A Review of Ongoing Trials of Stereotactic Ablative Radiotherapy for Oligometastatic Cancers: Where Will the Evidence Lead?

Frontiers in Oncology

卷:9

Alexander V. Louie¹  David A. Palma²  Andrew J. Arifin²  George B. Rodrigues²  Faiez Al-Shafa² 

[1] Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, ON, Canada;

[2] Division of Radiation Oncology, London Regional Cancer Program, London, ON, Canada;

关键词: stereotactic;    radiotherapy;    SBRT;    SABR;    oligometastasis;   

DOI  :  10.3389/fonc.2019.00543

来源: DOAJ

【 摘 要 】

Purpose: The oligometastatic state is a proposed entity between localized cancer and widely metastatic disease, comprising an intermediate subset of metastatic cancer patients. Most data to support locally-directed treatment, such as stereotactic ablative radiotherapy (SABR), for oligometastases are from retrospective institutional reports. Following the success of a recently completed and reported phase II trial demonstrating important clinical outcomes, herein we review the current landscape of ongoing clinical trials in this context.Materials and methods: A review of currently activated and registered clinical trials was performed using the clinicaltrials.gov database from inception to February 2019. A search of actively recruiting trials, using the key words oligometastases, SABR, and various related terms was performed. Search results were independently reviewed by two investigators, with discrepancies settled by a third. Data abstracted from identified studies included study type, primary disease site, oncologic endpoints, and inclusion/exclusion criteria.Results: Of the initial 216 entries identified, 64 met our review eligibility criteria after full-text review. The most common study type was a phase II clinical trial (n = 35, 55%) with other study designs ranging from observational registry trials to phase III randomized controlled trials (RCTs). A minority of trials were randomized in design (n = 17, 27%). While most studies allowed for metastases from multiple primary disease sites (n = 22, 34%), the most common was prostate (n = 13, 15%), followed by breast, gastrointestinal, non-small cell lung cancer (NSCLC), and renal (n = 6, 9% each). In studies with a solitary target site, the most common was liver (n = 6, 9%) followed by lung (n = 3, 5%). The most common primary endpoints were progression-free survival (PFS) (n = 20, 31%) and toxicity (n = 10, 16%). A combined strategy of systemic therapy and SABR was an emerging theme (n = 23, 36%), with more recent studies specifically evaluating SABR and immunotherapy (n = 9, 14%).Conclusion: The safety and efficacy of SABR as oligometastasis-directed treatment is increasingly being evaluated within prospective clinical trials. These data are awaited to compliment the abundance of existing observational studies and to guide clinical decision-making.

【 授权许可】

Unknown