Publications by authors named "Lucas Mendez"

Background And Objective: Long-term (LT) androgen deprivation therapy (ADT) has been found to be beneficial to patients with high-risk prostate cancer (PCa). However, administration of LT-ADT to all patients with high-risk PCa may lead to overtreatment. Enhanced risk stratification using genomic classifiers (such as the recently developed prostate subtyping classifier [PSC]) might be useful.

View Article and Find Full Text PDF
Article Synopsis
  • - The SABR-SYNC trial aims to evaluate the effectiveness of stereotactic ablative radiotherapy (SABR) in patients with oligometastatic cancers that have a synchronous primary tumor, addressing a gap in phase III data currently available.
  • - One hundred and eighty patients will be randomly assigned to receive either standard care treatment or standard care plus SABR, with various dosing and treatment modalities used depending on the physician's clinical judgement.
  • - The trial will focus on overall survival as the main goal, while also examining factors like progression-free survival, quality of life, and potential biomarkers from circulating tumor DNA to improve future treatment decisions.
View Article and Find Full Text PDF
Article Synopsis
  • Prostate cancer (PCa) is a major health issue for men, being the most common cancer and the second leading cause of cancer death, particularly affecting those with metastatic castration-resistant PCa (mCRPC).
  • The study aimed to compare the effectiveness and safety of four PARP inhibitors (olaparib, niraparib, rucaparib, and talazoparib) in treating mCRPC patients through indirect comparisons, addressing a gap in clinical knowledge.
  • A systematic review and network meta-analysis (NMA) were conducted using comprehensive literature searches of multiple databases, ultimately analyzing six high-quality clinical trials that included over 3,200 participants to assess key outcomes like survival rates and adverse effects.
View Article and Find Full Text PDF

High dose-rate brachytherapy is a treatment technique for gynecologic cancers where intracavitary applicators are placed within the patient's pelvic cavity. To ensure accurate radiation delivery, localization of the applicator at the time of insertion is vital. This study proposes a novel method for acquiring, registering, and fusing three-dimensional (3D) trans-abdominal and 3D trans-rectal ultrasound (US) images for visualization of the pelvic anatomy and applicators during gynecologic brachytherapy.

View Article and Find Full Text PDF

The global cancer burden, especially in low- and middle-income countries (LMICs), worsens existing disparities, amplified by the rising costs of advanced treatments. The shortage of radiation therapy (RT) services is a significant issue in LMICs. Extended conventional treatment regimens pose significant challenges, especially in resource-limited settings.

View Article and Find Full Text PDF

Radiotherapy (RT) has a fundamental role in the treatment of gynecologic malignancies, including cervical and uterine cancers. Hypofractionated RT has gained popularity in many cancer sites, boosted by technological advances in treatment delivery and image verification. Hypofractionated RT uptake was intensified during the COVID-19 pandemic and has the potential to improve universal access to radiotherapy worldwide, especially in low-resource settings.

View Article and Find Full Text PDF

Objective: The aim of this work was to evaluate the acute toxicity and quality-of-life (QOL) impact of ultrahypofractionated whole pelvis radiation therapy (WPRT) compared with conventional WPRT fractionation after high-dose-rate prostate brachytherapy (HDR-BT).

Methods And Materials: The HOPE trial is a phase 2, multi-institutional randomized controlled trial of men with prostate-confined disease and National Comprehensive Cancer Network unfavorable intermediate-, high-, or very-high-risk prostate cancer. Patients were randomly assigned to receive conventionally fractionated WPRT (standard arm) or ultrahypofractionated WPRT (experimental arm) in a 1:1 ratio.

View Article and Find Full Text PDF

Background: Accurate segmentation of the clinical target volume (CTV) corresponding to the prostate with or without proximal seminal vesicles is required on transrectal ultrasound (TRUS) images during prostate brachytherapy procedures. Implanted needles cause artifacts that may make this task difficult and time-consuming. Thus, previous studies have focused on the simpler problem of segmentation in the absence of needles at the cost of reduced clinical utility.

View Article and Find Full Text PDF

Introduction: Our objective was to assess the effect of F-DCFPyL prostate-specific membrane antigen (PSMA) positron emission tomography (PET) on the management and outcomes of patients receiving salvage radiotherapy following biochemical failure (BF) post-radical prostatectomy (RP) using a matched cohort analysis.

Methods: A PSMA-PET cohort of patients with BF post-RP was identified through a prospective registry. Patients from this registry were included if they did not have disease outside of the pelvis and underwent salvage radiotherapy to the prostate and/or pelvis.

View Article and Find Full Text PDF

Background: Isolated local failure (ILF) can occur in patients who initially receive definitive radiation therapy for prostate cancer. Salvage therapy for ILF includes high dose rate (HDR) brachytherapy. Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) can accurately detect ILF and can exclude extraprostatic disease.

View Article and Find Full Text PDF

Purpose: High-dose-rate (HDR) interstitial brachytherapy (BT) is a common treatment technique for localized intermediate to high-risk prostate cancer. Transrectal ultrasound (US) imaging is typically used for guiding needle insertion, including localization of the needle tip which is critical for treatment planning. However, image artifacts can limit needle tip visibility in standard brightness (B)-mode US, potentially leading to dose delivery that deviates from the planned dose.

View Article and Find Full Text PDF

Purpose: The purpose of this study was to evaluate and clinically implement a deformable surface-based magnetic resonance imaging (MRI) to three-dimensional ultrasound (US) image registration algorithm for prostate brachytherapy (BT) with the aim to reduce operator dependence and facilitate dose escalation to an MRI-defined target.

Methods And Materials: Our surface-based deformable image registration (DIR) algorithm first translates and scales to align the US- and MR-defined prostate surfaces, followed by deformation of the MR-defined prostate surface to match the US-defined prostate surface. The algorithm performance was assessed in a phantom using three deformation levels, followed by validation in three retrospective high-dose-rate BT clinical cases.

View Article and Find Full Text PDF

Purpose: Decipher is a genomic classifier (GC) prospectively validated postprostatectomy. We validated the performance of the GC in pretreatment biopsy samples within the context of 3 randomized phase 3 high-risk definitive radiation therapy trials.

Methods And Materials: A prespecified analysis plan (NRG-GU-TS006) was approved to obtain formalin-fixed paraffin-embedded tissue from biopsy specimens from the NRG biobank from patients enrolled in the NRG/Radiation Therapy Oncology Group (RTOG) 9202, 9413, and 9902 phase 3 randomized trials.

View Article and Find Full Text PDF

Purpose: To validate the association between body composition and mortality in men treated with radiation for localized prostate cancer (PCa). Secondarily, to integrate body composition as a factor to classify patients by risk of all-cause mortality.

Materials And Methods: Participants of NRG/Radiation Therapy Oncology Group (RTOG) 9406 and NRG/RTOG 0126 with archived computed tomography were included.

View Article and Find Full Text PDF

Background: Localized Gleason Grade Group 5 (GG5) prostate cancer has a poor prognosis and is associated with a higher risk of treatment failure, metastases, and death. Treatment intensification with the addition of a brachytherapy (BT) boost to external beam radiation (EBRT) maximizes local control, which may translate into improved survival outcomes.

Methods: A systematic review and meta-analysis was performed to compare survival outcomes for Gleason GG5 patients treated with androgen deprivation therapy (ADT) and either EBRT or EBRT + BT.

View Article and Find Full Text PDF
Article Synopsis
  • This study looked at how much pain patients felt and how many pain meds they needed after a special type of radiation therapy called interstitial brachytherapy (ISBT).
  • It compared two types of anesthesia: spinal anesthesia (SA) and general anesthesia (GA).
  • Results showed that patients with spinal anesthesia had less pain and used fewer pain medications right after the procedure than those with general anesthesia.
View Article and Find Full Text PDF

Advances in imaging have changed prostate radiotherapy through improved biochemical control from focal boost and improved detection of recurrence. These advances are reviewed in the context of prostate stereotactic body radiation therapy (SBRT) and the ARGOS/CLIMBER trial protocol. ARGOS/CLIMBER will evaluate 1) the safety and feasibility of SBRT with focal boost guided by multiparametric MRI (mpMRI) and F-PSMA-1007 PET and 2) imaging and laboratory biomarkers for response to SBRT.

View Article and Find Full Text PDF

Importance: Adjuvant radiation plays an important role in reducing locoregional recurrence in patients with uterine cancer. Although hypofractionated radiotherapy may benefit health care systems and the global community while decreasing treatment burden for patients traveling for daily radiotherapy, it has not been studied prospectively nor in randomized trials for treatment of uterine cancers, and the associated toxic effects and patient quality of life are unknown.

Objective: To evaluate acute genitourinary and bowel toxic effects and patient-reported outcomes following stereotactic hypofractionated adjuvant radiation to the pelvis for treatment of uterine cancer.

View Article and Find Full Text PDF

Background: To compare toxicities in relation to standard radiation treatments [conventional fractionation RT (CRT) and moderate hypofractionated RT (MRT)] with ultrahypofractionated RT (URT) in the treatment of patients with localized PCa.

Methods: A searched was performed in Medline, Embase, Cochrane CENTRAL, and LILACS to January 2020 for studies comparing URT to CRT and/or MRT in relation to genitourinary (GU) and gastrointestinal (GI) toxicity in the treatment of patients with localized PCa. URT, MRT and CRT were defined as protocols delivering a daily dose of ≥5 Gy, 2.

View Article and Find Full Text PDF

Introduction: Stereotactic Ablative Radiotherapy (SABR) is increasingly used to treat metastatic oligorecurrence and locoregional recurrences but limited evidence/guidance exists in the setting of pelvic re-irradiation. An international Delphi study was performed to develop statements to guide practice regarding patient selection, pre-treatment investigations, treatment planning, delivery and cumulative organs at risk (OARs) constraints.

Materials And Methods: Forty-one radiation oncologists were invited to participate in three online surveys.

View Article and Find Full Text PDF

Purpose: In this study, we propose combining three-dimensional (3D) transrectal ultrasound (TRUS) and 3D transabdominal ultrasound (TAUS) images of gynecologic brachytherapy applicators to leverage the advantages of each imaging perspective, providing a broader field-of-view and allowing previously obscured features to be recovered. The aim of this study was to evaluate the feasibility of fusing these 3D ultrasound (US) perspectives based on the applicator geometry in a phantom prior to clinical implementation.

Methods: In proof-of-concept experiments, 3D US images of application-specific multimodality pelvic phantoms were acquired with tandem-and-ring and tandem-and-ovoids applicators using previously validated imaging systems.

View Article and Find Full Text PDF

External beam radiotherapy is an effective curative treatment option for localized prostate cancer, the most common cancer in men worldwide. However, conventionally fractionated courses of curative external beam radiotherapy are usually 8-9 weeks long, resulting in a substantial burden to patients and the health-care system. This problem is exacerbated in low-income and middle-income countries where health-care resources might be scarce and patient funds limited.

View Article and Find Full Text PDF