Linda Jorgov 1,2, Jean-Noёl Talbot2, Françoise Montravers2, Christine Ragu3, Judith Landmann-Parker3, Tamás Györke 1
1׃ Department of Nuclear Medicine, Semmelweis University, Budapest
2׃ Department of Nuclear Medicine and PET Centre, Hôpital Tenon, Paris
3: Department of Paediatric Oncology, Hôpital Trousseau, Paris
Possible clinical impact of „non-specific” uptake on FDG PET/CT in paediatric Hodgkin lymphoma
Our study is based on the observation that “non-specific” uptake of FDG is frequently observed in paediatric patients referred for PET/CT due to lymphoma. In the process to predict the response to chemotherapy, beside the decrease of FDG uptake in the lymphomatous lesions, the clinical significance of the “non-specific” uptake may have been overlooked.
In the PET/CT center of Hôpital Tenon (Paris), we included to our study 19 patients with the age range 6-17 years, in all cases with Hodgkin lymphoma. We evaluated the baseline and interim FDG PET/CT (iPET) after 2 cycles of chemotherapy searching for the next five “non-specific” signs: diffuse uptake of bone marrow, thymus, spleen, spinal cord and activation of the brown fat. We made visual and semiquantitative analysis (with SUVmax).
Based on the visual interpretation of the „non-specific” uptakes we had the following results: diffuse thymus hyperactivity was detected in 16% at baseline and in only 5% on the iPET; diffuse bone marrow hyperactivity was detected in 37% at baseline and in 16% on the iPET; diffuse spleen hyperactivity was detected in 48% at baseline and in 5% on the iPET; diffuse spinal cord hyperactivity was detected in 31% at baseline and in 16% on the iPET; 5% of the patients had brown adipose tissue uptake on the baseline and the iPET as well. The semiquantitative analysis showed a significantly decreased uptake on the iPET in diffuse spleen uptake and a significant increase of diffuse liver uptake which was measured as reference value.
Our preliminary conclusions: in paediatric Hodgkin lymphoma the diffuse spleen hyperactivation at baseline was more frequent than in adults, elevated diffuse thymus uptake was not frequent on the iPET and the liver uptake was elevated after 2 cycles of treatment.
Doctoral school: Clinical Medicine
Program: Lymphoma Diseases
Supervisor: Györke Tamás