Whole Pelvis versus Bladder Only Radiotherapy in Trimodality Therapy for Negative Lymph Node Muscle Invasive Bladder Cancer

Background: Trimodality therapy has been recommended as a valid treatment option for well-selected patients of muscle invasive bladder cancer (MIBC). The benefit of elective nodal irradiation during bladder radiotherapy (RT) remains a controversial topic.
Objectives: Our study comparing bladder only (BO) versus whole pelvis (WP) radiotherapy, concurrent with cisplatin to evaluate BO radiotherapy outcome and toxicity.
Patients and methods: A randomized prospective study comparing BO versus WP radiotherapy using 3D conformal radiotherapy concurrent with cisplatin followed by 4 cycles gemcitabine/cisplatin in nonmetastatic negative lymph node MIBC.
Results: Our cohortincluded 28 and 30 patients in BO and WP group, respectively. No statistically significant difference (P =0.59) was detected between 2 groups as regard disease free survival (DFS)rate at 3 years, which was 81% and 85 % in BO and WP group, respectively. At 3 years the reported bladder cancer specific survival and  overall survival(OS) rate in BO group was 83% and 75 %, respectively while for WP group the results were 80 % and 73%, respectively with no statistically significant difference between the 2 groups. Regarding RT toxicity, acute small bowel (P=0.03) and acute rectal toxicity (P=0.007) showed statistically significant difference favouring BO radiotherapy while acute genitourinary toxicity (P=0.91), late genitourinary (P =0.33) and late GIT toxicity (P=0.4) showed no statistically significant difference between the 2 groups.
Conclusion: BO radiotherapy concurrent with chemotherapy is an effective treatment option in patients with lymph node-negative MIBC with comparable oncologic outcomes and less RT toxicity when compared with WP radiotherapy.