Stereotactic image-guided lung radiotherapy (SBRT) for clinical early-stage NSCLC: a long-term report from a multi-institutional database of patients treated with or without a pathologic diagnosis

PURPOSE: Early stage lung cancer is treated with stereotactic body radiation therapy (SBRT) in patients who are unable or unwilling to undergo surgical resection. Some patients' comorbidities are so severe that they are unable to even undergo a biopsy. A clinical diagnosis without biopsy before SBRT has been used, but there are limited data on its efficacy. METHODS AND MATERIALS: Data on patients treated with SBRT for non-small cell lung cancer, with and without tissue confirmation, were collected from multiple institutions across Europe, Canada, and the United States. Patients with a minimum of 2 years of comprehensive follow up were selected for analysis. Treatment and patient characteristics were compared. Overall survival (OS), disease-free survival (DFS), cause-specific survival (CSS), and rates of local recurrence (LR), regional recurrence (RR), and distant metastasis (DM) were calculated and analyzed. RESULTS: A total of 701 patients were identified, of which 67% had tissue confirmation of their tumors. The 3- and 5-year outcomes for OS, CSS, and DFS were 83.8%, 93.1%, 69%, and 60.6%, 86.7%, 45.5%, respectively. The rates for LR, RR, and DM at 3 and 5 years were 6.4%, 9.3%, 14.3%, and 10.5%, 14.3%, 19.7%, respectively. There were no statistically significant differences in survival outcomes or recurrences between the biopsy and no-biopsy cohorts. CONCLUSIONS: SBRT for clinically diagnosed lung cancers is efficacious in appropriately selected patients, with similar outcomes as those with a pathologic diagnosis. Thorough clinical and radiographic evaluations in a multidisciplinary setting are critical to the management of these patients

Correlating metabolic and anatomic responses of primary lung cancers to radiotherapy by combined F-18 FDG PET-CT imaging

<p>Abstract</p> <p>Background</p> <p>To correlate the metabolic changes with size changes for tumor response by concomitant PET-CT evaluation of lung cancers after radiotherapy.</p> <p>Methods</p> <p>36 patients were studied pre- and post-radiotherapy with¹⁸FDG PET-CT scans at a median interval of 71 days. All of the patients were followed clinically and radiographically after a mean period of 342 days for assessment of local control or failure rates. Change in size (sum of maximum orthogonal diameters) was correlated with that of maximum standard uptake value (SUV) of the primary lung cancer before and after conventional radiotherapy.</p> <p>Results</p> <p>There was a significant reduction in both SUV and size of the primary cancer after radiotherapy (p < 0.00005). Among the 20 surviving patients, the sensitivity, specificity, and accuracy using PET (SUV) were 94%, 50%, 90% respectively and the corresponding values using and CT (size criteria) were 67%, 50%, and 65% respectively. The metabolic change (SUV) was highly correlated with the change in size by a quadratic function. In addition, the mean percentage metabolic change was significantly larger than that of size change (62.3 ± 32.7% vs 47.1 ± 26.1% respectively, p = 0.03)</p> <p>Conclusion</p> <p>Correlating and incorporating metabolic change by PET into size change by concomitant CT is more sensitive in assessing therapeutic response than CT alone.</p

Determinants of change in prostate-specific antigen over time and its association with recurrence after external beam radiation therapy for prostate cancer in five large cohorts.: Determinants of change of prostate-specific antigen over time

International audiencePURPOSE: To assess the relationship between prognostic factors, postradiation prostate-specific antigen (PSA) dynamics, and clinical failure after prostate cancer radiation therapy using contemporary statistical models. METHODS AND MATERIALS: Data from 4,247 patients with 40,324 PSA measurements treated with external beam radiation monotherapy in five cohorts were analyzed. Temporal change of PSA after treatment completion was described by a specially developed linear mixed model that included standard prognostic factors. These factors, along with predicted PSA evolution, were incorporated into a Cox model to establish their predictive value for the risk of clinical recurrence over time. RESULTS: Consistent relationships were found across cohorts. The initial PSA decline after radiation therapy was associated with baseline PSA and T-stage (p < 0.001). The long-term PSA rise was associated with baseline PSA, T-stage, and Gleason score (p < 0.001). The risk of clinical recurrence increased with current level (p < 0.001) and current slope of PSA (p < 0.001). In a pooled analysis, higher doses of radiation were associated with a lower long-term PSA rise (p < 0.001) but not with the risk of recurrence after adjusting for PSA trajectory (p = 0.63). Conversely, after adjusting for other factors, increased age at diagnosis was not associated with long-term PSA rise (p = 0.85) but was directly associated with decreased risk of recurrence (p < 0.001). CONCLUSIONS: We conclude that a linear mixed model can be reliably used to construct typical patient PSA profiles after prostate cancer radiation therapy. Pretreatment factors along with PSA evolution and the associated risk of recurrence provide an efficient and quantitative way to assess the impact of risk factors on disease progression