Presenter(s)
H. Mishra1, and L. Khurbuli2; 1Institute of Medical Sciences, Banaras Hindu University, Varanasi, India, Varanasi, India, 2IMS, BHU, VARANASI, India
Purpose/Objective(s): To compare treatment outcomes of Dysphagia-Optimised RT(Do-IMRT) with Standard IMRT(S-IMRT) in patients of post-operative oral cavity squamous cell cancer(POOCSCC)
Materials/Methods: Patients of POOCSCC of age 18-70 years of either sex, having ECOG 0-2, pT1-pT4, pN0-3 disease were randomized to receive either Dysphagia-optimised IMRT(DO-IMRT) or Standard IMRT(S-IMRT). Primary end point was acute toxicity measured weekly during RT and for the first three months post-RT; recorded as per CTCAE criteria version 5. The high-risk planning target volume (PTV-HR) was prescribed a total dose of 60 Gy delivered in 30 fractions, at 2 Gy per fraction. The low-risk planning target volume (PTV-LR) received a total dose ranging from 51 to 54 Gy in 30 fractions, with a per-fraction dose of 1.7 to 1.8 Gy, administered five days per week for six weeks. Dose constraints were prescribed to critical organs including dysphagia and aspiration related structures (DARS). The dosimetric parameters were compared with student T test and Chi-square test was used to compare patient related characteristics and toxicities. Survival rates were estimated using Kaplan-Meyer method. Statistical Analysis was performed using SPSS (Statistical Package for the Social Science) version 2025. P value of <0.05 was considered significant
Results: Sixty one patients were deemed eligible for the study, 29 patients in the DO-IMRT arm and 32 in S-IMRT. The mean age of the whole population was 47 years. Most patients were males (n=57). Carcinoma buccal mucosa was the most common primary site in both the arms (31%Vs 46.9% in DO-IMRT vs S-IMRT respectively). Most patients had group stage IV disease (31% in DO-IMRT arm Vs 50.0% in S-IMRT arm). The patient and tumor related characteristics were equally balanced in both the groups. In both the arms, all patients received 60 Gy to the PTV HR and 54 Gy to PTV LR. The mean RT duration of whole cohort was 7.05 weeks.The volume receiving 95% of the prescribed dose for PTV-HR and PTV-LR were comparable in the Do-IMRT group and the S-IMRT group. The doses received to the DARS were comparable. The most pronounced reduction to the DARS was observed in the inferior constrictor muscle in the Do-IMRT arm when compared to S-IMRT(p=0.439). The maximum dysphagia toxicity developed was Grade 2 observed in both the arms (17.2% in Do-IMRT arm vs 31.3% in S-IMRT arm). No Grade 3 dysphagia was recorded. Four patients in Do-IMRT group and 5 patients in S-IMRT group developed loco-regional recurrence. The LRC was 77.2% in the Do-IMRT group and 81.3% in the S-IMRT at 12 months (p = 0.502). At 12 months, DFS was 61.3% in the Do-IMRT and 81.3% in the S-IMRT group (p= 0.186). OS was comparable in both the arms with 80% in the Do- IMRT and 91.5% in the S-IMRT group at 12 months (p value .262).
Conclusion: D0-IMRT is not having advantage over S-IMRT for dysphagia relief in POOCSCC.