Therapeutic impact of [18F]fluoride positron-emission tomography/computed tomography on patients with unclear foot pain

Abstract

Purpose To evaluate the therapeutic impact of [18 F]fluoride positron-emission tomography/computed tomography ([ 18 F]fluoride PET/CT) imaging on patients with unclear foot pain. Methods Twenty-eight patients were prospectively included in this study. Therapeutic management was defined by two experienced dedicated foot surgeons before and after [18 F] fluoride PET/CT imaging. Twenty-six patients underwent cross-sectional imaging [CT, magnetic resonance (MR)] prior to PET/CT. A retrospective analysis of the magnetic resonance imaging (MRI) diagnoses was performed when a therapy change occurred after PET/CT imaging. Results In 13/28 (46%) patients therapeutic management was changed due to PET/CT results. Management changes occurred in patients with the following diagnoses: os trigonum syndrome; sinus tarsi syndrome; os tibiale externum syndrome; osteoarthritis of several joints; nonconsolidated fragments; calcaneo-navicular coalition; plantar fasciitis; insertional tendinopathy; suggestion of periostitis; neoarticulations between metatarsal bones. Os trigonum, os tibiale externum, subtalar osteoarthritis and plantar fasciitis were only seen to be active on PET/CT images but not on MR images. Conclusion [18 F]fluoride PET/CT has a substantial therapeutic impact on management in patients with unclear foot pain.

Evaluation of 18F-Fluoride PET/MR and PET/CT in Patients with Foot Pain of Unclear Cause

“…more specific therapy in 13 of 28 patients (4). Therefore, we hypothesize that the use of 18 F-fluoride PET/MR can provide additional therapeutically relevant information in patients with foot pain of unclear cause.…”

“…Various reports have described the value of 18 F-fluoride in helping direct therapeutic management to the right regions because of the relation between the intensity of bone metabolism and the complaints of the patient (4,5). Especially in patients with multifocal disease, the maximum 18 F-fluoride uptake can help the clinician tailor the therapy to the region of greatest clinical relevance or highest disease activity (e.g., the joint that is affected the most by osteoarthritis).…”

“…Several PET-only studies have shown that it is not possible to differentiate benign from malignant lesions on the basis of the intensity of 18 F-fluoride uptake and that diagnostic accuracy can be significantly improved by additional morphologic CT or MR imaging (1)(2)(3). A study of Fischer et al revealed that 18 F-fluoride PET/CT has a substantial therapeutic impact on management in patients with foot pain of unclear cause (4). However, it is well known that for most musculoskeletal pathologies, MR imaging is superior to CT because MR imaging has increased soft-tissue contrast and the possibility of imaging bone marrow edema (BME).…”

Pearls and Pitfalls of 18F Sodium Fluoride PET-CT Bone Imaging for Evaluation of Back Pain and Spine Pathology

“…Retention of the radiotracer is a 2-step process. The 18F ion first covalently exchanges with OH-ion on the surface of hydroxyapatite matrix of bone, and then the 18F ion migrates to the crystalline matrix where it is retained until the bone is remodeled [6,8,9]. Uptake is higher in osteoid or new bone because of higher availability of these binding sites [6,9,10].…”

“…The 18F ion first covalently exchanges with OH-ion on the surface of hydroxyapatite matrix of bone, and then the 18F ion migrates to the crystalline matrix where it is retained until the bone is remodeled [6,8,9]. Uptake is higher in osteoid or new bone because of higher availability of these binding sites [6,9,10]. Because bone with inflammation, osteoblastic neoplasm, infection and trauma are undergoing a high rate of reformation, 18F accumulates in these areas making focal increased uptake of 18F-labeled NaF a useful marker for these pathological processes.…”