Late-course hypofractionated stereotactic radiotherapy for locally advanced non-small cell lung cancer

Objective: To evaluate the effect of late-course hypofractionated stereotactic radiotherapy (LCHSRT) on locally advanced non-small cell lung cancer. Methods: From October 1997 to June 1999, 106 patients with locally advanced non-small cell lung cancer were randomized into conventional radiotherapy group (CRT) and LCHSRT group. Ninety-one patients with complete data were analyzed including 43 patients in CRT group and 48 patients in LCHSRT group. In CRT group, 18 patients were staged IIIa and 25 IIIb; whereas 19 patients were staged IIIa and 29 IIIb in LCHSRT group. The initial median dose of 43.5 Gy was given in CRT group to the primary tumor, ipsilateral hilum and mediastinum using AP-PA fields with 1.8-2.0 Gy per fraction, then 21.7 Gy was boosted to the residual primary and metastatic regional lymph nodes to the median total dose of 65.2 Gy. In LCHSRT group, after the first 44.4 Gy to the primary tumor, ipsilateral hilar region and mediastinum by AP-PA fields with a dose fraction of 1.8-2.0 Gy, noncoplanar arc hypofractionated stereotactic radiotherapy was delivered to the residual primary and metastatic lymph nodes to the total dose of (22.8 ± 5.5) Gy with 4-7 Gy per fraction treated every other day. Results: The radiation pneumonitis rates were 11.6% and 14.6% in CRT group and LCHSRT group, respectively. The radiation pulmonary fibrosis rates diagnosed by CT scan 6 months after radiotherapy were 48.8% and 66.7% in CRT group and LCHSRT group, respectively. The complete regression (CR) rates evaluated by CT scan 3 months after treatment in CRT and LCHSRT group were 30.2% and 63.5%, respectively (P<0.01). The 1-year local tumor control rates and the 1-year survival rates in CRT and LCHSRT group were 62%, 86.5% (P=0.054) and 55.8%, 79.2% (P<0.05), respectively. However, there was no statistical difference in 2-year survival between the two groups. Conclusions: Late-course hypofractionated stereotactic radiotherapy is a way to escalate the radiation dose to locally advanced non-small cell lung cancer. (and others)