Minimally invasive laser-induced thermal therapy (LITT) for head and neck cancer: A comprehensive review

Abstract

5572 Background: Laser induced thermal therapy (LITT) has been developed in a step-wise fashion at UCLA as a minimally invasive treatment for head and neck cancer. Initial Phase-I studies demonstrated the feasibility and safety of using the Nd:YAG laser (near infra-red nm) for thermal ablation of tumors as a palliative treatment in 62 patients. This was followed by the current Phase II study that confirmed such finding using higher laser power densities (P.D. = 1,600–2,200 J/cm2). Patients and Methods: This was a single group study in patients with recurrent carcinoma of the head and neck, who failed at least one treatment modality, and had a Karnofsky performance status ≥ 70%, and ECOG performance status ≤ 2. The primary end points of the study were objective tumor response, and survival. Prognostic values were assessed by uni- and multivariate analysis using the Kaplan-Meier method and Cox model, respectively. Results: In this Phase II study, we review our results on 104 patients with recurrent head and neck cancer that were treated by LITT. Best results were seen in oral cavity tumors where Kaplan Meyer curves showed average survival of 20.3 months (10.7–30 mo; 95% CI) compared to neck (avg. = 14.4 months, 7.5–20.7 mo; 95% CI) and other tumor sites, (avg. = 18 months, 13.8–22.3 mo; 95% CI). Further analysis of neck treatments showed that tumors away from the common carotid in cervical lymph nodes located in levels I, IV, and V had median survival of 25.9 months (mean = 37.7 mo), compared to 11.4 months (mean = 10.9 mo) in patients with tumors near, or encroaching the carotid in upper and lower jugular levels II and III. In univariate analysis, a trend toward a better survival was observed when tumor proximity to carotid artery was considered prognostic categories (log-rank P = .0007). However, in multivariate analysis, TNM stage, and reconstruction using free flap transfer, but not age and histology, were retained as independent prognostic variables (P < .001). Conclusion: LITT Patients tolerated LITT well on an outpatient basis, and were successfully palliated for periods ranging from 39 days to 90 months post-treatment. Based on the findings of this study it was possible to show that proximity to the carotid artery was the most relevant factor in projecting patient survival. No significant financial relationships to disclose.