A Study of Treatment for Medulloblastoma Using Sodium Thiosulfate to Reduce Hearing Loss

This phase III trial tests two hypotheses in patients with low-risk and average-risk medulloblastoma. Medulloblastoma is a type of cancer that occurs in the back of the brain. The term, risk, refers to the chance of the cancer coming back after treatment. Subjects with low-risk medulloblastoma typically have a lower chance of the cancer coming back than subjects with average-risk medulloblastoma. Although treatment for newly diagnosed average-risk and low-risk medulloblastoma is generally effective at treating the cancer, there are still concerns about the side effects of such treatment. Side effects or unintended health conditions that arise due to treatment include learning difficulties, hearing loss or other issues in performing daily activities. Standard therapy for newly diagnosed average-risk or low-risk medulloblastoma includes surgery, radiation therapy, and chemotherapy (including cisplatin). Cisplatin may cause hearing loss as a side effect. In the average-risk medulloblastoma patients, this trial tests whether the addition of sodium thiosulfate (STS) to standard of care chemotherapy and radiation therapy reduces hearing loss. Previous studies with STS have shown that it may help reduce or prevent hearing loss caused by cisplatin. In the low-risk medulloblastoma patients, the study tests whether a less intense therapy (reduced radiation) can provide the same benefits as the more intense therapy. The less intense therapy may cause fewer side effects. Radiation therapy uses high energy x-rays to kill tumor cells and shrink tumors. Cisplatin is in a class of medications known as platinum-containing compounds. It works by killing, stopping or slowing the growth of cancer cells. The overall goals of this study are to see if giving STS along with standard treatment (radiation therapy and chemotherapy) will reduce hearing loss in medulloblastoma patients and to compare the overall outcome of patients with medulloblastoma treated with STS to patients treated without STS on a previous study in order to make sure that survival and recurrence of tumor is not worsened.