(11)C-methionine PET/CT and MRI of primary central nervous system diffuse large B-cell lymphoma before and after high-dose methotrexate.

Abstract

PURPOSE:

Although the optimum treatment of primary central nervous system lymphoma (PCNSL) remains a challenge, there is increasing interest in methotrexate-based chemotherapy as an effective strategy. Here, we report evidence supporting the utility of methionine PET/CT for evaluating PCNSL disease extent and response to high-dose methotrexate therapy.

PATIENTS AND METHODS:

Four patients newly diagnosed with diffuse large B-cell PCNSL underwent methionine PET/CT and MRI of the brain at baseline and again after completion of high-dose methotrexate combination chemotherapy. Three patients also received pretreatment FDG PET/CT, and the intervals between MRI and both PET/CTs were within 3 weeks. The results of methionine PET/CT were compared with MRI and clinical findings.

RESULTS:

Pretreatment methionine PET/CT demonstrated clear demarcation of PCNSL tumors with high contrast in 3 patients and only faint uptake in the remaining patient, which also showed low FDG uptake. In 1 patient, methionine PET/CT displayed more tumor lesions than FDG PET/CT did. After high-dose methotrexate chemotherapy, methionine images displayed complete disappearance of abnormal uptake in all 4 patients. In 3 of the patients, posttreatment MRI and clinical follow-up corroborated findings of complete remission. In the remaining patient, MRI showed nonenhancing T2 hyperintensities in the periventricular white matter, for which the significance was inconclusive.

CONCLUSIONS:

Methionine PET/CT may provide clinically useful information complementary to MRI for monitoring the response to systemic chemotherapy in patients with PCNSL.

• Authors: Su Jin Jang, Kyung-Han Lee, Ji Young Lee, Joon Young Choi, Byung-Tae Kim, Seok Jin Kim, Won Seog Kim
• Journal: Clinical nuclear medicine (Clin Nucl Med) Vol. 37 Issue 10 Pg. e241-4 (Oct 2012) ISSN: 1536-0229 [Electronic] United States
• PMID: 22955084 (Publication Type: Case Reports, Journal Article)

Chemical References

• Antineoplastic Agents
• carbon-11 methionine
• Methionine
• Methotrexate

Topics

• Antineoplastic Agents (pharmacology, therapeutic use)
• Brain (diagnostic imaging, drug effects)
• Dose-Response Relationship, Drug
• Female
• Humans
• Lymphoma, Large B-Cell, Diffuse (diagnosis, diagnostic imaging, drug therapy)
• Magnetic Resonance Imaging
• Male
• Methionine
• Methotrexate (pharmacology, therapeutic use)
• Middle Aged
• Multimodal Imaging
• Positron-Emission Tomography
• Tomography, X-Ray Computed
• Treatment Outcome