Vivian Yau

Reasons for Poor Accrual in Palliative Radiation Therapy Research Studies

BACKGROUND Patients with advanced-stage cancer commonly have multiple symptoms, poor performance status, and limited life expectancies. Despite the need for evidence-based practice and guidelines for palliative radiation therapy (RT), conducting clinical palliative research has proven to be a challenge in the past because of low accrual rates and high patient attrition. We explore the change in accrual rates, reasons for nonparticipation in palliative RT clinical research trials, and factors that contributed to the increase in accrual over a 3-year period. PATIENTS AND METHODS A record was kept for all patients seen at the Rapid Response Radiotherapy Program between 2002 and 2005, including information on patient demographics, disease characteristics, and whether patients were accrued into >/=1 palliative research study at the time of clinic visit. If a patient did not participate in a study, the reason for nonaccrual was recorded. RESULTS Despite previous difficulties, changes to the methods of conducting palliative research and study design have resulted in an increase in patient accrual, from 14% to an average of approximately 60%. The implementation of a full-time clinical research assistant and a simple study design with realistic eligibility criteria contributed to the increase in patient participation. CONCLUSION Difficulties in conducting palliative clinical research trials were improved through changes in study design and research administration. Future clinics should use a dedicated clinical research assistant responsible for patient recruitment and study management. Studies should be designed specifically for the patient population receiving palliative care and should involve clearly defined and realistic eligibility criteria and brief assessments.

Survival Impact of Cardiac Dose Following Lung Stereotactic Body Radiotherapy

Micro‐Abstract Heart dose has been emerging as a strong predictor of outcomes in radiation therapy treatment for lung cancer. It is necessary to determine the impact of dose to substructures of the heart on overall survival. Heart substructures were contoured retrospectively on 189 patients treated with stereotactic body radiotherapy. Clinical variables and the dose to these structures were correlated with non–cancer‐related deaths. Higher bilateral ventricles max dose is associated with poorer survival. Heart dose parameters should be considered when planning patients for stereotactic body radiotherapy. Introduction: The purpose of this study was to determine the impact of radiation dose to substructures of the heart in lung stereotactic body radiotherapy (SBRT) patients on non–cancer‐related deaths. Methods: Patients treated with lung SBRT at a single institution from 2005 to 2013 were included. The heart and its substructures were contoured, and dose was calculated including mean, max, and max 10 cc dose. Clinical variables including stage, histology, age, gender, Charlson comorbidity index (CCI), preexisting cardiac disease, pulmonary function (forced expiratory volume in 1 second, diffusion capacity), and smoking status were explored for association with non–cancer‐related deaths in univariable (UVA) and multivariable (MVA) analyses. Heart dosimetric parameters were correlated with the risk of radiation pneumonitis (RP) using UVA and MVA. Results: A total of 189 patients were included with median age of 76 years (range, 48‐93 years). Of these patients, 45.5% were female, 27.5% were T2, 16.9% were current smokers, 64% had preexisting cardiac risk factors, and 34.5% had CCI score of ≥ 3. Mean lung dose ± SD was 456 ± 231 cGy. Heart max, mean, and 10 cc doses were 1867 ± 1712 cGy, 265 ± 269 cGy, and 1150 ± 1075 cGy, respectively. There were 14 (7.4%) ≥ Grade 2 RP and 3 (1.6%) were ≥ Grade 3. The median overall survival was 37.3 months (95% confidence interval, 29.8‐45.3 months). On UVA, female gender (P < .01), higher Eastern Cooperative Oncology Group (P = .01), cardiac risk (P < .01), CCI (P < .01), and bilateral ventricles max dose (P = .02) were associated with non–cancer‐related deaths; on MVA, bilateral ventricles max dose was significant (P = .05). No heart parameters were associated with RP. Conclusions: Higher bilateral ventricles max dose is associated with poorer survival. Heart dose parameters should be considered when planning patients for SBRT.

Ultracentral Tumors Treated With Stereotactic Body Radiotherapy: Single-Institution Experience

Micro‐abstract: A review of institutional outcomes for treating central and ultracentral lung tumors with stereotactic body radiotherapy found no differences in recurrence rates, survival, or grade 2 or higher toxicities between the 2 groups, and no grade 4 or higher toxicities were observed. These results support the use of 60 Gy in 8 fractions in the treatment of ultracentral tumors. Introduction: Patients with ultracentral lung tumors, whose planning target volume directly contacts or overlaps the proximal bronchial tree, trachea, esophagus, pulmonary vein, or pulmonary artery, may be at higher risk of toxicity when treated with stereotactic body radiotherapy (SBRT). We reviewed the outcomes and toxicities of ultracentral lung tumors and compared the results with central lung tumors. Patients and Methods: A review of our institutional prospective database of patients treated with lung SBRT from January 2006 to December 2015 was conducted. Patients with central tumors (RTOG 0813 definition) and ultracentral tumors were included. Results: In total, 180 central and 26 ultracentral tumors were analyzed. The majority of patients received 60 Gy in 8 fractions (53.9%) or 48 Gy in 4 fractions (29.1%). The rates of any grade 2 or higher toxicity were 8.4% (n = 16) in the central group and 7.9% (n = 2) in the ultracentral group (P = .88). There were no observed grade 4 or 5 toxicities. In the nonmetastatic primary lung cancer cohort (n = 182), the median overall survival was 39.4 months versus 23.8 months (P = .40) and cause‐specific survival was 55.5 months versus 28.2 months (P = .34) for central and ultracentral tumors, respectively. The 2‐year cumulative local, regional, and distant failure rates were 3.3% versus 0 (P = .36), 9.1% versus 5.0% (P = .5), and 17.7% versus 18.7% (P = .63) in the central and ultracentral groups, respectively. Conclusion: In our experience, with strict adherence to planning parameters, SBRT to ultracentral tumors resulted in effective local control and no excessive risk of toxicity compared to central tumors.