SBRT (Stereotactic Body Radiation Therapy) vs. Surgery in High Risk Patients With Early Stage Lung Cancer

The development of SBRT for treatment of stage I NSCLC (non-small cell lung cancer) inspired the collaboration between thoracic surgery and radiation oncology and has prompted the investigators to work closely together to evaluate the relative role of SBRT and surgery. Comparative studies of these modalities have been limited in number and are often difficult to interpret due to variability in methodological issues. The productive collaboration has resulted in publication of several studies comparing SBRT and surgery utilizing propensity score based analyses to match patients from each group. However, matching on limited numbers of variables between patients ultimately selected for therapy based largely on their real or perceived comorbidity leads to significant reporting bias, and therefore methods to comprehensively assess comorbidity are necessary.

As extension of above, a very real ongoing challenge that the investigators have evaluated within clinical practice is that current guidelines defining the high risk patient are subjective and prone to physician bias. A recent secondary analysis of clinical trial inclusion criteria for SBRT underscored this bias by demonstrating that many patients that were considered inoperable were perhaps reasonable surgical candidates. Based on standard pulmonary function tests the inoperable SBRT patients had a diffusion capacity 33% higher than the high risk surgical patients in ACOSOG Z4032. Conversely, stratification of high risk surgical patients within ACOSOG Z4032 trial identified an extremely high risk subset (median DLCO% 30%, FEV1% 39%) with a 90-day 3+ adverse event rate of 48% compared to the lowest risk subset (DLCO% 69%, FEV1% 56%) with a 90-day 3+ adverse event rate of only 24%. In the absence of a clinical trial or a prospective database, there is currently no objective algorithm to guide the assignment of surgery versus SBRT.

Attempts to objectively stratify risk within the surgical population have been challenging. Risk models based on the European Thoracic Database and the Society of Thoracic Surgeons Database are not yet robust enough to guide decision-making regarding treatment assignment or classification of the very high risk surgical patient where alternative therapies may be preferable. Unfortunately, one of the current limitations to stratifying these high risk patients is that these patients are followed by physicians in independent specialties. The STS Thoracic Surgical Database does not include patients that undergo SBRT therefore it is difficult to create an inclusive algorithm for operable and inoperable patients. A principle objective of the study is to create a validated risk model for treatment selection. This will greatly enhance the ability to counsel patients regarding their specific risks/benefit ratio for surgery or SBRT. This will improve informed decision making on the part of the patient, and remove much of the subjectivity of treatment selection. Inclusion of unique metrics such as HRQOL data will further bolster the benefit to the patient by making it more patient-centric, rather than focusing on cancer outcomes alone.

As the implementation of the Affordable HealthCare Act (AHCA) continues, physicians will experience additional pressure to cut costs while maintaining or improving the quality of care provided. The current fee-for-service system is often criticized for being compartmentalized and fragmented without well-defined incentives for quality improvement.

Initiatives of the AHCA have included efforts to test care models to reduce hospital associated conditions, bundled payment plans for care improvement, and shared savings programs for accountable care organizations whereby participating providers who meet certain quality standards share in any savings achieved for the Medicare program. These are just some of the efforts designed to rein in the cost of medical care while improving the transparency and quality of care. Pilot efforts involving bundling of payments for coronary artery bypass grafting resulted in Medicare savings of $40 million with simultaneous reduced in-hospital mortality. These types of initiatives are likely to become more commonplace in the United States as efforts to create new models of care to constrain cost are introduced.

With the stimulus of these initiatives for novel systems of healthcare delivery the investigators recognized that a model of bundled payment for treatment of stage I NSCLC may not only reduce overall costs associated with treatment of stage I lung cancer but potentially improve the quality of care provided. At Washington University the investigators have taken a preemptive measure to create an accountable care organization (ACO) between the Department of Radiation Oncology and the Department of Thoracic Surgery with a focused approach on the treatment of stage I NSCLC. Important components of this collaborative effort include a bundled payment system for episodes of care involving the treatment selection, implementation, and follow up care of patients with stage I lung cancer as well as prospective assessment of quality of care measures.

The impetus for the development of this unique collaboration between radiation oncology and thoracic surgery stems from the ongoing interest in improving the quality of care for patients with early stage NSCLC. The clinical research focus has been on determining the best treatment strategies for the significant number of patients with stage I lung cancer considered medically inoperable or high risk surgical candidates. In the aging population, pulmonary insufficiency, cardiac disease, as well as other comorbidities may preclude surgery or place patients at significant risk for complications after surgery. The evolution of stereotactic body radiotherapy (SBRT) in the medically inoperable population has resulted in relatively low local recurrence rates ranging from 3-20% with favorable overall and disease-free survival in inoperable patients with Stage I NSCLC.

Inclusion criteria

• Newly diagnosed suspected or proven clinical stage I NSCLC (T1 or T2, N0, M0) with no prior treatment for this disease.
• At least 18 years of age.
• Ability to understand and willingness to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable).