Radiotherapy of Hodgkin and Non-Hodgkin Lymphoma

Abstract

Purpose: To improve the contouring of clinical target volume for the radiotherapy of neck Hodgkin/non-Hodgkin lymphoma by localizing the prechemotherapy gross target volume onto the simulation computed tomography using [18 F]-fluorodeoxyglucose positron emission tomography/computed tomography. Material and Methods: The gross target volume delineated on prechemotherapy [18 F]-fluorodeoxyglucose positron emission tomography/computed tomography images was warped onto simulation computed tomography using deformable image registration. Fifteen patients with neck Hodgkin/non-Hodgkin lymphoma were analyzed. Quality of image registration was measured by computing the Dice similarity coefficient on warped organs at risk. Five radiation oncologists visually scored the localization of automatic gross target volume, ranking it from 1 (wrong) to 5 (excellent). Deformable registration was compared to rigid registration by computing the overlap index between the automatic gross target volume and the planned clinical target volume and quantifying the V 95 coverage. Results: The Dice similarity coefficient was 0.80 + 0.07 (median + quartiles). The physicians' survey had a median score equal to 4 (good). By comparing the rigid versus deformable registration, the overlap index increased from a factor of about 4 and the V 95 (percentage of volume receiving the 95% of the prescribed dose) went from 0.84 + 0.38 to 0.99 + 0.10 (median + quartiles). Conclusion: This study demonstrates the impact of using deformable registration between prechemotherapy [ 18 F]-fluorodeoxyglucose positron emission tomography/computed tomography and simulation computed tomography, in order to automatically localize the gross target volume for radiotherapy treatment of patients with Hodgkin/non-Hodgkin lymphoma.

Application of Multimodality Imaging Fusion Technology in Diagnosis and Treatment of Malignant Tumors under the Precision Medicine Plan

“…PET/CT can clearly indicate active regions of tumor metabolism and liquefaction of a necrotic area, in addition to accurately delineating tumor radiotherapy target volume that can help guide the radiation field and radiation dose distribution design, in order to prevent normal tissues from receiving unnecessary irradiation and improve the efficacy of tumor radiotherapy. [2930] Nam et al . [31] reported that the PET/CT plan was better than the conventional point A plan in terms of target coverage without subjecting the normal tissue to an increased dose, which made optimized three-dimensional (3D) brachytherapy treatment planning possible.…”