Combined kyphoplasty and intraoperative radiotherapy for painful vertebral metastases - a randomized phase III study

• Published in: BMC cancer Vol. 19; no. 1
• Main Authors: Bludau, Frederic, Welzel, Grit, Reis, Tina, Abo-Madyan, Yasser, Sperk, Elena, Schneider, Frank, Clausen, Sven, Ruder, Arne M, Obertacke, Udo, Ghaly, Maged M, Wenz, Frederik, Giordano, Frank A
• Format: Journal Article
• Language: English
• Published: BioMed Central Ltd 09.05.2019
• Subjects: Analgesia; Analysis; Cancer; Cancer metastasis; Care and treatment; Clinical trials; Medical research; Orthopedic surgery; Pain management; Radiotherapy; Skin; Tumors; Vertebroplasty
• ISSN: 1471-2407; 1471-2407
• DOI: 10.1186/s12885-019-5666-5

The spine is the most frequent location of bone metastases. Local treatment aims at palliation of pain and, given the increased likelihood of long-term cancer survival, at local control. Kyphoplasty and intraoperative radiotherapy (Kypho-IORT) provided instantaneous pain relief in 70% of patients at the first day after the intervention and resulted in local control rates of > 93% at 1 year in a recently conducted phase I/II trial. To assess its clinical value, we designed a phase III trial which tests Kypho-IORT against the most widespread standard-of-care, external beam radiotherapy (EBRT), in patients with painful vertebral metastases. This phase III study includes patients [greater than or equai to]50 years of age with up to 4 vertebral metastases and a pain score of at least 3/10 points on the visual/numeric analogy scale (VAS). Patients randomized into the experimental arm (A) will undergo Kypho-IORT (Kyphoplasty plus IORT with 8 Gy prescribed to 13 mm depth). Patients randomized into the control arm (B) will receive EBRT with either 30 Gy in 10 fractions or 8 Gy as a single dose. The primary end point is pain reduction defined as at least - 3 points on the VAS compared to baseline at day 1. Assuming that 40% of patients in the Kypho-IORT arm and 5% of patients in the control arm will achieve this reduction and 20% will drop out, a total of 54 patients will have to be included to reach a power of 0.817 with a two-sided alpha of 0.05. Secondary endpoints are evaluation of the percentage of patients with a pain reduction of at least 3 points at 2 and 6 weeks, local tumor control, frequency of re-intervention, secondary fractures/sintering, complication rates, skin toxicity/wound healing, progression-free survival (PFS), overall survival (OS) and quality of life. This trial will generate level 1 evidence on the clinical value of a one-stop procedure which may provide instantaneous pain relief, long-term control and shortened intervals to further adjuvant (systemic) therapies in patients with spinal metastases.