Apical dose versus volume dose of Ruthenium-106 brachytherapy for uveal melanoma.

Objective: Ruthenium-106 brachytherapy is commonly used to treat uveal melanomas. Most centres prescribe a radiation dose to the tumour apex that is calculated with the tumour located in the centre of the plaque. Recent work suggests that D-the minimum radiation dose delivered to 99% of tumour volume-may be a better predictor of tumour control than apex dose.

Quantifying the effect of eccentric ruthenium plaque placement on tumor volume dose.

Purpose: Ruthenium-106 brachytherapy is a common treatment for small to medium-sized uveal melanomas. In certain clinical contexts, plaques may be placed eccentrically to tumor center. The effect of plaque decentration, a common radiation dose measurement in radiotherapy: D, the percentage of the tumor volume receiving at least 98% of the prescribed dose (a commonly used term in radiation oncology), is unknown.

Iodine-125 brachytherapy for choroidal melanoma by using Ocuprosta seeds with indigenous non-collimated plaques: Our initial experience.

Purpose: Brachytherapy is the gold-standard treatment for choroidal melanoma. This study evaluated iodine-125 brachytherapy by using Ocuprosta seeds with indigenous non-collimated plaques in Asian patients.

Methods: Retrospective single-center study in a tertiary care hospital of 12 eyes with choroidal melanoma in 12 Asian patients who underwent brachytherapy with Ocuprosta seeds fixed on non-collimated plaques and had a follow-up of at least 32 months (mean: 42.

Radio-luminescent imaging for rapid, high-resolution eye plaque loading verification.

Background: Eye plaque brachytherapy is currently an optimal therapy for intraocular cancers. Due to the lack of an effective and practical technique to measure the seed radioactivity distribution, current quality assurance (QA) practice according to the American Association of Physicists in Medicine TG129 only stipulates that the plaque assembly be visually inspected. Consequently, uniform seed activity is routinely adopted to avoid possible loading mistakes of differential seed loading.

Annulus-shaped I-125 plaque brachytherapy for conjunctival melanoma.

Purpose: To report successful ring-shaped iodine-125 plaque brachytherapy for conjunctival melanoma.

Observations: Eye Physics (EP) plaque brachytherapy, designed with Plaque Simulator software, proved to be an effective treatment modality with some corneal irritation and no recurrence at 12-months post radiation.

Conclusion And Importance: Management of conjunctival melanoma is complicated by the lack of gold standard adjuvant treatments.

Long-term outcomes after enucleation or plaque brachytherapy of choroidal melanomas touching the optic disc.

Purpose: To investigate local and systemic outcomes after enucleation, brachytherapy with ruthenium-106, iodine-125, notched and non-notched plaques and transpupillary thermotherapy (TTT) of choroidal melanomas touching the optic disc.

Methods And Materials: All patients treated for choroidal melanoma touching the optic disc at St. Erik Eye Hospital, Stockholm, Sweden between 1984 and 2015 (n = 165) were included.

Quantifying Subclinical and Longitudinal Microvascular Changes Following Episcleral Plaque Brachytherapy Using Spectral Domain-Optical Coherence Tomography Angiography.

Purpose: To assess longitudinal microvascular changes in eyes treated with I-125 episcleral plaque brachytherapy (EPB).

Methods: High resolution OCT angiograms of the central 3×3mm macula were obtained from I-125 episcleral plaque brachytherapy treated and untreated fellow eyes of 61 patients. Capillary density (vessel skeleton density, VSD) and caliber (vessel diameter index, VDI) were quantified using previously validated semi-automated algorithms.

Novel Eye Plaque Designs for Brachytherapy of Iris and Ciliary Body Melanoma and the First Clinical Application.

Background: While traditional eye plaque brachytherapy can be used for the treatment of iris melanoma, it faces challenges of poor patient tolerability due to cornea-plaque touch caused by radius of curvature mismatch and potential dosimetric inaccuracy from incomplete coverage. We present novel plaque designs and the first clinical application of the plaques for iris melanoma.

Methods: Two dome-shaped plaques (EP2132 and EP1930) were designed to vault above the cornea to treat tumors of the iris and ciliary body.

Outcomes of choroidal melanomas treated with eye physics plaques: A 25-year review.

Purpose: To review long-term outcomes of the University of Southern California Plaque Simulator (PS) software and Eye Physics (EP) plaques. We hypothesize that the PS/EP system delivers lower doses to critical ocular structures, resulting in lower rates of radiation toxicity and favorable visual outcomes compared to Collaborative Ocular Melanoma Study plaques, while maintaining adequate local tumor control.

Methods And Materials: Retrospective review of 133 patients treated for choroidal melanoma with I brachytherapy, using PS software and EP plaques, from 1990 through 2015.

Incorporating patient-specific CT-based ophthalmic anatomy in modeling iodine-125 eye plaque brachytherapy dose distributions.

Purpose: To quantify the dosimetric impact of incorporating patient-specific CT-based models rather than the conventional stylized-standard model for eye plaque brachytherapy planning.

Methods And Materials: Plaque Simulator was used to plan 16 patients using both CT-based patient-specific eye model and stylized-standard (SS) eye models. Plaque position was initially based on the SS model and compared against their patient-specific model without changing the plaque loading pattern and seed strength.

Use of the Toric Surgical Marker to Aid in Intraoperative Plaque Placement for the USC Eye Physics Plaques to Treat Uveal Melanoma: A New Surgical Technique.

Background And Objective: To describe a new surgical technique for intraoperative placement of Eye Physics (EP) plaques for uveal melanoma using a toric marker.

Patients And Methods: A toric marker is designed for cataract surgery to align the axis of astigmatism; its use was modified in this protocol to mark the axis of suture coordinates as calculated by Plaque Simulator (PS) software.

Results: The toric marker can be used to localize suture coordinates, in degrees, during intraoperative plaque placement.

Outcomes of medium choroidal melanomas treated with ruthenium brachytherapy guided by three-dimensional pretreatment modeling.

Purpose: The Collaborative Ocular Melanoma Study (COMS) established iodine-125 (I-125) plaque brachytherapy for eye preserving treatment of medium-sized choroidal melanomas in the United States. Eye Physics I-125 plaque treatment modeled with Plaque Simulator (PS) software yields similar results to COMS. Herein, we report results from a series of 15 patients treated with ruthenium-106 (Ru-106) plaque brachytherapy using PS pretreatment modeling for plaque localization and dosimetry.

Outcomes of choroidal melanomas treated with eye physics: a 20-year review.

Importance: The University of Southern California Eye Physics plaques compare favorably with the Collaborative Ocular Melanoma Study plaques in terms of late adverse effects from radiation, metastasis, and local tumor recurrence.

Objective: To review the University of Southern California experience using Eye Physics plaques and Plaque Simulator software to treat choroidal melanomas and compare the outcomes with published results of the Collaborative Ocular Melanoma Study.

Design, Setting, And Participants: A retrospective case series of 82 patients treated for medium-sized choroidal melanoma from January 1, 1990, through December 30, 2010, using iodine 125 plaques and treatment simulation software developed at the University of Southern California.

The retina dose-area histogram: a metric for quantitatively comparing rival eye plaque treatment options.

Purpose: Episcleral plaques have a history of over a half century in the delivery of radiation therapy to intraocular tumors such as choroidal melanoma. Although the tumor control rate is high, vision-impairing complications subsequent to treatment remain an issue. Notable, late complications are radiation retinopathy and maculopathy.

Dosimetry of (125)I and (103)Pd COMS eye plaques for intraocular tumors: report of Task Group 129 by the AAPM and ABS.

Dosimetry of eye plaques for ocular tumors presents unique challenges in brachytherapy. The challenges in accurate dosimetry are in part related to the steep dose gradient in the tumor and critical structures that are within millimeters of radioactive sources. In most clinical applications, calculations of dose distributions around eye plaques assume a homogenous water medium and full scatter conditions.

Polymer coated fiber Bragg grating thermometry for microwave hyperthermia.

Purpose: Measuring tissue temperature distribution during electromagnetically induced hyperthermia (HT) is challenging. High resistance thermistors with nonmetallic leads have been used successfully in commercial HT systems for about three decades. The single 1 mm thick temperature sensing element is mechanically moved to measure tissue temperature distributions.

The relative importance of genetics and environment on mammographic density.

Background: Although several environmental factors predict mammographic density, estimates of its heritability have been quite high. We investigated whether part of the presumed heritability might be attributed to differential sharing of modifiable risk factors in monozygotic (MZ) and dizygotic (DZ) twins.

Methods: We measured percent and absolute mammographic density using mammograms from 257 MZ and 296 DZ twin pairs.

Some implications of linear-quadratic-linear radiation dose-response with regard to hypofractionation.

Recent technological advances enable radiation therapy to be delivered in a highly conformal manner to targets located almost anywhere in the body. This capability has renewed the clinical interest in hypofractionation wherein the tumor is delivered a few fractions of very large dose per fraction. Extrapolating clinical experience from conventional regimens to fractions of high dose is important to designing hypofractionated treatments.

Design and dosimetric considerations of a modified COMS plaque: the reusable "seed-guide" insert.

The Collaborative Ocular Melanoma Study (COMS) developed a standardized set of eye plaques that consist of a 0.5 mm thick bowl-like gold alloy backing with a cylindrical collimating lip. A Silastic seed carrier into which 125I seeds are loaded was designed to fit within the backing.

Improved treatment planning for COMS eye plaques.

Purpose: A recent reanalysis of the Collaborative Ocular Melanoma Study (COMS) medium tumor trial concluded that incorporating factors to account for anisotropy, line source approximation, the gold plaque, and attenuation in the Silastic seed carrier into the dose calculations resulted in a significant and consistent reduction of calculated doses to structures of interest within the eye. The authors concluded that future eye plaque dosimetry should be "performed using the most up-to-date parameters available." The reason these factors are important is attributable to the low energy (125)I radiation (approximately 28 keV) that is primarily absorbed by the photoelectric process.

HDR quality assurance methods for personal digital assistants.

An important component of every clinical high-dose-rate (HDR) brachytherapy program is quality assurance (QA). One of the QA recommendations of the AAPM TG59 report is an independent verification on the results of treatment planning. It is desirable for the verification procedure to be as quick and easy to perform as possible and yet to have a high probability of detecting significant errors.

Episcleral plaque 125I radiotherapy with episcleral LCF hyperthermia: a prospective randomized trial.

Purpose: The purpose of this study was to search for an optimal radiation dose in the treatment of patients with uveal melanoma using 125I episcleral plaque radiotherapy (EPRT) and episcleral hyperthermia (HT).

Methods And Materials: From 1991-1998, 35 patients with uveal melanoma were enrolled in a phase II prospective randomized trial of 125I EPRT combined with episcleral HT. Two groups were closely matched for pre-treatment patient and tumor characteristics.