Long-term outcomes of stereotactic body radiation therapy (SBRT) with fiducial tracking for inoperable stage I non-small cell lung cancer (NSCLC)

Abstract

BackgroundStereotactic body radiation therapy (SBRT) for stage I non-small cell lung cancer (NSCLC) is considered standard of care in the medically inoperable patient population. Multiple methods of SBRT delivery exist including fiducial-based tumor tracking, which allows for smaller treatment margins and avoidance of patient immobilization devices. We explore the long-term clinical outcomes of this novel fiducial-based SBRT method.MethodsIn this single institutional retrospective review, we detail the outcomes of medically inoperable pathologically confirmed stage I NSCLC. Patients were treated with the Cyberknife SBRT system using a planning target volume (PTV) defined as a 5-mm expansion from gross tumor volume (GTV) without creation of an internal target volume (ITV). Dose was delivered in three or five equal fractions of 10 to 20 Gy. Pretreatment and posttreatment pulmonary function test (PFT) changes and evidence of late radiological rib fractures were analyzed for the majority of patients. Actuarial local control, locoregional control, distant control, and overall survival were calculated using the Kaplan-Meier method.ResultsSixty-one patients with a median age of 75 years were available for analysis. The majority (80 %) of patients were deemed to be medically inoperable due to underlying pulmonary dysfunction. Eleven patients (18 %) developed symptomatic pneumothoraces secondary to fiducial placement under CT guidance, which precipitously dropped to 0 % following transition to bronchoscopic fiducial placement. The 2-year rib fracture risk was 21.4 % with a median time to rib fracture of 2.9 years. PFTs averaged over all patients and parameters demonstrated small absolute declines, 5.7 % averaged PFT decline, at approximately 1 year of follow-up, but only the diffusing capacity of lung for carbon monoxide (DLCO) demonstrated a statistically significant decline (10.29 vs. 9.01 mL/min/mmHg, p = 0.01). Five-year local control, locoregional control, and overall survival were 87.6, 71.8, and 39.3 %, respectively.ConclusionsDespite reduced treatment margins and lack of patient immobilization, SBRT with fiducial-based tumor tracking achieves clinically comparable long-term outcomes to other linac-based SBRT approaches.

Predictors of chest wall toxicity after stereotactic ablative radiotherapy using real-time tumor tracking for lung tumors

“…Difference of selection criteria of included patients and different fractionation scheme precludes direct comparison between studies, however, the incidence of RIRF in our study was lower than those in previous studies, in general. Recently, Lischalk et al reported long-term outcome of non-small cell lung cancer patients treated with Cyberknife® using fiducial tracking [25]. Although their incidence of rib fracture was higher (21.4% in 2 years) than that in our study, it was relatively lower than those in most other studies.…”

Survival After Stereotactic Body Radiation Therapy for Clinically Diagnosed or Biopsy-Proven Early-Stage NSCLC: A Systematic Review and Meta-Analysis

“…The pooled estimate for 5-year OS for biopsy-proven disease (n ¼ 8101) was not significantly different 17,19,25,27,28,[32][33][34][35]38,39,41,42,[44][45][46][48][49][50]52,53,55,59 respectively (Fig 3). For 3-year OS, there was no difference between clinical disease 19 21,26,30,31,36,40,46,49,51,54,56,58,59 for biopsy-proven disease (n ¼ 998 and n ¼7249), respectively.…”

MiR-99a Enhances the Radiation Sensitivity of Non-Small Cell Lung Cancer by Targeting mTOR

“…Therefore, the identification of methods to improve the survival rate of patients with NSCLC has become an important task [2]. At present, treatment for NSCLC includes surgery, chemotherapy, and radiotherapy [3], of which radiotherapy is the main approach [4]. Nevertheless, despite the great efforts that have been exerted to develop radiation therapies for NSCLC patients, the 5-year overall survival rate still remains less than 15% [1, 5].…”