Outcome in recurrent head neck cancer treated with salvage-IMRT

Recurrent head neck cancer (rHNC) is a known unfavourable prognostic condition.The purpose of this work was to analyse our rHNC subgroup treated with salvage-intensity modulated radiation therapy (IMRT) for curable recurrence after initial surgery alone.

Between 4/2003-9/2008, 44 patients with squamous cell rHNC were referred for IMRT, mean/median 33/21 (3-144) months after initial surgery. None had prior head neck radiation. 41% underwent definitive, 59% postoperative IMRT (66-72.6 Gy). 70% had simultaneous chemotherapy.

Retrospective analysis of the outcome following salvage IMRT in rHNC patients was performed.

After mean/median 25/21 months (3-67), 22/44 (50%) patients were alive with no disease; 4 (9%) were alive with disease. 18 patients (41%) died of disease. Kaplan Meier 2-year disease specific survival (DSS), disease free survival (DFS), local and nodal control rates of the cohort were 59/49/56 and 68%, respectively.Known risk factors (advanced initial pTN, marginal initial resection, multiple recurrences) showed no significant outcome differences. Risk factors and the presence of macroscopic recurrence gross tumor volume (rGTV) in oral cavity patients vs others resulted in statistically significantly lower DSS (30 vs 70% at 2 years, p = 0.03). With respect to the assessed unfavourable outcome following salvage treatment, numbers needed to treat to avoid one recurrence with initial postoperative IMRT have, in addition, been calculated.

A low salvage rate of only approximately 50% at 2 years was found. Calculated numbers of patients needed to treat with postoperative radiation after initial surgery, in order to avoid recurrence and tumor-specific death, suggest a rather generous use of adjuvant irradiation, usually with simultaneous chemotherapy.