NCCN Guidelines for Patients® | Diffuse Large B-cell Lymphoma

18 NCCN Guidelines for Patients ® : Diffuse Large B-cell Lymphoma, 2017 Imaging tests Imaging tests make pictures (images) of the insides of your body. They can show which sites have cancer. This information helps your doctors stage the cancer. More information on cancer staging is on page 21. Your treatment team will tell you how to prepare for the test. You may need to stop taking some medicines and stop eating and drinking for a few hours before the scan. Tell your doctors if you get nervous when in small spaces. You may be given a sedative to help you relax. Imaging machines are large. You will likely be lying down during testing. At least part of your body will be in the machine. Figure 5 shows one type of imaging machine. After the test, you will likely be able to resume your activities right away. If you took a sedative, you will have a waiting period. You may not learn of the results for a few days since a radiologist needs to see the pictures. A radiologist is a doctor who’s an expert in reading the images. Whole-body PET/CT PET ( p ositron e mission t omography) and CT ( c omputed t omography) are two types of imaging tests. When used together, they are called a PET/CT scan. PET/CT may be done with one or two machines depending on the cancer center. Whole-body PET/CT is a test that is needed to plan treatment for DLBCL. For PET, a sugar radiotracer will first be injected into your body. The radiotracer is detected with a special camera during the scan. Cancer cells appear brighter than normal cells because they use sugar more quickly. PET can show even small amounts of cancer because the images are based on the use of sugar (cell metabolism). CT takes many pictures of a body part from different angles using x-rays. A computer combines the x-rays to make detailed pictures. CT can show structural features of the cancer such as shape and size. The picture is saved for later viewing by the radiologist. Figure 5 Imaging machine Pictures of the insides of your body can be made with an imaging test. During the scan, you will lie on a table that will move into the tunnel of the imaging machine. The pictures will be viewed by a doctor who will look for signs of cancer. Copyright © 2017 National Comprehensive Cancer Network ® (NCCN ® ). 2 Treatment planning Imaging tests