Virginia Lockamy

Active Breathing Coordinator reduces radiation dose to the heart and preserves local control in patients with left breast cancer: Report of a prospective trial

PURPOSE Incidental radiation dose to the heart and lung during breast radiation therapy (RT) has been associated with an increased risk of cardiopulmonary morbidity. We conducted a prospective trial to determine if RT with the Active Breathing Coordinator (ABC) can reduce the mean heart dose (MHD) by ≥20% and dose to the lung. METHODS AND MATERIALS Patients with stages 0-III left breast cancer (LBC) were enrolled and underwent simulation with both free breathing (FB) and ABC for comparison of dosimetry. ABC was used during the patients RT course if the MHD was reduced by ≥5%. The median prescription dose was 50.4 Gy plus a boost in 77 patients (90%). The primary endpoint was the magnitude of MHD reduction when comparing ABC to FB. Secondary endpoints included dose reduction to the heart and lung, procedural success rate, and adverse events. RESULTS A total of 112 patients with LBC were enrolled from 2002 to 2011 and 86 eligible patients underwent both FB and ABC simulation. Ultimately, 81 patients received RT using ABC, corresponding to 72% procedural success. The primary endpoint was achieved as use of ABC reduced MHD by 20% or greater in 88% of patients (P < .0001). The median values for absolute and relative reduction in MHD were 1.7 Gy and 62%, respectively. RT with ABC provided a statistically significant dose reduction to the left lung. After a median follow up of 81 months, 8-year estimates of locoregional relapse, disease-free, and overall survival were 7%, 90%, and 96%, respectively. CONCLUSIONS ABC was well tolerated and significantly reduced MHD while preserving local control. Use of the ABC device during RT should be considered to reduce the risk of ischemic heart disease in populations at risk.

Clinical implementation and failure mode and effects analysis of HDR skin brachytherapy using Valencia and Leipzig surface applicators

PURPOSE The planning procedure for Valencia and Leipzig surface applicators (VLSAs) (Nucletron, Veenendaal, The Netherlands) differs substantially from CT-based planning; the unfamiliarity could lead to significant errors. This study applies failure modes and effects analysis (FMEA) to high-dose-rate (HDR) skin brachytherapy using VLSAs to ensure safety and quality. METHOD A multidisciplinary team created a protocol for HDR VLSA skin treatments and applied FMEA. Failure modes were identified and scored by severity, occurrence, and detectability. The clinical procedure was then revised to address high-scoring process nodes. RESULTS Several key components were added to the protocol to minimize risk probability numbers. (1) Diagnosis, prescription, applicator selection, and setup are reviewed at weekly quality assurance rounds. Peer review reduces the likelihood of an inappropriate treatment regime. (2) A template for HDR skin treatments was established in the clinics electronic medical record system to standardize treatment instructions. This reduces the chances of miscommunication between the physician and planner as well as increases the detectability of an error. (3) A screen check was implemented during the second check to increase detectability of an error. (4) To reduce error probability, the treatment plan worksheet was designed to display plan parameters in a format visually similar to the treatment console display, facilitating data entry and verification. (5) VLSAs are color coded and labeled to match the electronic medical record prescriptions, simplifying in-room selection and verification. CONCLUSIONS Multidisciplinary planning and FMEA increased detectability and reduced error probability during VLSA HDR brachytherapy. This clinical model may be useful to institutions implementing similar procedures.

Scalp-sparing total skin electron therapy in mycosis fungoides: Case report highlighting technique and outcome.

Among the classically described cutaneous T-cell lymphomas, mycosis fungoides (MF) is the most common. Patients typically present with pruritic patches or tumors of the skin. Prognosis relates to age, stage, and the presence of extracutaneous disease.1,2 Total skin electron therapy (TSET) has emerged as the single most effective targeted therapy for patients with MF. Historically, complete response rates improved with dose escalation from 8 Gy to 36 Gy. Also seen with dose escalation was an increase in toxicity including dry desquamation, skin erythema, alopecia, anhidrosis, and loss of fingernails.1,3 Therefore, more recent studies have focused on the impact of dose de-escalation on toxicity and response rates. A pooled analysis published by Hoppe et al. explored low-dose (12 Gy, 1 Gy per fraction) TSET for patients with stage IB to IIIA disease. Of the 33 evaluable patients, the majority experienced a rapid reduction of disease burden and minimal toxicities.1 Alopecia remains a common concern of patients preceding TSET. In the aforementioned study, 1 female patient with stage IIB

Dosimetric Impact of a Tumor Treating Fields Device for Glioblastoma Patients Undergoing Simultaneous Radiation Therapy

Purpose A recent randomized phase III clinical trial in patients with glioblastoma demonstrated the efficacy of tumor treating fields (TTFields), in which alternating electric fields are applied via transducer arrays to a patient’s scalp. This treatment, when added to standard of care therapy, was shown to increase overall survival from 16 to 20.9 months. These results have generated significant interest in incorporating the use of TTFields during postoperative concurrent chemoradiation. However, the dosimetric impact of high-density electrodes on the scalp, within the radiation field, is unknown. Methods The dosimetric impact of TTFields electrodes in the radiation field was quantified in two ways: (1) dose calculated in a treatment planning system and (2) physical measurements of surface and deep doses. In the dose calculation comparison, a volumetric-modulated-arc-therapy (VMAT) radiation plan was developed on a CT scan without electrodes and then recalculated with electrodes. For physical measurements, the surface dose underneath TTFields electrodes were measured using a parallel plate ionization chamber and compared to measurements without electrodes for various incident beam angles and for 12 VMAT arc deliveries. Deep dose measurements were conducted for five VMAT plans using Scandidos Delta4 diode array: measured doses on two orthogonal diode arrays were compared. Results In the treatment planning system, the presence of the TTFields device caused mean reduction of PTV dose of 0.5–1%, and a mean increase in scalp dose of 0.5–1 Gy. Physical measurement showed increases of surface dose directly underneath by 30–110% for open fields with varying beam angles and by 70–160% for VMAT deliveries. Deep dose measurement by diode array showed dose decrease of 1–2% in most areas shadowed by the electrodes (max decrease 2.54%). Conclusion The skin dose in patients being treating with cranial irradiation for glioblastoma may increase substantially (130–260%) with the addition of concurrent TTFields electrodes on the scalp. However, the impact of dose attenuation by the electrodes on deep dose during VMAT treatment is of much smaller, but measureable, magnitude (1–2%). Clinical trials exploring concurrent TTFields with cranial irradiation for glioblastoma may utilize scalp-sparing techniques to mitigate any potential increase in skin toxicity.

SU-C-BRB-03: Cross-Institutional Validation of An Ultrafast Automatic Planning Platform for Breast Irradiation

PURPOSE Recently an ultrafast automatic planning system for breast irradiation using tangential beams was developed by modeling relationships between patient anatomy and achieved dose distribution. This study evaluates the performance of this system when applied to a different patient population and dose calculation algorithm. METHODS The system and its anatomy-to-dose models was developed at institution A based on 20 cases, which were planned using manual fluence painting technique and calculated WITH heterogeneity correction. Institution B uses field-in-field planning technique and dose calculation WITHOUT heterogeneity correction. 11 breast cases treated at Institution B were randomly selected for retrospective study, including left and right sides, and different breast size (irradiated volumes defined by Jaw/MLC opening range from 875cc to 3516cc). Comparisons between plans generated automatically (Auto-Plans) and those used for treatment (Clinical-Plans) included: energy choice (single/mixed), volumes receiving 95%/100%/105%/110% Rx dose (V95%/V100%/V105%/V100%) relative to irradiated volume, D1cc, and LungV20Gy. RESULTS In 9 out of 11 cases single/mixed energy choice made by the software agreed with Clinical-Plans. For the remaining 2 cases software recommended using mixed energy and dosimetric improvements were observed. V100% were similar (p=0.223, Wilcoxon Signed-Rank test) between Auto-Plans and Clinical-Plans (57.6±8.9% vs. 54.8±9.5%). V95% is 2.3±3.0% higher for Auto-Plans (p=0.027), indicating reduced cold areas. Hot spot volume V105% were significantly reduced in Auto-Plan by 14.4±7.2% (p=0.004). Absolute V105% was reduced from 395.6±359.9cc for Clinical-Plans to 108.7±163cc for Auto-Plans. D1cc was 107.4±2.8% for Auto-Plans, and 109.2±2.4% for Clinical-Plans (p=0.056). LungV20Gy were 13.6±4.0% for Auto-Plan vs. 14.0±4.1% for Clinical-Plans (p=0.043). All optimizations were finished within 1.5min. CONCLUSION The performance of this breast auto-planning system remained stable and satisfactory when applied to a different patient population and dose calculation algorithm. The auto-planning system was able to produce clinically similar Rx dose coverage with significantly improved homogeneity inside breast tissue, in less than 1.5min.

SU‐E‐T‐408: Evaluation of the Type and Frequency of Variations Discovered During Routine Secondary Patient Chart Review

Purpose: Desire to improve efficiency and throughput inspired a review of our physics chart check procedures. Departmental policy mandates plan checks pre-treatment, after first treatment and weekly every 3–5 days. This study examined the effectiveness of the “after first” check with respect to improving patient safety and clinical efficiency. Type and frequency of variations discovered during this redundant secondary review was examined over seven months. Methods: A community spreadsheet was created to record variations in care discovered during chart review following the first fraction of treatment and before the second fraction (each plan reviewed prior to treatment). Entries were recorded from August 2014 through February 2015, amounting to 43 recorded variations out of 906 reviewed charts. The variations were divided into categories and frequencies were assessed month-to-month. Results: Analysis of recorded variations indicates an overall variation rate of 4.7%. The initial rate was 13.5%; months 2–7 average 3.7%. The majority of variations related to discrepancies in documentation at 46.5%, followed by prescription, plan deficiency, and dose tracking related variations at 25.5%, 12.8%, and 12.8%, respectively. Minor variations (negligible consequence on patient treatment) outweighed major variations 3 to 1. Conclusion: This work indicates that this redundant secondary check is effective. The first month spike in rates could be due to the Hawthorne/observer effect, but the consistent 4% variation rate suggests the need for periodical re-training on variations noted as frequent to improve awareness and quality of the initial chart review process, which may lead to improved treatment quality, patient safety and increased clinical efficiency. Utilizing these results, a continuous quality improvement process following Deming’s Plan-Do-Study-Act (PDSA) methodology was generated. The first iteration of this PDSA was adding a specific dose tracking checklist item in the pre-treatment plan check assessment; the ramification of which will be assessed in future data.

SU‐C‐BRD‐02: A Team Focused Clinical Implementation and Failure Mode and Effects Analysis of HDR Skin Brachytherapy Using Valencia and Leipzig Surface Applicators

PURPOSE and Leipzig applicators (VLAs) are single-channel brachytherapy surface applicators used to treat skin lesions up to 2cm diameter. Source dwell times can be calculated and entered manually after clinical set-up or ultrasound. This procedure differs dramatically from CT-based planning; the novelty and unfamiliarity could lead to severe errors. To build layers of safety and ensure quality, a multidisciplinary team created a protocol and applied Failure Modes and Effects Analysis (FMEA) to the clinical procedure for HDR VLA skin treatments. METHODS team including physicists, physicians, nurses, therapists, residents, and administration developed a clinical procedure for VLA treatment. The procedure was evaluated using FMEA. Failure modes were identified and scored by severity, occurrence, and detection. The clinical procedure was revised to address high-scoring process nodes. RESULTS Several key components were added to the clinical procedure to minimize risk probability numbers (RPN): -Treatments are reviewed at weekly QA rounds, where physicians discuss diagnosis, prescription, applicator selection, and set-up. Peer review reduces the likelihood of an inappropriate treatment regime. -A template for HDR skin treatments was established in the clinical EMR system to standardize treatment instructions. This reduces the chances of miscommunication between the physician and planning physicist, and increases the detectability of an error during the physics second check. -A screen check was implemented during the second check to increase detectability of an error. -To reduce error probability, the treatment plan worksheet was designed to display plan parameters in a format visually similar to the treatment console display. This facilitates data entry and verification. -VLAs are color-coded and labeled to match the EMR prescriptions, which simplifies in-room selection and verification. CONCLUSION Multidisciplinary planning and FMEA increased delectability and reduced error probability during VLA HDR Brachytherapy. This clinical model may be useful to institutions implementing similar procedures.

Process mapping and time study to improve efficiency of HDR prostate brachytherapy.

103 Background: New technologies and procedures have the potential to improve outcomes; however, initial implementation is often associated with a steep learning curve, decreased efficiency, and patient safety implications. Since process mapping, checklists and external benchmarks have been proven to be useful quality improvement (QI) tools in health care, we sought to use these QI tools in a novel setting to decrease new procedure times without sacrificing the quality of care. METHODS Implementation of a real-time, ultrasound based prostate high-dose-rate brachytherapy procedure involved a multidisciplinary team composed of approximately 6-8 team members and numerous complex tasks. To characterize time spent on various aspects of the procedure and improve efficiency, our team developed a detailed process map including checklists and team debriefings. A benchmark was created based on an experienced institution which has performed >100 procedures annually. Times for key events, such as induction of general anesthesia, acquisition of first image, catheter insertion and completion of planning were recorded during each case. The process map was analyzed based on clinical tasks and treatment planning tasks. RESULTS The expert institution completed a procedure in 65 minutes. Over the course of ten cases at our institution, total procedure time ranged from 222-107 minutes. Implementation of the process map resulted in a reduction of total time by 52% (51% for clinical tasks and 65% for planning). Process improvements included changes to room layout, availability of supplies and identification of parallel processes. Improvement in efficiency was done without compromising quality as defined by dosimetric parameters. CONCLUSIONS The implementation of a new procedure benefits from the integration and utilization of a process map. We were able to reduce procedure time significantly, which resulted in decreased time under general anesthesia, reduced risk of deep vein thrombosis and improved overall patient safety.