A Pineal Parenchymal Tumor of Intermediate Differentiation in an Octogenarian Contains a Rare KBTBD4 Insertion.

Pineal parenchymal tumors are rare central nervous system tumors that pose diagnostic challenges for surgical pathologists. Due to their paucity, their clinicopathologic features are still being defined. We report an 86-year-old woman with a remote history of breast lobular carcinoma who presented with a 2-month neurologic history that included gait instability, blurry vision, and headaches. Magnetic resonance imaging revealed a lobular, heterogeneously enhancing pineal region mass compressing the aqueduct of Sylvius. A biopsy performed concomitant with endoscopic third ventriculostomy consisted of small sheets of cells with eosinophilic to clear cytoplasm, multipolar processes, and ovoid nuclei with stippled chromatin. Whole exome sequencing revealed a small in-frame insertion (duplication) in exon 4 of KBTBD4 (c.931_939dup, p.P311_R313dup/ p.R313_M314insPRR), which has very recently been reported in 2 pineal parenchymal tumors of intermediate differentiation (PPTID). Additionally, variants of uncertain significance in CEBPA (c.863G > C, p.R288P) and MYC (c.655T > C, p.S219P) were identified. Although PPTID is considered a disease of young adulthood, review of 2 institutional cohorts of patients with pineal region tumors revealed that 25% of individuals with PPTID were over 65 years of age. In conclusion, PPTID should be considered in the differential diagnosis of pineal region tumors in older adults.

Fast Deformable Image Registration for Real-Time Target Tracking During Radiation Therapy Using Cine MRI and Deep Learning.

PURPOSE: We developed a deep learning (DL) model for fast deformable image registration using 2-dimensional sagittal cine magnetic resonance imaging (MRI) acquired during radiation therapy and evaluated its potential for real-time target tracking compared with conventional image registration methods. METHODS AND MATERIALS: Our DL model uses a pair of cine MRI images as input and provides a motion vector field (MVF) as output. The MVF is then applied to align the input images. A retrospective study was conducted to train and evaluate our model using cine MRI data from patients undergoing treatment for abdominal and thoracic tumors. For each treatment fraction, MR-linear accelerator delivery log files, tracking videos, and cine image files were analyzed. Individual MRI frames were temporally sampled to construct a large set of image registration pairs used to evaluate multiple methods. The DL model was optimized using 5-fold cross validation, and model outputs (transformed images and MVFs) using test set images were saved for comparison with 3 conventional registration methods (affine, b-spline, and demons). Evaluation metrics were 3-fold: (1) registration error, (2) MVF stability (both spatial and temporal), and (3) average computation time. RESULTS: We analyzed >21 hours of cine MRI (>629,000 frames) acquired during 86 treatment fractions from 21 patients. In a test set of 10,320 image registration pairs, DL registration outperformed conventional methods in both registration error (affine, b-spline, demons, DL; root mean square error: 0.067, 0.040, 0.036, 0.032; paired t test demons vs DL: t[20] = 4.2, P < .001) and computation time per frame (51, 1150, 4583, 8 ms). Among deformable methods, spatial stability of resulting MVFs was comparable; however, the DL model had significantly improved temporal consistency. CONCLUSIONS: DL-based image registration can leverage large-scale MR cine data sets to outperform conventional registration methods and is a promising solution for real-time deformable motion estimation in radiation therapy.

Perceptions and practices regarding women's vaginal health following radiation therapy: A survey of radiation oncologists practicing in the United States.

PURPOSE: Vaginal stenosis (VS) is a recognized complication of pelvic and vaginal radiation therapy (RT). METHODS AND MATERIALS: A 26-item survey assessing the signs/symptoms, risk factors, diagnosis, prevention, treatment, and impact of VS on women's sexual health was distributed to radiation oncologists. Descriptive statistics were calculated. Chi-square tests examined differences in categorical responses. RESULTS: A total of 233 (10.5%) participants completed the entire survey. Twelve percent, 21%, and 68% report treating gynecologic (GYN) tumors only, non-GYN pelvic tumors only, or both, respectively. Regarding risk factors, 78% believed that VS can be caused by pelvic RT alone, 91% by vaginal brachytherapy alone, and 98% by combined pelvic RT and vaginal brachytherapy. Approximately one-half of respondents felt that being postmenopausal and having a hysterectomy before radiation therapy were risk factors for VS, whereas the other half felt that these were not risk factors. All respondents agreed that VS is a clinical diagnosis. Respondents indicated that VS symptoms include dyspareunia, vaginal pain, dryness, and/or bleeding (100%, 90%, 85%, and 72%, respectively); 65% indicated all 4. The most commonly recommended treatment for VS is vaginal dilator use. Radiation oncologists who treat GYN-only versus non-GYN cancers were more likely to perform a vaginal examination, to distribute written instructions regarding vaginal dilator use (P = .002), to have vaginal bleeding reported after RT (P = .001), and to refer patients to a sexual counselor (P = .007). Most providers (73%) expressed willingness to participate in prospective research on the diagnosis and treatment of VS. CONCLUSIONS: This is the first large-scale survey of radiation oncologists' perceptions and practices regarding VS. There is agreement among providers regarding the signs/symptoms of VS and strategies for its prevention/treatment using vaginal dilators. Further prospective and observational research is needed. This survey shows a willingness on the part of providers to take part in prospective research regarding the diagnosis, impact, and treatment of VS on women's sexual health.

Optimizing efficiency and safety in a radiation oncology department through the use of ARIA 11 Visual Care Path.

PURPOSE: Visual Care Path (VCP) is a workflow tool within the ARIA 11 Record and Verify System. The purpose of this study was to quantify the impact of VCP implementation on the metrics of efficiency, safety, and staff satisfaction. METHODS AND MATERIALS: Our multidisciplinary quality improvement team reviewed the entire process of patient care and constructed VCP modules to chart serial and parallel events from consultation to treatment completion. A failure mode and effects analysis was performed to identify high-risk tasks within existing patient care workflow. Data on timeliness of task completion were collected for 612 patients (6560 tasks) in 3 time phases: pre-VCP, transition, and post-VCP. Errors detected during a physics plan check were also monitored. A survey about the VCP was distributed to all staff to evaluate the impact of the VCP on the department. Descriptive statistics were calculated for the metrics of efficiency, safety, and staff satisfaction. RESULTS: Notable improvements in efficiency and safety were observed. Radiation oncologists' compliance with timely completion of the Simulation Preparation VCP tasks increased from 45.9% ± 14.3% during the pre-VCP phase to 85.8% ± 10.9% during the post-VCP phase. Compliance with Treatment Planning VCP tasks also increased from 52.6% ± 9.9% during the pre-VCP phase to 76.0% ± 9.7% during the post-VCP phase. The monthly defect rate (ratio of plans with errors to the total number of plans checked by a physicist) decreased from 19.1% ± 1.3% during the pre-VCP phase to 5.2% ± 4.1% during the post-VCP phase. Ninety-four percent of staff members responded to the VCP survey; more than 80% of respondents found the VCP to have a favorable impact. CONCLUSIONS: Implementation of the VCP in our department improved workflow efficiency, reduced the number of errors, and was very well received within the department.

Medical student mentorship in radiation oncology at a single academic institution: A 10-year analysis.

PURPOSE: Mentorship has been identified by medical students, residents, and faculty as an important component of specialty selection and research productivity in radiation oncology. This study quantitatively analyzes the impact of a mentorship program in radiation oncology targeted to medical students at our institution. METHODS AND MATERIALS: We performed a retrospective review of 76 current or former medical students who were mentored by faculty radiation oncologists at our institution between 2004 and 2013. Data were collected from the medical school's Office of Student Affairs and from internal departmental records. Mentees were organized by mentorship tracks, which included a clinical track and a research track. For each track, data were compiled and analyzed for student specialty selection, and Fisher exact tests were used to determine the relative significance of exposure to clinical, research, or both tracks on student likelihood of pursuing residency in radiation oncology relative to other specialties. We further tracked the research productivity of mentees in the program, as determined by the number publications that were coauthored by mentees and mentors each year. RESULTS: The absolute number of mentees has grown each year, with a total of 76 mentees, including 58 alumni, at the end of 2013. Mentees in the program have produced a total of 53 manuscripts, given 75 presentations at national conferences, and received numerous national and internal medical school research awards. Of the 58 alumni, 17 (29.3%) applied to and matched into radiation oncology residencies. Alumni of both the research and the clinical track were 5.76 (P < .01) times more likely to enter a radiation oncology residency program than the average single-track alumnus. CONCLUSIONS: Mentorship in medical school is an important factor in the development of future radiation oncologists. These results demonstrate the positive impact mentorship has on specialty selection and research productivity.

Positron emission tomography combined with diagnostic chest computed tomography enhances detection of regional recurrence after stereotactic body radiation therapy for early stage non-small cell lung cancer.

OBJECTIVE(S): Recommendations for surveillance after stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) are not well defined. Prospective studies evaluating the efficacy of SBRT have used interval posttreatment imaging with computed tomography (CT). We set out to determine whether positron emission tomography (PET) combined with diagnostic chest CT (PET/d-chest) can enhance detection of potentially salvageable recurrence after SBRT. METHODS: We performed a retrospective analysis of posttreatment imaging for 35 patients consecutively treated with SBRT for biopsy-proven early-stage NSCLC. PET/d-chest was generally performed every 3 months after treatment. A board-certified radiologist who did not have access to the PET results retrospectively interpreted the CT scans. CT results were reported according to response criteria used in Radiation Therapy Oncology Group 0236 and compared with PET/d-chest readings. Local and regional recurrence-free survival was compared using the Mantle-Cox (log-rank) test. RESULTS: Median follow-up was 12.8 months. Twenty-four patients had stage IA, 7 stage IB, 3 stage IIA, and 1 stage IIB biopsy-proven NSCLC. Two-year overall survival was 62%. CT scans indicated no regional recurrences. PET/d-chest indicated 10 regional recurrences. The 1-year rate of regional recurrence-free survival as evaluated by CT and PET/d-chest was 100% and 69.4%, respectively (P = .0045). Four of 10 patients with a diagnosis of regional recurrence underwent salvage treatment with definitive chemoradiotherapy. CONCLUSIONS: PET/d-chest enhances the detection of regional progression of NSCLC after SBRT over currently recommended practices. In patients who are fit for salvage treatment, where early detection of recurrence can increase the likelihood of successful treatment, PET/d-chest appears critical for follow-up.

Daily orthogonal kilovoltage imaging using a gantry-mounted on-board imaging system results in a reduction in radiation therapy delivery errors.

PURPOSE: To determine whether the use of routine image guided radiation therapy (IGRT) using pretreatment on-board imaging (OBI) with orthogonal kilovoltage X-rays reduces treatment delivery errors. METHODS AND MATERIALS: A retrospective review of documented treatment delivery errors from 2003 to 2009 was performed. Following implementation of IGRT in 2007, patients received daily OBI with orthogonal kV X-rays prior to treatment. The frequency of errors in the pre- and post-IGRT time frames was compared. Treatment errors (TEs) were classified as IGRT-preventable or non-IGRT-preventable. RESULTS: A total of 71,260 treatment fractions were delivered to 2764 patients. A total of 135 (0.19%) TEs occurred in 39 (1.4%) patients (3.2% in 2003, 1.1% in 2004, 2.5% in 2005, 2% in 2006, 0.86% in 2007, 0.24% in 2008, and 0.22% in 2009). In 2007, the TE rate decreased by >50% and has remained low (P = .00007, compared to before 2007). Errors were classified as being potentially preventable with IGRT (e.g., incorrect site, patient, or isocenter) vs. not. No patients had any IGRT-preventable TEs from 2007 to 2009, whereas there were 9 from 2003 to 2006 (1 in 2003, 2 in 2004, 2 in 2005, and 4 in 2006; P = .0058) before the implementation of IGRT. CONCLUSIONS: IGRT implementation has a patient safety benefit with a significant reduction in treatment delivery errors. As such, we recommend the use of IGRT in routine practice to complement existing quality assurance measures.