Surgical Outcomes for Early Stage Non-small Cell Lung Cancer at Facilities With Stereotactic Body Radiation Therapy Programs.

BACKGROUND: Patients undergoing surgery for early stage non-small cell lung cancer (NSCLC) may be at high risk for postoperative mortality. Access to stereotactic body radiation therapy (SBRT) may facilitate more appropriate patient selection for surgery. RESEARCH QUESTION: Is postoperative mortality associated with early stage NSCLC lower at facilities with higher use of SBRT? STUDY DESIGN AND METHODS: Patients with early stage NSCLC reported to the National Cancer Database between 2004 and 2015 were included. Use of SBRT was defined by each facility's SBRT experience (in years) and SBRT to surgery volume ratios. Multivariate logistic regression was used to test for the associations between SBRT use and postoperative mortality. RESULTS: The study cohort consisted of 202,542 patients who underwent surgical resection of cT1-T2N0M0 NSCLC tumors. The 90-day postoperative mortality rate declined during the study period from 4.6% to 2.6% (P < .001), the proportion of facilities that used SBRT increased from 4.6% to 77.5% (P < .001), and the proportion of patients treated with SBRT increased from 0.7% to 15.4% (P < .001). On multivariate analysis, lower 90-day postoperative mortality rates were observed at facilities with > 6 years of SBRT experience (OR, 0.84; 95% CI, 0.76-0.94; P = .003) and SBRT to surgery volume ratios of more than 17% (OR, 0.85; 95% CI, 0.79-0.92; P < .001). Ninety-day mortality also was associated with surgical volume, region, year, age, sex, and race, among other covariates. Interaction testing between these covariates showed negative results. INTERPRETATION: Patients who underwent resection for early stage NSCLC at facilities with higher SBRT use showed lower rates of postoperative mortality. These findings suggest that the availability and use of SBRT may improve the selection of patients for surgery who are predicted to be at high risk of postoperative mortality.

Improved Progression-Free Survival for Bulky and Non-Bulky Advanced Stage Diffuse Large B-Cell Lymphoma With Consolidative Radiation Therapy: A Bi-Institutional Analysis.

Background The role of consolidative radiation therapy (RT) for advanced-stage diffuse large B-cell lymphoma (DLBCL) is not fully established. A growing body of data suggests a role for consolidative RT in select stage III-IV DLBCL patients and emerging data from randomized studies further address the role of RT in advanced-stage patients initially presenting with bulky disease. Methods Patients with treatment-naive stage III-IV DLBCL treated at two institutions who achieved a clinically complete response to systemic therapy were included. Patients with either bulky or non-bulky disease were included, but those with the relapsed or refractory disease were excluded. Kaplan-Meier analysis was performed to determine the impact of consolidative RT. Univariate and multivariable analyses were performed using a Cox proportional hazards model. Results One hundred eighty-eight patients received systemic therapy consisting of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 79%), another rituximab-based regimen (9%), or chemotherapy alone (12%). Clinical response was assessed using conventional CT or PET-CT. Sixty-eight patients (36%) received consolidative RT (median dose 30 Gy). Consolidative RT conferred a 36.7% absolute benefit in five-year progression-free survival (PFS; 85.9% vs. 49.2%, log rank p < 0.0001), a 14.5% absolute benefit in five-year overall survival (OS; 87.4% vs. 72.9%, log rank p = 0.0134), and a 37.0% absolute benefit in five-year LC (91.9% vs. 54.9%, log rank p < 0.0001). On multivariable analysis, consolidative RT was associated with improved PFS (HR 0.23, 95% CI 0.10-0.52, p < 0.001) and LC (HR 0.20, 95% CI 0.07-0.59, p = 0.003). Patients receiving consolidative RT demonstrated significantly improved PFS for tumors measuring both <5 cm (log rank p = 0.0454) and ≥5 cm (log rank p = 0.0003). Conclusions For patients with stage III-IV DLBCL who achieve clinical complete response after systemic therapy, consolidative RT improves PFS for all patients, including those with the non-bulky disease. This benefit persists in the setting of rituximab-based systemic therapy.

Virtual Away Rotations Increase Access to Radiation Oncology.

The COVID-19 pandemic altered the workplace for medical education. As restrictions ease, the opportunities provided by virtual rotations remain. Radiation oncology rotations based on virtual participation with patients (consultations, follow-ups, and brachytherapy), contouring and reviewing external beam plans, didactics, and unstructured office hours have been well received at multiple institutions. Virtual rotations decrease barriers to access including lack of a radiation oncology department at one's home institute and the high cost of travel and housing. Furthermore, rotations can be adapted to preclinical students and those with prior radiation oncology rotation experience. However, the virtual format creates and exacerbates several challenges including technical difficulties with electronic medical record or treatment planning software, lack of the spontaneous interactions common to in-person rotations, and unexpected delays in the clinic. We recommend early scheduled time with information technology services to troubleshoot any potential issues, scheduled office hours with faculty and videoconferencing with nonphysician team members to mitigate omission of in-person introductions, and provision of complete contact information for all staff scheduled to meet with students to facilitate communication when unexpected clinic issues arise. Although we are all excited for quarantine restrictions to safely be lifted, we support the continued development of virtual away rotations as a flexible, more affordable option to increase exposure to the field.

Comparison of Single- and Five-fraction Regimens of Stereotactic Body Radiation Therapy for Peripheral Early-stage Non-small-cell Lung Cancer: A Two-institution Propensity-matched Analysis.

PURPOSE: To evaluate differences in local control (LC), disease-specific (DC), and overall survival (OS) of patients with early-stage non-small-cell lung cancer (NSCLC) treated with single- (SF) versus 5-fraction (FF) stereotactic body radiation therapy (SBRT) at 2 institutions. PATIENTS AND METHODS: Peripheral early-stage NSCLC cases treated with a median dose of 30 Gy in SF or a median dose of 50 Gy in FF were included per institutional practice. Kaplan-Meier and Cox models were used to assess survival. A matched-pair analysis was performed to account for imbalances. Toxicities including Common Terminology Criteria for Adverse Events (CTCAE) grade 3 pneumonitis, chest wall pain requiring long-acting narcotics, and hospitalization for respiratory events 6 months posttreatment were recorded. RESULTS: A total of 163 lesions were treated between 2007 and 2015; 65 received SF SBRT and 98 received FF SBRT. Most tumors were T1 (n = 92) and T2 (n = 34) lesions and had adenocarcinoma (n = 77) and squamous cell carcinoma (n = 46) histologies, respectively. In the matched cohort, there were no differences in OS, LC, DC, or progression-free survival between the groups. LC and OS at 1 year in the matched cohort was 95% and 88%, and 87% and 84% in the SF and FF cohorts, respectively. There was 1 grade 3 pneumonitis in the FF group, and 9 total hospitalizations post-SBRT, 3 (5%) in the SF group and 6 (6%) in the FF group. CONCLUSIONS: No statistically significant differences were seen in LC or DC following SF or FF SBRT in this matched cohort of peripheral lesions. No grade 4 or higher toxicities were reported.

Three- Versus Five-Fraction Regimens of Stereotactic Body Radiotherapy for Peripheral Early-Stage Non-Small-Cell Lung Cancer: A Two-Institution Propensity Score-Matched Analysis.

PURPOSE: To evaluate differences in outcomes of early-stage peripheral non-small-cell lung cancer (NSCLC) treated with either 3- or 5-fraction stereotactic body radiotherapy (SBRT) at 2 institutions. PATIENTS AND METHODS: Patients diagnosed with peripherally located early-stage NSCLC who received either a median dose of 60 Gy (interquartile range [IQR], 60-60, biologically effective dose, 151-151) in 3 fractions or a median dose of 50 Gy (IQR, 50-50, biologically effective dose, 94-94) in 5 fractions were included in this study. All data were retrospectively collected and reviewed in an institutional review board-approved database. RESULTS: A total of 192 lesions in 192 patients were identified: 94 received 3-fraction SBRT and 98 received 5-fraction SBRT. Patients in the 5-fraction cohort had significantly smaller tumors (P = .0021). Larger tumor size was associated with worse overall survival (hazard ratio, 1.40, P = .0013) for all patients. A single grade 3 toxicity was reported in each cohort. A propensity score-matched cohort of 94 patients was constructed with a median follow-up of 29.3 months (IQR, 17.3-44.6) for the 3-fraction cohort and 31.0 months (IQR, 17.0-48.5) for the 5-fraction cohort (P = .84). There were no statistically significant differences between these 2 cohorts in overall survival (P = .33), progression-free survival (P = .40), local failure (P = .86), and nodal or distant failure (P = .57) at 2 years. CONCLUSION: The 3- and 5-fraction SBRT regimens for early-stage peripheral NSCLC had comparable clinical outcomes. Both regimens were well tolerated. A large tumor size was an adverse prognostic factor for worse survival.

Comparison of Single- and Three-fraction Schedules of Stereotactic Body Radiation Therapy for Peripheral Early-stage Non-Small-cell Lung Cancer.

BACKGROUND: To compare the clinical outcomes of patients with early-stage non-small-cell lung cancer (NSCLC) who had undergone either single-fraction (SF) or three-fraction (TF) stereotactic body radiation therapy (SBRT) at a single institution during over 8-year period. PATIENTS AND METHODS: Patients with peripherally located early-stage NSCLC who had undergone SBRT from February 2007 to November 2015 were included in the present study. SBRT was delivered without heterogeneity correction. Data were retrospectively reviewed and collected in an institutional review board-approved database. R software (version 3.3.2) was used for statistical analysis. RESULTS: Of 159 total lung tumors, 65 lesions received 30 Gy (median, 30 Gy) in 1 fraction, and 94 lesions received 48 to 60 Gy (median, 60 Gy) in 3 fractions. Patients with a Karnofsky performance status < 80 were more common in the SF-SBRT cohort (P = .050). After a median follow-up of 22.2 and 26.2 months for the SF-SBRT and TF-SBRT cohorts, respectively (P = .29), no statistically significant difference was found in overall survival (P = .86), progression-free survival (P = .95), local failure (P = .95), nodal failure (P = .91), and distant failure (P = .49) at 24 months. At 1 and 2 years, the overall survival rates were 86.1% and 63.2% for the SF-SBRT cohort and 80.8% and 61.6% for the TF-SBRT cohort, respectively. At 1 and 2 years, the local control rates were 95.1% and 87.8% for the SF-SBRT cohort and 92.7% and 86.2% for the TF-SBRT cohort, respectively. Both regimens were well tolerated. CONCLUSION: Despite more patients with poor performance status in the SF-SBRT cohort, the SF- and TF-SBRT regimens showed no differences in clinical outcomes. SF-SBRT is now our standard approach.

Stereotactic radiotherapy for prostate cancer: A review and future directions.

Prostate cancer affects over 200000 men annually in the United States alone. The role of conventionally fractionated external beam radiation therapy (RT) is well established as a treatment option for eligible prostate cancer patients; however, the use of stereotactic body radiotherapy (SBRT) in this setting is less well defined. Within the past decade, there have been a number of studies investigating the feasibility of SBRT as a potential treatment option for prostate cancer patients. SBRT has been well studied in other disease sites, and the shortened treatment course would allow for greater convenience for patients. There may also be implications for toxicity as well as disease control. In this review we present a number of prospective and retrospective trials of SBRT in the treatment of prostate cancer. We focus on factors such as biochemical progression-free survival, prostate specific antigen (PSA) response, and toxicity in order to compare SBRT to established treatment modalities. We also discuss future steps that the clinical community can take to further explore this new treatment approach. We conclude that initial studies examining the use of SBRT in the treatment of prostate cancer have demonstrated impressive rates of biochemical recurrence-free survival and PSA response, while maintaining a relatively favorable acute toxicity profile, though long-term follow-up is needed.

Comparison of single- and five-fraction schedules of stereotactic body radiation therapy for central lung tumours: a single institution experience.

BACKGROUND: Stereotactic body radiation therapy (SBRT) is a treatment option for patients with early-stage non-small cell lung cancer who are medically inoperable or decline surgery. Here we compare the outcome of patients with centrally located lung tumours who underwent either single fraction (SF)- or five-fraction (FF-) SBRT at a single institution over 5 years. METHODS: Between January 2009 and October 2014, patients with centrally located lung tumours who underwent SBRT were included in this study. Data were retrospectively collected using an institutional review board-approved database. For analysis, the Kaplan-Meier method and competing risks method were used. RESULTS: In total, 11 patients received 26-30 Gy in 1 fraction, whereas 31 patients received 50-60 Gy (median 55 Gy) in 5 fractions. After a median follow-up of 12 months for SF-SBRT and 17 months for FF-SBRT groups (p = 0.64), 1-year overall survival rates were 82 and 87%, respectively. SF- and FF-SBRT groups showed no significant difference in grade 3+ toxicity (p = 0·28). The only grade 4 toxicity (n = 1) was reported in the SF-SBRT group. All toxicities occurred >12 months after the SBRT. CONCLUSIONS: SF- and FF-SBRT have comparable overall survival. SF-SBRT may have some utility for patients unable to have multi-fraction SBRT.

A new finite element approach for near real-time simulation of light propagation in locally advanced head and neck tumors.

BACKGROUND AND OBJECTIVES: Several clinical studies suggest that interstitial photodynamic therapy (I-PDT) may benefit patients with locally advanced head and neck cancer (LAHNC). For I-PDT, the therapeutic light is delivered through optical fibers inserted into the target tumor. The complex anatomy of the head and neck requires careful planning of fiber insertions. Often the fibers' location and tumor optical properties may vary from the original plan therefore pretreatment planning needs near real-time updating to account for any changes. The purpose of this work was to develop a finite element analysis (FEA) approach for near real-time simulation of light propagation in LAHNC. METHODS: Our previously developed FEA for modeling light propagation in skin tissue was modified to simulate light propagation from interstitial optical fibers. The modified model was validated by comparing the calculations with measurements in a phantom mimicking tumor optical properties. We investigated the impact of mesh element size and growth rate on the computation time, and defined optimal settings for the FEA. We demonstrated how the optimized FEA can be used for simulating light propagation in two cases of LAHNC amenable to I-PDT, as proof-of-concept. RESULTS: The modified FEA was in agreement with the measurements (P = 0.0271). The optimal maximum mesh size and growth rate were 0.005-0.02 m and 2-2.5 m/m, respectively. Using these settings the computation time for simulating light propagation in LAHNC was reduced from 25.9 to 3.7 minutes in one case, and 10.1 to 4 minutes in another case. There were minor differences (1.62%, 1.13%) between the radiant exposures calculated with either mesh in both cases. CONCLUSIONS: Our FEA approach can be used to model light propagation from diffused optical fibers in complex heterogeneous geometries representing LAHNC. There is a range of maximum element size (MES) and maximum element growth rate (MEGR) that can be used to minimize the computation time of the FEA to 4 minutes.

Parametric control of collision rates and capture rates in geometrically enhanced differential immunocapture (GEDI) microfluidic devices for rare cell capture.

The enrichment and isolation of rare cells from complex samples, such as circulating tumor cells (CTCs) from whole blood, is an important engineering problem with widespread clinical applications. One approach uses a microfluidic obstacle array with an antibody surface functionalization to both guide cells into contact with the capture surface and to facilitate adhesion; geometrically enhanced differential immunocapture is a design strategy in which the array is designed to promote target cell­obstacle contact and minimize other interactions (Gleghorn et al. 2010; Kirby et al. 2012). We present a simulation that uses capture experiments in a simple Hele-Shaw geometry (Santana et al. 2012) to inform a target-cell-specific capture model that can predict capture probability in immunocapture microdevices of any arbitrary complex geometry. We show that capture performance is strongly dependent on the array geometry, and that it is possible to select an obstacle array geometry that maximizes capture efficiency (by creating combinations of frequent target cell­obstacle collisions and shear stress low enough to support capture), while simultaneously enhancing purity by minimizing nonspecific adhesion of both smaller contaminant cells (with infrequent cell­obstacle collisions) and larger contaminant cells (by focusing those collisions into regions of high shear stress).