Caitlin Gomez

Accuracy of UTE-MRI-based patient setup for brain cancer radiation therapy.

PURPOSE Radiation therapy simulations solely based on MRI have advantages compared to CT-based approaches. One feature readily available from computed tomography (CT) that would need to be reproduced with MR is the ability to compute digitally reconstructed radiographs (DRRs) for comparison against on-board radiographs commonly used for patient positioning. In this study, the authors generate MR-based bone images using a single ultrashort echo time (UTE) pulse sequence and quantify their 3D and 2D image registration accuracy to CT and radiographic images for treatments in the cranium. METHODS Seven brain cancer patients were scanned at 1.5 T using a radial UTE sequence. The sequence acquired two images at two different echo times. The two images were processed using an in-house software to generate the UTE bone images. The resultant bone images were rigidly registered to simulation CT data and the registration error was determined using manually annotated landmarks as references. DRRs were created based on UTE-MRI and registered to simulated on-board images (OBIs) and actual clinical 2D oblique images from ExacTrac™. RESULTS UTE-MRI resulted in well visualized cranial, facial, and vertebral bones that quantitatively matched the bones in the CT images with geometric measurement errors of less than 1 mm. The registration error between DRRs generated from 3D UTE-MRI and the simulated 2D OBIs or the clinical oblique x-ray images was also less than 1 mm for all patients. CONCLUSIONS UTE-MRI-based DRRs appear to be promising for daily patient setup of brain cancer radiotherapy with kV on-board imaging.

Dosimetric parameters predict short-term quality-of-life outcomes for patients receiving stereotactic body radiation therapy for prostate cancer

PURPOSE Stereotactic body radiation therapy (SBRT) is a treatment option for patients with localized prostate cancer, with reported clinical and health-related quality-of-life (QOL) outcomes comparable to standard fractionation radiation therapy. The goal of this study was to evaluate correlations between short-term QOL outcomes and dosimetric parameters to guide future prostate SBRT planning. METHODS AND MATERIALS From 2010 to 2013, QOL data were prospectively collected from 75 patients enrolled in a prostate SBRT clinical trial. A comparison was made between Expanded Prostate Cancer Index Composite scores for patients with the top 25th percentile versus the bottom 75th percentile of the following dose-volume histogram parameters: planning target volume V100; bladder V50 and V100; and rectum V50, V80, V90, and V100. A linear mixed-effect model was used to estimate the difference between the 2 strata for each parameter. RESULTS Median follow-up was 12 months. Patients with planning target volume V100 volumes >120 cm(3) had the worst reduction in urinary QOL. Urinary QOL was also decreased significantly in patients with bladder V100 volumes >5.5 cm(3). Bowel QOL was decreased significantly in patients with rectal V90 and V100 volumes >4.2 and >1.5 cm(3), respectively. CONCLUSIONS Patients with large prostate size or large volumes of rectum and bladder that receive ≥90% of the prescribed radiation dose are more susceptible to short-term QOL decrements after prostate SBRT. These volumes should be minimized to maximize recovery to baseline QOL after prostate SBRT.

Plan quality and dosimetric association of patient-reported rectal and urinary toxicities for prostate stereotactic body radiotherapy

BACKGROUND AND PURPOSE To study the association between dosimetric parameters with patient-reported quality-of-life (QOL) in urinary irritative/incontinency and bowel functions for prostate stereotactic body radiotherapy (SBRT). MATERIAL AND METHODS The patient-reported QOL was evaluated using the Expanded Prostate Cancer Index Composite (EPIC-26). According to the progression in QOL score over 12months, patients were assigned to one of three subgroups: score decrement, no change, or increment. The dosimetric parameters were cross-compared among subgroups in urinary and bowel domains using univariate Analysis of Variance (ANOVA). The evaluated dosimetric metrics included target volume, V100 (volume receiving 100% prescription dose); rectal volume/dose-volume endpoints, maximum/mean doses; bladder volume/dose-volume endpoints, and maximum/mean doses. RESULTS Patients with consistent QOL reduction in urinary irritation function were significantly associated with greater mean bladder dose, greater V85/V90/V95/V100 and D2cc/D10cc. Patients with QOL reduction in urinary incontinence were marginally associated with greater mean bladder dose (p=0.06). None of the evaluated dosimetric parameters showed a significant correlation with QOL score change in bowel function. CONCLUSIONS Patients with large prostate size were more susceptible to QOL decrements for urinary irritative and incontinency functions. Large bladder V85/V90/V95/V100 was associated with QOL decrements in the urinary irritative domain at 1-year after prostate SBRT.

Multidisciplinary breast clinic: Impact on patient satisfaction, timeliness, and guideline concordant care.

124 Background: After recent implementation of a multidisciplinary breast clinic (MDC) for newly diagnosed women at our institution, we sought to examine the impact of MDC on patient satisfaction, timeliness and guideline concordant care. METHODS Women with newly diagnosed breast cancer at our institution are referred to MDC where they are seen by a team of breast specialists for initial consultation. The MDC model is further facilitated by a patient navigator/coordinator who serves as a single point of contact across disciplines and through the continuum of care. We deployed patient satisfaction surveys querying helpfulness of the care coordinator and satisfaction with seeing breast cancer specialty physicians together in one visit. We further retrospectively analyzed timeliness of care and guideline concordant care since MDC implementation. RESULTS Patient satisfaction survey response rate was 42% (n=133).On a scale of 1 (very poor) - 5 (excellent), 93% of respondents rated helpfulness of care coordinator as excellent and seeing specialty physicians together in one visit as excellent. 99% of respondents rated these factors as either excellent (5) or good (4). Regarding timeliness, among 202 women with newly diagnosed, non-metastatic breast cancer seen in MDC between June 2012 and April 2014, mean time from neoadjuvant chemotherapy to surgery was 43.1 days (range 26-78 days), from surgery to adjuvant radiation was 39.2 days (range 22-79 days), from surgery to adjuvant chemotherapy was 40.6 days (range 19-89 days), and from adjuvant chemotherapy to radiation was 34.9 days (range 13-67 days). All timeliness metrics well exceeded established national standards of 60-90 days. Regarding guideline concordant care, 94% and 90% respectively received indicated radiation therapy and chemotherapy in accordance with National Comprehensive Cancer Network (NCCN) Guidelines. Those not receiving guideline concordant care either declined, were of advanced age, or had prohibitive co-morbidities. CONCLUSIONS The MDC model, which emphasizes care coordination via a team approach and patient navigation, is associated with excellent patient satisfaction and timely, guideline concordant breast cancer care.

Pineocytoma with diffuse dissemination to the leptomeninges

Pineal parenchymal tumors are rare. Of the three types of pineal parenchymal tumors, pineocytomas are the least aggressive and are not known to diffusely disseminate. In this paper, we report the successful treatment of a case of pineocytoma with diffuse leptomeningeal relapse following initial stereotactic radiotherapy. A 39-year-old female presented with headaches, balance impairment, urinary incontinence, and blunted affect. A pineal mass was discovered on magnetic resonance imaging (MRI). A diagnosis of pineocytoma was established with an endoscopic pineal gland biopsy, and the patient received stereotactic radiotherapy. Ten years later, she developed diffuse leptomeningeal dissemination. The patient was then successfully treated with craniospinal radiation therapy. Leptomeningeal spread may develop as late as 10 years after initial presentation of pineocytoma. Our case demonstrates the importance of long-term follow-up of patients with pineal parenchymal tumors following radiation therapy, and the efficacy of craniospinal radiation in the treatment of leptomeningeal dissemination.

SU-E-J-90: MRI-Based Treatment Simulation and Patient Setup for Radiation Therapy of Brain Cancer

PURPOSE Traditional radiation therapy of cancer is heavily dependent on CT. CT provides excellent depiction of the bones but lacks good soft tissue contrast, which makes contouring difficult. Often, MRIs are fused with CT to take advantage of its superior soft tissue contrast. Such an approach has drawbacks. It is desirable to perform treatment simulation entirely based on MRI. To achieve MR-based simulation for radiation therapy, bone imaging is an important challenge because of the low MR signal intensity from bone due to its ultra-short T2 and T1, which presents difficulty for both dose calculation and patient setup in terms of digitally reconstructed radiograph (DRR) generation. Current solutions will either require manual bone contouring or multiple MR scans. We present a technique to generate DRR using MRI with an Ultra Short Echo Time (UTE) sequence which is applicable to both OBI and ExacTrac 2D patient setup. METHODS Seven brain cancer patients were scanned at 1.5 Tesla using a radial UTE sequence. The sequence acquires two images at two different echo times. The two images were processed using in-house software. The resultant bone images were subsequently loaded into commercial systems to generate DRRs. Simulation and patient clinical on-board images were used to evaluate 2D patient setup with MRI-DRRs. RESULTS The majority bones are well visualized in all patients. The fused image of patient CT with the MR bone image demonstrates the accuracy of automatic bone identification using our technique. The generated DRR is of good quality. Accuracy of 2D patient setup by using MRI-DRR is comparable to CT-based 2D patient setup. CONCLUSION This study shows the potential of DRR generation with single MR sequence. Further work will be needed on MR sequence development and post-processing procedure to achieve robust MR bone imaging for other human sites in addition to brain.

Rates of appropriate genetic testing referral for breast cancer patients treated in a multidisciplinary cancer care setting.

45 Background: Approximately 5% to 10% of women diagnosed with breast cancer have a genetic predisposition, which can affect management recommendations. The National Comprehensive Cancer Network (NCCN) has established guidelines for genetics referral and testing, however recent publications have indicated low rates of family history documentation and appropriate genetics referral. We sought to assess the impact of standardized family history documentation on rates of appropriate genetics referral in a multidisciplinary breast clinic (MDC) setting. METHODS In advance of MDC consultation, women with newly diagnosed breast cancer complete an intake questionnaire which includes documentation of Ashkenazi Jewish ancestry along with a thorough family history. We retrospectively analyzed family history documentation to inform eligibility for genetic testing and rates of appropriate genetics referral. RESULTS Between June 2012 and April 2014, 202 women with newly diagnosed, nonmetastatic breast cancer were seen in MDC. We noted 100% compliance with family history documentation. Per NCCN Guidelines, genetic testing was indicated in 52% (106 patients), of which 77% were appropriately referred to a genetic counselor for evaluation. All patients who met criteria based on personal history factors including age ≤ 45, triple-negative disease under age 60, or two or more breast primaries under age 50 were appropriately referred. Patients who were eligible but not referred ranged in age from 46 to 93 and were eligible for testing based on Ashkenzi Jewish ancestry (3 patients) or family history factors including a relative with ovarian cancer (3 patients), ≥2 relatives with breast cancer (5 patients), or a relative with breast cancer < age 50 (7 patients). CONCLUSIONS Compared with recently published national averages, rates of appropriate family history documentation and genetic testing referrals are significantly higher in our MDC setting. However, this analysis has identified significant opportunity for improvement via identification of overlooked referral indications. Initiatives are underway to improve future compliance.