Browsing by Author "Zellars, Richard"

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    Histology, Tumor Volume, and Radiation Dose Predict Outcomes in NSCLC Patients After Stereotactic Ablative Radiotherapy
    (Elsevier, 2018) Shiue, Kevin; Cerra-Franco, Alberto; Shapiro, Ronald; Estabrook, Neil; Mannina, Edward M.; Deig, Christopher R.; Althouse, Sandra; Liu, Sheng; Wan, Jun; Zang, Yong; Agrawal, Namita; Ioannides, Pericles; Liu, Yongmei; Zhang, Chen; DesRosiers, Colleen; Bartlett, Greg; Ewing, Marvene; Langer, Mark P.; Watson, Gordon; Zellars, Richard; Kong, Feng-Ming; Lautenschlaeger, Tim; Radiation Oncology, School of Medicine
    Introduction It remains unclear if histology should be independently considered when choosing stereotactic ablative body radiotherapy dose prescriptions for NSCLC. Methods The study population included 508 patients with 561 lesions between 2000 and 2016, of which 442 patients with 482 lesions had complete dosimetric information. Eligible patients had histologically or clinically diagnosed early-stage NSCLC and were treated with 3 to 5 fractions. The primary endpoint was in-field tumor control censored by either death or progression. Involved lobe control was also assessed. Results At 6.7 years median follow-up, 3-year in-field control, involved lobe control, overall survival, and progression-free survival rates were 88.1%, 80.0%, 49.4%, and 37.2%, respectively. Gross tumor volume (GTV) (hazard ratio [HR] = 1.01 per mL, p = 0.0044) and histology (p = 0.0225) were independently associated with involved lobe failure. GTV (HR = 1.013, p = 0.001) and GTV dose (cutoff of 110 Gy, biologically effective dose with α/β = 10 [BED10], HR = 2.380, p = 0.0084) were independently associated with in-field failure. For squamous cell carcinomas, lower prescription doses were associated with worse in-field control (12 Gy × 4 or 10 Gy × 5 versus 18 Gy or 20 Gy × 3: HR = 3.530, p = 0.0447, confirmed by propensity score matching) and was independent of GTV (HR = 1.014 per mL, 95% confidence interval: 1.005–1.022, p = 0.0012). For adenocarcinomas, there were no differences in in-field control observed using the above dose groupings (p = 0.12 and p = 0.31, respectively). Conclusions In the absence of level I data, GTV and histology should be considered to personalize radiation dose for stereotactic ablative body radiotherapy. We suggest lower prescription doses (i.e., 12 Gy × 4 or 10 G × 5) should be avoided for squamous cell carcinomas if normal tissue tolerances are met.
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    Impact of Lung Parenchymal-Only Failure on Overall Survival in Early-Stage Lung Cancer Patients Treated With Stereotactic Ablative Radiotherapy
    (Elsevier, 2021) Elbanna, May; Shiue, Kevin; Edwards, Donna; Cerra-Franco, Alberto; Agrawal, Namita; Hinton, Jason; Mereniuk, Todd; Huang, Christina; Ryan, Joshua L.; Smith, Jessica; Aaron, Vasantha D.; Burney, Heather; Zang, Yong; Holmes, Jordan; Langer, Mark; Zellars, Richard; Lautenschlaeger, Tim; Radiation Oncology, School of Medicine
    Introduction: The impact of lung parenchymal-only failure on patient survival after stereotactic ablative body radiotherapy (SABR) for early-stage non-small-cell lung cancer (NSCLC) remains unclear. Patients and methods: The study population included 481 patients with early-stage NSCLC who were treated with 3- to 5-fraction SABR between 2000 and 2016. The primary study objective was to assess the impact of out-of-field lung parenchymal-only failure (OLPF) on overall survival (OS). Results: At a median follow-up of 5.9 years, the median OS was 2.7 years for all patients. Patients with OLPF did not have a significantly different OS compared to patients without failure (P = .0952, median OS 4.1 years with failure vs. 2.6 years never failure). Analysis in a 1:1 propensity score-matched cohort for Karnofsky performance status, comorbidity score, and smoking status showed no differences in OS between patients without failure and those with OLPF (P = .8). In subgroup analyses exploring the impact of time of failure on OS, patients with OLPF 6 months or more after diagnosis did not have significantly different OS compared to those without failure, when accounting for immortal time bias (P = .3, median OS 4.3 years vs. 3.5 years never failure). Only 7 patients in our data set experienced failure within 6 months of treatment, of which only 4 were confirmed to be true failures; therefore, limited data are available in our cohort on the impact of OLPF for ≤ 6 months on OS. Conclusion: OLPF after SABR for early-stage NSCLC does not appear to adversely affect OS, especially if occurring at least 6 months after SABR. More studies are needed to understand if OLPF within 6 months of SABR is associated with adverse OS. These data are useful when discussing prognosis of lung parenchymal failures after initial SABR.
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    The need for dedicated time for medical physicists practice quality improvement efforts in radiation oncology department: A commentary
    (Wiley, 2022) Zellars, Richard; Njeh, Christopher; Marquette, Scott; Radiation Oncology, School of Medicine
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    Predictors of Nodal and Metastatic Failure in Early Stage Non-Small Cell Lung Cancer after Stereotactic Body Radiation Therapy
    (Elsevier, 2019) Cerra-Franco, Alberto; Liu, S.; Azar, M.; Shiue, Kevin; Freije, S.; Hinton, J.; Deig, Christopher R.; Edwards, D.; Estabrook, Neil C.; Ellsworth, S. G.; Huang, K.; Diab, K.; Langer, Mark P.; Zellars, Richard; Kong, Feng-Ming; Wan, Jun; Lautenschlaeger, Tim; Radiation Oncology, School of Medicine
    Introduction/Background Many early-stage non-small cell lung cancer (ES-NSCLC) patients undergoing stereotactic body radiation therapy (SBRT) develop metastases, which is associated with poor outcomes. We sought to identify factors predictive of metastases after lung SBRT and created a risk stratification tool. Materials and Methods We included 363 patients with ES-NSCLC who received SBRT; median follow-up was 5.8 years. The following patient and tumor factors were retrospectively analyzed for their association with metastases (defined as nodal and/or distant failure): sex; age; lobe involved; centrality; previous NSCLC; smoking status; gross tumor volume (GTV); T-stage; histology; dose; minimum, maximum, and mean GTV dose; and parenchymal lung failure. A metastasis risk-score linear-model using beta coefficients from a multivariate Cox model was built. Results A total of 111/406 (27.3%) lesions metastasized. GTV volume and dose were significantly associated with metastases on univariate and multivariate Cox proportional hazards modeling (p<0.001 and HR=1.02 per mL, p<0.05 and HR=0.99 per Gy, respectively). Histology, T-stage, centrality, lung parenchymal failures, and previous NSCLC were not associated with development of metastasis. A metastasis risk-score model using GTV volume and prescription dose was built: [risk score=(0.01611 x GTV)–(0.00525 x dose (BED10))]. Two risk-score cutoffs separating the cohort into low-, medium-, and high-risk subgroups were examined. The risk-score identified significant differences in time to metastases between low-, medium-, and high-risk patients (p<0.001), with 3-year estimates of 81.1%, 63.8%, and 38%, respectively. Conclusion GTV volume and radiation dose are associated with time to metastasis and may be used to identify patients at higher risk of metastasis after lung SBRT.