Comparative Study of 3D Conformal Radiation Therapy by 3 Fields v/s 5 Fields Treatment Planning Techniques for Head and Neck Cancer

Purpose: The purpose of this study was to compare conventional 3 field versus 5 field treatment planning techniques during 3-dimensional conformal radiotherapy(3D-CRT) in respect of OAR, PTV coverage, treatment response & toxicities in head and neck Cancer. Materials and methods: This study included 50 biopsy proven and registered patients of head and neck cancer. Twenty five patients randomized to each arm. Arm A- 3D- conformal radiotherapy by 3 field delivery technique. Arm B--3D- conformal radiotherapy by 5 field delivery technique. All patients were irradiated on linear accelerator with concurrent chemotherapy in form of 3 weekly Cisplatin. Target volumes and normal structures were manually contoured on the axial slices of the planning CT scan. Patients were evaluated at end of treatment, 1st, 3rd & 6th months follow up visits. Results: At the end of treatment 22 (88%) patient in 3 field and 23 (92%) patients in 5 field had complete response. At 6 months complete response was 76% and 80 % in Arm A and B respectively (p value=0.6836). Grade 3rd xerostomia was seen 12% Vs 4% in Arm A and B respectively ( p value= 0.92 ) Mean V95 was 90.93 for conventional 3 field technique and 93.28 with 5 field technique ( p value=0.08).Conclusion: 5 field 3D-CRT technique can be used to spare parotid and other OAR and better PTV coverage specially in larynx carcinoma , patient with N2 or less nodal involvement and not involving higher neck node level.