5 Questions About Utilizing Imaging in a Treat-to-Target Approach in PsA

The treat-to-target approach has changed the management of rheumatic and musculoskeletal diseases. But how do imaging techniques, such as musculoskeletal ultrasonography and magnetic resonance imaging (MRI), fit into this approach?

The authors of 3 recent studies have applied imaging to a treat-to-target approach in rheumatoid arthritis (RA), which has raised considerable interest and generated debate among experts as to the role of imaging in monitoring disease activity. Peter Mandl, MD, PhD, from the Division of Rheumatology at the Medical University of Vienna in Vienna, Austria, and colleagues conducted a review of the 3 studies’ findings to determine the advantages and disadvantages of implementing imaging into the treat-to-target approach in psoriatic arthritis (PsA) and RA.¹ 

Rheumatology Consultant caught up with Dr Mandl about the research and what the review findings mean for the future of PsA and RA management.

Rheumatology Consultant: How has the treat-to-target approach changed the overall management of PsA?

Peter Mandl: My impression, and that of many experts in PsA, is that despite the fact that the Tight Control of Psoriatic Arthritis (TICOPA) trial showed that treating to target improved arthritis, skin, functional, and quality of life outcomes in PsA²—as reflected also in the updated European League Against Rheumatism (EULAR) recommendations for the management of PsA from 2015³—the treat-to-target strategy in PsA has been less widely implemented in clinical practice compared with in RA. There are a number of reasons for this, including the more heterogenous nature of PsA, the often variable response to treatment among the different domains (skin, joint, and entheses), and common comorbidities. This leads to physicians “tolerating” higher levels of disease activity in this disease as compared with other arthritides, particularly RA.

RHEUM CON: What prompted you to conduct the review?

PM: The fact that we have seen a number of treat-to-target trials in recent years—particularly ones that feature musculoskeletal ultrasonography—was the impetus for our review. The results of the trials have invoked a lively debate among the rheumatologist community. Most of the viewpoints and opinions took either a pro or a con approach, which is something we tried to avoid.

RHEUM CON: Based on your review findings, what role do ultrasonography and MRI currently have in treat-to-target strategies for PsA, and what should their future role be?

PM: That is difficult to answer based on the review, because so far there have been no trials published that have examined the role of imaging techniques as part of a treat-to-target strategy in PsA, only in RA. However, based on the results of other studies, both imaging modalities are recommended by EULAR as tools to monitor disease activity (particularly synovitis and enthesitis) in peripheral spondylarthritis, including PsA, providing additional information on top of clinical and biochemical assessments.⁴ MRI and/or ultrasonography were also found to provide additional information beyond conventional radiography for monitoring structural damage in peripheral spondylarthritis.

RHEUM CON: What should clinicians consider when deciding whether to implement imaging techniques into their treat-to-target strategy in PsA?

PM: For me, what makes the case for imaging in PsA is the fact that patients commonly report pain that is extra-articular—not articular—in origin. Common examples of this are enthesitis or enthesopathy, which are often difficult to evaluate clinically. Dactylitis is a clinical diagnosis; however, we know very little of the underlying pathology and often have difficulties in judging whether it is an active or a chronic lesion.

RHEUM CON: What are the challenges clinicians may face when implementing imaging into their treat-to-target strategy in PsA, and how can these challenges be overcome?

PM: Given the nature of PsA, clinicians who want to implement imaging into their treat-to-target strategy in PsA should certainly consider investigating not only joints, but also tendons, entheses, and dactylitis. Functional ability might also be considered. In RA, there is limited evidence on whether combining ultrasonography and clinical examination may improve reliability of a composite index⁵, but this has not been looked at so far in PsA. There is still an ongoing debate about which index to use to monitor disease activity and whether a composite disease activity index is the right approach in the first place. When doing imaging in a systematic way, clinicians must also consider their access to the technique in a way that enables monitoring, as well as the need for trained experts who are necessary to interpret the images and, in the case of ultrasonography, reliably perform the examinations.

References:

1. Mandl P, Aletaha D. The role of ultrasound and magnetic resonance imaging for treat to target in rheumatoid arthritis and psoriatic arthritis [published online September 13, 2019]. Rheumatology. doi:10.1093/rheumatology/kez397.
2. Coates LC, Moverley AR, McParland L, et al. Effect of tight control of inflammation in early psoriatic arthritis (TICOPA): a UK multicentre, open-label, randomised controlled trial. Lancet. 2015;386(10012):2489-2498. doi:10.1016/S0140-6736(15)00347-5.
3. Gossec L, Smolen JS, Ramiro S, et al. European League Against Rheumatism (EULAR) recommendations for the management of psoriatic arthritis with pharmacological therapies: 2015 update. Ann Rheum Dis. 2016;75(3):499-510. doi:10.1136/annrheumdis-2015-208337.
4. Mandl P, Navarro-Compán V, Terslev L, et al; EULAR. EULAR recommendations for the use of imaging in the diagnosis and management of spondyloarthritis in clinical practice. Ann Rheum Dis. 2015;74(7):1327-1339. doi:10.1136/annrheumdis-2014-206971.
5. Mandl P, Balint PV, Brault Y, et al. Clinical and ultrasound-based composite disease activity indices in rheumatoid arthritis: results from a multicenter, randomized study. Arthritis Care Res. 2013;65(6):879-887. doi:10.1002/acr.21913.