Stereotactic body radiation therapy for stage I medically operable non-small cell lung cancer

Establishing a prognostic scoring system and exploring prognostic value of examined lymph node numbers for stage I non-small cell lung cancer: a retrospective study of Surveillance, Epidemiology, and End Results (SEER) database and a Chinese cohort

Background

There is currently no recognized assessment system to predict disease outcomes for stage I non-small cell lung cancer (NSCLC). This research aimed to develop a prognostic scoring system for predicting 5-year overall survival (OS) of individuals with stage I NSCLC following definitive therapeutic intervention. Additionally, the optimal number of examined lymph nodes (ELNs) count for tumors no larger than 30 mm was determined.

Methods

Patients (n=22,617) diagnosed with stage I NSCLC from 2007 to 2015 who underwent definitive treatment (pulmonary lobectomy, pulmonary sublobectomy, or radiotherapy) were identified from the Surveillance, Epidemiology, and End Results (SEER) database. There were 400 Chinese patients with stage I NSCLC diagnosed in 2017 enrolled for external validation. The nomogram was constructed based on gradient boosting machine. The optimal ELNs in patients with tumors ≤30 mm and node-negative undergoing pulmonary lobectomy or pulmonary sublobectomy were determined using log-rank test and validated by multivariable analysis.

Results

Age at diagnosis, histology, differentiated grade, tumor staging, number of ELNs, and definitive treatment pattern were recognized as important factors for 5-year OS. The prognostic scoring system exhibited superior discrimination accuracy, calibration ability, and net clinical benefit compared to the tumor, node, metastasis (TNM) staging system. For patients with tumors ≤30 mm, more than 10 and 20 ELNs demonstrated the maximum OS difference during lobectomy and sublobectomy, respectively.

Conclusions

This prognostic scoring system will anticipate the prognosis of stage I NSCLC patients after radical treatment, thereby offering individualized treatment recommendations for both clinicians and patients. A minimum of 10 ELNs during lobectomy and 20 ELNs during sublobectomy are necessary for small-sized NSCLC.

Quantitative evaluation of accumulated and planned dose deviations in patients undergoing gated and non-gated lung stereotactic body radiation therapy patients: a retrospective analysis

Background

Stereotactic body radiation therapy (SBRT) is crucial for treating early-stage inoperable non-small cell lung cancer (NSCLC) due to its precision and high-dose delivery. This study aimed to investigate the dosimetric deviations in gated (GR) versus non-gated radiotherapy (NGR), analyzing the impact of tumor location, target volume, and tumor motion range on dose distribution accuracy.

Methods

Sixty patients treated with either gated (n=30) or non-gated (n=30) SBRT for early-stage NSCLC were retrospectively analyzed. The planned dose distributions were determined using four-dimensional computed tomography simulations to account for breathing motion, while the actual dose delivered was determined by accumulating each fractional dose with synthetic computed tomography (sCT) methods. The deviations between the planned and actual accumulated doses were statistically analyzed for both groups. The effects of tumor location and volume on dose distribution were also assessed.

Results

Gated SBRT showed significantly higher dosimetric precision with median relative changes in the minimum dose within the ITV (ITV_Dmin), mean dose received by the ITV (ITV_Dmean), and maximum dose within the ITV (ITV_Dmax) of -0.44%, -0.33%, and -0.49%, respectively. Non-gated SBRT presented with larger median relative changes in these parameters (P<0.001 for the ITV_Dmin). In gated SBRT, the PTV_Dmin (minimum dose within the PTV) and PTV_Dmean (mean dose received over the entire PTV) differences were significantly lower favoring gated SBRT (P=0.01 and P=0.007, respectively), and for the prescribed dose volumes, the volume of PTV receiving 90% prescription dose (PTV_V90%PD) and the volume of PTV receiving 100% prescription dose (PTV_V100%PD) were more accurately delivered, also favoring gated SBRT (P=0.006 and P=0.03, respectively). The tumor location and volume analyses demonstrated that the dosimetric benefits of gated SBRT were particularly significant in the smaller internal target volumes (ITVs) and in the left lower central lung region (P<0.001 for the ITV_Dmin in small volumes).

Conclusions

Gated SBRT affords dosimetric accuracy compared to non-gated SBRT, and thus could improve the therapeutic outcomes of NSCLC patients. These results should advocate for the preferential use of gated SBRT in cases requiring precise dose delivery due to large respiratory motion or small target volumes.

Robotic Stereotactic Ablative Radiotherapy for Patients with Early-Stage Lung Cancer: Results of an Interim Analysis

BACKGROUND/OBJECTIVES

Surgery is the primary treatment for early-stage lung cancer. Patients with medically inoperable lung carcinomas and patients who refuse to undergo surgery are treated with definite radiotherapy. Stereotactic ablative radiotherapy (SABR) is a compelling non-invasive therapeutic modality for this group of patients that confers promising results.

METHODS

We report an interim analysis of an ongoing trial. Eighty-one patients with medically inoperable early-stage (T1,2N0) lung cancer underwent SABR in our institution. SABR was delivered via the CyberKnife M6 robotic radiosurgery system. The endpoints of the analysis were treatment efficacy and tolerance.

RESULTS

There were no acute or late toxicities from the skin or the connective tissue of the thorax. A grade 2/3 lung injury of non-clinical significance was noted in 6% of patients, which was directly related to a higher biologically effective dose (BEDα/β = 3) and larger irradiation lung volumes in both univariate and multivariate analyses. A local control (LC) was achieved in 100% of the patients at the first follow-up, and the projected 24-month local progression-free survival (LPFS) rate was 95%. The projected 24-month disease-specific overall survival (OS) was 94%.

CONCLUSIONS

High LC and OS rates can be achieved with SABR for early-stage lung cancer, with minimal toxicity. This study continues to recruit patients.

Advances in lung cancer surgery: the role of segmentectomy in early-stage management

INTRODUCTION

The evolving landscape of surgical interventions for early-stage non-small cell lung cancer (NSCLC) necessitates a reassessment of the traditional gold standard of lobectomy versus emerging sublobar resections, prompting this critical narrative review.

AREAS COVERED

This review encompasses recent randomized controlled trials, notably JCOG0802/WJOG4607L and CALGB140503, comparing lobectomy and sublobar resections for early-stage NSCLC, focusing on tumor size and recurrence rates. It also discusses the importance of individualized decision-making, future research avenues, and technological advancements in lung cancer surgery.

EXPERT OPINION

In this rapidly evolving field, sublobar resections emerge as a viable alternative to lobectomy for tumors smaller than 2 cm in early-stage NSCLC, necessitating precise patient selection and ongoing technological advancements to optimize outcomes.