Conformal radiotherapy for paranasal sinus and nasal cavity tumors: Three-dimensional treatment planning and preliminary results in 40 patients

Purpose: To assess the possibility to deliver a high and homogeneous irradi ation with respect to maximal tolerated dose to the visual pathways for par anasal sinus and nasal cavity tumors. Methods and Materials: Forty patients with advanced stage malignant tumors were treated with postoperative (30) or primary (10 patients) conformal rad iotherapy (CRT), Five patients were previously irradiated. Six to 15 indivi dually shaped isocentric noncoplanar field arrangements, using a multileaf collimator were designed. Dose-volume histograms (DVH) for the planning tar get volumes (PTV) and the optic pathways were analyzed in 31 cases. Results: Median and maximal delivered doses to the PTV were 60 (+/-3) and 6 6 (+/-4) Gy, Dose distributions for critical organs are detailed. Median fo llow-up was 19 months (3 to 48), Local, nodal, and metastatic recurrences o ccurred in 8, 2, and 7 cases, respectively. Major prognostic factor for loc al recurrences was central nervous system (CNS) involvement. One patient di ed of meningitis. Two patients developed cataract, and 1 patient ipsilatera l blindness due to vascular glaucoma. Conclusion: CRT for locally advanced paranasal sinus and nasal cavity tumor s enables the delivery of high homogeneous doses to the PTV with respect to critical organs, with a low toxicity and a high local control. (C) 2000 El sevier Science Inc.