Importance of the treatment package time in surgery and postoperative radiation therapy for squamous carcinoma of the head and neck

Background. To determine the effect of treatment time-related factors on outcome in patients treated with surgery and postoperative radiation therapy (RT) for locally advanced squamous cell carcinoma of head and neck (SCCHN). Methods. A retrospective review was performed on 208 consecutive patients treated from 1992 to 1997 with surgery and postoperative RT (≥55 Gy) for SCCHN. The treatment time factors considered were (1) interval from surgery to the start of RT; (2) RT duration; and (3) the total time from surgery to completion of RT (treatment package time). Treatment package time was dichotomized into short (≤100 days) vs long (>100 days) categories. Other variables considered were clinical and pathologic staging, margin status, RT dose, and tumor site. Patients were also divided into intermediate- and high-risk groups on the basis of eligibility for RTOG 95-01. Univariate (logrank) and multivariate analyses were performed. Results. Median follow-up for surviving patients was 24 months. Actuarial 2-year locoregional control (LRC) and survival rates were 82% and 71%, respectively. In univariate analysis, factors associated with higher locoregional failure were high-risk group (p = .011), margin status (p = .038), pathologic stage (p = .035), clinical N stage (p = .006), package time (p = .013), and RT treatment time (p = .03). Package time was also a significant predictor of survival in univariate analysis (p = .021). The other two individual time factors, tumor factors, and RT dose were not significant. Both risk status and treatment package time were significant factors in a multivariate model of LRC. Conclusions. A total treatment package time of <100 days is associated with improved tumor control and survival. Every effort should be made to keep the time from surgery to the completion of postoperative RT to <100 days.