysis, World Health Organization (WHO) stage (I, II, III, or IV), using systemic anti-cancer therapies, tumour burden at the time of RT (macroscopic vs. subclinical), radiation dose intensity (weekly vs. biweekly), and treatment planning type (manual vs. computerized). The median PFS and OS times for all dogs (n = 101) were 171 and 232 days, respectively. On univariate analysis PFS and OS were significantly longer (p = <.05) with subclinical tumour burden, WHO stages I or II, and weekly irradiation. On multivariable analysis, only tumour stage remained significant; therefore, cases were grouped by WHO stage (I/II vs. III/IV). With low WHO stage (I/II), PFS and OS were longer when irradiating subclinical disease (PFS: risk ratio = 0.449, p = .032; OS: risk ratio = 0.422, p = .022); this was not true for high WHO stage (III/IV). When accounting for other factors, radiation dose intensity had no measurable impact on survival in either staging group.
一种用于治疗犬口腔黑色素瘤（OM）的放射治疗（RT）方案总剂量为 36Gy，每周或每两周进行 6 次分割（6Gy×6）。本回顾性研究对一组接受该方案治疗的犬的肿瘤学结果进行了特征描述，并确定了放射剂量强度（每周与每两周）是否影响无进展生存期或总生存期（PFS 和 OS）。符合以下条件的犬纳入研究：使用 6Gy×6 治疗明显的 OM，或在亚临床疾病阶段术后使用 RT。采用 Kaplan-Meier 统计学和 Cox 回归模型来确定核分裂计数、骨溶解、世界卫生组织（WHO）分期（I、II、III 或 IV）、使用全身性抗癌治疗、RT 时肿瘤负荷（宏观与亚临床）、放射剂量强度（每周与每两周）和治疗计划类型（手动与计算机化）的预测或预后价值。所有犬（n=101）的中位 PFS 和 OS 时间分别为 171 天和 232 天。单因素分析显示，PFS 和 OS 随亚临床肿瘤负荷、WHO 分期 I 或 II 以及每周照射时间的延长而显著延长（p<.05）。多因素分析显示，只有肿瘤分期仍然具有显著意义；因此，根据 WHO 分期（I/II 与 III/IV）对病例进行分组。在低 WHO 分期（I/II）时，当照射亚临床疾病时，PFS 和 OS 更长（PFS：风险比=0.449，p=.032；OS：风险比=0.422，p=.022）；而在高 WHO 分期（III/IV）时则不然。当考虑其他因素时，在两个分期组中，放射剂量强度对生存均无明显影响。
