Intensity-Modulated Radiation Therapy Alone Versus Intensity-Modulated Radiation Therapy and Brachytherapy for Early-Stage Oropharyngeal Cancers: Results From a Randomized Controlled Trial

Purpose: The objective of this study was to compare clinical outcomes of intensity -modulated radiation therapy (IMRT) alone versus IMRT + brachytherapy (BT) in patients with T1-T2N0M0 oropharyngeal squamous cell cancers (OPSCC). Methods and Materials: This open -label randomized controlled trial was conducted at Tata Memorial Hospital, Mumbai, India. Patients with stage I and II OPSCC were considered for IMRT to a dose of 50 Gy/25 fractions/5 weeks in phase I followed by randomization (1:1) to further treatment with IMRT (20 Gy/10 fractions/2 weeks) or BT ( Ir-192 high dose rate, 21 Gy/7 fractions/2 fractions per day). The primary endpoint of the trial was the reduction in xerostomia at 6 months evaluated using Tc-99m salivary scintigraphy. Severe salivary toxicity (xerostomia) was de fi ned as posttreatment salivary excretion fraction ratio < 45%. Secondary endpoints were local control, disease -free survival, and overall survival. Results: Between November 2010 and February 2020, 90 patients were randomized to IMRT (n = 46) alone or IMRT + BT (n = 44). Eleven patients (8 residual/recurrent disease, 2 lost to follow-up, 1 second primary) in the IMRT arm and 9 patients (8 residual/recurrence, 1 lost to follow-up) in the BT arm were not evaluable at 6 months for the primary endpoint. At 6 months, xerostomia rates using salivary scintigraphy were 14% (5/35: 95% CI, 5%-30%) in the BT arm while it was seen in 44% (14/32: 95% CI, 26%-62%) in the IMRT arm ( P = .008). Physician -rated Radiation Therapy Oncology Group grade >= 2 xerostomia at any time point was observed in 30% of patients (9/30) in the IMRT arm and 6.7% (2/30) in the BT arm ( P = .02). At a median follow-up of 42.5 months, the 3 -year local control in the IMRT arm was 56.4% (95% CI, 43%-73%) while it was 66.2% (95% CI, 53%-82%) in the BT arm ( P = .24). Conclusions: The addition of BT to IMRT for T1-T2N0M0 OPSCC results in a signi fi cant reduction in xerostomia. This strongly supports the addition of BT to IMRT in suitable cases. (c) 2023 Elsevier Inc. All rights reserved.