Japanese Multi-institutional Study of Stereotactic Body Radiation Therapy for Totally 380 Patients With Lung Metastases

Stereotactic Body Radiotherapy versus Surgery for Lung Metastases from Colorectal Cancer: Single-Institution Results

BACKGROUND

Surgery and stereotactic body radiotherapy (SBRT) are two of the options available as local treatments for pulmonary oligometastases from colorectal cancer (CRC). We hypothesized that SBRT would have, at least, a similar local control rate to surgery.

METHODS

We identified an initial cohort of 100 patients with CRC who received SBRT or surgery for lung metastases. This was then narrowed down to 75 patients: those who underwent surgery (n = 50) or SBRT (n = 25) as their first local thoracic treatment between 1 January 2004 and 29 December 2017. The Kaplan-Meier method was used to calculate lung-progression-free survival (L-PFS) and overall survival (OS).

RESULTS

The 1 and 2-year L-PFS was 85% and 70% in the surgical group and 87% and 71% in the SBRT group, respectively (p = 0.809). No significant differences were found between the two groups in terms of OS. The biologically effective dose (BED), age and initial CRC stage did not have a significant effect on local control or survival. No grade 3 or above acute- or late-toxicity events were reported.

CONCLUSIONS

These results add retrospective evidence that SBRT and surgery have similar results in terms of OS and local control in patients with lung oligometastases from CRC.

Local Recurrence Outcomes of Colorectal Cancer Oligometastases Treated With Stereotactic Ablative Radiotherapy

PURPOSE

The aim of this study was to report local failure (LF) outcomes and associated predictors in patients with oligometastatic colorectal cancer (CRC) treated with stereotactic ablative radiotherapy (SABR).

MATERIALS AND METHODS

We retrospectively reviewed patients with CRC metastases to the brain, liver, spine, or lung treated with SABR between 2001 and 2016. Time to LF was summarized using cumulative incidence of LF curves with death as a competing risk.

RESULTS

The analysis included a total of 130 patients and 256 lesions. Of the metastases treated, 129 (50%) were brain, 50 (20%) liver, 49 (19%) spine, and 28 (11%) lung. Median gross tumor volume was 24 mL for liver metastases, 2 mL for brain metastases, 4 mL for spine metastases, and 1 mL for lung metastases. The overall 1, 2, and 3-year cumulative incidence of LF rates were 21.6% (16.5, 27.1), 28.2% (22.3, 34.4), and 31.5% (25.2, 38.0), respectively. LF was highest among the liver metastases (1 y: 26.0%, 2 y: 38.5%), followed by spine (1 y: 25.1%, 2 y: 31.1%), brain (1 y: 20%, 2 y: 25.2%), and lung (1 y: 13.7%, 2 y: insufficient data). Metastases from right-sided primary CRC were significantly more likely to have LF (P=0.0146, HR=2.23). Biologically effective dose>70 Gy, defined using a standard linear quadratic model using α/β ratio of 10 on the individual lesion level, and pre-SABR chemotherapy were also significant predictors of LF (P= 0.0009 and 0.018, respectively).

CONCLUSIONS

CRC metastases treated with SABR had significantly higher rates of LF if they originated from right-sided primary CRC, compared with left-sided. Liver metastases had the highest rates of LF compared with other metastatic sites. Thus, CRC liver metastases and metastases from right-sided CRC may benefit from more aggressive radiotherapy.

Prognostic factors for local control and survival for inoperable pulmonary colorectal oligometastases treated with stereotactic body radiotherapy

PURPOSE

The study aimed to evaluate overall survival and local control, and to identify factors independently associated with overall survival (OS) and local control (LC).

MATERIALS AND METHODS

This retrospective study examined 118 patients with primary colorectal cancer, in whom 202 inoperable pulmonary oligometastases were treated with stereotactic body radiotherapy between 2005 and 2015. Primary endpoint was to evaluate OS and identify prognostic factors associated with OS. Secondary aim was to evaluate LC and identify prognostic factors associated with LC.

RESULTS

Median follow-up was 31 months (range 3-88 months). Median OS was 39.2 months (95% CI 34.8-43.6 months). Two-, three-, and five-year OS was 69%, 55% and 36%, respectively. LC at 2-, 3-, and 5-year was 83%, 81% and 77% respectively. Factors independently associated with OS in the multivariable analysis included BED₁₀ ≥ 100 Gy (HR 0.52), male gender (HR 0.52), age < 70 years (HR 0.52) and presence of single metastasis (HR 0.37). BED₁₀ < 100 Gy (HR 3.67) and pre-SBRT chemotherapy (HR 2.66) were independently associated with poor LC in a multivariable analysis.

CONCLUSIONS

SBRT was associated with 2- year OS of 69% and 2-year LC of 83%. SBRT dose ≥ 100 Gy BED₁₀ was independently associated with both better overall survival and local control.

Survival and prognostic factors of pulmonary oligometastases treated with stereotactic body radiotherapy

BACKGROUND

Stereotactic body radiotherapy (SBRT) for pulmonary oligometastatic disease achieves excellent treatment outcomes in terms of local control and toxicity. Patients treated with SBRT are often elderly and have multiple co-morbidities. This subset of patients may experience different survival as compared to young and fit patients subjected to radical metastasectomies. The purpose of this retrospective study was to evaluate OS and identify factors associated with OS for inoperable pulmonary oligometastases treated with SBRT.

MATERIAL AND METHODS

Criteria used for selection of patients with oligometastases included: metastases limited to ≤2 organs and in total ≤5 metastases at the time of treatment. Peripheral tumors were treated with 51 Gy to 60 Gy in three fractions or a single fraction of 30 Gy. Central tumors received a dose of 45-60 Gy in 5-8 fractions. Survival probabilities were estimated by means of Kaplan-Meier method and the relation between potential prognostic factors and OS was studied by means of Cox regression analyses.

RESULTS

In this study, 327 inoperable pulmonary oligometastases in 206 patients were treated with SBRT from the year 2005 to 2015. Primary sites of pulmonary oligometastases included colorectal carcinoma (n = 118), lung carcinoma (n = 36), melanoma (n = 11), sarcoma (n = 10), breast carcinoma (n = 7), and other tumors sites (n = 24). Median follow-up was 26 months. Median survival was 33 months. The 2-year and 5-year OS rates were 63% and 30%, respectively. On univariate analysis synchronous oligometastases (HR 0.59) and colorectal primary (HR 0.64) were associated with improved OS. On multivariable analysis synchronous oligometastases (HR 0.56), colorectal primary (HR 0.62) and tumor size <3 cm (HR 0.68) were independently associated with OS.

CONCLUSIONS

SBRT to pulmonary oligometastases was associated with a 2-year OS of 63%. Tumor size <3 cm and colorectal primary tumors experienced improved OS compared to tumors >3 cm and non-colorectal primary tumors.

Stereotactic Body Radiotherapy for Lung Metastases from Colorectal Cancer: Prognostic Factors for Disease Control and Survival

OBJECTIVES

To evaluate disease control and survival after stereotactic body radiotherapy (SBRT) for lung metastases from colorectal cancer and to identify prognostic factors after treatment.

METHODS

Patients with metastatic colorectal cancer to the lungs treated with SBRT from 2002 to 2013 were identified from a prospectively maintained database. Patients may have received prior systemic therapy, radiotherapy to nonthoracic sites and/or resection of thoracic and/or nonthoracic metastases. Endpoints were timed from end of SBRT and included overall survival (OS), progression-free survival, distant metastases-free survival, and local failure-free survival. Univariate and multivariate analysis using Cox proportional hazard modeling was used to identify prognostic factors.

RESULTS

Sixty-five patients were identified. Before SBRT, 69.2% and 33.8% of patients received systemic therapy and lung-directed local therapy, respectively, for metastatic disease. At the time of SBRT, 64.6% had lung-only involvement. Median survivals were: OS of 20.3 months (95% confidence intervals [CI], 15.9-27.0 mo), progression-free survival of 5.7 months (95% CI, 3.2-7.0 mo), distant metastases-free survival of 5.8 months (95% CI, 3.2-7.6 mo), and local failure-free survival of 15.4 months (95% CI, 8.5-21.1 mo). Nearly all (98%) patients developed distant progression. Extra lung and liver involvement at the time of initial metastases (hazard ratios [HR] 2.10) and extra lung involvement at SBRT (HR 2.67) were the only independent predictors of OS. Net gross target volume of >14.1 mL (HR 2.49) was the only independent predictor of local failure-free survival.

CONCLUSIONS

Reasonable survival and local control can be achieved with SBRT. We identified several prognostic factors testable in future prospective trials that may help improve patient selection.

Cost-Effectiveness of Surgery, Stereotactic Body Radiation Therapy, and Systemic Therapy for Pulmonary Oligometastases

INTRODUCTION

Pulmonary oligometastases have conventionally been managed with surgery and/or systemic therapy. However, given concerns about the high cost of systemic therapy and improvements in local treatment of metastatic cancer, the optimal cost-effective management of these patients is unclear. Therefore, we sought to assess the cost-effectiveness of initial management strategies for pulmonary oligometastases.

METHODS AND MATERIALS

A cost-effectiveness analysis using a Markov modeling approach was used to compare average cumulative costs, quality adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) among 3 initial disease management strategies: video-assisted thoracic surgery (VATS) wedge resection, stereotactic body radiation therapy (SBRT), and systemic therapy among 5 different cohorts of patient disease: (1) melanoma; (2) non-small cell lung cancer adenocarcinoma without an EGFR mutation (NSCLC AC); (3) NSCLC with an EGFR mutation (NSCLC EGFRm AC); (4) NSCLC squamous cell carcinoma (NSCLC SCC); and (5) colon cancer. One-way sensitivity analyses and probabilistic sensitivity analyses were performed to analyze uncertainty with regard to model parameters.

RESULTS

In the base case, SBRT was cost effective for melanoma, with costs/net QALYs of $467,787/0.85. In patients with NSCLC, the most cost-effective strategies were SBRT for AC ($156,725/0.80), paclitaxel/carboplatin for SCC ($123,799/0.48), and erlotinib for EGFRm AC ($147,091/1.90). Stereotactic body radiation therapy was marginally cost-effective for EGFRm AC compared to erlotinib with an incremental cost-effectiveness ratio of $126,303/QALY. For colon cancer, VATS wedge resection ($147,730/2.14) was the most cost-effective strategy. Variables with the greatest influence in the model were erlotinib-associated progression-free survival (EGFRm AC), toxicity (EGFRm AC), cost of SBRT (NSCLC SCC), and patient utilities (all histologies).

CONCLUSIONS

Video-assisted thoracic surgery wedge resection or SBRT can be cost-effective in select patients with pulmonary oligometastases, depending on histology, efficacy, and tolerability of treatment and patient preferences.

The role of stereotactic body radiation therapy in the management of oligometastatic lung cancer

A growing body of evidence has surfaced over the past 20 years that supports the use of surgery for metastasis limited in number termed ‘oligometastases’. Local therapy for oligometastases results in long progression free survival in the absence of systemic therapy, including non-small-cell lung cancer (NSCLC). Stereotactic body radiation therapy (SBRT) allows for the delivery of anatomically precise, ablative doses of radiation therapy able to achieve local control rates of approximately 80% with minimal toxicity. In NSCLC, SBRT is emerging as an effective therapy in the management of sites resistant to targeted therapy. This review summarizes the published evidence for the use of local therapy in the management of oligometsatic cancer, with a focus on SBRT and NSCLC.