Single Institute Experience with the Use of ConPaS Technique for the Treatment of Head and Neck Cancer

Abstract

Aim: In the complex therapy of head neck cancers modern 3D based radiotherapy plays an important role. The parotid sparing effect of intensity modulated radiotherapy is proven, but in many patients the conventional 3D based techniques are still being used. Since 2006 the “Conpas” technique has been routinely used in our institution for the treatment of locally advanced head neck tumor patients. The aim of our study was to analyze the dosimetry, survival and side effect profile of this 3D based treatment modality. Patient and Methods: Between 01.07.2006 and 31.11.2008 a total of 83 patients were treated using this technique. An elective dose of 50,4 Gy was prescribed to the primary tumor and the bilateral neck node regions, followed by a simple two field boost to the primary tumor region (up to 70Gy). We retrospectively analyzed the following factors related to this method: dosimetry profile (PTV and OR doses, focusing on parotid gland doses), clinical responses, local and distant progression free survival profile, acute and late side effects. Results: The mean dose of primary tumors was 71.98 Gy, the elective region dose of 50.4 Gy was achieved in all cases. Following the treatment in 37 patients complete clinical response in 25 cases partial response in 5 cases stable disease and in 16 cases progressive disease was registered. The mean overall survival was 30,06 months, the mean disease free survival was 25,82 months. When reporting the superficial lobe volumes in “lower” tumor locations good mean parotid doses were achieved (25.3 Gy and 23.4 Gy). Comparing the acute side effect profiles in the “upper” localized group higher rate of Grade III xerostomia (21% vs. 2%, p?0.05) and dermatitis (27% vs. 6%, p?0.05) were observed compared to “lower” localization group. In the “upper” localized group the late xerostomia (grade 2-3) rate was also higher (8% vs. 0%, p?0.05). Conclusion: Based on our experience Conpas technique is feasible technique for treatment of advanced head neck cancer patients. Our clinical outcome, dosimetry and follow up results show that this technique should be used successfully in patients with ”lower” localized primer tumor sites. High attention should be addressed when reporting parotid doses.