Role of ¹⁸F-fluoride PET/CT over dual-phase bone scintigraphy in evaluation and management of lesions causing foot and ankle pain

The purpose of this study was to assess the potential role of ¹⁸F-fluoride PET/CT over dual-phase bone scintigraphy (DBS) in evaluation and management of lesions causing foot and ankle pain.

^99mTc-HDP DBS and ¹⁸F-fluoride PET/CT were performed in consecutive patients who visited rehabilitation department due to foot or ankle pain. Focal painful lesions in fore, mid, and hindfoot or ankle, and diffuse pain in foot were evaluated on DBS and ¹⁸F-fluoride PET/CT (conclusive, inconclusive, nonvisible) and lesions on each modality were correlated. The clinical course was followed to see if the results of ¹⁸F-fluoride PET/CT affected the decision of patient management.

Sixty-one painful lesions in 31 patients included 16 forefoot (26.2 %), 11 midfoot (18.0 %), 19 hindfoot (31.2 %), 6 ankle (9.8 %), and 9 diffuse footpain (14.8 %). Forty lesions (40/61, 65.6 %) were detected on DBS, including 21 conclusive diagnostic (21/40, 52.5 %), mainly including hindfoot lesions (n = 11). The inconclusive 19 lesions (19/40, 47.5 %) on DBS showed conclusive diagnostic findings on ¹⁸F-fluoride PET/CT, mainly in fore and midfoot lesions (n = 15). Twenty-one painful lesions (21/61, 34.4 %) which were nonvisible on DBS revealed conclusive diagnostic findings on ¹⁸F-fluoride PET/CT in 7 lesions (7/21, 33.3 %), including 5 hindfoot lesions. Fourteen nonvisible lesions (14/21, 66.7 %) on both modalities included all 9 diffuse painful foot lesions. Patient management was affected by findings of ¹⁸F-fluoride PET/CT in 31 lesions (31/61, 50.8 %).

¹⁸F-fluoride PET/CT provided more confirmative diagnostic information in painful foot and ankle over DBS, and influenced patient management in many inconclusive or nonvisible cases on DBS. Increasing role of ¹⁸F-fluoride PET/CT in benign diseases including foot and ankle pain is expected in the near future.