[Analysis of the effectiveness of radiotherapy in postoperative residual tumors in patients with thyroid papillary carcinoma].

OBJECTIVE: The aim of this study was to assess the impact of radiotherapy on patients with postoperative residual or recurrent papillary thyroid cancer (PTC).

METHODS: We retrospectively reviewed the medical records of 34 patients with PTC, who underwent surgery and radiotherapy in other hospitals, and treated at the Department of Head and Neck Surgery at Cancer Institute & Hospital CAMS from January 2011 to January 2014. Among the 34 cases, 22 were in stage I, 5 in stage II and 7 in stage IVa. The 34 patients received 1.5 times of surgery before radiotherapy in average. All the cases received radiotherapy (mean, 56 Gy; range, 50-70 Gy). The patients were re-operated in our hospital, and the specimens were examined by pathology. The pre- and post-radiotherapy images (CT and B-ultrasound) were compared, and the changes of tumor volume were examined. The objective effect of treatment on the tumor residual focus was evaluated using RECIST, and analyzed by t-test (SPSS 17.0).

RESULTS: All the re-resected lesions after radiotherapy were proved by pathology to be papillary thyroid cancer (PTC) or metastatic PTC in cervical lymph nodes. Among the 34 patients, 22 cases showed mild or moderate cell degeneration and the other 12 cases showed no obvious degeneration. The largest tumor diameter was 27.18 mm before radiotherapy and 27.76 mm after radiotherapy, with a non-significant difference between them (t=-1.618, P>0.05). Among the 34 patients, only 3 patients received reoperation, all other 31 cases had complete resection, and no severe complications were observed except recurrent laryngeal nerve injury in one case.

CONCLUSIONS: Radiotherapy has few therapeutic benefit to PTC patients after surgery with residual tumor or local recurrence. It should be used in the PTC patients, in which the tumor invasion involves important organ tissues and is difficult for a single operation to achieve safe resection margin, or in patients who can't bear a surgery because of severe coronary heart disease or others.