Efficacy and safety of stereotactic radiosurgery in advanced and/or recurrent head and neck cancer: Over 5-year Follow-up

Surgery or conventional chemoradiotherapy is difficult to salvage advanced and/or recurrent head and neck cancer expanded close to critical organs. Similarly, radical treatment for large recurrent tumors is limited by overall radiation doses for the body and the possibility of severe postoperative dysfunction. In cases where further surgery is not feasible, reirradiation offers the potential to gain locoregional control and achieve remission. Recently, stereotatic radiosurgery (SRS) has been used for advanced and/or recurrent lesions of head and neck cancer. The aim of this long-term retrospective study was to investigate the efficacy and safety of SRS for advanced and/or recurrent head and neck cancer.

Between March 2006 and February 2011, 52 patients (median age 75 years; range, 27-93 years) with advanced and/or recurrent head and neck cancer were treated with CyberKnife (Accuray Inc., Sunnyvale, USA) as SRS. Patients included 9 rT2, 12 rT3, 13 rT4, 5 T2, 6 T3, and 6 T4; 12 of the patients had lymph node metastases and 2 of the patients had lung metastases. All patients were monitored at both clinics by oral and maxillofacial surgeons and radiation oncologists using PET/CT, MRI and Ultrasound. The outcome was assessed based on Response Evaluation Criteria in Solid Tumors, ver. 1.1, and toxicities were graded using Common Terminology Criteria for Adverse Events, ver. 4. Overall survival (OS) rate post SRS was used by Kaplan- Meier analysis.

All patients completed the prescribed treatment, which was delivered 20-42 Gy of median marginal doses (range, 20-42 Gy) in 2 to 5 fractions. Median target volume treated was 28.3cm³(range, 3.4-74.4 cm³). In addition to SRS, all the patients received a low dose (40-80 mg/body for 2 weeks, drug holiday for 1 week) of oral chemotherapy S-1 (Taiho Pharmaceutical Co Ltd, Tokyo, Japan), an oral 5-FU.

At median follow-up for survivors of 86.4months (range, 4-119 months), in primary advanced patients’ five-year OS and locoregional control were 64.2% and 71.4%. On the other hand, in recurrent patients’ five-year OS was 33.8%; five-year OS with and without lymph node metastases were 20.0% and 47.5%.

All patients had grade 1-3 acute toxicity with stomatitis. Nine patients had grade 3 late toxicity with osteonecrosis of maxilla or mandible within 5-20 months post SRS (17.3%). At 114 months post SRS grade 3 late toxicity with osteonecrosis of maxilla was unexpectedly occurred in one elderly patient (1.9%).

Advanced and/or recurrent tumors were solid masses that were well suited to a SRS given the proximity of critical organs. SRS alone may safely replace surgery in patients who are not operable candidates. However, the low OS rate was recognized in cases with lymph node metastases, and we strongly recommend that patients eligible for surgery undergo a combined salvage treatment strategy of neck dissection for the regional lymph node metastases and SRS for the locally recurrent lesion. SRS was feasible, safe, and well-tolerated for patients with advanced primary and recurrent tumors without lymph node metastases. Toxicity was acceptable because of no appearance of grade 4 and 5 toxicity.

SRS may contribute to locoregional control with low toxicity and OS for the patients with head and neck cancer.

References:

Kreses M.-A.S. et al: Head Neck DOI 10.1002/hed.23763, 2014

Cengiz M. et al: Salvage reirradiation with stereotactic body radiotherapy for locally recurrent head and neck tumor Int J Radiat Oncol Biol Phys 1;81(1)9:104-9, 2011