SURVIVAL AND LONGTERM TOXICITIES OUTCOMES IN ADAPTIVE INTENSITY-MODULATED RADIOTHERAPY (ART) VS IMRT IN LOCALLY ADVANCED HEAD AND NECK CANCER.

Background: Anatomic complexity is a challenge for radiation oncologist.Repeated CT scans and replanning can
overcome the variations in terms of size or shape a tumour has undergone during treatment , this process has been termed
as Adaptive Radiotherapy(ART). The use of adaptive approach or IMRT-SIB is still under debate since there is not enough evidence of long-term
clinical outcomes , metastasis free survival. Total Sixty patients Materials And Methods: with locally advanced HNC with a intent to cure were
assigned into two arms to receive IMRT up to a dose of 70 Gy with concurrent weekly chemotherapy and were prospectively analyzed between
March 2018 and March 2019. Repeat CT scan was acquired after the 3rd week of radiation and those in the study arm were replannned and those
in the controlarm continued with the rst IMRT plan. For the entire cohort, patients were assessed weekly till the end of treatment and at 1, 3, and6
months, 1 year and 2 years thereafter. Main focus was on Xerostomia status at end of 6 months and end of 2 years and Survival (OS) rates at end of
2-years was calculated and hence compared. 2 years overall survival rate wa Results: s almost similar with 73.33% vs 76.66% in adaptive
IMRTand conventional IMRT respectively; p value= 0. 23 Xerostomia was statistically signicantly higher in the conventional arm at 6
months(p=0.01).Grade ≥II xerostomia at end of 2 years reduced to 0% vs 4.43 %in adaptive and conventional IMRT respectively (p= 0.78).
Conclusion: Adaptive IMRT can help to minimise xerostomia at end of 6 months .However no major benet in survival when compared 2 year
after completion of treatment.