Trial study on design of irradiated fields of radiotherapy in cervical and upper thoracic esophageal cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To compare three kinds of irradiation treatment plans for cervical and upper thoracic esophageal cancer,in order to arrived at proper decision for the patient.Methods From February 2001 to June 2004,43 such patients were studied with three different simulated treatment plans made including conformal plan,conventional four-field plan and conventional two-field plan for every one.All plans were evaluated with iso- dose curve and dose-volume histogram.Results GTV on 95% isodose curve was 99.5%,98.2% and 87.4% in conforaml plan,conventional four-field plan and conventional two-field plan,respectively;PTV_1 and PTV_2 on 95% isodose with 97.8%,97.2%,94.8% and 95.8%,86.6%,73.7%.The volume of＞20 Gy dose of left lung accepted was 18.6%,17.2% and 32.3%,in conformal plan,conventional four-field plan and conventional two-field plan,respectively;the right lung received 20.5%,19.9% and 35.5%.Conclusions Conformal plan is the best in radiotherapy,as it can provide ideal dose distribution of irradiated target with adequate protection of the normal tissues.Conventional four-field plan,being easy to carry out,can replace the conformal plan in most situations.Conventional two-field has the most uneven dose distribution and largest lung volume irradiated.