Evaluation of Xerostomia and Dysphagia in Cases of Well Lateralized Carcinoma Oral Cavity Treated with IMRT or VMAT: Comparison of Dosimetry and Toxicity Outcome

Introduction: Radiotherapy plays a pivotal role in the treatment of carcinoma of the oral cavity. However, associated toxicities like xerostomia and dysphagia significantly affect patient quality of life. Advancements in radiotherapy techniques, including Intensity-Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT), have aimed to improve dosimetric outcomes and reduce toxicity to organs at risk (OARs). Aims: To compare acute and late toxicity in patients of well lateralized carcinoma of oral cavity treated with two different radiotherapy techniques: Intensity modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) with special interest in xerostomia and dysphagia Materials and Methods: It was a Prospective Observational Study this study was conducted 2 years at the Department of Radiotherapy, Medical College Kolkata. 36 Patients were included in this study Results: Target coverage was comparable in both groups with no significant differences in D95%, D50%, D2%, or D98%. VMAT demonstrated a significantly better conformity index (p < 0.002) and reduced doses to the parotid glands and pharyngeal constrictors (p < 0.001). Treatment time and MUs were significantly lower in the VMAT group (p < 0.0001). Although not statistically significant, VMAT showed a trend toward lower incidences of Grade 2 dysphagia and xerostomia at all-time points. No Grade 3 toxicities were reported in either group. Conclusion: VMAT provides superior conformity and reduced dose to critical OARs, along with shorter treatment times and fewer monitor units compared to IMRT. Clinically, VMAT is associated with a trend toward lower rates of xerostomia and dysphagia, supporting its potential as the preferred technique in well-lateralized oral cavity cancers.