Simultaneous Integrated Boost Radiotherapy in Unresectable Stage IV (M0) Head and Neck Squamous Cell Cancer Patients: Daily Clinical Practice

Aim: To evaluate clinical outcome in locally-advanced stage IV (M0) head and neck cancer patients treated using intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) in daily clinical practice.

Background: Despite SIB-IMRT has been reported as a feasible and effective advanced head and neck cancer treatment, there are few data about its concurrent use with systemic therapies.

Material and methods: We reviewed 41 staged IV (M0) head and neck cancer patients treated in two radiotherapy units in the city of Messina (Italy) during the last six years, using intensity modulated techniques-SIB. 22/41 patients had concomitant chemotherapy or cetuximab. Acute and late toxicities, objective response (OR) rate, local control (LC) and overall survival (OS) have been evaluated.

Results: 37/41 patients received the planned doses of radiotherapy, 2 patients died during the therapy. The major acute regional toxicities were skin reaction and mucositis. A case of mandibular osteoradionecrosis was recorded. At completion of treatment, OR was evaluated in 38 patients: 32/38 patients (84.2%) had complete (55.3%) and partial (28.9%) response. The 1- and 5-year LC rates were 73.4% and 69.73%, respectively. The 1-, 3-, and 5-year OS rates were 85.93%, 51.49% and 44.14%, respectively. No statistically significant differences in outcomes have been observed in patients treated with radiotherapy alone vs. irradiation concomitant to chemo/biotherapy. The median OS was 45 months.

Conclusion: SIB-IMRT is safeand can be used with concomitant chemotherapy/biotherapy in real-life daily clinical practice. SIB-IMRT alone is a valid alternative in patients unfit for systemic therapies.