Advanced olfactory neuroblastoma treated with combined conventional and hypofractionated stereotactic radiotherapy

Three patients with olfactory neuroblastoma (ONB) of the nasal and/or paranasal cavity were treated with a combination of conventional radiotherapy (RT) and hypofractionated stereotactic radiation therapy (SRT). Radiation doses of 30 to 50 Gy were delivered in 12 to 25 fractions using conventional RT, and then an additional 20 to 25 Gy was delivered in 5 fractions using SRT. Follow-up time was 42, 53, 65 months, three patients were alive, and local control was obtained in all, complete response (CR) in 2 and partial response (PR) in 1. Two patients had recurrence out of the radiation field and received salvage therapy. According to the Radiation Therapy Oncology Group (RTOG) acute/late radiation morbidity scoring criteria, there were no adverse effects of grade 3 or higher. The combined treatment with conventional RT and hypofractionated SRT achieved excellent local control without serious adverse effects.