TY - JOUR
T1 - The development and external validation of an overall survival nomogram in medically inoperable centrally located early-stage non-small cell lung carcinoma
AU - Duijm, M.
AU - Oomen-de Hoop, E.
AU - van Voort van der Zyp, N.
AU - van de Vaart, P.
AU - Tekatli, H.
AU - Hoogeman, M.
AU - Senan, S.
AU - Nuyttens, J.
N1 - Publisher Copyright: © 2021 Elsevier B.V.
PY - 2021/3/1
Y1 - 2021/3/1
N2 - Background and purpose: Current nomograms predicting survival prognosis after stereotactic body radiation therapy (SBRT) in non-small cell lung cancer (NSCLC) are based on peripherally located tumors. However, patients with a central lung tumor tend to be older, the tumor is often larger and fraction-schedules are risk-adapted. Therefore, we developed and externally validated a nomogram to predict overall survival (OS) in patients having centrally located early-stage NSCLC treated with SBRT. Materials and methods: Patients who underwent SBRT for centrally located NSCLC were identified and baseline characteristics were obtained. A nomogram was built to predict 6-month, 1-, 2- and 3-year OS using Cox proportional hazards model. The model building procedure was validated using bootstrap sampling. To determine generalizability, external validation was performed on a cohort of patients with central NSCLC treated with SBRT from another center. Discriminatory ability was measured with the concordance index (C-index) and calibration plots were used to compare Kaplan–Meier-estimated and nomogram-predicted OS. Results: The nomogram was built on data of 220 patients and consisted of the following variables: PTV, age, WHO performance status, tumor lobe location and ultracentral location. The C-index of the nomogram (corrected for optimism) was moderate at 0.64 (95% confidence interval (CI) 0.59–0.69). Calibration plots showed favorable predictive accuracy. The external validation showed acceptable validity with a C-index of 0.62 (95% CI 0.61–0.64). Discussion: We developed and externally validated the first nomogram to estimate the OS-probability in patients with centrally located NSCLC treated with SBRT. This nomogram is based on 5 patient and tumor characteristics and gives an individualized survival prediction.
AB - Background and purpose: Current nomograms predicting survival prognosis after stereotactic body radiation therapy (SBRT) in non-small cell lung cancer (NSCLC) are based on peripherally located tumors. However, patients with a central lung tumor tend to be older, the tumor is often larger and fraction-schedules are risk-adapted. Therefore, we developed and externally validated a nomogram to predict overall survival (OS) in patients having centrally located early-stage NSCLC treated with SBRT. Materials and methods: Patients who underwent SBRT for centrally located NSCLC were identified and baseline characteristics were obtained. A nomogram was built to predict 6-month, 1-, 2- and 3-year OS using Cox proportional hazards model. The model building procedure was validated using bootstrap sampling. To determine generalizability, external validation was performed on a cohort of patients with central NSCLC treated with SBRT from another center. Discriminatory ability was measured with the concordance index (C-index) and calibration plots were used to compare Kaplan–Meier-estimated and nomogram-predicted OS. Results: The nomogram was built on data of 220 patients and consisted of the following variables: PTV, age, WHO performance status, tumor lobe location and ultracentral location. The C-index of the nomogram (corrected for optimism) was moderate at 0.64 (95% confidence interval (CI) 0.59–0.69). Calibration plots showed favorable predictive accuracy. The external validation showed acceptable validity with a C-index of 0.62 (95% CI 0.61–0.64). Discussion: We developed and externally validated the first nomogram to estimate the OS-probability in patients with centrally located NSCLC treated with SBRT. This nomogram is based on 5 patient and tumor characteristics and gives an individualized survival prediction.
KW - Nomogram
KW - Non-small cell lung carcinoma
KW - Stereotactic body radiotherapy
KW - Survival
UR - http://www.scopus.com/inward/record.url?scp=85100152150&partnerID=8YFLogxK
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85100152150&origin=inward
UR - https://www.ncbi.nlm.nih.gov/pubmed/33418006
U2 - https://doi.org/10.1016/j.radonc.2020.12.038
DO - https://doi.org/10.1016/j.radonc.2020.12.038
M3 - Article
C2 - 33418006
SN - 0167-8140
VL - 156
SP - 223
EP - 230
JO - Radiotherapy and oncology
JF - Radiotherapy and oncology
ER -