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.

Pencil Beam Scanning Proton Therapy as Single Vocal Cord Irradiation for Early-Stage Glottic Cancer.

Purpose: Single vocal cord irradiation (SVCI) is a promising technique to maintain excellent oncologic control and potentially improve upon toxicities for treatment of early-stage glottic squamous cell carcinomas. We sought to investigate whether pencil beam scanning (PBS) proton therapy could improve upon the already favorable dose gradients demonstrated with volumetric modulated arc therapy (VMAT) SVCI.

Patients And Methods: A 64-year-old gentleman was treated in our department with 6X-flattening filter-free VMAT SVCI to 58.

Conditional Risk and Predictive Factors Associated With Late Toxicity in Patients With Prostate Cancer Treated With External Beam Radiation Therapy Alone in the Randomized Trial RTOG 0126.

Purpose: The objective of this study was to characterize the conditional risk of developing grade 2+ urinary or gastrointestinal (GI) toxicity for patients treated with external beam radiation therapy in Radiation Therapy Oncology Group 0126. A secondary objective was to analyze baseline patient and treatment characteristics and determine their relevance in predicting toxicity both at the time of trial enrollment and at later points of follow-up.

Methods And Materials: One thousand five hundred thirty-two patients with localized prostate cancer were enrolled between March 2002 and August 2008, of whom 1499 were eligible and included in data analysis with a median follow-up of 8.

Proton therapy re-irradiation outcomes and genomic landscape of patients with recurrent head and neck cancer.

Introduction: Re-irradiation (re-RT) for recurrent head and neck cancer (rHNC) is challenging. We describe clinical outcomes and toxicity of proton therapy (PT) for recurrent HNC, and report genomic alterations associated with patterns of failure.

Materials & Methods: We performed a retrospective analysis of rHNC patients treated with PT.

PTCOG Gastrointestinal Subcommittee Lower Gastrointestinal Tract Malignancies Consensus Statement.

Purpose: Radiotherapy delivery in the definitive management of lower gastrointestinal (LGI) tract malignancies is associated with substantial risk of acute and late gastrointestinal (GI), genitourinary, dermatologic, and hematologic toxicities. Advanced radiation therapy techniques such as proton beam therapy (PBT) offer optimal dosimetric sparing of critical organs at risk, achieving a more favorable therapeutic ratio compared with photon therapy.

Materials And Methods: The international Particle Therapy Cooperative Group GI Subcommittee conducted a systematic literature review, from which consensus recommendations were developed on the application of PBT for LGI malignancies.

Radiomic biomarkers of locoregional recurrence: prognostic insights from oral cavity squamous cell carcinoma preoperative CT scans.

Introduction: This study aimed to identify CT-based imaging biomarkers for locoregional recurrence (LR) in Oral Cavity Squamous Cell Carcinoma (OSCC) patients.

Methods: Computed tomography scans were collected from 78 patients with OSCC who underwent surgical treatment at a single medical center. We extracted 1,092 radiomic features from gross tumor volume in each patient's pre-treatment CT.

Radiomic Biomarkers of Locoregional Recurrence: Prognostic Insights from Oral Cavity Squamous Cell Carcinoma preoperative CT scans.

This study aimed to identify CT-based imaging biomarkers for locoregional recurrence (LR) in Oral Cavity Squamous Cell Carcinoma (OSCC) patients. Our study involved a retrospective review of 78 patients with OSCC who underwent surgical treatment at a single medical center. An approach involving feature selection and statistical model diagnostics was utilized to identify biomarkers.

Disease and toxicity outcomes for a modern cohort of patients with squamous cell carcinoma of cutaneous origin involving the parotid gland: Comparison of volumetric modulated arc therapy and pencil beam scanning proton therapy.

Objectives: We sought to describe outcomes for locally advanced cutaneous squamous cell carcinoma (SCC) involving the parotid treated with volumetric modulated arc therapy (VMAT) versus pencil beam scanning proton beam therapy (PBT).

Materials And Methods: Patients were gathered from 2016 to 2022 from 5 sites of a large academic RT department; included patients were treated with RT and had parotid involvement by: direct extension of a cutaneous primary, parotid regional spread from a previously or contemporaneously resected but geographically separate cutaneous primary, or else primary parotid SCC (with a cutaneous primary ostensibly occult). Acute toxicities were provider-reported (CTCAE v5.

Dosimetric Evaluation and Reproducibility of Breath-hold Plans in Intensity Modulated Proton Therapy: An Initial Clinical Experience.

Purpose: Breath-hold (BH) technique can mitigate target motion, minimize target margins, reduce normal tissue doses, and lower the effect of interplay effects with intensity-modulated proton therapy (IMPT). This study presents dosimetric comparisons between BH and nonbreath-hold (non-BH) IMPT plans and investigates the reproducibility of BH plans using frequent quality assurance (QA) computed tomography scans (CT).

Methods And Materials: Data from 77 consecutive patients with liver (n = 32), mediastinal/lung (n = 21), nonliver upper abdomen (n = 20), and malignancies in the gastroesophageal junction (n = 4), that were treated with a BH spirometry system (SDX) were evaluated.

A Longitudinal Metagenomic Comparative Analysis of Oral Microbiome Shifts in Patients Receiving Proton Radiation versus Photon Radiation for Head and Neck Cancer.

Introduction: Due to the radiation-sparing effects on salivary gland acini, changes in the composition of the oral microbiome may be a driver for improved outcomes in patients receiving proton radiation, with potentially worse outcomes in patients exposed to photon radiation therapy. To date, a head-to-head comparison of oral microbiome changes at a metagenomic level with longitudinal sampling has yet to be performed in these patient cohorts.

Methods And Materials: To comparatively analyze oral microbiome shifts during head and neck radiation therapy, a prospective pilot cohort study was performed at the Maryland Proton Treatment Center and the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center.

Identification of CT-based non-invasive radiomic biomarkers for overall survival prediction in oral cavity squamous cell carcinoma.

This study addresses the limited non-invasive tools for Oral Cavity Squamous Cell Carcinoma (OSCC) survival prediction by identifying Computed Tomography (CT)-based biomarkers to improve prognosis prediction. A retrospective analysis was conducted on data from 149 OSCC patients, including CT radiomics and clinical information. An ensemble approach involving correlation analysis, score screening, and the Sparse-L1 algorithm was used to select functional features, which were then used to build Cox Proportional Hazards models (CPH).

Proton beam stereotactic body radiotherapy and hypofractionated therapy with pencil beam scanning is safe and effective for advanced hepatocellular carcinoma and intrahepatic cholangiocarcinoma: A single center experience.

Background: Proton beam therapy (PBT) is a non-surgical treatment that spares adjacent tissues compared to photon radiation and useful for Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). We present a single center experience in HCC and iCCA treated with Pencil Beam Scanning (PBS) PBT.

Methods: Forty-four consecutive patients (22 patients in each group) receiving PBT were included and reviewed.

Is noncoplanar plan more robust to inter-fractional variations than coplanar plan in treating bilateral HN tumors with pencil-beam scanning proton beams?

Purpose: Noncoplanar plans (NCPs) are commonly used for proton treatment of bilateral head and neck (HN) malignancies. NCP requires additional verification setup imaging between beams to correct residual errors of robotic couch motion, which increases imaging dose and total treatment time. This study compared the quality and robustness of NCPs with those of coplanar plans (CPs).

Low contralateral failure rate with unilateral proton beam radiotherapy for oropharyngeal squamous cell carcinoma: A multi-institutional prospective study from the proton collaborative group.

Introduction: Unilateral radiation therapy is appropriate for select patients with oropharyngeal squamous cell carcinoma (OPSCC). The use of proton beam therapy (PBT) in the unilateral setting decreases the dose to the contralateral neck and organs at risk. This study aims to evaluate contralateral recurrences in patients who received ipsilateral PBT.

TP53 structure-function relationships in metastatic castrate-sensitive prostate cancer and the impact of APR-246 treatment.

Purpose: Despite well-informed work in several malignancies, the phenotypic effects of TP53 mutations in metastatic castration-sensitive prostate cancer (mCSPC) progression and metastasis are not clear. We characterized the structure-function and clinical impact of TP53 mutations in mCSPC.

Patients And Methods: We performed an international retrospective review of men with mCSPC who underwent next-generation sequencing and were stratified according to TP53 mutational status and metastatic burden.

Post-treatment PET/CT for p16-positive oropharynx cancer treated with definitive proton therapy.

Objectives: Given emerging data suggesting that uncertainty in the relative biologic effectiveness at the distal end of the Bragg peak results in increased mucosal injury in patients with oropharynx cancer receiving adjuvant proton therapy, we evaluated the results of post-treatment positron emission tomography-computed tomography (PET/CT) in patients with p16-positive oropharynx cancer (p16+OPC) treated with definitive intensity-modulated proton therapy (IMPT).

Material And Methods: A retrospective cohort study of patients with p16+OPC treated with definitive IMPT between 2016 and 2022 was performed at a single institution. Patients with PET/CT scans within 6 months following completion of IMPT were included in the study.

Conditional Risks of Biochemical Failure and Prostate Cancer-Specific Death in Patients Undergoing External Beam Radiotherapy: A Secondary Analysis of 2 Randomized Clinical Trials.

Importance: As patients achieve years of survival after treatment for prostate cancer, the risk of biochemical failure (BF) or prostate cancer-specific death (PCSD) may evolve over time, with clinical relevance to both patients and clinicians.

Objective: To determine conditional BF-free survival, PSCD, and overall survival estimates for patients with low- or intermediate-risk prostate cancer enrolled in the Radiation Therapy Oncology Group (RTOG) 0126 and RTOG 0415 clinical trials. A secondary objective was to determine whether prognostic factors at diagnosis remain relevant at later points in follow-up.

Identification of CT-based non-invasive Radiographic Biomarkers for Overall Survival Stratification in Oral Cavity Squamous Cell Carcinoma.

This study addresses the limited non-invasive tools for Oral Cavity Squamous Cell Carcinoma OSCC survival prediction by identifying Computed Tomography (CT)-based biomarkers for improved prognosis. A retrospective analysis was conducted on data from 149 OSCC patients, including radiomics and clinical. An ensemble approach involving correlation analysis, score screening, and the Sparse-L1 algorithm was used to select functional features, which were then used to build Cox Proportional Hazards models (CPH).

Early Childbearing and Child Marriage: An Update.

Eliminating child marriage is seen by policy makers and advocates as a path toward reducing births to girls below age 18, as most early births have been previously found to occur within marriage. There has been little recent evidence, however, of the marital context in which early childbearing occurs or how this relationship varies across space and levels of development. Using survey and vital registration data covering approximately 95 percent of the world's births to mothers younger than 18 years, we estimated the share of first births that occur within marriage at the global, regional and national levels.

Regionalization of Head and Neck Oncology Tumor Boards: Perspectives of Collaborating Physicians.

Objectives: To survey academic and community physician preferences regarding the virtual multidisciplinary tumor board (MTB) for further improvement and expansion.

Study Design: This anonymous 14-question survey was sent to individuals that participated in the head and neck virtual MTBs. The survey was sent via email beginning August 3, 2021, through October 5, 2021.

Gross tumor volume margin and local control in p16-positive oropharynx cancer patients treated with intensity modulated proton therapy.

Background: To determine if the extent of high-dose gross tumor volume (GTV) to clinical target volume (CTV) expansion is associated with local control in patients with p16-positive oropharynx cancer (p16+ OPC) treated with definitive intensity modulated proton therapy (IMPT).

Methods: We performed a retrospective analysis of patients with p16+ OPC treated with IMPT at a single institution between 2016 and 2021. Patients with a pre-treatment PET-CT and restaging PET-CT within 4 months following completion of IMPT were analyzed.

Pancreatic cancer derived 3D organoids as a clinical tool to evaluate the treatment response.

Background And Purpose: Pancreatic cancer (PC) is the fourth leading cause of cancer death in both men and women. The standard of care for patients with locally advanced PC of chemotherapy, stereotactic radiotherapy (RT), or chemo-radiation-therapy has shown highly variable and limited success rates. However, three-dimensional (3D) Pancreatic tumor organoids (PTOs) have shown promise to study tumor response to drugs, and emerging treatments under conditions.