The Role of Intensity Modulated Radiation Therapy for Favorable Stage Tumor of the Nasal Cavity or Ethmoid Sinus

Objectives:To compare intensity-modulated radiation therapy (IMRT), 4-field conformal, and the standard 3-field conventional technique of radiotherapy for favorable stage tumors of the nasal cavity or ethmoid sinus. Methods and Materials:We compared the 3 techniques in 3 patients with tumors of the nasal cavity or ethmoid sinus that did not involve the eye or optic pathways. We required that each plan deliver the prescription dose (70.2 Gy at 1.8 Gy per fraction) to 95% of the planning target volume. We compared the maximum point dose to critical normal structures (brainstem, optic chiasm, optic nerves, retina, lens). Results:IMRT and the 4-field conformal technique were clearly better than the 3-field conventional technique. The 4-field conformal plan was as good as IMRT. Conclusions:The conventional 3-field technique is not the best way to treat most patients with tumors between the eyes. A 4-field conformal plan is an excellent alternative to IMRT for some patients with tumors of the nasal cavity or ethmoid sinus. Conformal radiotherapy with a noncoplaner field that exits into the low neck may make it difficult to electively irradiate the neck lymphatics. IMRT may be a better option in this situation.