Post SBRT Pulmonary Metastasectomy (PSPM) Trial
Post SBRT Pulmonary Metastasectomy (PSPM) Trial
The goal of this study is to determine the effectiveness of SBRT on reducing tumor viability
 at a pathologic level and also to evaluate the effects of combined modality treatment on low
 volume pulmonary metastases, in hopes of extrapolating this information to both primary and
 secondary lung cancer.
The role of SBRT as a potentially non-invasive treatment for small-volume tumors in the lung
 is well established, but the effectiveness of tumor eradication has yet to be determined.
 This prospective Phase 2 trial will provide several novel contributions to the literature: 1)
 the assessment of SBRT effectiveness in metastatic tumor control (radiotherapeutic
 metastasectomy), 2) the evaluation of pathologic response to SBRT by surgical resection, 3)
 identification of histologic predictors of radiation effect and toxicity (i.e. what are the
 effects of SBRT on different type of metastatic disease), and 4) the effect of combined
 modality SBRT and surgery on survival and local recurrence as compared to either modality
 alone. This trial will uniquely assess whether surgery as an adjunct to radiotherapy offers
 better tumor control as compared to SBRT alone, and whether it decreases locoregional
 recurrence. The study is an open-label unblinded single-arm prospective trial evaluating
 induction SBRT followed by pulmonary metastasectomy. This is a collaborative effort between
 the divisions of Thoracic Surgery and Radiation Oncology to evaluate the effects of dual
 treatment of pulmonary metastasis amenable to curative resection with neoadjuvant SBRT
 followed by surgical resection. Study recruitment and analysis will be conducted at St.
 Joseph Healthcare Hamilton and the Juravinski Cancer Center. Institutional data suggests that
 the Division of Thoracic Surgery at McMaster University performs an average of 450 pulmonary
 resections per year with approximately 10-15% being pulmonary metastasectomies for a spectrum
 of malignancies (including colorectal carcinoma, renal cell carcinoma and soft tissue
 sarcoma).

 Surgical resection and stereotactic body radiation therapy (SBRT) are generally regarded as
 mutually exclusive treatment options for the local management of pulmonary malignancies. The
 Primary Outcome will be measured as the Rates of complete pathologic response (pCR) in
 surgical specimens post SBRT as assessed using the Junker grading scale for lung
 malignancies: Grade I, no regression or only spontaneous tumor regression; Grade II,
 morphologic evidence of tumor regression with at least 10% (grade IIa) or <10% (grade IIb)
 viable tumor tissue; and Grade III, complete tumor regression with no viable tumor. The
 Secondary Outcomes: Overall survival (OS) at 3 years, Disease-free survival (DFS) at 3 years,
 local recurrence rates, radiation related toxicity, postoperative pulmonary complication rate
 (including prolonged air leak, need for invasive or noninvasive mechanical ventilation,
 postop pneumonia and empyema), the effect on time-to-resection and tumour histology on pCR.
 In addition, it will be explored whether cancer specific tumor biomarkers correlate with SBRT
 effects and related toxicity. Based on institutional data from other local prospective
 trials, the Thoracic Surgery division at McMaster averages a study accrual rate of 25-30% and
 retention rate of approximately 80%. The most pertinent metric in determining the necessary
 sample size is the effect size estimate of pCR. The MISSILE study preliminary data
 demonstrated a pCR of 60%. This serves as the only representative value in the literature,
 even though our study evaluates SBRT and surgery for metastatic disease and NOT primary lung
 cancer. In contrast, the SBRT literature (using post-treatment CT scan surveillance only)
 reports local control rates of nearly 90%. Using the Fleming procedure, in order to measure
 the true pCR with a 95% confidence interval ± 10% using an estimated true pCR of 70%,
 estimated dropout rate of 20%, and 80% power, the calculated sample size requirement is 39
 patients. It is estimated being able to recruit approximately 1-2 patients per month.
Inclusion Criteria:

 -  Patient age >18, resectable pulmonary metastases without a more effective systemic
 therapy option (regardless of type of primary malignancy, excluding hematologic
 malignancies) with the primary malignancy already having been treated without evidence
 of local recurrence

 -  Patient having single-organ metastasis to lung only (with the exception of colorectal
 CA (Cancer) with synchronous hepatic metastasis)

 -  Tumors <5cm

 -  Patient with no evidence of nodal disease on pre-treatment CT scan

 -  Patient having adequate pulmonary function to tolerate lung resection (post-operative
 predictive FEV1≥40%).

 Exclusion Criteria:• Patient having comorbidities not amenable to surgery

 -  Patient with uncontrolled primary malignancy

 -  Patient with hematologic malignancies (leukemia or lymphoma)

 -  Patient having more than 5 tumors in one lung

 -  Patient with prior history of thoracic radiation

 -  Patient having history of lung cancer diagnosis within 5 years of assessment