Importance of PET/CT Scan Use in Planning Radiation Therapy for Lymphoma

Abstract

<b>Background:</b> Radiation therapy is a key part of the combined modality treatment for Hodgkin’s lymphoma(HL) and non-Hodgkin’s lymphoma (NHL), which can achieve locoregional control of disease. The 3D-conformalradiation oncology can be extended-field (EFRT), involved-field (IFRT) and involved node (INRT). Newtechniques have resulted in a smaller radiation field and lower dose for critical organs such as lung heart andbreast. Materials and <br/><b>Methods</b>: In our research, we made a virtual simulation for one patient who was treatedin four different radiotherapeutic techniques: mantle field (MFRT), EFRT, IFRT and INRT. After delineatiionwe compared dose-volume histograms for each technique. The fusion of CT for planning radiotherapy withthe initial PET/CT was made using Softver Xio 4.6 in the Focal program. The dose for all four techniques was36Gy. <br/><b>Results</b>: Our results support the use of PET/CT in radiation therapy planning. With IFRT and INRT,the burden on the organs at risk is less than with MFRT and EFRT. On the other hand, the dose distributionin the target volume is much better with the latter. <br/><b>Conclusions</b>: The aim of modern radiotherapy of HL andNHL is to reduce the intensity of treatment and therefore PET/CT should be used to reduce and not increasethe amount of tissue receiving radiation.