Radiation therapy. Trends in treatment

Newer techniques in radiation therapy allow delivery of high-dose irradiation to selected, limited-size volumes. Trials of interstitial brain implantation of radioactive ¹²⁵Iodine or ¹⁹²Iridium, direct instillation of the radiocolloid ³²Phosphorus, or high-technology focused radiosurgery address the impact of very high local doses to improve tumor control while limiting exposure to the surrounding normal brain. In conjunction with conventional radiation techniques and ongoing trials of the radiosensitizing capabilities of cisplatin or other agents, the new approaches provide improvements in the therapeutic ratio for several types of childhood brain tumors.