diff --git a/IRaCIS.Core.Application/IRaCIS.Core.Application.xml b/IRaCIS.Core.Application/IRaCIS.Core.Application.xml
index 8a9e4ad66..b936e7141 100644
--- a/IRaCIS.Core.Application/IRaCIS.Core.Application.xml
+++ b/IRaCIS.Core.Application/IRaCIS.Core.Application.xml
@@ -1375,7 +1375,7 @@
         </member>
         <member name="M:IRaCIS.Core.Application.Service.ReadingCalculate.IRECIST1Point1CalculateService.GetComparedTriggeringSODChange(IRaCIS.Core.Application.Service.Reading.Dto.ReadingCalculateDto)">
             <summary>
-            与前一访视SOD相比变化量
+            与触发iRECIST访视相比SOD变化量
             </summary>
             <param name="inDto"></param>
             <returns></returns>
diff --git a/IRaCIS.Core.Application/Service/ReadingCalculate/IRECIST1Point1CalculateService.cs b/IRaCIS.Core.Application/Service/ReadingCalculate/IRECIST1Point1CalculateService.cs
index a172609b6..709fed196 100644
--- a/IRaCIS.Core.Application/Service/ReadingCalculate/IRECIST1Point1CalculateService.cs
+++ b/IRaCIS.Core.Application/Service/ReadingCalculate/IRECIST1Point1CalculateService.cs
@@ -1321,16 +1321,16 @@ namespace IRaCIS.Core.Application.Service.ReadingCalculate
         }
         #endregion
 
-        #region 与前一访视SOD相比变化量
+        #region 与触发iRECIST访视相比SOD变化量
         /// <summary>
-        /// 与前一访视SOD相比变化量
+        /// 与触发iRECIST访视相比SOD变化量
         /// </summary>
         /// <param name="inDto"></param>
         /// <returns></returns>
         public async Task<decimal?> GetComparedTriggeringSODChange(ReadingCalculateDto inDto)
         {
-            var lastTaskId = await this.GetLastVisitTaskId(inDto);
-            var lastSOD = (await _readingTaskQuestionAnswerRepository.Where(x => x.VisitTaskId == lastTaskId && x.ReadingQuestionTrial.QuestionType == QuestionType.SOD).Select(x => x.Answer).FirstOrDefaultAsync()).IsNullOrEmptyReturn0();
+            var firstChangeTaskId = await this.GetFirstChangeTaskId(inDto);
+            var firstChangeSOD = (await _readingTaskQuestionAnswerRepository.Where(x => x.VisitTaskId == firstChangeTaskId && x.ReadingQuestionTrial.QuestionType == QuestionType.SOD).Select(x => x.Answer).FirstOrDefaultAsync()).IsNullOrEmptyReturn0();
 
             var value = await GetSODData(inDto);
 
@@ -1338,7 +1338,7 @@ namespace IRaCIS.Core.Application.Service.ReadingCalculate
             {
                 return null;
             }
-            return value.NullChange0() - lastSOD;
+            return value.NullChange0() - firstChangeSOD;
         }
         #endregion