Risk of sinonasal-cutaneous fistula after treatment for advanced sinonasal cancer.

BACKGROUND AND OBJECTIVES: To determine the rate and the risk factors for sinonasal-cutaneous fistula formation after treatment for sinonasal malignancy. METHODS: Between 1991 and 2002, 99 patients with advanced sinonasal malignancy received radiation therapy +/- surgery. Primary site was maxillary sinus in 30, ethmoid sinus in 19, nasal cavity in 32, nasopharynx in 3, and sphenoid sinus in 15 patients. Eighty-two percent of patients had T4 disease. Sixty-eight percent of patients had undergone surgical resection. Median follow-up was 70.6 months. RESULTS: Eight patients developed ≥ grade 3 sinonasal-cutaneous fistulas at a median time of 3.8 months after radiation. The overall rates of developing ≥ grade 3 fistulas in the entire group at 2 and 5 years were 6% and 10%, respectively. The fistulas were in the medial canthus in seven patients and in the infraorbital region in one patient. Fistulas developed exclusively along the transfacial incision scar and in patients whose tumors extended to the subcutaneous tissues. In univariate analysis, squamous cell carcinoma histology (P » 0.008), ≤ T4a primary tumor category (P » 0.02), and transfacial incision (P » 0.02) were associated with increased risk of fistula formation. CONCLUSIONS: Histologic subtype, T category, and quality of the skin and the underlying supporting tissues after transfacial incision are risk factors for sinonasal-cutaneous fistula formation.

Proton beam radiation therapy for skull base adenoid cystic carcinoma.

OBJECTIVE: To determine the treatment outcome and prognostic factors in patients with adenoid cystic carcinoma of the skull base treated with proton beam radiation therapy. DESIGN: Retrospective analysis. SETTING: Massachusetts General Hospital, Massachusetts Eye and Ear Infirmary, and Harvard Medical School, Boston. PATIENTS: From 1991 to 2002, 23 patients with newly diagnosed adenoid cystic carcinoma with skull base extension were treated with combined proton and photon radiotherapy. There was tumor involvement of the sphenoid sinus in 61% of patients (14), nasopharynx in 61% (14), clivus in 48% (11), and cavernous sinus in 74% (17). The extent of surgery was biopsy alone in 48% (11), partial resection in 39% (9), and gross total resection with positive margins in 13% (3). The median total dose to the primary site was 75.9 cobalt-gray equivalent. The median follow-up of all surviving patients was 64 months. MAIN OUTCOME MEASURES: Locoregional control and disease-free survival and overall survival rates. RESULTS: Tumors recurred locally in 2 patients at 33 and 68 months, respectively. No patients developed neck recurrence. Eight patients had distant metastasis as the first site of recurrence. The local control rate at 5 years was 93%. The rate of freedom from distant metastasis at 5 years was 62%. The disease-free and overall survival rates at 5 years were 56% and 77%, respectively. In multivariate analysis, significant adverse factors predictive for overall survival were change in vision at presentation (P = .02) and involvement of sphenoid sinus and clivus (P = .01). CONCLUSIONS: High-dose conformal proton beam radiation therapy results in a very encouraging local control rate in patients with adenoid cystic carcinoma of the skull base. Changes in vision at presentation and tumor involvement of the sphenoid sinus and clivus are important prognostic factors.