Clinical outcome prediction of percutaneous cementoplasty for metastatic bone tumor using ¹⁸F-FDG PET-CT

Objectives: Percutaneous cementoplasty (PC) is used for metastatic bone tumor. Bone metastases patients who are unable to avail regular surgery, because of their poor general condition, undergo PC to gain mechanical stability and pain relief. We evaluated the effect of PC using ¹⁸F-FDG PET-CT and investigated the correlation and predictability between quantitative parameters of ¹⁸F-FDG PET-CT and pain status after PC. Methods: Subjects comprised 18 patients (total 32 sites) who had undergone PC for the metastatic bone tumors. Pain degree of the patients was obtained by visual analog scale (VAS) in the pre-PC, immediate post-PC, and follow-up post-PC state. As PET-CT parameters, maximum and mean standardized uptake value (Max_SUV and Mean_SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured. Receiver operator characteristic curve analysis was performed for pre-PC, post-PC PET-CT, and delta (Δ) values of PET-CT parameters to correlate and predict the good pain improvement (VAS pain ≤2) after the PC procedure. Results: Patients' pain status improved significantly in immediate post-PC and follow-up post-PC pain (all p < 0.001). Among PET-CT parameters, Max_SUV (p = 0.004) and Mean_SUV (p = 0.007) showed significant interval decrease after PC procedure. All of the post-PC PET-CT and ΔPET-CT values showed significant prediction of pain improvement for follow-up post-PC pain, especially ΔTLG (AUC = 0.804, p = 0.0003) and ΔMTV (AUC = 0.804, p = 0.0004). Conclusions: There was significant reduction of patients' pain after PC, and ΔTLG and ΔMTV of PET-CT parameters showed best predictability for follow-up post-PC pain improvement. PET-CT can be the useful parameter to predict treatment response of PC.