“A Retrospective study comparing sequential boost versus integrated boost using volumetric Arc Radiotherapy along with concurrent chemotherapy for Locally Advanced Head and Neck Cancer”.
Purpose/Objective
Radiotherapy for LAHNC has changed considerably over the past two decades with the advent of conformal Radiotherapy techniques. Whereas these techniques differ in treatment related outcomes including survival and toxicity remains unanswered. Our objective of this study is to compare sequential versus Simultaneous Integrated boost using VMAT for LAHNC.
Material/Methods
A single institutional Retrospective data on Histologically proven squamous cell LAHNC treatment with Definitive chemoradiation 66-70Gy. Treatment was delivered via sequential boost or SIB using VMAT. Sequential Arm was delivered in 3 Phases, Phase I- 46-50Gy, Phase II- 10-14Gy, and Phase III- 10Gy, whereas SIB Arm 66Gy (High risk), 60Gy (Intermediate risk), and 54Gy (Low risk). Both arms received concurrent chemotherapy with weekly Inj.Cisplatin 40mg/m2. Toxicity was graded weekly during treatment and 3 monthly follow-ups. RFS, DFS and OS were estimated.
Results
At 2years, the estimated OS was 70% in sequential arm and 62% in SIB Arm. There was no difference in Local, regional, or distant RFS. There was No difference in weight loss and gastrostomy tube placement. But treatment Gaps were more appreciated in SIB Arm in comparison to sequential Arm. Rates of Acute toxicity Grade III/IV Dermatitis and Dysphagia were higher in SIB Arm in comparison to sequential Arm. Late Toxicity like Post RT Neck Oedema and Neck fibrosis seen more commonly seen in SIB Arm comparing to sequential Arm, whereas Xerostomia remains same in both arms.
Conclusion
There were no difference in disease related outcomes between the two treatment delivery approaches. A higher rates of Acute toxicity like Grade III/IV Radiation dermatitis, dysphagia and late toxicity like Post RT Neck Oedema, Fibrosis was observed more in SIB arm compared to sequential Arm.
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