P0013 Role of adaptive radiotherapy in locally advanced head and neck cancer: A dosimetric analysis

Clinical outcomes of adaptive radiotherapy in head and neck cancers

“…In our earlier publication, the mean VRR of primary GTV was 32% and mean daily VRR was 1.05% per day over a period of 4-5 weeks. 12 The mean VRR and daily VRR of nodal GTV were 41.48% and 1.38%, respectively. Thus, the reduction rates in our study were comparable with those reported in literature, but the regression in nodal volume was more than that in primary tumour.…”

“…In our dosimetric study, we also found significant reduction in the volume of parotids receiving a significant dose by adaptive planning using a rescan. 12 By adaptive replanning, a portion of ipsilateral and contralateral parotid could be saved from being exposed to high radiation doses. This sparing of parotid volumes may translate into decreased incidence of xerostomia for such patients.…”

“…This study was in continuation with the institutional review board-approved dosimetric study of ART in HNC. 12 3 patients had Stage III disease, while 33 patients had Stage IV disease. 33 patients received concurrent chemotherapy.…”

“…In our study, we found that mean volume reduction rates (VRRs) for gross tumour volume (GTV) for primary, node and planning target volume (PTV) were 32.44%, 41.48% and 62.95% and mean daily VRRs were 1.05%, 1.38% and 2.01%, respectively. 12 The mean reduction in maximum point dose (D max ) for the spine was 260 cGy (range, 257-658 cGy). Similarly, there was a significant reduction in the volume receiving 10 and 15 Gy for bilateral parotids when ART was applied.…”

“…An earlier publication from our group 12 has shown the feasibility of a single mid-therapy rescan to adapt anatomic and tumour volume changes to help reduce the treated volumes and doses received by normal structures, especially in locally advanced HNC. In our study, we found that mean volume reduction rates (VRRs) for gross tumour volume (GTV) for primary, node and planning target volume (PTV) were 32.44%, 41.48% and 62.95% and mean daily VRRs were 1.05%, 1.38% and 2.01%, respectively.…”