Int J Radiat Oncol Biol Phys. 2020 Oct 27:S0360-3016(20)34448-5. doi: 10.1016/j.ijrobp.2020.10.031. Online ahead of print.
BACKGROUND: /Objectives:Definitive radiotherapy (RT), with or without concurrent chemotherapy, is an alternative to radical cystectomy for patients with localized, muscle-invasive bladder cancer (MIBC) who are either not surgical candidates or prefer organ preservation. We aim to synthesize an evidence-based guideline regarding the appropriate use of RT.
METHODS: We performed a Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) literature review using the PubMed and Embase databases. Based upon the literature review, critical management topics were identified and reformulated into consensus questions. An expert panel was assembled to address key areas of both consensus and controversy using the modified Delphi framework.
RESULTS: A total of 761 articles were screened, of which 61 were published between 1975 to 2019 and included for full review. There were seven well-designed studies, 20 good quality studies, 28 quality studies with design limitations, and six references not suited as primary evidence. Adjuvant radiotherapy after cystectomy was not included due to lack of high-quality data or clinical utilization. An expert panel consisting of 14 radiation oncologists, one medical oncologist, and one urologist was assembled. We identified four clinical variants of MIBC: surgically fit patients who wish to pursue organ preservation, patients surgically unfit for cystectomy, patients medically unfit for cisplatin-based chemotherapy, and borderline cystectomy candidates based on age with unilateral hydronephrosis and normal renal function. We identified key areas of controversy, including use of definitive radiotherapy for patients with negative prognostic factors, appropriate radiotherapy dose, fractionation, fields and technique when used, and chemotherapy sequencing and choice of agent.
CONCLUSIONS: There is limited level-one evidence to guide appropriate treatment of MIBC. Studies vary significantly with regards to patient selection, chemotherapy utilization, and radiotherapy technique. A consensus guideline on the appropriateness of RT for MIBC may aid practicing oncologists in bridging the gap between data and clinical practice.