[Evaluation of preoperative effect for rectal cancer by transrectal ultrasonography].

The ultrasonographic examination was applied for the purpose of volume estimation of rectal cancer. We have performed 15 cases of echographic volume estimation compared with that of resected specimen (control group) and mean volume estimation error rate was 14.6% between two methods. And we also performed 17 preoperative irradiation cases of rectal cancer. Each tumor volume of pre- and post-irradiation was estimated echogenically and was compared with that of resected specimen. In the case when irradiation effect was remarkable, estimated volume by ultrasonography was much smaller in post-irradiation compared with that of pre-irradiation. Same tendency was also recognized in the study of resected specimen. Histopathological irradiation effect was also highly recognized in the case when echographic diminished rate was prominent. This method will useful for the judgement of preoperative irradiation effect in rectal cancer.