[en] Purpose: To determine the contribution of debulking surgery on local control and survival in paranasal sinus tumors. As most patients present with locally advanced disease, the possibility of radical surgery is limited. Consequently, radiotherapy is often needed as monotherapy or as an adjunct to surgery. Methods and Materials: Between 1977 and 1996, 73 patients (50 male: 23 female) with a paranasal sinus carcinoma were treated. The histology distribution was as follows: squamous cell carcinoma, 55%; adenocarcinoma, 19%; adenoid cystic carcinoma, 11%; and undifferentiated carcinoma, 15%.The clinical T classification was (UICC/TNM 1997): T2 14%, T3 27%, and T4 59%. Pathological neck nodes were found in 11% of patients. Treatment consisted of surgery only in 3, chemotherapy only in 1, radiotherapy only in 18, both surgery and radiotherapy in 50 patients. One patient did not receive any treatment at all. Three patients had concurrent chemotherapy. Median follow-up was 66 months (range, 1-213 months). Results: Five-year local control (LC) was 65% with combination of radiotherapy and debulking surgery in comparison with 47% with radiotherapy alone, but this difference was not statistically significant (p = 0.58). However, combination treatment gave significantly better 5-year overall survival (OS) (60% vs. 9%; p = 0.001) and 5-year disease-free survival (DFS) (53% vs. 6%; p < 0.0001). Cox-regression analysis showed that pathologic N status (p = 0.04), palliative intention of treatment (p = 0.018), clinical orbital invasion (p = 0.003), and orbital wall invasion (p = 0.003) were parameters significantly associated with poor local control. Total radiation dose of greater than 65 Gy (p = 0.05) and treatment consisting of radiotherapy alone (p = 0.002) were associated with worse overall survival; for disease-free survival clinical orbital invasion (p = 0.0005), age of greater than 65 years (p = 0.013) and pathologic T4 classification (p = 0.002) were significant factors for an unfavorable outcome. In 19 of 73 patients, 26 serious (mainly ophthalmological) complications were reported; in the majority of these, the visual tract was (partly) included in the treatment fields because of tumor extension. To analyze on which basis patients were selected for the combination therapy, a logistic regression was performed, concluding that clinical T4 classification (p = 0.05), radiological evidence of skull base invasion (p = 0.005), age of greater than 65 years (p = 0.026), radiological evidence of nasopharynx invasion (p = 0.02), clinical suspicion of palate invasion (p = 0.02), and radiological evidence of skin invasion (p = 0.009) were associated with choosing radiotherapy alone. Conclusion: Debulking surgery of paranasal sinus malignancies followed by high-dose radiotherapy to the involved sites was associated with better survival and (although not statistically significant) local control. Patient selection, based on clinical and radiological impression of tumor extension, was the main factor explaining these favorable results. We favor this combination regimen because the surgery gives quick relief of complaints and, at the same time, offers an excellent histologically proven staging method, enabling radiotherapy to be adjusted to the involved sites, thereby decreasing the risk of complications. This can all be achieved with a very low orbital exenteration rate