Most common types of lymphoma (eg, diffuse large B-cell NHL, follicular NHL, mantle cell NHL, HL) are routinely FDG avid with a sensitivity that exceeds 80% and a specificity of about 90%, which is superior to CT.
FDG PET/CT may be falsely negative in certain histological subtypes of NHL such as MZLs, peripheral T-cell lymphomas, small lymphocytic lymphomas, and primary FLs. In these cases, conventional morphological imaging techniques such as CT or MRI are a must.
18F-Fluorodeoxy glucose positron emission tomography‒computed tomography (18F-FDG-PET) can detect malignant lymph nodes of even normal size, thus overcoming one of the major limitations of CT.
Computed tomography (CT) scan
This scan can help tell if any lymph nodes or organs in your body are enlarged. CT scans are useful for looking for lymphoma in the abdomen, pelvis, chest, head, and neck. CT-guided needle biopsy: A CT can also be used to guide a biopsy needle into a suspicious area.
PET scans might be useful for some people with high grade non-Hodgkin lymphoma. Your doctor can tell you whether it may be helpful in your case. They are useful for staging some types of lymphoma and seeing how well treatment has worked.
When the scan lights up brightly, it means there is metabolic activity. Most aggressive cancers light up brightly, but the caveat is inflammation in the body also lights up because inflammatory cells are also metabolically active. That's why we need to verify the scan results with a needle biopsy.
Lymphoma that starts outside the lymph nodes is called 'extranodal' lymphoma. Extranodal lymphoma can cause many different symptoms, such as a swollen liver or spleen, a skin rash, or abnormal blood counts. These varied symptoms can make it difficult to diagnose T-cell lymphomas.
Burkitt lymphoma grows very rapidly, which means that symptoms usually develop quickly, over just a few days or weeks. The most common symptom is one or more lumps, which often develop in several parts of your body. These are swollen lymph nodes.
Positron-emission tomography (PET) scans
Lymphoma cells are quite active, so take up quite a lot of sugar. A special camera recognises the radioactivity in the cells, which shows up as 'hot spots' on the scan image.
False positive results are commonly observed in areas of active inflammation or infection (Gupta et al., 20000), with a reported false positive rate of 13% and false negative rate of 9% (Alavi et al., 2002).
For nodules that are not metabolically active during the PET/CT scan, it's not recommended to follow up with a biopsy. So patients avoid the risks of an unnecessary procedure. However, if the nodule positively reacts to the radiotracer, further investigation and a biopsy are strongly recommended.
Certain areas of skin may also thicken, harden and form plaques that itch and ulcerate. Typically, these plaques develop on the face or buttocks or within skin folds. As a skin lymphoma rash progresses, papules (small bumps) may start to appear.
PET scanning can give false results if chemical balances within the body are not normal. Specifically, test results of diabetic patients or patients who have eaten within a few hours prior to the examination can be adversely affected because of altered blood sugar or blood insulin levels.
When comparing the abilities of CT and PET/CT to detect metastatic lymph nodes, the sensitivity, specificity, and accuracy of PET/CT were 71%–89%, 89%–96%, and 81%–93%, respectively. However, nodal staging requires accurate and reliable interpretation of the information provided by PET/CT.
Lymphoplasmacytic lymphoma or Waldenstrom macroglobulinemia.
This is a rare, slow-growing type of lymphoma. It's found mainly in the bone marrow, lymph nodes, and spleen. This type of lymphoma can't be cured. But people can live with it for many years.
Getting diagnosed with any type of cancer can be difficult to hear. But you should know that Hodgkin's lymphoma is one of the most curable types of cancer. Even if the disease has spread, your chances of survival are very high.
Lymphoma most often spreads to the liver, bone marrow, or lungs. Stage III-IV lymphomas are common, still very treatable, and often curable, depending on the NHL subtype. Stage III and stage IV are now considered a single category because they have the same treatment and prognosis.
Burkitt lymphoma: Considered the most aggressive form of lymphoma, this disease is one of the fastest growing of all cancers. Burkitt lymphoma, named for the surgeon who first identified the cancer in the 1950s, accounts for about 2 percent of all lymphoma diagnoses.
Lymphoma is considered one of the most treatable forms of cancer if found early. For NHL, the overall five- and 10-year relative survival rates are 69% and 59%, respectively. For Hodgkin's lymphoma, the survival rates are equally improved, with a five-year survival rate of 85% and a 10-year survival rate of 80%.
The 5-year survival rate for NHL in the United States is 74%. The survival rates for NHL vary based on several factors. These include the stage and subtype of cancer, a person's age and general health, and how well the treatment plan works.
1. Although 82% of confirmed cancers had positive PET scans, 69% of benign lesions (mostly granulomatous disease) had positive PET scans. 2. Although there was an 85% probability that a positive PET was cancerous, there was only a 26% probability that a negative PET scan was not cancer.
PET scans detect areas of activity (like cell growth) in the body. More radioactive material collects in cancer cells than normal cells and will appear brighter on the image. Not all cancers show up on a PET scan. PET scan results are often used with other imaging and lab test results.
Conclusions: The optimal time to perform a repeat FDG-PET/CT scan after the completion of neoadjuvant chemotherapy and high-dose radiotherapy to maximize its accuracy for restaging patients with NSCLC is about 1 month after the last dose of radiation.