¹⁸F-sodium fluoride bone PET-CT in symptomatic lumbosacral transitional vertebra

To analyse the relationship between ¹⁸F-labelled sodium fluoride (NaF) uptake and lumbar back pain in patients with lumbosacral transitional vertebra (LSTV) a congenital malformation of the lumbosacral spine.

The study population comprised 55 patients (mean age, 51.42 years; median age 52 years) with LSTV. All patients underwent integrated positron-emission tomography (PET)/computed tomography (CT) by injecting 0.06 mCi/kg of ¹⁸F-NaF. A three-point grading system was used to evaluate ¹⁸F-NaF uptake (grade 0, no uptake; grade 1, mild uptake; and grade 2, marked increase uptake.

In total, 55 cases of LSTV (34 symptomatic and 21 asymptomatic) were included. Asymptomatic patients had no uptake in the majority of cases, i.e., grade 0 (n=18) and grade 1 (n=3), whereas symptomatic patients demonstrated focal increase tracer uptake of grade 2 (n=24), grade 1 (n=4), and grade 0 (n=6). There is a strong linear trend between the intensity of ¹⁸F-NaF uptake and presence of symptoms (p<0.0001). The sensitivity and specificity of ¹⁸F-NaF uptake at LSTV as a cause of pain were 82% (95% confidence interval [CI]: 65-93%) and 86% (95% CI: 64-97%). The positive and negative predictive values were 90% (95% CI: 74-98%) and 75% (95% CI: 53-90%).

¹⁸F-NaF PET/CT can be useful in evaluating back pain and ¹⁸F-NaF may be used as an adjunctive biological maker for assessing LSTV as a potential cause of pain.