An economic analysis of sublobar resection versus thermal ablation for early-stage non-small-cell lung cancer

Pre-operative lung ablation prediction using deep learning

OBJECTIVE

Microwave lung ablation (MWA) is a minimally invasive and inexpensive alternative cancer treatment for patients who are not candidates for surgery/radiotherapy. However, a major challenge for MWA is its relatively high tumor recurrence rates, due to incomplete treatment as a result of inaccurate planning. We introduce a patient-specific, deep-learning model to accurately predict post-treatment ablation zones to aid planning and enable effective treatments.

MATERIALS AND METHODS

Our IRB-approved retrospective study consisted of ablations with a single applicator/burn/vendor between 01/2015 and 01/2019. The input data included pre-procedure computerized tomography (CT), ablation power/time, and applicator position. The ground truth ablation zone was segmented from follow-up CT post-treatment. Novel deformable image registration optimized for ablation scans and an applicator-centric co-ordinate system for data analysis were applied. Our prediction model was based on the U-net architecture. The registrations were evaluated using target registration error (TRE) and predictions using Bland-Altman plots, Dice co-efficient, precision, and recall, compared against the applicator vendor's estimates.

RESULTS

The data included 113 unique ablations from 72 patients (median age 57, interquartile range (IQR) (49-67); 41 women). We obtained a TRE ≤ 2 mm on 52 ablations. Our prediction had no bias from ground truth ablation volumes (p = 0.169) unlike the vendor's estimate (p < 0.001) and had smaller limits of agreement (p < 0.001). An 11% improvement was achieved in the Dice score. The ability to account for patient-specific in-vivo anatomical effects due to vessels, chest wall, heart, lung boundaries, and fissures was shown.

CONCLUSIONS

We demonstrated a patient-specific deep-learning model to predict the ablation treatment effect prior to the procedure, with the potential for improved planning, achieving complete treatments, and reduce tumor recurrence.

CLINICAL RELEVANCE STATEMENT

Our method addresses the current lack of reliable tools to estimate ablation extents, required for ensuring successful ablation treatments. The potential clinical implications include improved treatment planning, ensuring complete treatments, and reducing tumor recurrence.

Radiofrequency ablation for stage <IIB non-small cell lung cancer: Opportunities, challenges, and the road ahead

Pulmonary carcinoma represents the second common cancer for human race while its mortality rate ranked the first all over the world. Surgery remains the primary option for early-stage non-small cell lung cancer (NSCLC) in some surgical traditions. Nevertheless, only less than half of patients are operable subjected to the limited lung function and multiple primary/metastatic lesions. Recent improvements in minimally invasive surgical techniques have made the procedure accessible to more patients, but this percentage still does not exceed half. In recent years, radiofrequency ablation (RFA), one of the thermal ablation procedures, has gradually advanced in the treatment of lung cancer in addition to being utilized to treat breast and liver cancer. Several guidelines, including the American College of Chest Physicians (ACCP), include RFA as an option for some patients with NSCLC although the level of evidence is mostly limited to retrospective studies. In this review, we emphasize the use of the RFA technique in patients with early-stage NSCLC and provide an overview of the RFA indication population, prognosis status, and complications. Meanwhile, the advantages and disadvantages of RFA proposed in existing studies are compared with surgical treatment and radiotherapy. Due to the high rate of gene mutation and immunocompetence in NSCLC, there are considerable challenges to clinical translation of combining targeted drugs or immunotherapy with RFA that the field has only recently begun to fully appreciate.

Survival benefit of thermal ablation combined with chemotherapy for the treatment of stage IV nonsmall cell lung cancer: a propensity-matched analysis

OBJECTIVE

To investigate the survival benefit of thermal ablation (TA) plus chemotherapy for Stage-IV nonsmall cell lung cancer (NSCLC).

METHODS

From the Surveillance, Epidemiology and End Results (SEER) database, data of Stage-IV NSCLC patients receiving different treatment modalities (TA plus chemotherapy vs. chemotherapy) from 2004 to 2016 were retrospectively analyzed using propensity-score matching (PSM) for covariates. Kaplan-Meier curves and the log-rank test for intergroup comparison of overall survival (OS) and lung cancer-specific survival (LCSS) and subgroup analyses in the PSM cohort evaluated possible survival benefits. Cox proportional risk models evaluated independent prognostic factors.

RESULTS

Among 52,574 patients, 152 received TA plus chemotherapy. After PSM, the TA plus chemotherapy and chemotherapy groups included 150 and 445 patients, respectively. Compared to the chemotherapy group, the TA plus chemotherapy group had better OS (p = 0.042) and LCSS (p = 0.031), especially in patients aged 70 and older in age-stratified subgroup analysis; no statistically significant beneficial trend was noted for patients younger than 70 years. Subgroup analysis by tumor size showed superior OS and LCSS with TA plus chemotherapy than chemotherapy for tumors ≤3.0 cm; however, no significant difference was found in subgroups with larger tumors. Multivariate analysis showed that TA plus chemotherapy was an independent prognostic factor for OS and LCSS (hazard ratio 0.70 [95% confidence interval 0.59-0.84] and 0.70 [0.58-0.84], respectively; p < 0.001).

CONCLUSION

TA plus chemotherapy is a potential treatment option for Stage-IV NSCLC, especially for patients aged 70 or older with tumor size ≤3 cm.

National Utilization, Survival, and Costs Analysis of Treatment Options for Stage I Non-Small Cell Lung Cancer: A SEER-Medicare Database Analysis

RATIONALE AND OBJECTIVES

To compare utilization, outcomes, and costs of surgery, radiation therapy, and percutaneous ablation for the treatment of stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Using 2006-2016 Medicare-linked Surveillance, Epidemiology, and End Results (SEER) databases, stage I NSCLC patients who underwent surgery, radiotherapy, or percutaneous ablation were identified using relevant billing codes. National utilization rates were determined. Overall survival for treatment arms were compared using log-rank test and Cox-proportional hazard modeling. Mean direct costs for each treatment strategy during the first year after diagnosis were compared using Analysis of Variance.

RESULTS

A total of 15,847 Stage I NSCLC patients were identified; mean age at diagnosis was 75.5 years (minimum age = 66 years) and 59.2% were female. A total of 10,732 patients (67.7%) underwent only surgery, 5013 (31.6%) only radiotherapy, and 102 (0.6%) only ablation. Utilization of surgery and ablation decreased while radiotherapy utilization increased from 2007 to 2015 (p < 0.0001). Compared to the ablation group, overall survival was greater for the surgery group (HR: 0.7, 95% CI of HR: 0.6-0.9, p = 0.0047) and lower for the radiotherapy group (HR: 1.4, 95% CI of HR: 1.1-1.8, p = 0.002). The mean first year cost of therapy for ablation = $11,976) was significantly less (p < 0.05) than for radiotherapy ($15,447) and surgery ($22,669).

CONCLUSION

In Medicare patients with stage I NSCLC, the utilization of radiation therapy has increased and surgery has declined, while utilization of percutaneous ablation has remained uniformly low. Although overall survival is best for surgery, then ablation, and then radiation therapy, first year treatment costs are lowest for ablation.

SPECT/CT versus planar imaging to determine treatment strategy for non-small-cell lung cancer: a cost-effectiveness analysis

Aim: SPECT/CT has been found to improve predicted postoperative forced expiratory volume in one second (ppoFEV₁) assessments in patients with non-small-cell lung cancer (NSCLC). Methods: An economic simulation was developed comparing the cost-effectiveness of SPECT/CT versus planar scintigraphy for a US payer. Clinical outcomes and cost data were obtained through review of the published literature. Results: SPECT/CT increased the accuracy ppoFEV₁ assessment, changing the therapeutic decision for 1.3% of nonsurgical patients to a surgical option, while 3.3% of surgical patients shifted to more aggressive procedures. SPECT/CT led to an expected cost of $4694 per life year gained, well below typical thresholds. Conclusion: SPECT/CT resulted in substantially improved health outcomes and was found to be highly cost-effective.

Society of Interventional Radiology Multidisciplinary Position Statement on Percutaneous Ablation of Non-small Cell Lung Cancer and Metastatic Disease to the Lungs: Endorsed by the Canadian Association for Interventional Radiology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology

PURPOSE

To state the Society of Interventional Radiology's position on the use of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease to the lung.

MATERIALS AND METHODS

A multidisciplinary writing group, with expertise in treating lung cancer, conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 63 studies, including existing systematic reviews and meta-analysis, retrospective cohort studies, and single-arm trials were identified. The expert writing group developed and agreed on 7 recommendations on the use of image-guided thermal ablation in the lung.

CONCLUSION

SIR considers image-guided thermal ablation to be an acceptable treatment option for patients with inoperable Stage I NSCLC, those with recurrent NSCLC, as well as patients with metastatic lung disease.

Defining the Value of Interventional Radiology to Healthcare Stakeholders: Proceedings from a Society of Interventional Radiology Research Consensus Panel

Interventional radiology (IR) has collectively struggled to articulate and prove its value to several external stakeholders. The goal of this research consensus panel was to provide a summary of the existing knowledge, identify current gaps in knowledge, identify the strengths and weaknesses in existing data, and prioritize research needs related to the value of IR. Panelists were asked to identify the critical relationships/alliances that should be fostered to advance the prioritized research and determine how the Society of Interventional Radiology and the Society of Interventional Radiology Foundation can further support these initiatives. Following presentations and discussions, it was determined that proving and quantifying how IR decreases the length of stay and prevents hospital admissions are the most salient, value-related research topics to pursue for the specialty.

Is There a Role for Percutaneous Ablation for Early Stage Lung Cancer? What Is the Evidence?

PURPOSE OF REVIEW

For patients with early stage non-small-cell lung cancer (NSCLC), thermal ablation (TA) has become in the least two decades an option of treatment used worldwide for patients with comorbidities who are not surgical candidates. Here, we review data published with different TA techniques: radiofrequency ablation (RFA), microwave ablation (MWA) and cryoablation. This paper reviews also the comparison that has been made between TA and stereotactic radiotherapy (SBRT).

RECENT FINDINGS

A majority of retrospective studies, the absence of comparative studies, and the variety of techniques make difficult to get evident data. Nevertheless, these stand-alone techniques have demonstrated local efficacy for tumors less than 3 cm and good tolerance on fragile patients. Many recent reviews and database analyses show that outcomes after TA (mainly RFA and MWA) are comparable to SBRT in terms of survival rates. For patients who are unfit for surgery, TA has demonstrated interesting results for safety, benefits in overall survival, and acceptable local control.

Alternatives to Surgery for Early-Stage Non-Small Cell Lung Cancer: Thermal Ablation

Thermal ablation involves the application of heat or cold energy to the lung under image guidance to eradicate tumors. It is indicated for treatment of early-stage non-small cell lung cancer in nonsurgical patients. Ablation technologies have advanced, such that nearly all small tumors can now be treated safely and effectively. Ablation does not cause a lasting decline in pulmonary function tests and may therefore be used to treat multiple synchronous and metachronous lung tumors, a chief advantage over other treatments. Large series with intermediate- and long-term data have been reported showing favorable overall survival, similar to radiation therapy.

Lung Ablation: Indications and Techniques

Lung ablation is ever more recognized since its initial report and use almost two decades ago. With technological advancements in thermal modalities, particularly microwave ablation and cryoablation, better identification of the cohort of patients who best benefit from ablation, and understanding the role of imaging after ablation, image-guided thermal ablation for primary and secondary pulmonary malignancies is increasingly recognized and accepted as a cogent form of local therapy.

Decision Making in Interventional Oncology: Ablative Options in the Lung

Image-guided ablation is safe and effective for the treatment of both primary and metastatic tumors in the lung. This article reviews the three most commonly used ablative options: radiofrequency ablation, microwave ablation, and cryoablation. We describe the advantages of each ablation modality in the lung and how to choose the most appropriate ablation device based on patient and tumor characteristics. The optimal technique for lung ablation is discussed and technical tips for improving clinical outcome are described.

Lung Ablation: Whats New?

Lung cancer had an estimated incidence of 221,200 in 2015, making up 13% of all cancer diagnoses. Tumor ablation is an important treatment option for nonsurgical lung cancer and pulmonary metastatic patients. Radiofrequency ablation has been used for over a decade with newer modalities, microwave ablation, cryoablation, and irreversible electroporation presenting as additional and possibly improved treatment options for patients. This minimally invasive therapy is best for small primary lesions or favorably located metastatic tumors. These technologies can offer palliation and sometimes cure of thoracic malignancies. This article discusses the current available technologies and techniques available for tumor ablation.

Clinical experiences with microwave thermal ablation of lung malignancies

Approximately 30% of early stage lung cancer patients are not surgical candidates due to medical co-morbidities, poor cardiopulmonary function and advanced age. These patients are traditionally offered chemotherapy and radiation, which have shown relatively modest improvements in mortality. For over a decade, percutaneous image-guided ablation has emerged as a safe, cost-effective, minimally invasive treatment alternative for patients who would otherwise not qualify for surgery. Although radiofrequency ablation (RFA) is currently the most extensively studied and widely utilised technique in the treatment of lung malignancies, there is a growing body of evidence that microwave ablation (MWA) has several unique benefits over RFA and cryoablation in the lung. This article reviews our institution's clinical experiences in the treatment of lung malignancies with MWA including patient selection, procedural technique, imaging follow-up, treatment outcomes and comparison of ablation techniques.

A Cross-Sectional Survey of Interventional Radiologists and Vascular Surgeons Regarding the Cost and Reimbursement of Common Devices and Procedures

PURPOSE

To evaluate knowledge of interventional radiologists (IRs) and vascular surgeons (VSs) on the cost of common devices and procedures and to determine factors associated with differences in understanding.

MATERIALS AND METHODS

An online survey was administered to US faculty IRs and VSs. Demographic information and physicians' opinions on hospital costs were elicited. Respondents were asked to estimate the average price of 15 commonly used devices and to estimate the work relative value units (wRVUs) and average Medicare reimbursements for 10 procedures. Answer estimates were deemed correct if values were ± 25% of the actual costs. Multivariate logistical regression was used to calculate odds ratios and 95% confidence intervals.

RESULTS

Of the 4,926 participants contacted, 1,090 (22.1%) completed the questionnaire. Overall, 19.8%, 22.8%, and 31.9% were accurate in price estimations of devices, Medicare reimbursement, and wRVUs for procedures. Physicians who thought themselves adequately educated about wRVUs were more accurate in predicting procedural costs in wRVUs than physicians who responded otherwise (odds ratio = 1.40, 95% confidence interval, 1.29-1.52; P < .0001). Estimation accuracies for procedures showed a positive trend in more experienced physicians (≥ 16 y), private practice physicians, and physicians who practice in rural areas.

CONCLUSIONS

This study suggests that IRs and VSs have limited knowledge regarding device costs. Given the current health care environment, more attention should be placed on cost education and awareness so that physicians can provide the most cost-effective care.

Radiofrequency ablation of stage IA non-small cell lung cancer in medically inoperable patients: Results from the American College of Surgeons Oncology Group Z4033 (Alliance) trial

BACKGROUND

This study evaluated the 2-year overall survival rate, adverse event rate, local control rate, and impact on pulmonary function tests for medically inoperable patients with stage IA non-small cell lung cancer (NSCLC) undergoing computed tomography (CT)-guided radiofrequency ablation (RFA) in a prospective, multicenter trial.

METHODS

Fifty-four patients (25 men and 29 women) with a median age of 76 years (range, 60-89 years) were enrolled from 16 US centers; 51 patients were eligible for evaluation (they had biopsy-proven stage IA NSCLC and were deemed medically inoperable by a board-certified thoracic surgeon). Pulmonary function tests were performed within the 60 days before RFA and 3 and 24 months after RFA. Adverse events were recorded and categorized. Patients were followed with CT and fludeoxyglucose positron emission tomography. Local control rate and recurrence patterns were analyzed.

RESULTS

The overall survival rate was 86.3% at 1 year and 69.8% at 2 years. The local tumor recurrence-free rate was 68.9% at 1 year and 59.8% at 2 years and was worse for tumors > 2 cm. In the 19 patients with local recurrence, 11 were re-treated with RFA, 9 underwent radiation, and 3 underwent chemotherapy. There were 21 grade 3 adverse events, 2 grade 4 adverse events, and 1 grade 5 adverse event in 12 patients within the first 90 days after RFA. None of the grade 4 or 5 adverse events were attributable to RFA. There was no significant change in the forced expiratory volume in the first second of expiration or the diffusing capacity of lung for carbon monoxide after RFA. A tumor size less than 2.0 cm and a performance status of 0 or 1 were associated with statistically significant improved survival of 83% and 78%, respectively, at 2 years.

CONCLUSIONS

RFA is a single, minimally invasive procedure that is well tolerated in medically inoperable patients, does not adversely affect pulmonary function tests, and provides a 2-year overall survival rate that is comparable to the rate reported after stereotactic body radiotherapy in similar patients.