Systematic reviewSystemic review of the patterns of failure following stereotactic body radiation therapy in early-stage non-small-cell lung cancer: Clinical implications
Section snippets
Methods and materials
This systematic review was designed to investigate the patterns of failure following SBRT for early-stage NSCLC; the impact of dose expressed as the BED at the isocenter and/or at the periphery of the target volume, and tumor size as predictors for local control and survival; the toxicity profile of SBRT, and the feasibility of SBRT for centrally located tumors. A search based on PubMed electronic databases was conducted to select studies outlining the following: local–regional control, distant
Patterns of failure after SBRT
Thirty-five studies detailing the clinical outcome of SBRT in early-stage NSCLC published from 2002 to 2009 were analyzed. These studies included primarily medically inoperable stage I tumors ⩽5–6 cm, with some including T3, recurrent, and metastatic lesions as well [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [63]. The median patient age
Discussion
Excellent local control following SBRT in early stage, and mostly stage I, NSCLC has been demonstrated in most studies. This finding is fairly consistent among studies regardless of follow-up duration [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [63]. Furthermore, a 5-year OS of 45.29 ± 20.10% (Table 2) after SBRT for stage I NSCLC is
Conclusion
SBRT can be safely delivered with clinical efficacy comparable to surgery in mostly medically inoperable stage I NSCLC. BEDiso of ⩾100 Gy10 has been associated with superior local control and survival rates, and adopted widely. However, BEDperiphery accounting for the dose at the target volume margin is also very important and should be maintained to approximately 80–100 Gy10. A higher total dose than that needed for T1 lesions is necessary for tumors >3 cm in order to achieve optimal tumor
Future directions
Multiple RTOG phase I/II or phase II studies are currently ongoing to further define the toxicity profile and treatment efficacy of SBRT in early-stage NSCLC ⩽5 cm. SBRT’s efficacy in inoperable and operable patients is being investigated in RTOG 0236, and RTOG 0618, respectively. Its feasibility in centrally located tumors is being assessed in RTOG 0813. A Japanese phase II study JCOG 0403 was opened to evaluate the efficacy of SBRT in stage IA NSCLC [25]. To further evaluate the efficacy of
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