Bruce Libby

Parallelized patient-specific quality assurance for high-dose-rate image-guided brachytherapy in an integrated computed tomography–on-rails brachytherapy suite

PURPOSEnTo describe a parallelized patient-specific quality assurance (QA) program designed to ensure safety and quality in image-guided high-dose-rate brachytherapy in an integrated computed tomography (CT)-on-rails brachytherapy suite.nnnMATERIALS AND METHODSnA patient-specific QA program has been modified for the image-guided brachytherapy (IGBT) program in an integrated CT-on-rails brachytherapy suite. In the modification of the QA procedures of Task Group-59, the additional patient-specific QA procedures are included to improve rapid IGBT workflow with applicator placement, imaging, planning, treatment, and applicator removal taking place in one room.nnnRESULTSnThe IGBT workflow is partitioned into two groups of tasks that can be performed in parallel by two or more staff members. One of the unique components of our implemented workflow is that groups work together to perform QA steps in parallel and in series during treatment planning and contouring. Coordinating efforts in this systematic way enable rapid and safe brachytherapy treatment while incorporating 3-dimensional anatomic variations between treatment days.nnnCONCLUSIONSnImplementation of these patient-specific QA procedures in an integrated CT-on-rails brachytherapy suite ensures confidence that a rapid workflow IGBT program can be implemented without sacrificing patient safety or quality and deliver highly-conformal dose to target volumes. These patient-specific QA components may be adapted to other IGBT environments that seek to provide rapid workflow while ensuring quality.

Development of a novel remote-controlled and self-contained audiovisual-aided interactive system for immobilizing claustrophobic patients

In radiotherapy, only a few immobilization systems, such as open‐face mask and head mold with a bite plate, are available for claustrophobic patients with a certain degree of discomfort. The purpose of this study was to develop a remote‐controlled and self‐contained audiovisual (AV)‐aided interactive system with the iPad mini with Retina display for intrafractional motion management in brain/H&N (head and neck) radiotherapy for claustrophobic patients. The self‐contained, AV‐aided interactive system utilized two tablet computers: one for AV‐aided interactive guidance for the subject and the other for remote control by an operator. The tablet for audiovisual guidance traced the motion of a colored marker using the built‐in front‐facing camera, and the remote control tablet at the control room used infrastructure Wi‐Fi networks for real‐time communication with the other tablet. In the evaluation, a programmed QUASAR motion phantom was used to test the temporal and positional accuracy and resolution. Position data were also obtained from ten healthy volunteers with and without guidance to evaluate the reduction of intrafractional head motion in simulations of a claustrophobic brain or H&N case. In the phantom study, the temporal and positional resolution was 24 Hz and 0.2 mm. In the volunteer study, the average superior–inferior and right–left displacement was reduced from 1.9 mm to 0.3 mm and from 2.2 mm to 0.2 mm with AV‐aided interactive guidance, respectively. The superior–inferior and right–left positional drift was reduced from 0.5 mm/min to 0.1 mm/min and from 0.4 mm/min to 0.04 mm/min with audiovisual‐aided interactive guidance. This study demonstrated a reduction in intrafractional head motion using a remote‐controlled and self‐contained AV‐aided interactive system of iPad minis with Retina display, easily obtainable and cost‐effective tablet computers. This approach can potentially streamline clinical flow for claustrophobic patients without a head mask and also allows patients to practice self‐motion management before radiation treatment delivery. PACS number: 87.55.Gh

Quality Assurance in Brachytherapy

Quality assurance for high dose rate brachytherapy is governed not only by AAPM task group reports, but also by state and federal regulations. These regulations cover the periodic (treatment day) and quarterly (source exchange) tests that are required to ensure proper treatment. In addition, other task group reports review advances in brachytherapy treatments, such as improved dose calculations, as well as QA for imaging equipment including CT and ultrasound. Furthermore, a brachytherapy program audit can be conducted by the group to ensure the entire program is being properly managed.

Breast Brachytherapy and Clinical Appendix

Breast brachytherapy delivers partial breast irradiation after breast-conserving surgery. The goal is to reduce local recurrence while minimizing dose to normal tissue. The majority of ipsilateral breast tumor recurrences occur within the index quadrant. It provides options for shorter treatment duration compared to traditional whole breast external beam radiation therapy (5 days vs. 5 weeks). Guidelines from several groups exist with recommendations for selecting appropriate patients. Multiple imaging modalities may be used to identify the lumpectomy cavity and confirm applicator placement. Cross-sectional imaging allows for evaluation of the implant (confirms placement, adjustment, manipulation). HDR or LDR can be utilized to deliver dose: 34 Gy in 10 fractions over 5 days (HDR), 32 Gy in 8 fractions over 4 days (HDR), 10 Gy in 2 fractions over 1–2 days (HDR boost), 45–50 Gy/0.50 Gy per hour (LDR), or 15–20 Gy/0.50 Gy per hour (LDR boost). NSABP B-39/RTOG 0413 will allow for comparison of treatment-related toxicity and cosmesis between accelerated partial breast irradiation and whole breast irradiation (results pending). Good to excellent cosmetic and high treatment-related satisfaction have been reported in many series.