Hypo-Fractionated Palliative QUADSHOT Radiotherapy and Concurrent CDDP in Patients with LAHNSCC: Toxicities and Clinical Outcomes

Abstract

Shorter palliative hypo-fractionated radiotherapy regimens given concurrently with chemotherapy, preferably cisplatin (radiosensitizer), increase response rates with acceptable toxicity, leading to better compliance of patients with locally advanced squamous cell carcinoma of the head and neck (LAHNSCC) in whom late toxicities due to chemoradiotherapy are less relevant. This single institution prospective interventional phase II study was conducted with the goal of achieving high rates of locoregional control with acceptable treatment-related toxicity. In this prospective interventional phase- II study, 60 patients with LAHNSCC (treatment naive), the majority in stage IVB and ECOG PS ≤ 3, were treated with QUAD SHOT RT using the conventional 2D technique (14Gy in 4 fractions on 2 consecutive days twice daily with a 6-hour interval between the two fractions) and concurrent cisplatin (CDDP) at a dose of 6 mg/m2. This treatment was repeated at 4-week intervals for 2 additional cycles if tumor progression did not occur. The Kaplan-Meier method was used to determine survival probability for progression-free survival (PFS) and overall survival (OS). Descriptive statistics with number and percentage were used for each toxicity and tumor response at different time points. A P value of less than 0.05 was considered significant. In our study, all patients received at least one cycle of QUADSHOT chemoradiotherapy (CTRT), while 35 and 18 patients received the 2nd and 3rd QUADSHOT CTRT, respectively. Of the patients who completed the first cycle of QUADSHOT CTRT, 27 (45%) patients had a partial response (PR) and 22 (36.7%) had stable disease (SD). Of the patients who completed the second cycle QUADSHOT CTRT, 77.2% had SD, while 11.4% had PR and 11.4% had PD. After the 3rd QUADSHOT CTRT, 72.2% had SD, while 11.1% had PR and 16.7% had PD. The overall response rate (SD +PR) in our study was 81%, 88.6%, and 83% after the 1st, 2nd, and 3rd QUADSHOT CTRT, respectively. After the 3rd QUADSHOT CTRT, no patient showed grade 4 toxicity. Most patients had grade I/ II toxicities e.g., skin (grade I -83%), mucositis (grade II -50%), salivary gland toxicity (grade II -50%), grade I laryngitis (83.3%). Grade- III oral mucositis and pharyngitis were seen in 27% and 6.7% of patients, respectively. Median OS and PFS were 7.9 months and 6.2 months, respectively. Concurrent chemotherapy acts as a radiosensitizer and provides a synergistic effect when coupled with hypo-fractionated radiation, resulting in more effective control of locoregional disease in locally advanced head and neck tumors with acceptable toxicities. This study is hypothesis-generating and may serve as a basis for developing optimal CTRT regimens for patients with LAHNSCC who are not suitable for curative treatment.