PT  - JOURNAL ARTICLE
AU  - Kaste, Sue C.
AU  - Snyder, Scott E.
AU  - Metzger, Monika L.
AU  - Sandlund, John T.
AU  - Howard, Scott C.
AU  - Krasin, Matthew
AU  - Shulkin, Barry L.
TI  - Comparison of <sup>11</sup>C-Methionine and <sup>18</sup>F-FDG PET/CT for Staging and Follow-up of Pediatric Lymphoma
AID  - 10.2967/jnumed.116.178640
DP  - 2017 Mar 01
TA  - Journal of Nuclear Medicine
PG  - 419--424
VI  - 58
IP  - 3
4099  - http://jnm.snmjournals.org/content/58/3/419.short
4100  - http://jnm.snmjournals.org/content/58/3/419.full
SO  - J Nucl Med2017 Mar 01; 58
AB  - Methionine transport across plasma membranes occurs via the large amino acid transporter, which is overexpressed in malignant cells, leading to tracer accumulation within tumors. We investigated the uptake of 11C-methionine (11C-MET) in children and young adults with Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL) and compared the biodistribution of 11C-MET PET/CT with that of 18F-FDG PET/CT. Methods: Conducted under an investigational new drug authorization, we prospectively enrolled patients with newly diagnosed HL (n = 19) and NHL (n = 2) onto the Institutional Review Board–approved investigation of 11C-MET PET/CT. After a minimum 4-h fast, patients received 740 MBq/1.7 m2 (maximum, 740 MBq [20 mCi/1.7 m2; maximum, 20 mCi]) of 11C-methionine intravenously. PET/CT was performed 5 min after injection from the vertex to thighs at 3 min per bed position. In a separate session, patients received 5.5 MBq/kg (maximum, 485 MBq [0.15 mCi/kg; maximum, 12 mCi]) of 18F-FDG with imaging initiated approximately 1 h after radiopharmaceutical administration. All studies were reviewed by consensus of 2 senior imaging specialists. The presence of metabolic activity on baseline studies was compared among 17 nodal groups. Results: Eighteen patients (11 male; median age, 15.2 y; age range, 9.5–22.6 y) comprised the study cohort. All had paired 11C-MET PET/CT and 18F-FDG PET/CT studies at diagnosis. At baseline, 3 nodal groups demonstrating discordant metabolic activity by both 18F-FDG PET/CT and 11C-MET PET/CT were Waldeyer’s ring, paraaortic region, and the liver. All others were found to have concordant metabolic activity. Normal intense 11C-MET uptake in the pancreas and liver reduced sensitivity for disease detection in these regions. At follow-up, 14 of 15 study pairs had concordant results. Conclusion: 11C-MET uptake is elevated in most regions involved with lymphoma at diagnosis and follow-up. Its utility in the abdomen is limited by uptake in normal structures.