Tumor recurrence criteria for postoperative contrast-enhanced computed tomography after surgical treatment of oral cancer and flap repair

Objective. To characterize the computed tomography (CT) findings that disti nguish cancer recurrence from postoperative changes that mimic such recurre nce. Study design. We evaluated a total of 72 CT scans from 32 patients who had undergone surgery with either pectoralis major myocutaneous flap or forearm flap. The observers evaluated the presence and pattern of enhancement, the presence of low density areas, and changes in the adipose tissue of the fl ap. Results, A persistent zone of high attenuation over 6 months suggested the high possibility of recurrence. However, an enhancement within 6 months occ urred both with the recurrent tumor and with postoperative tissue. In the p atients with recurrence (n = 12), the enhanced areas were focal (n = 8) or diffuse (n = 4). Focal-type recurrence often occurred at the posterior marg in. The presence of low-density areas and changes in the adipose tissue in the flap are also helpful for detecting recurrence. Conclusions. The combination of several features seen on CT images can be u seful in differentiating tumor recurrence from postoperative tissue changes .