Imaging Findings in Patients with Immune Checkpoint Inhibitor-Induced Arthritis

Abstract

Immune checkpoint inhibitor (ICI)-induced arthritis is an increasingly recognized adverse event in patients with oncologic disease during immunotherapy. Four patterns are well described, including rheumatoid arthritis (RA)-like, polymyalgia rheumatica (PMR)-like, psoriatic arthritis (PsA)-like, and oligo-monoarthritis, among others. Despite better clinical recognition of these syndromes, information about the main imaging findings is limited. Methods: We conducted a retrospective observational study including all adult patients referred to the Rheumatology Department of a single-center due to ICI-induced arthritis who underwent imaging studies [ultrasound (US), magnetic resonance imaging (MRI), and 18F-FDG PET/CT)] between January 2017 and January 2022. Results: Nineteen patients with ICI-induced arthritis with at least one diagnostic imaging assessment were identified (15 US, 4 MRI, 2 18F-FDG PET/CT). Most patients were male (84.2%), with a median age at inclusion of 73 years. The main underlying diagnoses for ICI treatment were melanoma in five cases. The distribution of ICI-induced arthritis was as follows: PMR-like (5, 26.2%), RA-like (4, 21.1%), PsA-like (4, 21.1%), and others (6, 31.6%). All RA-like patients had US findings indistinguishable from conventional RA patients. In addition, 3/5 (60%) of PMR-like patients had significant involvement of the hands and wrists. Abnormal findings on MRI or PET-CT were reported by clinical symptoms. No erosions or myofascitis were seen. Conclusions: ICI-induced arthritis patients present inflammatory patterns on imaging studies similar to conventional inflammatory arthropathies, and therefore these syndromes should be followed carefully and treated according to these findings.

18F-FDG PET molecular imaging: A relevant tool to investigate chronic inflammatory rheumatisms in clinical practice?

“…One third exhibited peripheral 18 F-FDG uptake. These results were confirmed recently by Ponce et al ( 44 ). To note, patients experienced irAEs induced by ICI had a better cancer prognosis than those in non – irAEs patients ( 46 ).…”

“…Compared with classical PMR, PMR-like syndromes showed higher prevalence of peripheral arthritis and the biologic inflammation can be lacking ( 43 ). Previous report ( 44 ) and van der Geest et al ( 45 ) assessed the role of 18 F-FDG PET-CT before the initiation of corticosteroid in 6 patients with PMR – like syndrome. He found the same symmetric 18 F-FDG uptake locations than those in classical PMR, without LVV associated.…”

Is 18F-FDG-PET/CT an Optimal Imaging Modality for Detecting Immune-Related Adverse Events after Immune-Checkpoint Inhibitor Therapy? Pros and Cons

“…FDG PET patterns mimic rheumatoid arthritis (RA), polymyalgia rheumatica (PMR), psoriatic arthritis (PsA), and oligo-monoarthritis [105]. Ponce et al (2022) categorized ICI-arthritis into self-limiting (>50%), intermittent (25%), or persistent chronic types (20%) [74,93,104,106]. A review by Cappelli et al (2017) indicated that the incidence of the two most common irAEs, arthralgia and myalgia, was found in 1-43% and 1-21% of patients, respectively [54,107].…”

“…Arthritis has typically been controlled by ultrasound, MRI, or CT; however, FDG PET use has been growing in the field of arthritis, and it is even more sensitive in cases of soft tissue irAEs, such as synovitis, myositis, and fasciitis, where it shows diffuse periarticular uptake [ 104 ]. FDG PET patterns mimic rheumatoid arthritis (RA), polymyalgia rheumatica (PMR), psoriatic arthritis (PsA), and oligo-monoarthritis [ 105 ].…”

Rheumatic Immune-Related Adverse Events due to Immune Checkpoint Inhibitors—A 2023 Update

“…In recent years, reports of inflammatory arthritis after ICI administration have been increasing [ 81 , 82 , 83 , 84 , 85 , 86 ]. Arthritis is more common with PD-1/PD-L1 blockade than with CTLA-4 blockade [ 39 ], but the combination carries the highest risk [ 87 ].…”