Head and neck cancer is one of the most common malignancies in India. IMRT technique results in better sparing of OAR and homogenous dose distribution to the target. Adaptive radiotherapy is another step forward in that direction. We did a repeat CT scan during the radiotherapy treatment course followed by recontouring and replanning which resulted in better coverage to PTV and resulted decreased dose to OARs. In our study we found that mean difference between CTV and PTV volumes between Actual Plan and Hybrid Plan is 69.95 (p value 0.001) and 109.24(0.001) respectively. There was a significant reduction in doses received by both parotids. Right parotidgland received 3.03 Gy less in actual plan as compared to hybrid plan and Left parotid gland showed difference of 1.97 Gy between both the plans. Also, the D mean in right Eye was in AP 15.38 ± 10.56 and that of HP19.34 ± 11.27 with a mean difference of 3.96 (p value = 0.001); left eye, the D mean dose with AP 14.43 ± 9.15 and that in HP 18.33 ± 10.24 with a mean difference 3.89 ( p value=0.001).

Keywords: Head and neck cancer; Adaptive radiotherapy; IMRT.