Percutaneous vertebroplasty for the treatment of spinal metastasis:evaluation of the therapeutic efficacy

Objective: To discuss the efficacy of percutaneous vertebroplasty (PVP) for the treatment of vertebral metastases, and to analyze the factors influencing the efficacy. Methods: At our institution PVP was performed in 163 consecutive patients with vertebral metastasis. A total of 266 vertebral lesions were detected. All the patients had complete medical records. The clinical data were retrospectively analyzed. The primary carcinomas included lung cancer (n = 42), hepatic carcinoma (n = 19), esophageal and gastrointestinal cancer (n = 34), renal cancer (n = 10), mammary cancer (n = 46), prostate cancer (n = 8), lymphoma (n = 2), nasopharyngeal carcinoma (n = 1) and ureteral cancer (n = 1). CT scanning was performed within 3 days after PVP to observe the distribution of bone cement(polymethylmethacrylate, PMMA) within the vertebrae and to determine whether there was any cement leakage or not. The patients were followed up periodically at the time of 24 hours, one week, one, 3, 6 and 12 months after PVP. The clinical condition, the recurrence of back pain and the survival time were observed, and the therapeutic results were evaluated. Results: Technical success was achieved in all 266 diseased vertebrae. The mean injected amount of PMMA was (3.57 ± 1.50) ml for thoracic vertebrae and (4.53 ± 1.72) ml for lumbar vertebrae. The mean follow-up time was (12.0 ± 10.6) months. The pain remission rate at 24 hours, one week, 1, 3, 6 and over 12 months after PVP was 87.7% (143 /163), 92.6% (151 /163), 91.4% (149 /163), 84.5% (136 /161), 78.3% (108 /138) and 77.2% (71 /92), respectively. Twelve months after PVP recurrent back pain developed in 39 patients, with a recurrence of 23.9% (39 /163). Of these 39 patients, cancerous infiltration around bone cement was seen in 6 and new vertebral metastases in 33. The average survival time of 163 patients was (10.48 ± 10.47) months. The survival time in 54 patients with breast or prostate cancer was (15.4 ± 11.7) months, which was significantly longer than that in 105 patients with lung, liver, gastrointestinal or kidney cancer (8.5 ± 8.1 months, P < 0.05). During the following-up period 136 patients died. The main cause of death was the deterioration of primary cancer and multi-systemic failure due to metastases. Fifty-eight patients showed paravertebral bone cement leakage on CT scans, but clinically they were asymptomatic. Conclusion: PVP is an effective and safe procedure for treating symptomatic vertebral metastases. It can rapidly relieve the pain and keep the vertebral condition stable for long time. The recurrence of back pain is mainly caused by newly-developed vertebral metastasis. Patient's survival time is closely related to the pathologic behavior of the primary cancer and co-existing visceral metastases. (authors)