The ACR’s State-of-the-Art Clinical Symposium: Rheumatologists Weigh in on Tough-to-Treat Cases, Paget’s Disease, Imaging

This treatment regimen was followed by a course of IV pamidronate, which did reduce bone turnover markers by 50%. Over the ensuing months, though, the levels of biomarkers quickly rose again. Pamidronate resistance has been reported with repeated cycles. When the patient’s urine N-terminal telopeptide and serum alkaline phosphatase continued to rise to levels matching those at presentation, the patient was treated with 4 mg of zoledronic acid by infusion, which normalized bone turnover markers.

Dr. Seton

Zoledronic acid, Dr. Seton said, “is very effective therapy for Paget’s disease. It’s even very effective in patients who have failed other bisphosphonates.”

Although studies have shown that zoledronic acid—now approved for Paget’s disease at a 5 mg dose—can result in a sustained biochemical remission of 6.5 years or longer, long-term outcomes may not differ in patients who have been treated aggressively to normalize the serum alkaline phosphatase compared with those patients treated symptomatically.⁴ This may be due to the nature of the patients treated and captured in this study, for example, those with long-term disease and coexisting morbidities, she said.

“My own interpretation is that they’ve remodeled bone to such an extent that maybe it’s too much to ask of a drug, at the age of 80, to change that [outcome].”

Imaging

With so many ways to image patients now available, the choices of which to use have become more complicated, said Imran Omar, MD, chief of musculoskeletal radiology at the Northwestern University Feinberg School of Medicine, Chicago. Each modality has strengths and drawbacks that can help guide their use, he said.

Clinicians should always start with radiographs because, with well-established patterns of disease, X-rays can give an accurate diagnosis in a lot of patients. They are also highly reproducible and inexpensive.

On the other hand, X-rays are fairly insensitive to bony erosions, soft tissues cannot be seen very well, and they expose patients to radiation, Dr. Omar said.

MRI, with excellent spatial and contrast resolution and clear depictions of anatomy, is frequently used to assess active disease and the extent of disease. But they’re expensive and uncomfortable for some patients.

CT imaging often results in findings similar to X-rays, but soft tissue can be seen more clearly and cross-sectional images can be used to localize findings more accurately.

At his center, CT is often used as a problem-solving tool, Dr. Omar said. “If there is a question on radiography or another imaging study, such as MRI, we often will go to CT,” he said.