Specific toxicity after stereotactic body radiation therapy to the central chest. A comprehensive review

The toxicity of stereotactic body radiation therapy in the central chest remains an unsettled issue. The collected data concerning the observed complications are poorly understood and are limited in their quantity and quality, thus hampering a precise delineation of treatment-specific toxicity. The majority of complications scored as toxicity grade 5, namely respiratory failure and fatal hemoptysis, are most likely related to multiple competing risks and occurred at different dose fractionation schemas, e. g., 10-12 fractions of 4-5 Gy, 5 fractions of 10 Gy, 3 fractions of 20-22 Gy, and 1 fraction of 15-30 Gy. Further investigations with longer follow-up and more details of patients' pretreatment and tumor characteristics are required. Furthermore, satisfactory documentation of complications and details of dosimetric parameters, as well as limitation of the wide range of possible fractionation schemes is also warranted for a better understanding of the risk factors relevant for macroscopic damage to the serially organized anatomic structure within the central chest. (orig.)