A newly designed radiation port for medulloblastoma to prevent metastasis to the cribriform plate region.

Nine children with medulloblastoma were treated at Chiba University Hospital from 1977 to 1983. Of these cases, metastases to the cribriform plate region were found in two cases. Portal film showed that cribriform-plate region was not included in a conventional whole-brain radiation port to shield the eyes. Since 1983, we have applied a newly designed radiation port to treat childhood medulloblastoma. The new method consists of two parallel, opposed, lateral ports including the cribriform plate and the first two cervical vertebrae, similar to Pinkel's method. It has been confirmed that this method covers completely the whole brain and is safe for the lens. A characteristic of our method is that the landmark of the lower margin of the radiation port can be easily delineated on the patient's face. We believe that this method contributes to the treatment of medulloblastoma.