ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 1649

Parameters by FDG-PET/CT Are Useful for Predicting Spontaneous Regression in MTX Associated Lymphoproliferative Disorder

Tomohiro Kameda1, Shusaku Nakashima1, Hiromi Shimada1, Risa Wakiya1, Mai Fahmy Mansour1, Mikiya Kato1, Koichi Sugihara1, Rina Semba1, Mao Mizusaki1, Norimitsu Kadowaki1 and Hiroaki Dobashi2, 1Kagawa University, Takamatsu, Japan, 2Department of Internal Medicine, Division of Hematology, Rheumatology and Respiratory Medicine, Faculty of Medicine, Kagawa University, Kita-gun, Japan

Meeting: ACR Convergence 2021

Keywords: ,

Session Information

Date: Tuesday, November 9, 2021

Title: RA – Diagnosis, Manifestations, & Outcomes Poster IV: Outcomes, Trajectory of Disease, & Epidemiology (1645–1673)

Session Type: Poster Session D

Session Time: 8:30AM-10:30AM

Background/Purpose: Methotrexate associated lymphoproliferative disorder (MTX-LPD) has various histological types from benign and malignant. Some MTX-LPDs spontaneously regress after discontinuation of MTX, even though they have been diagnosed with malignant lymphoma. However it is difficult to predict spontaneous regression (SR) of MTX-LPD. On the other hand, FDG-PET/CT is used for diagnosis of malignant lymphoma.

We investigate the usefulness of FDG-PET/CT for predictive factor of SR in MTX-LPD.

Methods: We enrolled 18 MTX-RA-LPD patients, which was histopathologically determined to be malignant and performed FDG-PET/CT from 2005 to 2019. We divided these cases into spontaneous regression cases (SR group; 9 cases) and cases that treated with chemotherapy after MTX discontinuation (CTx group; 9 cases), and compared the difference as follow subjects between two groups; biomarker (serum LDH and sIL-2R) at LPD onset, SUVmax to evaluate malignant tumor activity by FDG-PET/CT, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) which refer to metabolically active volume of the tumor segmented FDG-PET/CT. In addition, we analyzed cut off levels, sensitivity and specificity using statistical software JMP.

Results: The level of sIL-2R was significantly lower in SR group. In addition, MTV and TLG by FDG-PET/CT was significantly lower in SR group, although SUVmax is no difference between two groups. Cut off levels of sIL-2R, MTV and TLG were1728 U/ml (sensitivity; 77.8%, specificity; 88.9%) 103.42 ml (sensitivity; 88.9%, specificity; 88.9%) and 361.75 ml (sensitivity; 88.9%, specificity; 88.9%), respectively.

Conclusion: We suggested that serum sIL-2R, MTV and TLG were useful for predict of SR in MTX-LPD.

Disclosures: T. Kameda, None; S. Nakashima, None; H. Shimada, None; R. Wakiya, None; M. Fahmy Mansour, None; M. Kato, None; K. Sugihara, None; R. Semba, None; M. Mizusaki, None; N. Kadowaki, None; H. Dobashi, None.

To cite this abstract in AMA style:

Kameda T, Nakashima S, Shimada H, Wakiya R, Fahmy Mansour M, Kato M, Sugihara K, Semba R, Mizusaki M, Kadowaki N, Dobashi H. Parameters by FDG-PET/CT Are Useful for Predicting Spontaneous Regression in MTX Associated Lymphoproliferative Disorder [abstract]. Arthritis Rheumatol. 2021; 73 (suppl 9). https://acrabstracts.org/abstract/parameters-by-fdg-pet-ct-are-useful-for-predicting-spontaneous-regression-in-mtx-associated-lymphoproliferative-disorder/. Accessed .

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