Clinical Impact of Contouring Variability for Prostate Cancer Tumor Boost.

Purpose: The focal radiation therapy (RT) boost technique was shown in a phase III randomized controlled trial (RCT) to improve prostate cancer outcomes without increasing toxicity. This technique relies on the accurate delineation of prostate tumors on MRI. A recent prospective study evaluated radiation oncologists' accuracy when asked to delineate prostate tumors on MRI and demonstrated high variability in tumor contours.

Comparing brass mesh to tissue equivalent bolus materials for volumetric modulated arc therapy chest wall irradiation.

Purpose: To compare the superficial dose when using brass mesh bolus (BMB), no bolus, or 3 mm tissue-equivalent bolus with a pseudo-flash volumetric modulated arc therapy (VMAT) breast treatment planning technique.

Methods: Two different beam arrangements for right-sided irradiation and one beam arrangement for bilateral irradiation were planned on an inhomogeneous thorax phantom in accordance with our clinical practice for VMAT postmastectomy radiotherapy (PMRT). Plans were optimized using pseudo-flash and representative critical organ optimization structures were used to shape the dose.

Specific Absorbed Fractions for Spontaneous Fission Neutron Emitters in the ICRP Reference Pediatric Voxel Phantom Series.

Specific absorbed fractions (SAFs) are key components in the workflow of internal exposure assessment following the intake of a radionuclide, allowing quick conversion of particle energy released in a source region to the expected absorbed dose in target regions throughout the body. For data completeness, SAFs for spontaneous fission neutron emitters are currently needed for the recently adopted ICRP reference pediatric voxel phantom series. With 77 source regions within each reference individual and 28 radionuclides decaying via spontaneous fission, full Monte Carlo simulation requires significant computation time.

Assessing the performance of an automated breast treatment planning software.

Purpose: To assess the dosimetric performance of an automated breast planning software.

Methods: We retrospectively reviewed 15 breast cancer patients treated with tangent fields according to the RTOG 1005 protocol and 30 patients treated off-protocol. Planning with electronic compensators (eComps) via manual, iterative fluence editing was compared to an automated planning program called EZFluence (EZF) (Radformation, Inc.

Benchmarking failure mode and effects analysis of electronic brachytherapy with data from incident learning systems.

Purpose: Failure modes and effects analysis (FMEA) is a prospective risk assessment tool for identifying failure modes in equipment or processes and informing the design of quality control systems. This work aims to benchmark the performance of FMEAs for electronic brachytherapy (eBT) of the skin and for breast by comparing predicted versus actual failure modes reported in multiple incident learning systems (ILS).

Methods And Materials: Two public and our institution's internal ILS were queried for Xoft Axxent eBT-related events over 9 years.

Lung Stereotactic Body Radiation Therapy (SBRT) dose gradient and PTV volume: a retrospective multi-center analysis.

Background: The treatment of lung lesions with stereotactic body radiation therapy calls for highly conformal dose, which is evaluated by a number of metrics. Lung stereotactic body radiation therapy clinical trials constrain a plans gradient index. The purpose of this work is to describe the dependence of clinically achievable dose gradient on planning target volume.

Technical Note: Assessing the performance of monthly CBCT image quality QA.

Purpose: To assess the performance of routine cone-beam computed tomography (CBCT) quality assurance (QA) at predicting and diagnosing clinically recognizable linac CBCT image quality issues.

Methods: Monthly automated linac CBCT image quality QA data were acquired on eight Varian linacs (Varian Medical Systems, Palo Alto, CA) using the CATPHAN 500 series phantom (The Phantom Laboratory, Inc., Greenwich, NY) and Total QA software (Image Owl, Inc.

Risk analysis of electronic intraoperative radiation therapy for breast cancer.

Purpose: To evaluate the process and improve safety of intraoperative radiation therapy (IORT) for early-stage breast cancers treated with electronic brachytherapy.

Methods And Materials: A multidisciplinary team conducted a failure mode and effects analysis (FMEA) for IORT breast cancer treatments by first developing a process map. This map was then used to identify failure modes for all steps in the treatment workflow.

Improving the treatment planning and delivery process of Xoft electronic skin brachytherapy.

Purpose: To develop an improved Xoft electronic skin brachytherapy process and identify areas of further improvement.

Methods And Materials: A multidisciplinary team conducted a failure modes and effects analysis (FMEA) by developing a process map and a corresponding list of failure modes. The failure modes were scored for their occurrence, severity, and detectability, and a risk priority number (RPN) was calculated for each failure mode as the product of occurrence, severity, and detectability.

The impact of daily bladder filling on small bowel dose for intensity modulated radiation therapy for cervical cancer.

Research demonstrates that instructing patients to have a full bladder for pelvic radiotherapy results in highly variable bladder volumes at daily treatment. We aimed to determine bladder volume variation in patients with intact cervical cancer treated with intensity-modulated radiotherapy (IMRT) on an empty bladder and estimate the difference in radiation dose to the small bowel compared to treating on a full bladder. We identified 29 patients treated with IMRT from 2010 to 2013 who underwent 2 planning computed tomography (CT) scans, 1 with a full bladder followed by 1 with an empty bladder.

Tolerance design of patient-specific range QA using the DMAIC framework in proton therapy.

Purpose: To implement the DMAIC (Define-Measure-Analyze-Improve-Control) can be used for customizing the patient-specific QA by designing site-specific range tolerances.

Methods: The DMAIC framework (process flow diagram, cause and effect, Pareto chart, control chart, and capability analysis) were utilized to determine the steps that need focus for improving the patient-specific QA. The patient-specific range QA plans were selected according to seven treatment site groups, a total of 1437 cases.

Evaluation of a surface imaging system's isocenter calibration methods.

AlignRT is a surface imaging system that has been utilized for localizing and tracking patient position during radiotherapy. AlignRT has two calibration procedures that can set the system's isocenter called "Monthly Calibration" (MC) and "Isocentre Calibration" (IC). The MC utilizes a calibration plate.

Dosimetric assessment of brass mesh bolus for postmastectomy photon radiotherapy.

Brass mesh bolus has been shown to be an acceptable substitute for tissue-equivalent bolus to increase superficial dose for chest wall tangent photon radiotherapy. This work investigated the increase in surface dose, the change in the dose at depth, and the safety implications of higher energy photon beams when using brass mesh bolus for postmastectomy chest wall radiotherapy. A photon tangent plan was delivered to a thorax phantom, and the superficial dose ranged from 40%-72% of prescription dose with no bolus.

A comparison of two prospective risk analysis methods: Traditional FMEA and a modified healthcare FMEA.

Purpose: To examine the abilities of a traditional failure mode and effects analysis (FMEA) and modified healthcare FMEA (m-HFMEA) scoring methods by comparing the degree of congruence in identifying high risk failures.

Methods: The authors applied two prospective methods of the quality management to surface image guided, linac-based radiosurgery (SIG-RS). For the traditional FMEA, decisions on how to improve an operation were based on the risk priority number (RPN).

Application of systems and control theory-based hazard analysis to radiation oncology.

Purpose: Both humans and software are notoriously challenging to account for in traditional hazard analysis models. The purpose of this work is to investigate and demonstrate the application of a new, extended accident causality model, called systems theoretic accident model and processes (STAMP), to radiation oncology. Specifically, a hazard analysis technique based on STAMP, system-theoretic process analysis (STPA), is used to perform a hazard analysis.

Increased dose near the skin due to electromagnetic surface beacon transponder.

The purpose of this study was to evaluate the increased dose near the skin from an electromagnetic surface beacon transponder, which is used for localization and tracking organ motion. The bolus effect due to the copper coil surface beacon was evaluated with radiographic film measurements and Monte Carlo simulations. Various beam incidence angles were evaluated for both 6 MV and 18 MV experimentally.

Failure mode and effects analysis and fault tree analysis of surface image guided cranial radiosurgery.

Purpose: Surface image guided, Linac-based radiosurgery (SIG-RS) is a modern approach for delivering radiosurgery that utilizes optical stereoscopic imaging to monitor the surface of the patient during treatment in lieu of using a head frame for patient immobilization. Considering the novelty of the SIG-RS approach and the severity of errors associated with delivery of large doses per fraction, a risk assessment should be conducted to identify potential hazards, determine their causes, and formulate mitigation strategies. The purpose of this work is to investigate SIG-RS using the combined application of failure modes and effects analysis (FMEA) and fault tree analysis (FTA), report on the effort required to complete the analysis, and evaluate the use of FTA in conjunction with FMEA.

Guidance on the use of handheld survey meters for radiological triage: time-dependent detector count rates corresponding to 50, 250, and 500 mSV effective dose for adult males and adult females.

In June 2006, the Radiation Studies Branch of the Centers for Disease Control and Prevention held a workshop to explore rapid methods of facilitating radiological triage of large numbers of potentially contaminated individuals following detonation of a radiological dispersal device. Two options were discussed. The first was the use of traditional gamma cameras in nuclear medicine departments operated as makeshift wholebody counters.