The Effectiveness and Prognostic Factors of CT-Guided Radioactive I-125 Seed Implantation for the Treatment of Recurrent Head and Neck Cancer After External Beam Radiation Therapy.

PURPOSE

To analyze the efficacy and safety of radioactive I-125 seed implantation in the treatment of recurrent head and neck tumors after radiation therapy.

METHODS AND MATERIALS

The data of 101 patients with recurrent head and neck cancer after radiation therapy who received computed tomography guided radioactive I-125 seed implantation were analyzed. The median previous cumulative external irradiation dose was 66 Gy, and the median dose to 90% of the target volume (D90) after operation was 117 Gy. The short-term efficacy was evaluated by Response Evaluation Criteria in Solid Tumors version 1.1, and the adverse event was evaluated by Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

The 5-year local control rate was 26.6%, and the 5-year overall survival rate was 15.5%. Univariate analysis showed that factors related to local control rate included age, pathologic type, implantation site, lesion volume, and D90. The 5-year local control rate was 11.5% (2-year) if D90 was <120 Gy and 44.2% if D90 was ≥120 Gy (P = .001). Multivariate analysis showed that pathologic type, lesion volume, and D90 were independent factors related to local control (P = .002, 0, .014, respectively); Karnofsky performance status and lesion volume were independent factors associated with survival (P = .021 and 0, respectively). For the side effects, there were 26 cases of skin or mucosa ulceration (25.7%), 14 cases of pain (13.9%), and 2 cases of dry mouth (2%). The correlation between toxicity and dose had not been found.

CONCLUSIONS

Radioactive I-125 seed implantation in the treatment of recurrent head and neck cancer after radiation therapy showed acceptable efficacy and safety. Nonsquamous carcinoma, small lesion volume, and high dose (D90) were correlated with better local control.