Kelly Stuhr

A Phase II Study of Bevacizumab in Combination With Definitive Radiotherapy and Cisplatin Chemotherapy in Untreated Patients With Locally Advanced Cervical Carcinoma: Preliminary Results of RTOG 0417

PURPOSE Concurrent cisplatin-based chemoradiotherapy (CRT) is the standard treatment for locally advanced cervical cancer. RTOG 0417 was a Phase II study exploring the safety and efficacy of the addition of bevacizumab to standard CRT. METHODS AND MATERIALS Eligible patients with bulky tumors (Stage IB-IIIB) were treated with once-weekly cisplatin (40 mg/m(2)) chemotherapy and standard pelvic radiotherapy and brachytherapy. Bevacizumab was administered at 10 mg/kg intravenously every 2 weeks for three cycles. Treatment-related serious adverse event (SAE) and other adverse event (AE) rates within the first 90 days from treatment start were determined. Treatment-related SAEs were defined as any Grade ≥ 4 vaginal bleeding or thrombotic event or Grade ≥ 3 arterial event, gastrointestinal (GI) bleeding, or bowel/bladder perforation, or any Grade 5 treatment-related death. Treatment-related AEs included all SAEs and Grade 3 or 4 GI toxicity persisting for >2 weeks despite medical intervention, Grade 4 neutropenia or leukopenia persisting for >7 days, febrile neutropenia, Grade 3 or 4 other hematologic toxicity, and Grade 3 or 4 GI, renal, cardiac, pulmonary, hepatic, or neurologic AEs. All AEs were scored using the National Cancer Institute Common Terminology Criteria (CTCAE) v 3.0 (MedDRA version 6.0). RESULTS A total of 60 patients from 28 institutions were enrolled between 2006 and 2009, and of these, 49 patients were evaluable. The median follow-up was 12.4 months (range, 4.6-31.4 months).The median age was 45 years (range, 22-80 years). Most patients had FIGO Stage IIB (63%) and were of Zubrod performance status of 0 (67%). 80% of cases were squamous. There were no treatment-related SAEs. There were 15 (31%) protocol-specified treatment-related AEs within 90 days of treatment start; the most common were hematologic (12/15; 80%). 18 (37%) occurred during treatment or follow-up at any time. 37 of the 49 patients (76%) had cisplatin and bevacizumab administered per protocol, and 46 of the 49 (94%) had both external beam and brachytherapy administered per protocol or with acceptable variation. CONCLUSION Bevacizumab in addition to standard pelvic chemoradiotherapy for locally advanced cervical cancer is feasible and safe with respect to the protocol-specified treatment-related SAEs and AEs.

RTOG 0417: Efficacy of Bevacizumab in Combination With Definitive Radiation Therapy and Cisplatin Chemotherapy in Untreated Patients With Locally Advanced Cervical Carcinoma

PURPOSE Radiation Therapy Oncology Group 0417 was a phase II study that explored the safety and efficacy of the addition of bevacizumab to chemoradiation therapy. The safety results have been previously reported. Herein we report the secondary efficacy endpoints of overall survival (OS), locoregional failure (LRF), para-aortic nodal failure (PAF), distant failure (DF), and disease-free survival (DFS). METHODS AND MATERIALS Eligible patients with bulky Stage IB-IIIB disease were treated with once-weekly cisplatin (40 mg/m2) chemotherapy and standard pelvic radiation therapy and brachytherapy. Bevacizumab was administered at 10 mg/kg intravenously every 2 weeks for 3 cycles during chemoradiation. For OS, failure was defined as death of any cause and was measured from study entry to date of death. LRF was defined as any failure in the pelvis. PAF was defined as any para-aortic nodal failure. DF was analyzed both including and excluding PAF. DFS was measured from study entry to date of first LRF. DF was measured with or without PAF or death. OS and DFS were estimated by the Kaplan-Meier method, and LRF and DF rates were estimated by the cumulative incidence method. RESULTS 49 eligible patients from 28 institutions were enrolled between 2006 and 2009. The median follow-up time was 3.8 years (range, 0.8-6.0 years). The surviving patients had a median follow-up time of 3.9 years (range, 2.1-6.0 years). Most patients had tumors of International Federation of Gynecology and Obstetrics Stage IIB (63%), and 80% were squamous. The 3-year OS, DFS, and LRF were 81.3% (95% confidence interval [CI], 67.2%-89.8%), 68.7% (95% CI, 53.5%-79.8%), and 23.2% (95% CI, 11%-35.4%), respectively. The PAF, DF without PAF, and DF with PAF at 3 years were 8.4% (95% CI, 0.4%-16.3%), 14.7% (95% CI, 4.5%-24.9%), and 23.1% (95% CI 11.0%-35.2%), respectively. CONCLUSION In this study, bevacizumab in combination with standard pelvic chemoradiation therapy for locally advanced cervical cancer showed efficacy results that are promising and may warrant further investigation.

How should we describe the radiobiologic effect of extracranial stereotactic radiosurgery: Equivalent uniform dose or tumor control probability?

Extracranial stereotactic radiosurgery (ESR) is now undergoing clinical investigation at numerous institutions as a treatment for solitary malignant lesions. Because there is no standard ESR technique, the same minimum dose might be applied through widely variable target dose-volume histograms. For multicenter trials of ESR or interinstitutional comparisons, a reliable index of radiobiological dose equivalency might facilitate the evaluation of dose-response relationships. Equivalent uniform dose (EUD) and tumor control probability (TCP) were considered for this application. While EUD appears more robust for the prospective description of ESR, TCP is expected to remain more valuable for a post hoc estimation of radiosensitivity parameters.

Regional Normal Lung Tissue Density Changes in Patients Treated With Stereotactic Body Radiation Therapy for Lung Tumors

PURPOSE To describe regional lung tissue density changes in normal lung tissue of patients with primary and metastatic lung tumors who received stereotactic body radiation therapy (SBRT). METHODS AND MATERIALS A total of 179 post-SBRT follow-up computed tomography (CT) scans of 62 patients who received SBRT between 2003 and 2009 were studied. Median prescription dose was 54 Gy (range, 30-60 Gy) in 3 to 5 fractions. SBRT-induced lung density changes on post-SBRT follow-up CT were evaluated at approximately 3, 6, 12, 18, 24, and 30 months after treatment. Dose-response curves (DRC) were generated for SBRT-induced lung damage by averaging CT number (HU) changes for regions of the lungs receiving the same dose at 5-Gy intervals. RESULTS For all follow-up interval periods, CT numbers linearly increased with dose until 35 Gy and were constant thereafter. For 3, 18, 24, and 30 months, the rate of relative electron density increase with dose was approximately 0.24% per Gy. At 6 months, the rate was also similar below 20 Gy but then rose to 0.6% per Gy above this threshold. After 6 months, DRCs were mostly time-independent. When split between patients treated with 3 fractions of 12 to 20 Gy (median, 20 Gy; average tumor volume, 12±16 cm3) and with >3 fractions of 6 to 12.5 Gy (median, 9 Gy; average tumor volume, 30±40 cm3), DRCs differed significantly. In both cases, CT changes at 3, 18, 24, and 30 months were identical to those of the population DRC; however, patients who received >3 fractions showed 6-month CT changes that were more than twice those for the group that received 3 fractions. CONCLUSIONS This analysis of SBRT-induced normal lung density changes indicates that lung normal tissue has more pronounced self-limited acute effects than late effects. Differences in acute CT changes following treatments in 3 fractions were considerably less than for treatments in >3 fractions.

Phase I Trial of Hypofractionated Intensity-Modulated Radiotherapy With Temozolomide Chemotherapy for Patients With Newly Diagnosed Glioblastoma Multiforme

PURPOSE To determine the maximal tolerated biologic dose intensification of radiotherapy using fractional dose escalation with temozolomide (TMZ) chemotherapy in patients with newly diagnosed glioblastoma multiforme. METHODS AND MATERIALS Patients with newly diagnosed glioblastoma multiforme after biopsy or resection and with adequate performance status, bone marrow, and organ function were eligible. The patients underwent postoperative intensity-modulated radiotherapy (IMRT) with concurrent and adjuvant TMZ. All patients received a total dose of 60 Gy to the surgical cavity and residual tumor, with a 5-mm margin. IMRT biologic dose intensification was achieved by escalating from 3 Gy/fraction (Level 1) to 6 Gy/fraction (Level 4) in 1-Gy increments. Concurrent TMZ was given at 75 mg/m(2)/d for 28 consecutive days. Adjuvant TMZ was given at 150-200 mg/m(2)/d for 5 days every 28 days. Dose-limiting toxicity was defined as any Common Terminology Criteria for Adverse Events, version 3, Grade 3-4 nonhematologic toxicity, excluding Grade 3 fatigue, nausea, and vomiting. A standard 3+3 Phase I design was used. RESULTS A total of 16 patients were accrued (12 men and 4 women, median age, 69 years; range, 34-84. The median Karnofsky performance status was 80 (range, 60-90). Of the 16 patients, 3 each were treated at Levels 1 and 2, 4 at Level 3, and 6 at Level 4. All patients received IMRT and concurrent TMZ according to the protocol, except for 1 patient, who received 14 days of concurrent TMZ. The median number of adjuvant TMZ cycles was 7.5 (range, 0-12). The median survival was 16.2 months (range, 3-33). One patient experienced vision loss in the left eye 7 months after IMRT. Four patients underwent repeat surgery for suspected tumor recurrence 6-12 months after IMRT; 3 had radionecrosis. CONCLUSIONS The maximal tolerated IMRT fraction size was not reached in our study. Our results have shown that 60 Gy IMRT delivered in 6-Gy fractions within 2 weeks with concurrent and adjuvant TMZ is tolerable in selected patients with a T(1)-weighted enhancing tumor <6 cm.

Radiographic and histopathologic observations after combined EGFR inhibition and hypofractionated stereotactic radiosurgery in patients with recurrent malignant gliomas.

PURPOSE To describe the radiographic and histopathologic changes after stereotactic radiosurgery (SRS) and epidermal growth factor receptor inhibition in patients with recurrent malignant gliomas. METHODS AND MATERIALS A total of 15 patients with recurrent high-grade gliomas were treated on a prospective Phase I trial combining SRS and gefitinib. The SRS dose was escalated from 18 to 36 Gy in three fractions. The planning target volume was the T(1)-weighted contrast-enhancing (T(1)C) lesion plus 2 mm. Gefitinib was given at 250 mg daily. Serial brain magnetic resonance imaging scans were analyzed to characterize the volumetric changes in the T(1)C and T(2) abnormalities after treatment. Two patients underwent resection for suspected recurrence. RESULTS The median pretreatment magnetic resonance imaging T(1)C and T(2) volume was 40.9 and 184.1 cm(3), respectively. The median post-SRS percentage of increases in the T(1)C volume at 1, 2-4, and 5-7 months was 8.9%, 41.3%, and 99.6%, respectively. The median percentage increase in the T(2) volume likewise showed a trend upward after SRS, from 18.0% at 1 month to 37.8% at 5-7 months. For the 2 patients who underwent resection after SRS for an increasing T(1)C volume, the histopathologic analysis revealed therapy-induced vascular injury and necrosis. One patient with an asymptomatic increase in the T(1)C volume after SRS was treated conservatively. After a peak T(1)C volume increase at 9 months, the T(1)C volume had declined to 50% of the maximal volume at 15 months. The patients with the most dramatic increase in T(1)C volume experienced the longest overall survival. CONCLUSION Patients experienced a notable increase in magnetic resonance imaging T(1)C and T(2) volumes after the combination of SRS and epidermal growth factor receptor inhibition. The tissue changes were consistent with a potent treatment effect.

Dosimetric errors during treatment of centrally located lung tumors with stereotactic body radiation therapy: Monte Carlo evaluation of tissue inhomogeneity corrections.

Early experience with stereotactic body radiation therapy (SBRT) of centrally located lung tumors indicated increased rate of high-grade toxicity in the lungs. These clinical results were based on treatment plans that were computed using pencil beam-like algorithms and without tissue inhomogeneity corrections. In this study, we evaluated the dosimetric errors in plans with and without inhomogeneity corrections and with planning target volumes (PTVs) that were within the zone of the proximal bronchial tree (BT). For 10 patients, the PTV, lungs, and sections of the BT either inside or within 2cm of the PTV were delineated. Two treatment plans were generated for each patient using the following dose-calculation methods: (1) pencil beam (PB) algorithm without inhomogeneity correction (IC) (PB - IC) and (2) PB with inhomogeneity correction (PB + IC). Both plans had identical beam geometry but different beam segment shapes and monitor units (MU) to achieve similar conformal dose coverage of PTV. To obtain the baseline dose distributions, each plan was recalculated using a Monte Carlo (MC) algorithm by keeping MUs the same in the respective plans. The median maximum dose to the proximal BT and PTV dose coverage in the PB + IC plans were overestimated by 8% and 11%, respectively. However, the median maximum dose to the proximal BT and PTV dose coverage in PB - IC plans were underestimated by 15% and 9%. Similar trends were observed in low-dose regions of the lung within the irradiated volume. Our study indicates that dosimetric bias introduced by unit tissue density plans cannot be characterized as underestimation or overestimation of dose without taking the tumor location into account. This issue should be considered when analyzing clinical toxicity data from early lung SBRT trials that utilized unit tissue density for dose calculations.

A complete 4DCT-ventilation functional avoidance virtual trial: Developing strategies for prospective clinical trials

Introduction 4DCT‐ventilation is an exciting new imaging modality that uses 4DCT data to calculate lung‐function maps. Because 4DCTs are acquired as standard of care for lung cancer patients undergoing radiotherapy, 4DCT‐ventiltation provides functional information at no extra dosimetric or monetary cost to the patient. The development of clinical trials is underway to use 4DCT‐ventilation imaging to spare functional lung in patients undergoing radiotherapy. The purpose of this work was to perform a virtual trial using retrospective data to develop the practical aspects of a 4DCT‐ventilation functional avoidance clinical trial. Methods The study included 96 stage III lung cancer patients. A 4DCT‐ventilation map was calculated using the patients 4DCT‐imaging, deformable registration, and a density‐change‐based algorithm. Clinical trial inclusion assessment used quantitative and qualitative metrics based on the patients spatial ventilation profile. Clinical and functional plans were generated for 25 patients. The functional plan aimed to reduce dose to functional lung while meeting standard target and critical structure constraints. Standard and dose‐function metrics were compared between the clinical and functional plans. Results Our data showed that 69% and 59% of stage III patients have regional variability in function based on qualitative and quantitative metrics, respectively. Functional planning demonstrated an average reduction of 2.8 Gy (maximum 8.2 Gy) in the mean dose to functional lung. Conclusions Our work demonstrated that 60–70% of stage III patients would be eligible for functional planning and that a typical functional lung mean dose reduction of 2.8 Gy can be expected relative to standard clinical plans. These findings provide salient data for the development of functional clinical trials.

Excellent Outcomes with Radiosurgery for Multiple Brain Metastases in ALK and EGFR Driven Non–Small Cell Lung Cancer

Introduction: Patients with brain metastases (BMs) arising from EGFR‐mutated and anaplastic lymphoma kinase gene (ALK)‐rearranged NSCLC have a favorable prognosis compared with patients with non–oncogene‐addicted NSCLC, emphasizing the importance of minimizing toxicities such as the cognitive sequelae of whole brain radiation therapy (WBRT). Although radiosurgery without WBRT is the preferred strategy for one to three BMs, this paradigm remains controversial for patients with multiple BMs. Methods: We reviewed the cases of patients with EGFR‐mutated and ALK‐rearranged NSCLC presenting to our cancer center between 2008 and 2017 and included only patients receiving treatment to four or more BMs in a single radiosurgery session. Results: We identified 35 patients with a median follow‐up of 4.1 years. The maximum number of BMs treated in a single radiosurgery session ranged from four to 26 (median number of BM treated per radiosurgery course: 6), and in total over all courses the number ranged from four to 47 (median: 10). The median survival was 3.0 years (4.2 for ALK‐rearranged NSCLC; 2.4 for EGFR‐mutated NSCLC) from the diagnosis of BM, and survival was comparable regardless of number of radiosurgery courses, number of BMs treated in total, or number of BMs treated in a single radiosurgery session. The mean hippocampal and whole‐brain doses were exceedingly low even for patients receiving treatment to more than 10 BMs (1.2 and 0.8 Gy, respectively). Radiosurgery was well tolerated overall and the 5‐year rate of freedom from neurologic death was 84%. The 5‐year rate of freedom from WBRT was 97%. Conclusions: Radiosurgery for multiple BMs is controversial, yet patients with EGFR‐mutated and ALK‐rearranged NSCLC may be uniquely suited to benefit from this approach. These results support single and multiple courses of radiosurgery without WBRT for patients with oncogene‐addicted NSCLC with four or more BMs.

SU‐E‐T‐201: Safety‐Focused Customization of Treatment Plan Documentation

PURPOSE Plan report documentation contains numerous details about the treatment plan, but critical information for patient safety is often presented without special emphasis. This can make it difficult to detect errors from treatment planning and data transfer during the initial chart review. The objective of this work is to improve safety measures in radiation therapy practice by customizing the treatment plan report to emphasize safety-critical information. METHODS Commands within the template file from a commercial planning system (Eclipse, Varian Medical Systems) that automatically generates the treatment plan report were reviewed and modified. Safety-critical plan parameters were identified from published risks known to be inherent in the treatment planning process. Risks having medium to high potential impact on patient safety included incorrect patient identifiers, erroneous use of the treatment prescription, and incorrect transfer of beam parameters or consideration of accessories. Specific examples of critical information in the treatment plan report that can be overlooked during a chart review included prescribed dose per fraction and number of fractions, wedge and open field monitor units, presence of beam accessories, and table shifts for patient setup. RESULTS Critical information was streamlined and concentrated. Patient and plan identification, dose prescription details, and patient positioning couch shift instructions were placed on the first page. Plan information to verify the correct data transfer to the record and verify system was re-organized in an easy to review tabular format and placed in the second page of the customized printout. Placeholders were introduced to indicate both the presence and absence of beam modifiers. Font sizes and spacing were adjusted for clarity, and departmental standards and terminology were introduced to streamline data communication among staff members. CONCLUSIONS Plan reporting documentation has been customized to concentrate and emphasize safety-critical information, which should allow for a more efficient, robust chart review process.