Method to assess the need for re-planning HDR brachytherapy tandem and ring treatments.

High dose rate (HDR) brachytherapy procedures for cervical cancer require multiple applicator insertions for multiple (typically 5) fractions of a single plan, which carries a risk for variability in applicator position between fractions. Due to applicator displacement relative to patient anatomy, the dose to nearby organs-at-risk (OARs) may vary significantly from one fraction to the next. The purpose of this study was to evaluate the effect of changes in HDR tandem and ring (T&R) applicator position on doses to nearby OARs and to present a quick and simple method to estimate doses to OARs inter-fractionally without having to perform a re-plan.

Outcomes for posterior uveal melanoma: Validation of American Brachytherapy Society Guidelines.

Purpose: To assess outcomes of small and medium choroidal melanoma (less than 5.0 mm in height) following Iodine-125 episcleral brachytherapy.

Methods And Materials: Patients with small and medium choroidal melanoma that underwent Iodine-125 brachytherapy with apical height of 1.

Small choroidal melanoma: outcomes following apical height dose brachytherapy.

Aim: To assess the outcomes of small choroidal melanoma following iodine-125 episcleral brachytherapy (apical height dose of 85 Gy).

Methods: Patients with small choroidal melanoma that underwent iodine-125 episcleral brachytherapy between January 2004 and December 2017 were reviewed. Inclusion criterion for this study was the COMS small tumour size (tumour apical height of 1.

Addition of magnetic resonance imaging to real time trans-rectal ultrasound-based treatment planning for prostate implants.

Purpose: The greater soft tissue contrast of magnetic resonance imaging (MRI) allows improved accuracy in prostate contouring compared to transrectal ultrasound (TRUS) and helps in identifying specific regions within the prostate. This study attempts to evaluate the potential benefit of MRI-TRUS fusion in treatment planning for more accurate prostate contouring and tumor dose escalation.

Material And Methods: 14 patients with previous MRI-guided prostate biopsy and an low-dose-rate (LDR) permanent prostate seed implant have been selected.

Animal models of radiation retinopathy - From teletherapy to brachytherapy.

Radiation retinopathy is a serious vision-impairing complication of radiation therapy used to treat ocular tumors. Characterized by retinal vasculopathy and subsequent retinal damage, the first sign of radiation retinopathy is the preferential loss of vascular endothelial cells. Ensuing ischemia leads to retinal degradation and late stage neovascularization.

Principles and practice of high-dose rate penile brachytherapy: Planning and delivery techniques.

Purpose: To allow for organ preservation, high-dose rate (HDR) brachytherapy may be used in the treatment of localized penile cancer. Penile cancer is a rare malignancy that accounts for <1% of cancers in men in the United States. The standard treatment for localized disease is partial amputation of the penis.

A method for confirming a third-party assay of I-125 seeds used for prostate implants.

The purpose of this work is to describe a method and apparatus that can be used to confirm the source strength of a large number of I-125 seeds while maintaining sterility, accuracy, reproducibility, and time efficiency. Source strengths ranging from 0.395 to 0.

Local Failure After Episcleral Brachytherapy for Posterior Uveal Melanoma: Patterns, Risk Factors, and Management.

Purpose: To evaluate the patterns, the risk factors, and the management of recurrence following brachytherapy in patients with posterior uveal melanoma, given that an understanding of the recurrence patterns can improve early recognition and management of local treatment failure in such patients.

Design: Retrospective cohort study.

Methods: Setting: Multispecialty tertiary care center.

Episcleral brachytherapy of uveal melanoma: role of intraoperative echographic confirmation.

Purpose: To compare the rates of tumour recurrence following episcleral brachytherapy for uveal melanoma before and after implementation of intraoperative echographic confirmation of plaque placement.

Materials And Methods: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between 1 January 2004 and 30 December 2013 were included. Exclusion criteria were patients with previous radiation treatment and patients who received adjuvant transpupillary thermotherapy.

Vision Loss Following Episcleral Brachytherapy for Uveal Melanoma: Development of a Vision Prognostication Tool.

Importance: Vision loss following episcleral brachytherapy for uveal melanoma is difficult to predict for individual patients.

Objective: To generate a risk calculator for vision loss following episcleral brachytherapy for uveal melanoma.

Design, Setting, And Participants: A retrospective review of data was conducted at a multispecialty tertiary care center in Cleveland, Ohio.

Long-Term Efficacy and Toxicity of Low-Dose-Rate ¹²⁵I Prostate Brachytherapy as Monotherapy in Low-, Intermediate-, and High-Risk Prostate Cancer.

Purpose/objectives: To report long-term efficacy and toxicity for a single-institution cohort of patients treated with low-dose-rate prostate brachytherapy permanent implant (PI) monotherapy.

Methods And Materials: From 1996 to 2007, 1989 patients with low-risk (61.3%), intermediate-risk (29.

Influence of zonal dosimetry on prostate brachytherapy outcomes.

Purpose: To examine the influence of zone-specific dosimetry on outcomes during permanent prostate implantation (PI), where the peripheral zone (PZ) and transitional zone (TZ) may receive varying radiation doses.

Material And Methods: Four hundred and sixteen patients treated with I-125 PI (target dose: 144 Gy) between 1996 and 2003 were included in this Institutional Review Board (IRB) approved, retrospective analysis. Whole prostate (WP), TZ, and PZ were contoured, and zone-specific D90 and V100 were computed.

Method for verifying the air kerma strength of I-125 plaques for the treatment of ocular melanoma.

The purpose of this work was to develop a method for easily verifying that the activity or air kerma strength of pre-assembled eye plaques, used in the treatment of ocular melanomas, agrees with the activity or air kerma strength called for in the treatment plan. A Capintec CRC-7 Dose Calibrator with its standard vial/syringe sample holder was used to measure the activity of pre-assembled COMS and Eye Physics EP917 eye plaques using IsoAid Advantage I-125 seeds. Plaque activity measurements were made by placing the plaque face up in the center of a 5 cm tall Styrofoam insert in the source holder.

Brachytherapy.

Brachytherapy is the preferred radiation treatment modality for various intraocular tumors, most commonly, uveal melanoma. Radioactive sources are placed directly onto or around the tumor with the aid of episcleral plaques, whereby the employed sources exhibit an extremely sharp fall-off of dosage outside the few millimeters around the tumor. With such high focality, radiation dose to vision critical structures is minimized.

Failure modes and effects analysis applied to high-dose-rate brachytherapy treatment planning.

Purpose: To apply failure modes and effects analysis to high-dose-rate treatment planning to identify the most likely and significant sources of error in the process.

Methods: We have made a list of 25 failure modes grouped into six categories (imaging, catheter reconstruction, dwell position activity, dose points/normalization, optimization/dose, and evaluation). Each mode was rated on a one to five scale for severity, likelihood of occurrence, and probability of escaping detection.

Lung dose calculation with SPECT/CT for ⁹⁰Yittrium radioembolization of liver cancer.

Purpose: To propose a new method to estimate lung mean dose (LMD) using technetium-99m labeled macroaggregated albumin ((99m)Tc-MAA) single photon emission CT (SPECT)/CT for (90)Yttrium radioembolization of liver tumors and to compare the LMD estimated using SPECT/CT with clinical estimates of LMD using planar gamma scintigraphy (PS).

Methods And Materials: Images of 71 patients who had SPECT/CT and PS images of (99m)Tc-MAA acquired before TheraSphere radioembolization of liver cancer were analyzed retrospectively. LMD was calculated from the PS-based lung shunt assuming a lung mass of 1 kg and 50 Gy per GBq of injected activity shunted to the lung.

Dosimetric benefit of a new ophthalmic radiation plaque.

Purpose: To determine whether the computed dosimetry of a new ophthalmic plaque, EP917, when compared with the standard Collaborative Ocular Melanoma Study (COMS) plaques, could reduce radiation exposure to vision critical structures of the eye.

Methods And Materials: One hundred consecutive patients with uveal melanoma treated with COMS radiation plaques between 2007 and 2010 were included in this study. These treatment plans were generated with the use of Bebig Plaque Simulator treatment-planning software, both for COMS plaques and for EP917 plaques using I-125.

PSA bounce predicts early success in patients with permanent iodine-125 prostate implant.

Objectives: To determine the clinical and dosimetric factors that predict prostate-specific antigen (PSA) bounce after iodine-125 prostate brachytherapy and to determine the predictive value of PSA bounce relative to biochemical relapse-free survival (bRFS).

Methods: A multivariate analysis of factors thought to predict for PSA bounce was performed in 295 consecutive patients with T1-T2 prostate cancer treated by prostate brachytherapy as the sole radiotherapeutic modality and a minimum follow-up of 2 years. The variables examined included age, initial PSA level, biopsy Gleason score, use of androgen deprivation, occurrence of PSA bounce, dose received by 90% of the prostate gland, and volume of gland receiving 100% of the prescribed dose.

Effect of anatomic, procedural, and dosimetric variables on urinary retention after permanent iodine-125 prostate brachytherapy.

Objectives: To correlate anatomic, procedural, and dosimetric parameters with the rate of intermittent self-catheterization (ISC).

Methods: The records of 402 patients with a median age of 69 years treated with 125I prostate seed implantation from 1996 to 2001 were reviewed for the use of ISC. The records were examined for the preimplant factors: prostate volume, use of androgen deprivation, and prostate length.