Robert Carr, one of the authors of the IAEA paper, receiving the Journal of Nuclear Medicine Editor’s choice award among other recipients at the Society of Nuclear Medicine and Molecular Imaging annual meeting. (Photo: R. Kashyap/IAEA)
A paper helping doctors to effectively evaluate and treat patients with a form of non-Hodgkin’s lymphoma, a very fast growing and aggressive type of cancer, using a nuclear diagnostic imaging technique, has received an Editor’s Choice Award from the Journal of Nuclear Medicine. The paper is a result of an IAEA initiated, sponsored and coordinated research project.
“The Journal of Nuclear Medicine has the highest circulation in the field of nuclear medicine and the highest impact factor of any nuclear medicine journal worldwide,” said Diana Paez, Head of the Nuclear Medicine and Diagnostic Imaging Section at the IAEA. “Our publication was selected as one of the top three papers published last year.”
The paper titled, ‘Prospective International Cohort Study Demonstrates Inability of Interim PET to Predict Treatment Failure in Diffuse Large B-Cell Lymphoma’, is the outcome of a coordinated research project involving the IAEA in cooperation with eight research centres from Brazil, Chile, Hungary, India, Italy, Philippines, South Korea, and Thailand, and the advice of researchers from France, Italy, Turkey and the United Kingdom.
The research project involved 383 patients with a form of Non-Hodgkin’s lymphoma called Diffuse Large B-Cell Lymphoma (DLBCL), who were monitored over the course of two years using positron-emission tomography (PET) scans, a type of medical imaging procedure using nuclear techniques. Non-Hodgkin’s lymphoma (NHL) is a form of blood cancer, the incidence of which varies across geographical distribution and accounts for about 4% of all cancers in the United States. The overall 5-year relative survival rate for people with NHL is 69%, and the 10-year relative survival rate is 59%. DLBCL is the most common form of NHL, accounting for up to 48% of newly diagnosed cases in the United Kingdom.
Three sets of PET scans of each patient’s entire body were taken to evaluate their cancerous tumour before, during and after treatment. The second PET scan, called the interim PET or I-PET, is a follow-up scan taken during the course of treatment and was the focus of the study.
In the past, some medical researchers believed good results on the I-PET could be an indication that a patient does not need further treatment, but this research has shown that this is not actually the case.
“The study found that a single, interim PET scan cannot reliably predict the effectiveness of the treatment, and to intensify therapy on the basis of this single scan could put patients at risk of unjustified, treatment-related toxicity,” Paez explained. “It is important to not solely rely on the results of the interim PET for patient management that may mislead both physician and the patient into thinking they were in remission or not responding and consequently stop or modify further treatment. It is possible for the interim PET to show no tumour activity and yet the patient is not tumour-free, or show tumour activity and the patient could be cured by the next cycle,” she added.
An international comparison
The research project involved different health care systems and populations of different ethnicities to ensure that responses to therapy were comparable globally. With researchers from eleven developed and developing countries involved, the paper concluded that the responses were the same worldwide. “There may be a misconception that if a study is performed in a developed country, the results would be different than a study performed in a developing country, but this is not the case,” said Paez. “If the appropriate protocol is followed by the health centre, the results are the same.”
The results of the project have led to the largest database of these types of PET scan studies to date, as well as a series of recommendations on how doctors can evaluate I-PET scans to effectively treat patients with this form of non-Hodgkin’s lymphoma. The database will be a resource for further research in this area of medicine, and the recommendations are expected to influence how patient treatment is managed throughout entire treatment cycles, helping to ensure that patients receive safe and appropriate care.
“It is our hope that the scientific and medical community are able to implement the recommendations coming from this study,” said Paez. “The study results really made a change in patient management.”