Three-dimensional conformal external radiotherapy using a cobalt-60 beam in patients with prostate cancer

Background: Three-dimensional (3-D) conformal is a new radiotherapy technique for patients with cancers, especially prostate cancer. This method combined with pelvic CT scan to target the lesion, is used to treat patients with low or intermediate risk of pelvic lymph node involvement. This allows for higher doses of irradiation, 70 Gy or higher, while lowering the dose imposed on nearby organs, such as the bladder and rectum. Depending on the risk of lymph node involvement, part or all of the treatment dose can be administered by the 3-D method. Methods: In this study, 27 patients received this treatment method, 14 of whom had received conventional radiotherapy first. Results: The results showed that, using this 3-D technique, a radiation dose of 70 Gy was administered without considerable acute urinary or gastrointestinal complications. Conclusion: The dose volume histogram demonstrated that the doses to the bladder and rectum are within an acceptable range.