Publications by authors named "Marcio Fagundes"

Over 95% of breast cancer patients treated with radiation therapy (RT) undergo an adverse skin reaction known as radiation dermatitis (RD). Assessment of severity or grading of RD is clinically visual and hence subjective. Our objective is to determine sub-clinical tissue oxygenation (oxygen saturation) changes in response to RT in breast cancer patients using near-infrared spectroscopic imaging and correlate these changes to RD grading.

View Article and Find Full Text PDF

Introduction: The primary objective of this study is to evaluate the utility and value of an institutional, multi-disciplinary radiation oncology team review process prior to radiotherapy (RT) simulation.

Methods: Over a period of 3 months and through an iterative team-based process, a standardized simulation requisition directive (SSRD) was developed, piloted, modified, and subsequently implemented for all patients treated with external beam RT at a single tertiary care institution from January to December 2020. The SSRDs were reviewed at a daily multi-disciplinary radiation oncology team review conference; modifications consequential to the review were prospectively recorded in a quality database.

View Article and Find Full Text PDF

Purpose: The Hydrogel Spacer Prospective Randomized Pivotal Trial achieved mean rectoprostatic spacing of 12.6 mm resulting in lowering of rectal V70 from 12.4% (without spacer) to 3.

View Article and Find Full Text PDF

Radiation therapy plays an important role in the multidisciplinary management of breast cancer. Recent years have seen improvements in breast cancer survival and a greater appreciation of potential long-term morbidity associated with the dose and volume of irradiated organs. Proton therapy reduces the dose to nontarget structures while optimizing target coverage.

View Article and Find Full Text PDF

Purpose: Although peer review in radiation oncology (RO) has been recommended to improve quality of care, an analysis of modifications resulting from an RO multidisciplinary presimulation standardized review process has yet to be empirically demonstrated.

Methods And Materials: A standardized simulation directive was used for patients undergoing simulation for external beam radiation therapy at a single tertiary care institution. The simulation directives were presented, and all aspects were reviewed by representatives from key RO disciplines.

View Article and Find Full Text PDF

Background: Electrical isolation of the pulmonary veins is recognized as the cornerstone of non-pharmacological treatment of Atrial Fibrillation (AF), and therefore, has been recommended as the first step in AF ablation according to all guidelines. Even though the cryoballoon technology is widely used in North America and Europe, this experience is still incipient in many developing countries such as Brazil.

Objective: To evaluate initial results regarding success and safety of the new technology in patients with persistent and paroxysmal AF.

View Article and Find Full Text PDF

The purpose of this study was to evaluate intrafraction prostate motion in patients treated with proton therapy and an endorectal balloon or a hydrogel spacer using orthogonal x-rays acquired before and after each treatment field. This study evaluated 10 patients (662 fields throughout treatment) treated daily with an endorectal balloon (ERB) and 16 patients (840 fields throughout treatment) treated with a hydrogel spacer (GEL) without an ERB. Patient shifts were recorded before and after each treatment field, correlated with a treatment time, using x-ray imaging and implanted fiducial alignment.

View Article and Find Full Text PDF

The purpose of this study was to investigate the consistency of rectal sparing using multiple periodic quality assurance computerized tomography imaging scans (QACT) obtained during the course of proton therapy for patients with prostate cancer treated with a hydrogel spacer. Forty-one low- and intermediate-risk prostate cancer patients treated with image-guided proton therapy with rectal spacer hydrogel were analyzed. To assess the reproducibility of rectal sparing with the hydrogel spacer, three to four QACTs were performed for each patient on day 1 and during weeks 1, 3, and 5 of treatment.

View Article and Find Full Text PDF

Objectives: The management of recurrent NSCLC in the setting of prior radiation therapy is challenging. Proton radiotherapy (PRT) is ideally suited to minimize toxicity to previously irradiated organs. We report the safety/feasibility of PRT for NSCLC reirradiation in a prospective multi-institutional study.

View Article and Find Full Text PDF

Purpose: To present a practical image-guided method to position an endorectal balloon that improves in vivo thermoluminiscent dosimeter (TLD) measurements of rectal doses in proton therapy for prostate cancer.

Methods: TLDs were combined with endorectal balloons to measure dose at the anterior rectal wall during daily proton treatment delivery. Radiopaque metallic markers were employed as surrogates for balloon position reproducibility in rotation and translation.

View Article and Find Full Text PDF

Objectives: To analyze retrograde conduction during junctional ectopic tachycardia (JET) episodes and investigate the existence of a relationship between the presence of a retrograde block and the risk of atrioventricular block (AVB) development during radiofrequency ablation procedures in patients with nodal atrioventricular tachycardia (NAVT).

Methods: 145 male and female patients aged 16-84 years, with NAVT who had undergone radiofrequency catheter ablation in the posteroseptal region of the right atrium were studied. Evaluation criteria were anatomical location and electrophysiological behavior of retrograde conduction during NAVT, in order to understand the nodal reentrant circuit (classifying the tachycardia as typical or atypical), and monitoring of retrograde conduction during JET episodes for risk-predicting AVB events.

View Article and Find Full Text PDF

Background: The typical and most common tachycardia in patients with atriofascicular pathways is a macro reentrant tachycardia, with anterograde conduction over the decrementally conducting bypass tract and retrograde conduction over the right bundle branch-His-AV node axis resulting in a short V-right bundle branch and short V-H interval.

Objectives: To report on changes in rate and QRS configuration when right bundle branch block (RBBB) develops spontaneously during antidromic tachycardia using an atriofascicular fiber.

Methods: Three of 25 patients with an antidromic circus movement tachycardia using a right-sided atriofascicular pathway showed episodes of right bundle branch block (RBBB) during ventriculo-atrial conduction.

View Article and Find Full Text PDF

Objectives: The aim of this study was to prospectively evaluate the sensitivity, specificity, and positive and negative predictive values of previously described ECG criteria to identify preexcited tachycardia due to decrementally conducting accessory pathways (QRS axis between 0 and -75 degrees , QRS width < or = 0.15 seconds, an R wave in lead I, an rS pattern in lead V(1), RS > 1 QRS transition > V(4), and cycle length between 220 and 450 ms).

Background: Preexcited tachycardia associated with decrementally conducting right-sided accessory pathways usually shows a rather "narrow" QRS complex and can be difficult to differentiate from supraventricular tachycardia (SVT) with left bundle branch block (LBBB) aberrant conduction.

View Article and Find Full Text PDF

Unlabelled: Short A-V manheim fiber.

Introduction: A short atrioventricular decrementally conducting accessory pathway is an uncommon variant of preexcitation. Available data from small series suggest that their decremental properties might not be caused by A-V nodal-like tissue.

View Article and Find Full Text PDF

Introduction: Automatic rhythms associated with Mahaim fibers usually occur during radiofrequency catheter ablation. The incidence and significance of spontaneous automaticity in Mahaim fibers are unknown.

Methods And Results: Spontaneous automatic rhythms were observed in 5 (12.

View Article and Find Full Text PDF