The Radiosurgery Society Working Groups on GRID, LATTICE, Microbeam, and FLASH Radiotherapies: 2022 - 2023 Advancements Symposium and Subsequent Progress Made.

Purpose: Since the inaugural workshop "Understanding High-Dose, Ultra-High Dose Rate and Spatially Fractionated Radiotherapy." hosted by the NCI and sponsored by the Radiosurgery Society (RSS), growing collaborations and investigations have ensued among experts, practitioners, and researchers. The RSS GRID, Lattice, Microbeam & FLASH (GLMF) Working Groups were formed as a framework for these efforts and have focused on advancing the understanding of the biology, technical/physical parameters, trial design, and clinical practice of these new radiation therapy modalities.

Optimizing GRID and Lattice Spatially Fractionated Radiation Therapy: Innovative Strategies for Radioresistant and Bulky Tumor Management.

Treating radioresistant and bulky tumors is challenging due to their inherent resistance to standard therapies and their large size. GRID and lattice spatially fractionated radiation therapy (simply referred to GRID RT and LRT) offer promising techniques to tackle these issues. Both approaches deliver radiation in a grid-like or lattice pattern, creating high-dose peaks surrounded by low-dose valleys.

Practice Patterns of Spatially Fractionated Radiation Therapy: A Clinical Practice Survey.

Purpose: Spatially fractionated radiation therapy (SFRT) is increasingly used for bulky advanced tumors, but specifics of clinical SFRT practice remain elusive. This study aimed to determine practice patterns of GRID and Lattice radiation therapy (LRT)-based SFRT.

Methods And Materials: A survey was designed to identify radiation oncologists' practice patterns of patient selection for SFRT, dosing/planning, dosimetric parameter use, SFRT platforms/techniques, combinations of SFRT with conventional external beam radiation therapy (cERT) and multimodality therapies, and physicists' technical implementation, delivery, and quality procedures.

Moderately hypofractionated post-operative radiation therapy for breast cancer: preferences amongst radiation oncologists from countries in Latin America and the Caribbean.

Background: The safety and effectiveness of moderately hypofractionated post-operative radiation therapy for breast cancer were demonstrated by several trials. This study aimed to evaluate the current patterns of practice and prescription preference about moderately hypofractionated post-operative radiation therapy to assess possible aspects that affect the decision-making process regarding the use of fractionation in breast cancer patients in Latin America and the Caribbean (LAC). We also aimed to identify factors that can restrain the utilization of moderately hypofractionated post-operative radiation therapy for breast cancer.

High-dose-rate brachytherapy in scrotal extramammary Paget's disease: A case report.

Purpose: Extramammary Paget's disease (EMPD) is a rare but lethal intraepithelial malignancy without standardized guidelines concerning diagnostic or therapeutic approaches. We report a case of EMPD of the scrotum treated with excellent results using high-dose brachytherapy.

Methods And Materials: A 76-year-old male originally presented in 2015 with pruritus and erythema of the right scrotum, biopsy proved to represent extramammary Paget's disease.

Second Gamma Knife Treatment for Trigeminal Neuralgia: Anterior Target Spacing and 25 Gy as the Second Dose.

Objective Gamma Knife® radiosurgery (GKRS) has been demonstrated to be a well-known approach for treating patients with medical refractory trigeminal neuralgia (TN). Herein, the authors review the outcomes of pain among a large cohort of patients who had undergone a second GKRS delivered at a significantly reduced dose. Methods The authors conducted a prospective analysis of patients who have undergone two GKRS procedures between the years 2012 to 2021 at one institution.

An International Consensus on the Design of Prospective Clinical-Translational Trials in Spatially Fractionated Radiation Therapy for Advanced Gynecologic Cancer.

Despite the unexpectedly high tumor responses and limited treatment-related toxicities observed with SFRT, prospective multi-institutional clinical trials of SFRT are still lacking. High variability of SFRT technologies and methods, unfamiliar complex dose and prescription concepts for heterogeneous dose and uncertainty regarding systemic therapies present major obstacles towards clinical trial development. To address these challenges, the consensus guideline reported here aimed at facilitating trial development and feasibility through a priori harmonization of treatment approach and the full range of clinical trial design parameters for SFRT trials in gynecologic cancer.

Gamma knife radiosurgery of epidermoid tumors: an analysis of treatment results of eight patients.

Background: Epidermoid tumors (ETs) of the central nervous system (CNS) are rare tumors that typically occur in the 4 decade. They typically grow around vital neurovascular structures which makes surgical treatment difficult. The objective of this paper is to report on the effectiveness and safety in the management of epidermoid tumors with gamma knife surgery (GKS).

Folate hydrolase-1 (FOLH1) is a novel target for antibody-based brachytherapy in Merkel cell carcinoma.

Backgrounds: Folate Hydrolase-1 (FOLH1; PSMA) is a type II transmembrane protein, luminally expressed by solid tumour neo-vasculature. Monoclonal antibody (mAb), J591, is a vehicle for mAb-based brachytherapy in FOLH1+ cancers. Brachytherapy is a form of radiotherapy that involves placing a radioactive material a short distance from the target tissue (e.

Cross-Sectional International Survey to Determine the Educational Interests of Spanish-Speaking Latin American Radiation Oncologists.

Purpose: With the existing oncology disparities in Latin America, physician expertise has been cited as a possible contributor to inferior oncologic outcomes in some cancers. As two-dimensional radiotherapy rapidly evolved to intensity-modulated radiation therapy in Latin America, adequate contouring education is an actionable target to improving physician knowledge and clinical outcomes. Yet, topics of interest to Latin American radiation oncologists are underreported.

The Technical and Clinical Implementation of LATTICE Radiation Therapy (LRT).

The concept of spatially fractionated radiation therapy (SFRT) was conceived over 100 years ago, first in the form of GRID, which has been applied to clinical practice since its early inception and continued to the present even with markedly improved instrumentation in radiation therapy. LATTICE radiation therapy (LRT) was introduced in 2010 as a conceptual 3D extension of GRID therapy with several uniquely different features. Since 2014, when the first patient was treated, over 150 patients with bulky tumors worldwide have received LRT.

Spatially Fractionated Radiation Therapy Using Lattice Radiation in Far-advanced Bulky Cervical Cancer: A Clinical and Molecular Imaging and Outcome Study.

Spatially fractionated radiation therapy (SFRT) has shown promise in generating high tumor response and local control in the treatment of various palliative and locally advanced bulky tumors. SFRT has not yet been studied systematically in cancer of the cervix. Here we report the first series of patients receiving SFRT for advanced/bulky cervical cancer.

Understanding High-Dose, Ultra-High Dose Rate, and Spatially Fractionated Radiation Therapy.

The National Cancer Institute's Radiation Research Program, in collaboration with the Radiosurgery Society, hosted a workshop called Understanding High-Dose, Ultra-High Dose Rate and Spatially Fractionated Radiotherapy on August 20 and 21, 2018 to bring together experts in experimental and clinical experience in these and related fields. Critically, the overall aims were to understand the biological underpinning of these emerging techniques and the technical/physical parameters that must be further defined to drive clinical practice through innovative biologically based clinical trials.

Radiosurgery for brain metastases from ovarian cancer: an analysis of 25 years' experience with Gamma Knife treatment.

Purpose: We present our results in the treatment of brain metastases (BM) from ovarian cancer using Gamma Knife Radiosurgery (GKRS) over the last 25 years in a single institution.

Background: Gamma Knife Radiosurgery has become increasingly important in the management of brain metastases from ovarian cancer due to improving results from systemic disease and the need for better outcomes.

Material And Methods: The medical records of 9 patients with brain metastases from ovarian cancer treated with GKRS between 1993 and 2018 were reviewed.

Safety and Efficacy of Lattice Radiotherapy in Voluminous Non-small Cell Lung Cancer.

Objective Lattice radiotherapy (LRT) is a novel technique of delivering heterogeneous doses of radiation to voluminous tumors not amenable to surgery. Built from the conventional two-dimensional grid, LRT utilizes the power of new technology, three-dimensional radiation allowing the delivery of higher doses of radiation to small spheres, also called vertices, inside bulky tumors while limiting exposure to surrounding healthy tissue. The main goals of the study were the evaluation of tumor response and the overall safety of LRT in this cohort of patients with bulky non-small cell lung cancer.

Novel Pilot Curriculum for International Education of Lymphoma Management Using E-Contouring.

Purpose: The International Lymphoma Radiation Oncology Group (ILROG) published consensus guidelines on the management of Hodgkin disease (HD) and nodal non-Hodgkin lymphoma (NHL), which became the most downloaded articles from International Journal of Radiation Oncology, Biology, and Physics. E-contouring workshops allow for interactive didactic sessions, allowing participants to see case-based contouring in real time. A pilot 1-hour curriculum was developed with the objective of reviewing ILROG guidelines for HD and NHL management with incorporation of e-contouring tools.

Evaluation of CyberKnife Radiosurgery for Recurrent Trigeminal Neuralgia.

Stereotactic radiosurgery (SRS) has evolved as an accepted treatment for medication resistant trigeminal neuralgia. Initial results are very good but follow-up over three to five years shows a gradual return of pain in up to 50% of treated patients, often requiring further treatment. The results with repeat SRS using the isocentric Gamma Knife (GK) (Elekta, Stockholm, Sweden), especially in patients having initially good results, are very similar to the outcomes after the initial treatment although there is an increased risk of residual facial numbness secondary to the additional radiation dose to the trigeminal nerve.

Improved outcome of treating locally advanced lung cancer with the use of Lattice Radiotherapy (LRT): A case report.

The Lattice Radiotherapy (LRT) technique is mainly based on the GRID technology with the improved feature of the 3D treatment delivery. A 72 year old male presented with left shoulder pain due to a 6 cm pulmonary mass in the left upper lobe (LUL) histologically proven Non-Small Cell Lung Cancer (NSCLC) stage IIIA. In July 2011 he was treated in our center with LRT followed by conventional fractionated Volumetric Modulated Arc Therapy (VMAT) combined with chemotherapy.

Delayed Development of Trigeminal Neuralgia after Radiosurgical Treatment of a Tentorial Meningioma.

Trigeminal neuralgia is a known symptom of the tumors and aberrant vessels near the trigeminal nerve and the tentorial notch. There are very few reports of delayed development of trigeminal neuralgia after radiosurgical treatment of a tumor in these areas. This is a case report of a patient treated with radiosurgery for radiation induced meningiomas, 30 years after childhood whole brain radiation.

Volumetric arc therapy for total scalp irradiation: case report for a recurrent basal cell carcinoma of the scalp.

Total scalp irradiation may be used to treat numerous conditions including squamous and basal cell carcinomas. These conditions are relatively uncommon and patients are frequently treated with palliative intent. In this report, we describe a volumetric arc therapy technique using photon beams for curative intent in an 84 years old patient with recurrent basal cell carcinoma of the scalp.

Radiosurgery for liver metastases. A single institution experience.

Aim: To report our initial results on the use of radiosurgery for treatment of liver metastases.

Background: In recent years there has been increasing interest in the use of stereotactic body radiation therapy to treat metastatic disease to the liver as an alternative to interventional procedures.

Materials And Methods: Between November 2008 and June 2015 a total of 36 LINAC-based radiosurgeries using VMAT were performed in 27 patients with liver metastases from 10 different primary sites.

Perspectives on Patient Access to Radiation Oncology Services in South America.

Cancer represents a fast-growing challenge worldwide, and is being recognized as an emerging and critical issue in low- and middle-income countries, such most of South America. This subcontinent is unique for its geography, culture, and ethnical diversity. Most of its countries have large expanses of jungle and desert where underserved population groups including indigenous (native Indians), represent a challenge for cancer care.

Highlights from the first International ecancer Conference on Oncology and Radiotherapy, 6-7 May 2016, Santiago, Chile.

The first international ecancer conference on oncology and radiotherapy was held in Santiago de Chile on 6 and 7 May 2016. It was chaired by Dr Beatriz Amendola, Professor Gordon McVie and Professor Umberto Veronesi. Specialists from Europe and America were invited as guest lecturers.