[Percutaneous radio-frequency ablation (PRFA) in painful metastases involving bone]

The aim of the study was to determine the efficacy of PRFA in the palliative treatment of symptomatic bone metastases in regard to pain reduction, safety, and quality of life.

Over a period of 11 months, ten PRFA were performed in eight patients with painful metastases involving bone, where conventional treatment with radiation therapy, chemotherapy, and treatment with analgesics had failed to reduce the pain efficiently. Pain was measured with the visual analogue scale (VAS: 0 to 10) for the day and night before PRFA was performed, and daily for 7 days after release from the hospital via a dietary book, and at the follow-up periods of 1, 3, 6 weeks and 3 and 6 months after PRFA. Additionally, quality of life was self-assessed by the patient via the health surveys IQOLA SF-36 and EORTC QLQ-C30, and via the Karnofsky Performance Scale (KPS) by the physician at each follow-up. The patients' analgesics use was also recorded at the follow-up intervals and complications were monitored. Analysis of the primary end point was undertaken with paired comparison procedures.

Under conventional therapy, pain was specified by the patients as VAS min of 4.1 and VAS max of 9.3. Due to PRFA a reduction of the preinterventional pain (VAS) from 7.4 (+/- 1.9 SD) and 5.0 (+/- 2.7 SD) for day and night, subsequently, to 1.8 (+/- 1.6 SD, minus 75 percent) and 0.7 (+/- 0.7 SD, minus 86 percent) was achieved within one day after admission to the hospital. This significant reduction did not change during the whole follow-up period, and was also reflected in the ability to reduce analgesics and in the improvement of specific domains of SF-36 and QLQ-C30. However, no significant change was detected in the summary scales for mental and physical health. No serious complications were observed.

PRFA of symptomatic bone metastases is a safe technology to reduce pain intractable to conventional therapy, even in terminally ill patients.