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

Abstract

To assess the possibility to deliver a high and homogeneous irradiation with respect to maximal tolerated dose to the visual pathways for paranasal sinus and nasal cavity tumors. Forty patients with advanced stage malignant tumors were treated with postoperative (30) or primary (10 patients) conformal radiotherapy (CRT). Five patients were previously irradiated. Six to 15 individually shaped isocentric noncoplanar field arrangements, using a multileaf collimator were designed. Dose-volume histograms (DVH) for the planning target volumes (PTV) and the optic pathways were analyzed in 31 cases. Median and maximal delivered doses to the PTV were 60 (+/-3) and 66 (+/-4) Gy. Dose distributions for critical organs are detailed. Median follow-up was 19 months (3 to 48). Local, nodal, and metastatic recurrences occurred in 8, 2, and 7 cases, respectively. Major prognostic factor for local recurrences was central nervous system (CNS) involvement. One patient died of meningitis. Two patients developed cataract, and 1 patient ipsilateral blindness due to vascular glaucoma. CRT for locally advanced paranasal sinus and nasal cavity tumors enables the delivery of high homogeneous doses to the PTV with respect to critical organs, with a low toxicity and a high local control.