C.G. Robinson

Dose-response for stereotactic body radiotherapy in early-stage non-small-cell lung cancer

PURPOSE To compare the efficacy of three lung stereotactic body radiotherapy (SBRT) regimens in a large institutional cohort. METHODS Between 2004 and 2009, 130 patients underwent definitive lung cancer SBRT to a single lesion at the Mallinckrodt Institute of Radiology. We delivered 18 Gy × 3 fractions for peripheral tumors (n = 111) and either 9 Gy × 5 fractions (n = 8) or 10 Gy × 5 fractions (n = 11) for tumors that were central or near critical structures. Univariate and multivariate analysis of prognostic factors was performed using the Cox proportional hazard model. RESULTS Median follow-up was 11, 16, and 13 months for the 9 Gy × 5, 10 Gy × 5, and 18 Gy × 3 groups, respectively. Local control statistics for Years 1 and 2 were, respectively, 75% and 50% for 9 Gy × 5, 100% and 100% for 10 Gy × 5, and 99% and 91% for 18 Gy × 3. Median overall survival was 14 months, not reached, and 34 months for the 9 Gy × 5, 10 Gy × 5, and 18 Gy × 3 treatments, respectively. No difference in local control or overall survival was found between the 10 Gy × 5 and 18 Gy × 3 groups on log-rank test, but both groups had improved local control and overall survival compared with 9 Gy × 5. Treatment with 9 Gy × 5 was the only independent prognostic factor for reduced local control on multivariate analysis, and increasing age, increasing tumor volume, and poor performance status predicted independently for reduced overall survival. CONCLUSION Treatment regimens of 10 Gy × 5 and 18 Gy × 3 seem to be efficacious for lung cancer SBRT and provide superior local control and overall survival compared with 9 Gy × 5.

Impact of intensity-modulated radiation therapy technique for locally advanced non-small-cell lung cancer: A secondary analysis of the NRG oncology RTOG 0617 randomized clinical trial

Purpose Although intensity-modulated radiation therapy (IMRT) is increasingly used to treat locally advanced non-small-cell lung cancer (NSCLC), IMRT and three-dimensional conformal external beam radiation therapy (3D-CRT) have not been compared prospectively. This study compares 3D-CRT and IMRT outcomes for locally advanced NSCLC in a large prospective clinical trial. Patients and Methods A secondary analysis was performed to compare IMRT with 3D-CRT in NRG Oncology clinical trial RTOG 0617, in which patients received concurrent chemotherapy of carboplatin and paclitaxel with or without cetuximab, and 60- versus 74-Gy radiation doses. Comparisons included 2-year overall survival (OS), progression-free survival, local failure, distant metastasis, and selected Common Terminology Criteria for Adverse Events (version 3) ≥ grade 3 toxicities. Results The median follow-up was 21.3 months. Of 482 patients, 53% were treated with 3D-CRT and 47% with IMRT. The IMRT group had larger planning treatment volumes (median, 427 v 486 mL; P = .005); a larger planning treatment volume/volume of lung ratio (median, 0.13 v 0.15; P = .013); and more stage IIIB disease (30.3% v 38.6%, P = .056). Two-year OS, progression-free survival, local failure, and distant metastasis-free survival were not different between IMRT and 3D-CRT. IMRT was associated with less ≥ grade 3 pneumonitis (7.9% v 3.5%, P = .039) and a reduced risk in adjusted analyses (odds ratio, 0.41; 95% CI, 0.171 to 0.986; P = .046). IMRT also produced lower heart doses ( P < .05), and the volume of heart receiving 40 Gy (V40) was significantly associated with OS on adjusted analysis ( P < .05). The lung V5 was not associated with any ≥ grade 3 toxicity, whereas the lung V20 was associated with increased ≥ grade 3 pneumonitis risk on multivariable analysis ( P = .026). Conclusion IMRT was associated with lower rates of severe pneumonitis and cardiac doses in NRG Oncology clinical trial RTOG 0617, which supports routine use of IMRT for locally advanced NSCLC.

A comparison of surgical intervention and stereotactic body radiation therapy for stage I lung cancer in high-risk patients: A decision analysis

OBJECTIVE We sought to compare the relative cost-effectiveness of surgical intervention and stereotactic body radiation therapy in high risk patients with clinical stage I lung cancer (non-small cell lung cancer). METHODS We compared patients chosen for surgical intervention or SBRT for clinical stage I non-small cell lung cancer. Propensity score matching was used to adjust estimated treatment hazard ratios for the confounding effects of age, comorbidity index, and clinical stage. We assumed that Medicare-allowable charges were

Online Magnetic Resonance Image Guided Adaptive Radiation Therapy: First Clinical Applications

15,034 for surgical intervention and

Dosimetric predictors of chest wall pain after lung stereotactic body radiotherapy

13,964 for stereotactic body radiation therapy. The incremental cost-effectiveness ratio was estimated as the cost per life year gained over the patients remaining lifetime by using a decision model. RESULTS Fifty-seven patients in each arm were selected by means of propensity score matching. Median survival with surgical intervention was 4.1 years, and 4-year survival was 51.4%. With stereotactic body radiation therapy, median survival was 2.9 years, and 4-year survival was 30.1%. Cause-specific survival was identical between the 2 groups, and the difference in overall survival was not statistically significant. For decision modeling, stereotactic body radiation therapy was estimated to have a mean expected survival of 2.94 years at a cost of

Management of atypical cranial meningiomas, part 1: predictors of recurrence and the role of adjuvant radiation after gross total resection.

14,153 and mean expected survival with surgical intervention was 3.39 years at a cost of

Generating lung tumor internal target volumes from 4D-PET maximum intensity projections.

17,629, for an incremental cost-effectiveness ratio of

The metastatic spine disease multidisciplinary working group algorithms

7753. CONCLUSIONS In our analysis stereotactic body radiation therapy appears to be less costly than surgical intervention in high-risk patients with early stage non-small cell lung cancer. However, surgical intervention appears to meet the standards for cost-effectiveness because of a longer expected overall survival. Should this advantage not be confirmed in other studies, the cost-effectiveness decision would be likely to change. Prospective randomized studies are necessary to strengthen confidence in these results.

Management of Atypical Cranial Meningiomas, Part 2: Predictors of Progression and the Role of Adjuvant Radiation After Subtotal Resection.

PURPOSE To demonstrate the feasibility of online adaptive magnetic resonance (MR) image guided radiation therapy (MR-IGRT) through reporting of our initial clinical experience and workflow considerations. METHODS AND MATERIALS The first clinically deployed online adaptive MR-IGRT system consisted of a split 0.35T MR scanner straddling a ring gantry with 3 multileaf collimator-equipped (60)Co heads. The unit is supported by a Monte Carlo-based treatment planning system that allows real-time adaptive planning with the patient on the table. All patients undergo computed tomography and MR imaging (MRI) simulation for initial treatment planning. A volumetric MRI scan is acquired for each patient at the daily treatment setup. Deformable registration is performed using the planning computed tomography data set, which allows for the transfer of the initial contours and the electron density map to the daily MRI scan. The deformed electron density map is then used to recalculate the original plan on the daily MRI scan for physician evaluation. Recontouring and plan reoptimization are performed when required, and patient-specific quality assurance (QA) is performed using an independent in-house software system. RESULTS The first online adaptive MR-IGRT treatments consisted of 5 patients with abdominopelvic malignancies. The clinical setting included neoadjuvant colorectal (n=3), unresectable gastric (n=1), and unresectable pheochromocytoma (n=1). Recontouring and reoptimization were deemed necessary for 3 of 5 patients, and the initial plan was deemed sufficient for 2 of the 5 patients. The reasons for plan adaptation included tumor progression or regression and a change in small bowel anatomy. In a subsequently expanded cohort of 170 fractions (20 patients), 52 fractions (30.6%) were reoptimized online, and 92 fractions (54.1%) were treated with an online-adapted or previously adapted plan. The median time for recontouring, reoptimization, and QA was 26 minutes. CONCLUSION Online adaptive MR-IGRT has been successfully implemented with planning and QA workflow suitable for routine clinical application. Clinical trials are in development to formally evaluate adaptive treatments for a variety of disease sites.

Treatment Outcomes in Stage I Lung Cancer: A Comparison of Surgery and Stereotactic Body Radiation Therapy

PURPOSE To identify risk factors for the development of chest wall (CW) pain after thoracic stereotactic body radiotherapy (SBRT). METHODS AND MATERIALS A registry of patients with lung lesions treated with lung SBRT was explored to identify patients treated with 54 Gy in three fractions or 50 Gy in five fractions. One hundred and forty-six lesions in 140 patients were identified; complete electronic treatment plans were available on 86 CWs. The CW was contoured as a 3 cm outward expansion from the involved lung. Univariate and multivariate analyses were used to correlate patient, tumor, and dosimetric factors to the development of CW toxicity. RESULTS CW pain occurred in 22 patients (15.7%). The Kaplan-Meier estimated risk of CW pain at 2 years was 20.1% (95% C.I., 13.2-28.8%). On univariate analysis of patient factors, elevated BMI (p=0.026) and connective tissue disease (p=0.036) correlated with CW pain. The percent of CW receiving 30, 35, or 40 Gy was most predictive of CW pain on multivariate analysis using logistic regression, while V40 alone was predictive using Cox regression. A V30 threshold of 0.7% and V40 threshold of 0.19% was correlated with a 15% risk of CW pain. CONCLUSIONS We have described patient and dosimetric parameters that correlate with CW pain after lung SBRT. The risk of CW pain may be mitigated by attempting to reduce the relative proportion of CW receiving 30-40 Gy during treatment planning.