Mohammad Jaffar, Presenter: Nothing to Disclose

Purpose/Objectives:There is a paucity of data directly comparing Stereotactic Body Radiotherapy (SBRT) to Conventionally Fractioned Radiotherapy (CFR) for inoperable Non-Small Cell Lung Cancer (NSCLC). The study focused on comparing the two modalities while keeping variables as constant as possible, to determine and quantify the advantages, if any, from using SBRT.Methods:A retrospective chart review of patients with Stage I or IIA medically inoperable NSCLC was done at the MIMA Cancer Center in Melbourne, Florida. Inclusion criteria included: (i) Stage I or early stage IIA NSCLC; (ii) Tumor size of ≤5 cm; (iii) No lymph node involvement; (iv) No evidence of metastasis; (v) peripheral tumors only; (vi) dose fractionation (73 to 81 Gy for CFR and 35-60 Gy for SBRT); and (vii) must have been medically inoperable. Following the criteria, a total cohort of 82 patients was analyzed, 49 SBRT and 33 CFR patients. Local control, toxicity, disease status, 2 year survival, and overall survival were recorded for each treatment modality and then analyzed. Local control, toxicity, and disease status were placed into frequency tables and then evaluated using a Chi-Squared Test, with a p value <.05 considered to be significant to assess for an association between treatment modality and outcome. Overall survival and 2 year prognosis were displayed in a Kaplan-Meier curve and evaluated using the Cox-Proportional Hazard Model with a p value <.05 considered to be to be a statistically significant difference between the treatment modality and survival.Results:The frequency table for local control by treatment yielded a P value of 0.0344, indicating an association between local control and the treatment modality.The frequency table for disease status by treatment yielded a P value of 0.000245, indicating a strong association between disease status and treatment.The Kaplan-Meier plot for survival probability was tested with the Cox Proportional Hazard Model, yielding a P value of 0.0037, indicating a difference in survival probability between the two treatment methods. SBRT treated patients showed an increase of less than 4% in 2 year survival, but 30% in overall survival.Toxicity scores were placed into a frequency table, with a P value 0.381, and there was no significant difference between either treatment modality.Conclusion:SBRT demonstrated significant advantages in all categories except 2 year survival and toxicity. Results favor SBRT over CFR in NSCLC. The transition from CFR to SBRT is a statistically significant one, and marks a noteworthy change in treatment outcomes of medically inoperable NSCLC patients.

Jaffar, M, Comparison of Stereotactic Body Radiotherapy and Conventionally Fractioned Radiotherapy in Inoperable Non-small Cell Lung Cancer.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13041454.html