NCT07043543

Evaluation of the Clinical Utility of Online Adaptive Radiotherapy in Bladder Cancer (BLADAPT-GETUG V11)

Randomized Open Phase II Multienter Study Evaluating the Clinical Utility of Online Adaptive Radiotherapy in Bladder Cancer

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 120 (estimated)
• Sponsor: Institut du Cancer de Montpellier - Val d'Aurelle · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Trimodal therapy (TMT) consisting of transurethral resection of bladder tumors followed by radiotherapy and chemotherapy is a therapeutic alternative in patients with Muscle-Infiltrating Bladder Cancer who are inoperable or refuse surgery. One of the main challenges of TMT is the planning and delivery of radiation therapy. Indeed, the bladder is a mobile hollow organ subject to repletion, with variations in size and shape during and between radiotherapy sessions. Standard radiotherapy techniques require large planning target volume margins around the bladder, which can be responsible for irradiation of a large volume of large and small bowel with grade 2 and 3 toxicities. Adaptive radiotherapy allows for the generation of a treatment fraction personalized to a patient's anatomical modification with margin reduction and improves the dosimetric quality of the delivered plans. The hypothesis is that this improvement results in radiation-induced toxicity improvement.

Detailed description

In 2023, the incidence of muscle-infiltrating bladder cancer (MIBC) in France was 14062 cases, 81% of which were in men. The standard treatment for MIBC is cystectomy preceded by neoadjuvant chemotherapy. Trimodal therapy (TMT), consisting of transurethral resection of bladder tumors (TURBT) followed by radiotherapy (RT) and chemotherapy (CT), has emerged as a valuable therapeutic de-escalation alternative in patients who are inoperable or refuse surgery with its physical and psychological sequelae. TMT provides survival outcomes identical to cystectomy in selected patients and allows for bladder preservation in successful cases. TMT is an effective potential alternative to radical cystectomy for recurrent high-grade T1 urothelial cancer of the bladder who failed intravesical therapy. One of the main challenges of TMT is the planning and delivery of radiation therapy. Indeed, the bladder is a mobile hollow organ subject to repletion, with variations in size and shape during radiotherapy sessions (intra-fractional movement) and between sessions (inter-fractional movement). To take into account these movements, standard radiotherapy techniques require large planning target volume (PTV) margins around the bladder, which can be responsible for irradiation of a large volume of large and small bowel with grade 2 and 3 toxicities up to 42% and 17% respectively. Adaptive radiotherapy (ART) allows for the generation of a treatment fraction personalized to a patient's anatomical modification. While it was until recently only performed "offline", i.e. between two radiotherapy sessions, it is now possible to perform a daily customization of the radiotherapy session ("online") for a given patient to ensure optimal coverage of the target with minimized margins. ART allows PTV margins reduction for MIBC and improves therefore the dosimetric quality of the delivered plans. The hypothesis is that the dosimetric improvement induced by ART results in radiation-induced toxicity improvement.

Conditions

• Bladder Cancer

Interventions

Type	Name	Description
RADIATION	Adaptive radiotherapy	Patient will be treated by concomitant: * adaptive radiotherapy 5 days a week for 4 weeks with hypofractionated irradiation 55 Gy / 20 fractions +/- pelvic inclusion 44 Gy/20 fractions (SIB). * chemotherapy if not contraindicated : * Cisplatin : 20 mg/m2/day on day 1 to day 4 and day 22 to day 25 (or 80 mg/m2 during week 1 and 4 of radiotherapy) Or * Gemcitabine: 80 to 100 mg/m2/week Or * Mitomycin C: 12 mg/m2 on day 1 only + 5FU infusion 500 mg/m2/day during 5 days on week 1 and 4 of radiotherapy (alternatively : capecitabine taken twice daily at a dose of 825 per square meter per day on the days of radiotherapy)
RADIATION	standard radiotherapy	Patient will be treated by concomitant: * standard 5 days a week for 4 weeks with hypofractionated irradiation 55 Gy / 20 fractions +/- pelvic inclusion 44 Gy/20 fractions (SIB). * chemotherapy if not contraindicated : * Cisplatin : 20 mg/m2/day on day 1 to day 4 and day 22 to day 25 (or 80 mg/m2 during week 1 and 4 of radiotherapy) Or * Gemcitabine: 80 to 100 mg/m2/week Or * Mitomycin C: 12 mg/m2 on day 1 only + 5FU infusion 500 mg/m2/day during 5 days on week 1 and 4 of radiotherapy (alternatively : capecitabine taken twice daily at a dose of 825 per square meter per day on the days of radiotherapy)

Timeline

• Start date: 2026-01-15
• Primary completion: 2029-01-30
• Completion: 2033-09-30
• First posted: 2025-06-29
• Last updated: 2025-12-15

Locations

11 sites across 1 country: France