Gillette S M, Poulson J M, Deschesne K M, Chaney E L, Gillette E L
Department of Radiological Health Sciences, Colorado State University, Fort Collins 80523, USA.
Radiat Res. 1998 Sep;150(3):365-8.
One hundred twenty-eight beagle dogs were randomized to receive thoracic irradiation with doses between 0 and 72 Gy in 1.5-Gy fractions over 6 weeks. Dogs were randomized to have either 33, 67 or 100% of their lung volume irradiated. The entire thoracic portion of the esophagus and variable portions of the fundus of the stomach were included in the treatment field at all volumes. Sixteen of the 128 dogs entered in the study developed clinical signs of esophagitis. These 16 dogs received doses between 45 and 72 Gy. Clinical signs of esophagitis/gastritis included dysphagia, anorexia, emesis, excessive salivation and weight loss that required force-feeding of a liquid diet. An ED50 of 67.2 Gy (95% CI 61.45-79.7 Gy) was calculated for the occurrence of clinical signs that required some supportive treatment. Three of the 16 dogs receiving 63 or 72 Gy failed to respond to treatment and were euthanized. Twenty-five other dogs were euthanized prior to 2 years due to other treatment-related complications. Two dogs died of causes not related to treatment. No late esophageal complications were observed in the remaining 98 dogs out to 2 years after irradiation. Esophageal specimens from 79 dogs were available for quantitative histological analysis 2 years after irradiation. Histological analysis showed a decrease in the percentage of glandular tissue with a corresponding increase in lamina propria and muscle.
128只比格犬被随机分组，在6周内接受剂量为0至72戈瑞（Gy）、每次1.5戈瑞的胸部照射。犬只被随机分为照射肺体积的33%、67%或100%。所有照射体积下，食管的整个胸部部分和胃底的不同部分均包含在治疗野内。参与研究的128只犬中有16只出现了食管炎的临床症状。这16只犬接受的剂量在45至72戈瑞之间。食管炎/胃炎的临床症状包括吞咽困难、厌食、呕吐、流涎过多和体重减轻，需要强制喂食流食。计算出出现需要某种支持治疗的临床症状的半数有效剂量（ED50）为67.2戈瑞（95%置信区间61.45 - 79.7戈瑞）。接受63或72戈瑞照射的16只犬中有3只对治疗无反应，最终实施了安乐死。另外25只犬因其他与治疗相关的并发症在2年之前实施了安乐死。2只犬死于与治疗无关的原因。在其余98只犬中，照射后2年内未观察到晚期食管并发症。照射后2年，从79只犬获取了食管标本用于定量组织学分析。组织学分析显示腺组织百分比降低，固有层和肌肉相应增加。
