The Hopeless Case? Palliative Cryoablation and Cementoplasty Procedures for Palliation of Large Pelvic Bone Metastases

Abstract

Background: Metastases to the bone are common in cancer patients, and it has been estimated that up to 50% of patients with pelvic bone metastases will not achieve adequate pain control with medications alone. This has led to a paradigm shift over recent years towards the use and development of minimally invasive image-guided treatment options for palliation of bony metastases. Despite these developments, large metastatic lesions are still often considered to be "hopeless cases" that would garner little to no benefit from image-guided intervention. This study is the first large series to describe the novel use of combination percutaneous cryoablation and cementoplasty for palliation of such large metastases to the pelvis.

Objectives: We aim to evaluate the efficacy and safety of image-guided percutaneous cryoablation and cementoplasty for palliation of large pelvic bone metastases.

Study design: This retrospective analysis was approved by our institutional review board. This study was conducted from January 2013 to December 2016, where consecutive patients referred for pain management of large pelvic bone metastases underwent combination percutaneous cryoablation and cementoplasty.

Setting: This study took place at a tertiary care center after patients were referred following formal review from a multidisciplinary conference, which was comprised of interventional radiologists, pain management and palliative care physicians, radiation and medical oncologists, and when available, anesthesiologists.

Methods: Forty-eight patients (36 men and 12 women) with a mean cohort age of 77.5 years (range: 52 - 89 years) were referred from the multidisciplinary conference for palliation of pelvic bone metastases. The inclusion criteria included patients with metastases greater or equal to 5.0 cm and significant pain refractory to conventional pain management regimens. All of the patients were deemed not to be surgical candidates. Mean pain scores were collected at numerous time-points along with procedural technical success rates and complication rates.

Results: Combination cryoablation and cementoplasty was performed on 48 consecutively referred patients with a 100% technical success rate and no immediate complications. The pain levels demonstrated a significant decrease (P < 0.001) following intervention, with mean pain scores of 7.9 (range: 5 - 10) and 1.2 (range: 0 - 7) throughout the week prior to intervention and at 24 hours post-intervention, respectively. The post-intervention pain scores remained stable at 1 to 9 weeks follow-up (mean: 4.1 weeks). Three patents (6.3%) reported no change in pain following the intervention; however, no patients reported worsened pain.

Limitations: The limitations of this study include its retrospective nature and the length of follow-up, which was often restricted given the life expectancy of our patient cohort.

Conclusion: Combination cryoablation and cementoplasty is a novel and efficacious treatment option for palliation of large pelvic bone metastases. Marked improvements in pain, as well as mobility and quality of life, are often attainable.

Key words: Pain, palliative care, palliation, percutaneous, cryoablation, cementoplasty, metastases, pelvis, interventional radiology, thermal ablation.