As reported on Radiology Business, the American Society for Radiation Oncology (ASTRO) has released its inaugural clinical practice guideline dedicated to the use of radiation therapy in bladder cancer, highlighting bladder-preserving trimodal therapy as an effective curative option for carefully selected patients with muscle-invasive disease.
For decades, radical cystectomy, the surgical removal of the bladder, has been considered the standard treatment for muscle-invasive bladder cancer. While effective, the procedure requires urinary diversion following bladder removal. ASTRO’s new guidance emphasizes that some patients may achieve comparable curative outcomes while retaining their bladder through a trimodal treatment strategy that combines maximal transurethral tumor resection, radiation therapy, and concurrent chemotherapy.
Beyond bladder preservation, the recommendations outline broader applications for radiation therapy throughout the disease continuum. The guideline addresses postoperative treatment after cystectomy as well as radiation use in patients with advanced or symptomatic bladder cancer.
According to the guidance, the best candidates for bladder-preserving treatment are patients with cT2-4aN0M0 disease who present with a single tumor smaller than 7 cm, predominantly urothelial histology, and no extensive carcinoma in situ or hydronephrosis. The document also stresses the importance of post-treatment cystoscopic assessment and long-term surveillance to monitor for recurrence.
ASTRO additionally advises consideration of postoperative radiation therapy for patients facing a heightened risk of locoregional recurrence after cystectomy. This group includes individuals with pT3-4 disease, lymph node involvement, or positive surgical margins.
In advanced bladder cancer, radiation therapy may help manage local tumor growth and alleviate symptoms such as pain and bleeding. The guideline also notes that targeted radiation to a limited number of metastatic sites may be appropriate for select patients who have responded well to systemic therapy. However, bladder-directed radiation is not recommended for patients with asymptomatic, high-volume metastatic disease.
The recommendations include technical guidance on treatment delivery, favoring intensity-modulated radiation therapy (IMRT) paired with daily image guidance. Additional considerations cover radiation dose, treatment schedules, target volume selection, and situations in which clinicians should boost the primary tumor or include pelvic lymph nodes in the treatment field.
Developed by a multidisciplinary expert panel, the guideline is based on a systematic review of research published between 2009 and 2024. The effort was undertaken in collaboration with the American Society of Clinical Oncology, the European Association of Urology, and the European Society for Radiotherapy and Oncology, with endorsement from the European Association of Urology.
The new guidance provides clinicians with a comprehensive framework for incorporating radiation therapy into bladder cancer management, from organ-preserving curative treatment to postoperative care and symptom control in advanced disease.
