The Clinical Outcomes, Prognostic Factors and Nomogram Models for Primary Lung Cancer Patients Treated With Stereotactic Body Radiation Therapy

Li-Mei Luo,Chuang-Huang Su,Bao-Tian Huang,Pei-Xian Lin,Ying Wang

doi:10.3389/fonc.2022.863502

Abstract

PurposeStereotactic body radiation therapy (SBRT) is a standard treatment for early primary lung cancer patients. However, there are few simple models for predicting the clinical outcomes of these patients. Our study analyzed the clinical outcomes, identified the prognostic factors, and developed prediction nomogram models for these patients.Materials and MethodsWe retrospectively analyzed 114 patients with primary lung cancer treated with SBRT from 2012 to 2020 at our institutions and assessed patient’s clinical outcomes and levels of toxicity. Kaplan–Meier analysis with a log-rank test was used to generate the survival curve. The cut-off values of continuous factors were calculated with the X-tile tool. Potential independent prognostic factors for clinical outcomes were explored using cox regression analysis. Nomograms for clinical outcomes prediction were established with identified factors and assessed by calibration curves.ResultsThe median overall survival (OS) was 40.6 months, with 3-year OS, local recurrence free survival (LRFS), distant disease-free survival (DDFS) and progression free survival (PFS) of 56.3%, 61.3%, 72.9% and 35.8%, respectively, with grade 3 or higher toxicity rate of 7%. The cox regression analysis revealed that the clinical stage, immobilization device, and the prescription dose covering 95% of the target area (D95) were independent prognostic factors associated with OS. Moreover, the clinical stage, and immobilization device were independent prognostic factors of LRFS and PFS. The smoking status, hemoglobin (Hb) and immobilization device were significant prognostic factors for DDFS. The nomograms and calibration curves incorporating the above factors indicated good predictive accuracy.ConclusionsSBRT is effective and safe for primary lung cancer. The prognostic factors associated with OS, LRFS, DDFS and PFS are proposed, and the nomograms we proposed are suitable for clinical outcomes prediction.

Highlights

Lung cancer is the second most common malignancy and the main cause of cancer-related deaths worldwide [1]
We aimed to identify clinical and dosimetric factors associated with clinical outcomes and develop the prediction nomogram models to assess clinical prognosis to guide reasonable medical strategies
The bootstrap-corrected calibration curves showed that the nomogram models for overall survival (OS), local recurrence-free survival (LRFS), distant disease-free survival (DDFS), and progressionfree survival (PFS) all had good prediction efficiency (Figure 7). These results demonstrated that all the four prediction nomogram models might be prognostic tools used for the clinical management of lung cancer patients

Summary

Introduction

Lung cancer is the second most common malignancy and the main cause of cancer-related deaths worldwide [1]. Stereotactic body radiation therapy (SBRT) is considered a reasonable, efficient, noninvasive, and safe therapy in primary lung cancer patients who are declining surgery resection or medically inoperable due to comorbid diseases [2–4]. SBRT uses image guidance and a precise immobilization system while providing ablation radiation prescription dose to the tumor target and rapidly reducing the dose outside the target to weaken the effects in adjacent critical organs [5]. Many retrospective and prospective studies have suggested promising clinical outcomes and safety of lung cancer treated with SBRT, with 3-year overall survival approaching 56% and locoregional control achieving 88% [6]. The outcome of SBRT is superior to conventionally fractionated radiotherapy and comparable to surgery for patients who are suitable for surgery [7, 8]. There are still some failure patterns that have to be considered by the medical community

Objectives

Methods

Results

Discussion

Conclusion