Kymera Physicians Ajaz Bulbul, Emilio Araujo, and Masoud Khorsand led a study related to Diffuse Large B-Cell Lymphoma in patients. The retrospective study examined 114 cases in patients from Southeast New Mexico spanning 1996 to 2016 and is important to learning better ways to detect and stage this aggressive form of cancer.
PET/CT Versus Bone Marrow Biopsy
Current methods used to detect lymphoma involve a bone marrow biopsy, which is both invasive and painful. If the PET/CT scanner can be used for the procedure, future patients would be greatly benefited. Many leading Physicians and medical organizations believe it is time to make this change.
Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL). Morra, Lazzarino, and Castello, et al found that bone marrow was involved in up to 27% of cases. Positron emission tomography (PET), increasingly combined with computed tomography (CT), is now a routine part of staging DLBCL to accurately evaluate nodal involvement.
The International Prognostic Index (IPI) is based on risk factors and was developed to help predict overall survival in DLBCL. Histologic evidence of DLBCL in staging marrow biopsy adversely affected overall survival and event-free survival, independent of the IPI. Focal marrow deposits identified by PET-CT but not biopsy had progression-free survival (PFS) and overall survival similar to stage IV disease without involved marrow.
Whether the omission of staging Bone marrow biopsy would change the risk assessment or treatment strategy of diffuse large B-cell lymphoma is not known. Whether difficulties in the correct interpretation of diffuse FDG uptake in bone marrow, leading to false-positives and poor specificity likewise remains unclear.
What is a PET/CT?
A PET/CT scan uses radio-tracers, small quantities of radioactive materials, to allow Physicians to get a clear image of internal tissues. It is a type of nuclear medicine imaging which is noninvasive and generally painless except at injection sites.
Most important, the PET/CT can measure blood flow, oxygen use, and sugar metabolism among other important functions. The applications for this technology continue to grow.
What is a Bone Marrow Biopsy?
The currently accepted method of detecting and staging diffuse large B-cell lymphoma is through a bone marrow biopsy and aspriation. This involves local anesthesia and a syringe into which fluid is drawn from within the bone. It is not a comfortable procedure. The procedure itself can cause further complications to the patient.
What is Diffuse Large B-Cell Lymphoma (DLBCL)?
Diffuse large B-cell lymphoma (DLBCL) is a cancer of B-cells. The B-cell is a type of white blood cell responsible for producing antibodies. DLBCL is the most common type of non-Hodgkin lymphoma among adults with 7–8 cases per 100,000 people per year in the United States.
Diffuse large B-cell lymphoma occurs mostly in older individuals, with a median age of diagnosis at 70 years. It can also occur in children and young adults, but rarely.
DLBCL is an aggressive tumor which can appear nearly anywhere in the body. The first symptom is typically the observation of a rapidly growing mass, sometimes associated with symptoms like fever, weight loss, and night sweats.
Although the exact cause is unknown, DLBCL generally develops from normal B-cells; it may also be a malignant transformation of leukemia or other types of lymphoma. Underlying immunodeficiencies have also been identified as significant risk factors. Epstein–Barr virus (EBV) infections have also been found to contribute to the development of some subgroups of DLBCL.
What is Cancer Staging?
Staging refers to the size of a cancerous growth, how much it has spread, and to what extent it involves tissues and organs in the body. It is a key tool used by treatment teams to decide how best to approach and attack cancer in a patient.
Early stages allow for a more flexible treatment approach while patients in late stages may be advised to either stick to known, aggressive methods of treatment. Some of the expressions related to cancer staging a treatment team may use include:
- Stage 0 – Abnormal cells present, but there is no spread. May also be called In situ.
- Stage I – Cancer is present
- Stage II – A higher number refers to
- Stage II – size of tumor and degree of spread to other tissue
- Stage IV – The cancer is systemic, spread throughout the body
- Distant – Means the cancer has spread to distant parts of the body (see Stage IV)
- In situ – Abnormal cells present with no spread (see Stage 0)
- Localized – There is no spread; the cancer remains limited to where it started
- Regional – There is spread to other tissues, organs, or the lymph nodes
- Unknown – Physicians lack enough information to stage the cancer
The study confirmed previous retrospective data suggesting a high level of accuracy for detecting bone marrow involvement in patients with DLBCL. Patients with a Positive PET/CT had a Higher IPI, clinical Stage and Bone marrow involvement. The high negative predictive value may help to avoid bone marrow biopsies especially if clinically early stage disease.
As the regional experts in cancer care, Kymera Independent Physicians has the only stationary American College of Radiology (ACR) certified PET/CT scan machine in Southeast New Mexico.
To read the complete study, visit The Role of FDG-PET/CT in Detecting Bone Marrow involvement in Diffuse Large B-Cell Lymphoma