Organ at risk?

Is it necessary to include the prostate in the treatment volume for muscle invasive bladder cancer? The prostate is removed during radical cystoprostatectomy, but how often does MIBC actually involve the prostate? In this retrospective study of 211 men who had radical cystoprostatectomy for MIBC, 22% had pathologic prostate stromal involvement. While the rate of prostate involvement increased with increasing pre-operative clinical T stage (18% T2, 23% T3, 48% T4), there was no significant difference in the rate of involvement for T2 versus T3 disease. In other words, using T2 versus T3 for guidance on including the prostate may not be extremely helpful. In fact, multivariable analysis showed that clinical urethral involvement was the only factor predictive of prostate stromal involvement. | Preyra, Pract Radiat Oncol 2022