From basic principles advocated by Fletcher, it is thought that standard fractionated RT doses up to 100.0 Gy may be necessary to sterilize tumors of the size frequently encountered in clinical practice. Tumor control probability for bronchogenic carcinoma can be estimated to be 10% for tumors of greater than 4 cm at a dose of 80.0 Gy, with an assumption, that an average-size lung cancer may require doses beyond 100.0 Gy standard fractionated to have a 50% to 80% probability of controlling the tumor. This has been demonstrated in the "stereotactic radioablation" approach to patients with the medically inoperable Stage I NSCLC, in whom 20 Gy per fraction to a total of 60 Gy (a BED equivalent of >100 Gy) resulted in an excellent local control of >90% (Timmerman R et al, 2006; Onishi H et al, 2007).