A Current Review of Spatial Fractionation: Back to the Future?

摘要: Spatially fractionated radiation therapy represents a significant departure from canonical thinking in oncology despite having origins the early 1900s. The original and most common implementation of spatially uses commercially available blocks or multileaf collimators to deliver nonconfluent, sieve-like pattern target volume nonuniform dose distribution. Dosimetrically, this is parameterized by ratio valley cold spots peak hot spots, valley-to-peak ratio. radiobiologic mechanisms are postulated involve radiation-induced bystander effects, microvascular alterations, and/or immunomodulation. Current indications include bulky locally advanced disease that would not be amenable conventional has proved refractory chemoradiation. Early-phase clinical trials have shown remarkable success, with some response rates >90% minimal toxicity. This promoted technological developments 3-dimensional formats (LATTICE), micron-size beams (microbeam), proton arrays. Nevertheless, more biological data needed specify ideal dosimetry parameters formulate robust guidelines for optimal standardized care.