Povidone-Iodine Versus Homemade Salt/Soda Mouthwash for the Prophylaxis of Radiation-Induced Oral Mucositis in Head and Neck Cancer: A Quasi-experimental Study.

Background Radiation-induced oral mucositis (RIOM) is a common acute toxicity of radiotherapy for head and neck cancer and may compromise treatment delivery. Povidone-iodine is commonly used for prophylaxis at our centre, whereas a homemade salt/soda mouthwash is an inexpensive alternative. This study compared these two rinses for preventing RIOM. Methods This prospective quasi-experimental study enrolled 110 adults with histologically confirmed head and neck cancer receiving conventional two-dimensional external-beam radiotherapy (60-66 Gy over 6-6.5 weeks) at Dhaka Medical College Hospital, Bangladesh. Patients were assigned by odd/even registration number to the 1% povidone-iodine or salt/soda mouthwash group (n=55 each), which they used every six hours from the first day of radiotherapy until 14 days after completion. Oral mucositis was graded weekly and at two and four weeks after radiotherapy using the World Health Organization (WHO) scale, while oral pain was assessed using a 10-cm visual analogue scale. The primary outcome was WHO grade ≥3 mucositis; secondary outcomes included its duration, oral pain, analgesic and antifungal use, and treatment interruption or discontinuation. Results WHO grade ≥3 mucositis first appeared at week 3 and was less frequent with salt/soda than povidone-iodine at week 3 (0/55 (0%) vs. 10/55 (18.2%), p=0.001), week 4 (4/55 (7.3%) vs. 14/55 (25.5%), p=0.010), and week 5 (10/55 (18.2%) vs. 20/55 (36.4%), p=0.032). After Bonferroni correction, the week 3 difference remained significant, while the week 4 difference was at the adjusted threshold. Overall severe mucositis was less frequent with salt/soda (43.6% vs. 60.0%; absolute risk difference -16.4%, 95% CI -34.8 to 2.1), although the difference was not statistically significant (p=0.086). Median duration of severe mucositis was similar (16.5 vs. 20.0 days, p=0.21). Oral pain was lower with salt/soda at weeks 3 and 4 (p=0.001 and p=0.006). Antifungal use was higher with salt/soda (83.6% vs. 63.6%, p=0.017), while treatment interruption and discontinuation occurred only with povidone-iodine. Conclusion In this study, salt/soda mouthwash showed an early trend toward lower severe RIOM and oral pain than povidone-iodine, but overall incidence and duration did not differ significantly. Because allocation was predictable, baseline imbalances were present, and analyses were unadjusted, these findings should be considered exploratory. Salt/soda may be a practical low-cost option in resource-limited settings, but adequately powered randomized multicentre trials are required for confirmation.