Background and purpose: The aim was to investigate the incidence of isolated regional failure following stereotactic ablative radiotherapy (SABR) and risk factors for recurrence.Materials and... Show moreBackground and purpose: The aim was to investigate the incidence of isolated regional failure following stereotactic ablative radiotherapy (SABR) and risk factors for recurrence.Materials and methods: Early stage non-small cell lung cancer (NSCLC) patients treated with SABR were included in this retrospective cohort study, with isolated regional recurrence (IRR) as primary endpoint, distant recurrence (DR) and overall survival (OS) as secondary endpoints. Survival analyses were performed using the cumulative incidence function (IRR and DR) or the Kaplan-Meier method (OS) and Cox proportional hazards modelling for univariate and multivariate analyses. The prognostic effect of contact between the tumour and the pleura was investigated using the CT scans used for SABR planning.Results: A total of 554 patients were included, of whom 494 could be analysed for IRR. The median follow-up for surviving patients was 48.1 months. Twenty-one patients developed an IRR (4%). The cumulative incidence of IRR and DR after 1-, 2-, and 5 years was 2%, 3%, 7% and 8%, 15% and 21%, respectively. Two year OS was 71%. The presence and type of pleural contact was not associated with any of the studied outcomes.Conclusion: The presence, type and length of pleural contact as surrogate for visceral pleural invasion were not predictive for outcome. Further studies focussing on risk factors for occult nodal involvement, (I) RR, distant metastases and mortality in early stage NSCLC are warranted for the development of risk adapted diagnostic, treatment and follow-up strategies as more younger, operable and fitter patients receive SABR. (C) 2018 Elsevier B.V. All rights reserved. Show less
Wink, K.C.J.; Baardwijk, A. van; Troost, E.G.C.; Ruysscher, D. de 2017
Stereotactic body radiotherapy (SBRT) is an alternative to surgery for patients with early stage non-small cell lung cancer (NSCLC) who are inoperable due to comorbid disease or who refuse surgery.... Show moreStereotactic body radiotherapy (SBRT) is an alternative to surgery for patients with early stage non-small cell lung cancer (NSCLC) who are inoperable due to comorbid disease or who refuse surgery. SBRT results in an excellent local control rate of more than 90%, which is comparable to surgery, while short and long-term overall toxicity is low. Surgically treated patients are often more extensively staged pre-operatively, e.g. with endobronchial ultrasound and/or mediastinoscopy, and typically undergo intra-operative lymph node dissection or sampling. Occult nodal metastases (ONM), detected by lymph node dissection, have been shown to increase the incidence of regional recurrence (RR) after surgery, which is associated with poor outcome. In patients undergoing SBRT, however, definite pathological nodal staging is lacking and so other ways to identify patients at high risk for ONM and RR are desirable.The aim of this systematic review is to summarize the incidence of, and risk factors for, RR after SBRT and compare these to those after surgery. The available evidence shows the incidence of RR after SBRT or surgery to be comparable, despite more elaborate pre- and intra-operative lymph node evaluation in surgical patients. However, the fact that this finding is based on mostly retrospective studies in which the majority of patients treated with SBRT were inoperable, needs to be taken into consideration. For now, there is no evidence that inoperable clinical stage I patients with no indication of pathological lymph nodes on PET/CT will benefit from more invasive lymph node staging prior to SBRT. (C) 2017 Elsevier Ltd. All rights reserved. Show less
