⽐較使⽤低分次性強度調控放射治療與傳統治療在末期⽝⿐腔腫瘤之效果

Abstract

鼻腔腫瘤在狗是不常發生的惡性腫瘤，局部侵犯性強但在診斷時甚少發生轉移。 使用經驗性口服藥物通常會暫時改善鼻腔腫瘤的臨床症狀，但症狀還是會間歇性的反覆出現。鼻腔腫瘤的治療主要以局部控制為主，未接受治療的中位存活時間約為3.1個月。除了一般的規律分次性放射治療，低分次性放射治療療程較不密集，主要為了緩解影響病患生活品質的臨床症狀。 回溯國立台灣大學附設動物醫院於2011至2015年的病例，共有35隻患犬符合經病理學確診或臨床上強烈懷疑鼻腔腫瘤的病患。15隻患犬接受低分次性強度調控放射治療被歸類為放療組，非放療組有20隻患犬，其中17隻接受除了放射治療以外的治療方式，3隻沒有接受任何治療。 本研究大部分患犬臨床分期較末期（82.8%為第三或第四期），先前文獻末期病患比例較低，本研究治療成果與先前病患接受放射治療或化學治療的文獻不相上下。與非放療組相比，放療組患犬有顯著較長的無疾病進展期與存活時間。非放療組9隻患犬有接受化學治療，與同組沒接受化學治療的患犬的生存時間有顯著差異。 以多變數分析各因子與疾病進展的關係時，臉部變形 (P=0.012)與是否接受放療 (P=0.014)仍具顯著差異，危害比分別是3.741、0.347。以多變數分析各因子與生存時間的關係時，只有是否接受放療 (P=0.005)仍具顯著差異，危害比是0.259。 這是第一篇犬隻鼻腔腫瘤以低分次性強度調控放射治療的研究。即使本研究大部分患犬臨床分期較末期，經過低分次性強度調控放射治療後可以獲得一段可觀的無疾病進展期與存活時間。本研究的結果也指出當鼻腔腫瘤的患犬無法接受放射治療時，傳統的化學治療仍然可以提供病患一些幫助。

Canine nasal tumors is an uncommon malignancy, usually have a locally invasive behavior and rarely metastasis at the time of diagnosis. Clinical signs of nasal neoplasia usually are intermittent and progressive when empirical therapy administered. Treatment options of nasal tumors focus on local control. The MST of untreated canine nasal carcinoma is about 3.1 months. Besides regular fractionated radiation therapy for canine nasal tumors, coarse fractionated radiation therapy is less intensive and mainly focus on relieving clinical signs that affects patient’s quality of life. The medical records of histologically confirmed or clinically highly suspected nasal malignancy from 2011 to 2015 at National Taiwan University Veterinary Hospital were reviewed and 35 of client-owned dogs met the inclusion criteria. 15 patients treated with hypofractionated intensity-modulated radiation therapy (IMRT) were assigned to RT group. Non-RT group consisted of 20 patients either with treatment except RT (n=17) or no treatment (n=3) for further comparison. From the result of present study where most patients were advanced stage (82.8% are stage III and IV), our treatment outcome was comparable with previous studies of radiation therapy or chemotherapy in canine nasal tumor patients even though lower ratio of late stage patients were presented in most of the studies. Progression free interval and overall survival were significant longer in RT group when compared with non-RT group. In non-RT group, receiving chemotherapy (n=9) offered significant longer overall survival when compared with those patients that only received palliative oral medications. Facial deformity (P=0.012) and received radiation therapy or not (P=0.014) remained statistically significant in multivariable analysis of progression free interval. Hazard ratio of facial deformity and received radiation therapy or not was 3.741, and 0.347, respectively. Only received radiation therapy or not (P=0.005) remained statistically in multivariable analysis of overall survival. Hazard ratio of received radiation therapy or not was 0.259. This is the first IMRT study delivers weekly fractionated radiation therapy in canine nasal tumor patients. From the result of present study where most patients were in late stage, a durable progression free interval and comparable survival was obtained from our radiation treatment procedure. The result from present study also indicate that if radiation therapy is not an amenable option, traditional chemotherapy can still offer some benefit to canine nasal tumor patients.