Neutron Therapy of Bladder-carcinoma - Can a High-rate of Severe Complications Be Avoided in Neutron Therapy

We reviewed retrospectively a series of 58 patients with deeply invasive bladder cancer treated with fast neutron therapy (p(65) + Be) in order to evaluate its tolerance and side effects. Patients were divided into three groups according to treatment technique. Patients of group A received whole pelvis irradiation up to 50 Gy photon equivalent followed by a boost to the bladder up to 57-66 Gy photon equivalent (40-56 days). Group B patients were treated by a split course regimen of 30 Gy photon equivalent on the whole pelvis at 3-4 weeks interval (66-108 days). Group C patients, not suitable for radical treatment, received only 40-54 Gy photon equivalent (26-70 days). The overall 5-year actuarial survival rate was 30% (SE 8%). As expected, T stage was a statistically significant prognostic factor. The overall local control rate reached 21% at 4 years. Acute and late side effects were minimal to moderate. These results suggest that high-energy neutron beam treatment is at least as effective as photon beam treatment for bladder carcinoma, without a higher incidence of major side effects.