Hypofractionation for Lung Tumors (Primary Malignant, Secondary Malignant)

Surgery has traditionally been the standard of care for early-stage (T1–T2 N0) NSCLC and lung metastases as local control with conventionally fractionated EBRT was clearly inferior to surgical resection. However, the emergence of SBRT (1–5 fractions of >5 Gy/fx) for lung lesions is challenging this standard as local control rates of >80–95% can be achieved with either modality. Less extreme hypofractionation (15–25 fractions of 2.5–3.5 Gy/fx) regimens have also been utilized in an attempt to escalate the BED of radiation for more advanced (stages III–IV) NSCLC. Clinical experience has demonstrated that while these approaches can produce encouraging tumor control rates, they are not without the risk of severe, even fatal complications as a result of damage to the many critical structures located in the thorax. This chapter will review the sizeable literature for lung SBRT and hypofractionation regimens and highlight the technical considerations that are necessary to properly utilize these techniques.