Brachytherapy for primary and recurrent nasopharyngeal carcinoma: 20 years' experience at Long Beach Memorial

Purpose: We evaluated treatment outcomes of patients with mostly locally advanced primary and recurrent cancer of the nasopharynx managed with interstitial and intraluminal brachytherapy.

Methods and Materials: This is a retrospective analysis of 56 patients with cancer arising from the nasopharynx treated with interstitial and intracavitary afterloading brachytherapy from 1978 to 1997. Patients were divided into three treatment groups: 15 patients with primary cancer (Group 1), 34 patients with recurrent or persistent disease (Group 2), and 7 patients with cancer in the nasopharynx who had history of previous definitive radiation therapy to the nasopharynx for head and neck cancer (Group 3). Fifty-three percent of patients in Group 1 had 1992 AJCC Stage IV disease, and 49% of patients in Groups 2 and 3 had extensive disease (defined as T3, T4, or parapharyngeal extension). Group 1 received megavoltage radiation to 50–60 Gy followed by a boost to the primary site and neck (in cases of persistent neck disease) with a combination of interstitial and intracavitary brachytherapy (mean dose 33–37 Gy). Five patients received chemotherapy, and 6 patients received hyperthermia. Groups 2 and 3 patients were treated with brachytherapy implants (mean dose 50–58 Gy) without external beam radiation. Twenty-five patients received chemotherapy either before or during radiation, and 21 patients received hyperthermia.

Results: The overall survival at 2, 5, and 10 years for patients in Group 1 was 79%, 61%, and 61%, respectively, and for patients in Groups 2 and 3 combined was 48%, 30%, and 20%, respectively. Cause-specific survival at 2, 5, and 10 years was 87%, 74%, and 74%, respectively, for patients in Group 1; and 82%, 60%, and 60%, respectively, for patients in Groups 2 and 3. Local control at 2, 5, and 10 years was 93%, 93%, and 77%, respectively, for patients in Group 1; and 81%, 59%, and 49%, respectively, for patients in Groups 2 and 3. Control in the neck at 2, 5, and 10 years was achieved in 93%, 93%, and 93% of patients, respectively, in Group 1; and 88%, 81%, and 81%, respectively, for patients in Groups 2 and 3. Disease-free survival was 87%, 74%, and 62%, respectively, for patients in Group 1, and 56%, 41%, and 34%, respectively, for patients in Groups 2 and 3. There were 4 peri-operative deaths. One death (2%) was attributable to the development of late complications. Forty-five percent of patients experienced some form of late complications.

Conclusion: Interstitial afterloading brachytherapy can provide effective treatment for nasopharyngeal cancers, especially for locally persistent/recurrent and locally extensive lesions.