Stereotactic Body Radiation Therapy (SBRT) in prostate cancer in the presence of hip prosthesis - is it a contraindication? A narrative review.

Hip replacement is a common orthopedic surgery in the aging population. With the rising incidence of prostate cancer, metallic hip prosthetics can cause considerable beam hardening and streak artifacts, leading to difficulty in identifying the target volumes and planning process for radiation treatment. The growing use of Stereotactic Body Radiation Therapy (SBRT) to treat prostate cancer is now well established.

Automated review of patient position in DIBH breast hybrid IMRT with EPID images.

Deep Inspiration Breath Hold (DIBH) is a respiratory-gating technique adopted in radiation therapy to lower cardiac irradiation. When performing DIBH treatments, it is important to have a monitoring system to ensure the patient's breath hold level is stable and reproducible at each fraction. In this retrospective study, we developed a system capable of monitoring DIBH breast treatments by utilizing cine EPID images taken during treatment.

Endobronchially Implanted Real-Time Electromagnetic Transponder Beacon-Guided, Respiratory-Gated SABR for Moving Lung Tumors: A Prospective Phase 1/2 Cohort Study.

Purpose: Endobronchial electromagnetic transponder beacons (EMT) provide real-time, precise positional data of moving lung tumors. We report results of a phase 1/2, prospective, single-arm cohort study evaluating the treatment planning effects of EMT-guided SABR for moving lung tumors.

Methods And Materials: Eligible patients were adults, Eastern Cooperative Oncology Group 0 to 2, with T1-T2N0 non-small cell lung cancer or pulmonary metastasis ≤4 cm with motion amplitude ≥5 mm.

Optical scan and 3D printing guided radiation therapy - an application and provincial experience in cutaneous nasal carcinoma.

Background: Single field Orthovoltage radiation is an acceptable modality used for the treatment of nasal cutaneous cancer. However, this technique has dosimetric pitfalls and unnecessary excessive exposure of radiation to organs at risk (OAR). We present the clinical outcome of a case series of cutaneous nasal tumours using a novel technique incorporating an optical scanner and a 3-dimensional (3D) printer to deliver treatments using parallel opposed (POP) fields.

An anthropomorphic maxillofacial phantom using 3-dimensional printing, polyurethane rubber and epoxy resin for dental imaging and dosimetry.

Objective: The aim of this study was to construct an anthropomorphic maxillofacial phantom for dental imaging and dosimetry purposes using three-dimensional (3D) printing technology and materials that simulate the radiographic properties of tissues.

Methods: Stereolithography photoreactive resins, polyurethane rubber and epoxy resin were modified by adding calcium carbonate and strontium carbonate powders or glass bubbles. These additives were used to change the materials' CT numbers to mimic various body tissues.

4D in vivo dose verification for real-time tumor tracking treatments using EPID dosimetry.

The use of sophisticated techniques such as gating and tracking treatments requires additional quality assurance to mitigate increased patient risks. To address this need, we have developed and validated an in vivo method of dose delivery verification for real-time aperture tracking techniques, using an electronic portal imaging device (EPID)-based, on-treatment patient dose reconstruction and a dynamic anthropomorphic phantom. Using 4DCT scan of the phantom, ten individual treatment plans were created, 1 for each of the 10 separate phases of the respiratory cycle.

A modern mold room: Meshing 3D surface scanning, digital design, and 3D printing with bolus fabrication.

Purpose: This case series represents an initial experience with implementing 3-dimensional (3D) surface scanning, digital design, and 3D printing for bolus fabrication for patients with complex surface anatomy where traditional approaches are challenging.

Methods And Materials: For 10 patients requiring bolus in regions with complex contours, bolus was designed digitally from 3D surface scanning data or computed tomography (CT) images using either a treatment planning system or mesh editing software. Boluses were printed using a fused deposition modeling printer with polylactic acid.

Evaluating a potential technique with local optical flow vectors for automatic organ-at-risk (OAR) intrusion detection and avoidance during radiotherapy.

Various techniques of deep inspiration breath hold (DIBH) have been used to mitigate the likelihood and risk of exposing the heart, an organ-at-risk (OAR) for unintended radiation during left breast radiotherapy. However, issues of reproducibility of these techniques warrant further investigation into the feasibility of detecting the intrusion of an OAR into the treatment field during intra-fractional treatment delivery. The increase of high-dose, low-fraction radiotherapy treatments makes it important to immediately adapt treatment once an OAR is detected in the treatment field.

Reducing the tracking drift of an uncontoured tumor for a portal-image-based dynamically adapted conformal radiotherapy treatment.

Accurate tracking of organ motion during treatment is needed to improve the efficacy of radiation therapy. This work investigates the feasibility of tracking an uncontoured target using the motion detected within a moving treatment aperture. Tracking was achieved with a weighted optical flow algorithm, and three different techniques for updating the reference image were evaluated.

Low-cost optical scanner and 3-dimensional printing technology to create lead shielding for radiation therapy of facial skin cancer: First clinical case series.

Purpose: Three-dimensional printing has been implemented at our institution to create customized treatment accessories, including lead shields used during radiation therapy for facial skin cancer. To effectively use 3-dimensional printing, the topography of the patient must first be acquired. We evaluated a low-cost, structured-light, 3-dimensional, optical scanner to assess the clinical viability of this technology.

Creation of knowledge-based planning models intended for large scale distribution: Minimizing the effect of outlier plans.

Knowledge-based planning (KBP) can be used to estimate dose-volume histograms (DVHs) of organs at risk (OAR) using models. The task of model creation, however, can result in estimates with differing accuracy; particularly when outlier plans are not properly addressed. This work used RapidPlan to create models for the prostate and head and neck intended for large-scale distribution.

COMP report: CPQR technical quality control guidelines for radiation treatment centers.

The Canadian Organization of Medical Physicists (COMP), in close partnership with the Canadian Partnership for Quality Radiotherapy (CPQR) has developed a series of Technical Quality Control (TQC) guidelines for radiation treatment equipment. These guidelines outline the performance objectives that equipment should meet in order to ensure an acceptable level of radiation treatment quality. The TQC guidelines have been rigorously reviewed and field tested in a variety of Canadian radiation treatment facilities.

A quality assurance tool for high-dose-rate brachytherapy.

Purpose: The purpose of this work was to develop a quality assurance (QA) tool for high-dose-rate (HDR) brachytherapy that would quickly and easily verify both source positioning (dwell positions) and durations (dwell times).

Methods: The authors constructed a QA tool that combined radiochromic film to verify position with four photodiode detectors to verify dwell times. To characterize the temporal accuracy of the tool, a function generator powered four red light-emitting diodes that were optically coupled to the four photodiode detectors.

The dosimetric quality of brachytherapy implants in patients with small prostate volume depends on the experience of the brachytherapy team.

Purpose: To investigate the dosimetric outcome of brachytherapy in patients with small prostate volume (PV).

Methods And Materials: Forty-three patients with small PV (<25 cm(3)) as determined using transrectal ultrasound and 120 patients with non-small PV (>25 cm(3)) that had received (125)I seed implants were reviewed in a retrospective cohort study. Implantations were performed under transrectal ultrasound guidance, and the prescription dose was 145 Gy.

Leptospirosis in Hawaii, 1974-1998: epidemiologic analysis of 353 laboratory-confirmed cases.

The epidemiologic characterization of leptospirosis in the United States has been limited by difficulties associated with both case detection and confirmation. In addition, leptospirosis was eliminated from the list of National Notifiable Diseases in 1995. From 1974 until the cessation of national surveillance, Hawaii consistently had the highest reported annual incidence rate in the United States.

Evaluation of eight rapid screening tests for acute leptospirosis in Hawaii.

Leptospirosis is a major public health problem throughout the world. Clinical recognition of leptospirosis is challenging, and the definitive serologic diagnostic assay, the microscopic agglutination test, is time-consuming and difficult to conduct. Various serologic screening tests have been developed, but their performance among ill persons in the United States has not been established.