Correlation of Computerized Tomography density patterns of lymph nodes with treatment results and outcome in head and neck cancer patients treated by 2 different chemoradiotherapy schedules.

Aims/Background: Tumor necrosis is visualized on CT scan as non enhancing hypodense area. Necrotic areas contain less oxygen and results in poor response of chemo-radiotherapy. Literature review (1) has shown that for hypodense lesions in head and neck cancer the complete response rate is lower than the isodense lesions. Locally advanced head and neck cancer require the addition of surgery but after a radical dose of radiation that is, 7000 cGy, surgery become difficult but there is no tool initially that can be used for selection of patients after delivery of 4500 cGy, that is the dose after which surgery can be performed without much difficulty. The hypothesis is that, hypodense lymph nodes even when they are small will show less response to various schedules of chemoradiotherapy so hypodensity of lymph nodes can be used as a tool to select patient, who will go for surgery after initial 4500 cGy of radiotherapy. Surgery is usually performed 2 to 3 weeks after radiotherapy, so primary can be treated to full dose while the skin in region of lymph nodes radiation field will recover from acute radiation reaction. Correlation of C T density patterns of lymph nodes in head and neck cancer patients with treatment results when two different chemoradiotherapy schedules are used is studied. Materials and Methods: Eighty three patients with locally advanced head and neck cancer were treated with two schedules of concurrent chemoradiotherapy prospectively from August 2010 to July 2011. CT Scans of the entire neck region including primary were performed. An iodine based contrast material (150 ml) was injected intravenously starting with a bolus of 50ml (3ml/s), followed by a slow (1ml/s) infusion of the remaining dose. The total tumor volume of the primary and involved neck nodes was calculated as a cuboid volume using maximum dimension in each plane: Vc= (a x b x c). Nodal density was graded. Results and Conclusion: No statistically significant association between recovery and CT density was found (X-2 = 0.306; P > 0.05).