Cone-Beam CT Images as an Indicator of QACT During Adaptive Proton Therapy of Extremity Sarcomas.

Purpose: Periodic quality assurance CTs (QACTs) are routine in proton beam therapy. In this study, we tested whether the necessity for a QACT could be determined by evaluating the change in beam path length (BPL) on daily cone-beam CT (CBCT).

Patients And Methods: In this Institutional Review Board-approved study, we retrospectively analyzed 959 CBCT images from 78 patients with sarcomas treated with proton pencil-beam scanning.

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.

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.

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.

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.

Analysis of Radiation Therapy Quality Assurance in NRG Oncology RTOG 0848.

Purpose: NRG/Radiation Therapy Oncology Group 0848 is a 2-step randomized trial to evaluate the benefit of the addition of concurrent fluoropyrimidine and radiation therapy (RT) after adjuvant chemotherapy (second step) for patients with resected pancreatic head adenocarcinoma. Real-time quality assurance (QA) was performed on each patient who underwent RT. This analysis aims to evaluate adherence to protocol-specified contouring and treatment planning and to report the types and frequencies of deviations requiring revisions.

Proton Therapy for Unresectable and Medically Inoperable Locally Advanced Pancreatic Cancer: Results From a Multi-Institutional Prospective Registry.

Purpose: Compared with photon-based techniques, proton beam radiation therapy (PBT) may improve the therapeutic ratio of radiation therapy (RT) for locally advanced pancreatic cancer (LAPC), but available data have been limited to single-institutional experiences. This study examined the toxicity, survival, and disease control rates among patients enrolled in a multi-institutional prospective registry study and treated with PBT for LAPC.

Methods And Materials: Between March 2013 and November 2019, 19 patients with inoperable disease across 7 institutions underwent PBT with definitive intent for LAPC.

Multi-institutional study of clinical outcomes of patients with head and neck cancer presenting with cN3 disease.

Background: To evaluate disease control, toxicities, and variables associated with clinical outcomes for patients with head and neck squamous cell carcinoma and clinical N3 disease (HNSCC N3) treated with definitive chemoradiation therapy.

Methods: We performed a retrospective review of patients with HNSCC N3 treated at two high-volume academic centers between 1996 and 2019.

Results: We identified 85 patients with a median follow-up of 2.

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.

Radiation Therapy and Malignant Fistulae of Anorectal Cancers.

Purpose: Although fistulization is a well-studied late toxic effect of radiation therapy (RT), anorectal cancers (ARCs) can present with malignant fistulae (MF) and negatively affect quality of life. The effect of RT, often combined with concurrent chemotherapy, on MF needs systematic analysis, because practitioners are concerned that RT may exacerbate MF. We reviewed our institutional series evaluating the hypothesis that RT worsens MF.

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

Purpose: Spatially fractionated radiation therapy (SFRT), which delivers highly nonuniform dose distributions instead of conventionally practiced homogeneous tumor dose, has shown high rates of clinical response with minimal toxicities in large-volume primary or metastatic malignancies. However, prospective multi-institutional clinical trials in SFRT are lacking, and SFRT techniques and dose parameters remain variable. Agreement on dose prescription, technical administration, and clinical and translational design parameters for SFRT trials is essential to enable broad participation and successful accrual to rigorously test the SFRT approach.

Plan quality effects of maximum monitor unit constraints in pencil beam scanning proton therapy for central nervous system and skull base tumors.

Purpose/objective(s): With reports of CNS toxicity in patients treated with proton therapy at doses lower than would be expected based on photon data, it has been proposed that heavy monitor unit (MU) weighting of pencil beam scanning (PBS) proton therapy spots may potentially increase the risk of toxicity. We evaluated the impact of maximum MU weighting per spot (maxMU/spot) restrictions on PBS plan quality, prior to implementing clinic-wide maxMU/spot restrictions.

Materials/methods: PBS plans of 11 patients, of which 3 plans included boosts, for a total of 14 PBS sample cases were included.

Reirradiation for Rectal Cancer Using Pencil Beam Scanning Proton Therapy: A Single Institutional Experience.

Purpose: Reirradiation for rectal cancer (RC) after prior pelvic radiation therapy (RT) has been shown to be safe and effective. However, limited data exist for proton therapy (PT), including pencil beam scanning proton therapy (PBS-PT). We hypothesize that PT is safe and feasible for re-treatment and may allow for decreased toxicity and treatment escalation.

Immune checkpoint inhibition in patients treated with stereotactic radiation for brain metastases.

Purpose: Stereotactic radiation therapy (SRT) and immune checkpoint inhibitors (ICI) may act synergistically to improve treatment outcomes but may also increase the risk of symptomatic radiation necrosis (RN). The objective of this study was to compare outcomes for patients undergoing SRT with and without concurrent ICI.

Methods And Materials: Patients treated for BMs with single or multi-fraction SRT were retrospectively reviewed.

Spatially Fractionated Radiotherapy (GRID) Prior to Standard Neoadjuvant Conventionally Fractionated Radiotherapy for Bulky, High-Risk Soft Tissue and Osteosarcomas: Feasibility, Safety, and Promising Pathologic Response Rates.

Spatially fractionated radiotherapy (GRID) has been utilized primarily in the palliative and definitive treatment of bulky tumors. Delivered in the modern era primarily with megavoltage photon therapy, this technique offers the promise of safe dose escalation with potential immunogenic, bystander and microvasculature effects that can augment a conventionally fractionated course of radiotherapy. At the University of Maryland, an institutional standard has arisen to incorporate a single fraction of GRID radiation in large (>8 cm), high-risk soft tissue and osteosarcomas prior to a standard fractionated course.

Beyond the dermis-high-risk invasive squamous cell carcinoma: a retrospective review.

Objective: Most cutaneous squamous cell carcinomas (cSCC) are low risk and can be treated with simple excision or ablation. High-risk cSCC require invasive treatment, including radical surgery. We present our experience in treating invasive cSCC of the pelvis and extremities.

Pathologic complete response (pCR) rates and outcomes after neoadjuvant chemoradiotherapy with proton or photon radiation for adenocarcinomas of the esophagus and gastroesophageal junction.

Background: Pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) is associated with improved survival in patients treated for esophageal cancer. While proton beam therapy (PBT) has been demonstrated to reduce toxicities with nCRT, no data comparing pCR rates between modalities exist to date. We investigated pCR rates in patients with distal esophageal/GEJ adenocarcinomas undergoing trimodality therapy with nCRT-PBT or photon-based nCRT with the hypothesis that pathologic responses with PBT would be at least as high as with photon therapy.

Impact of Diabetes and Insulin Use on Prognosis in Patients With Resected Pancreatic Cancer: An Ancillary Analysis of NRG Oncology RTOG 9704.

Purpose: Diabetes mellitus (DM) has been proposed to be tumorigenic; however, prior studies of the association between DM and survival are conflicting. The goal of this ancillary analysis of RTOG 9704, a randomized controlled trial of adjuvant chemotherapy in pancreatic cancer, was to determine the prognostic effects of DM and insulin use on survival.

Methods And Materials: Eligible patients from RTOG 9704 with available data on DM and insulin use were included.

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.

Marital Status and Overall Survival in Patients with Resectable Pancreatic Cancer: Results of an Ancillary Analysis of NRG Oncology/RTOG 9704.

Background: Several registry-based analyses suggested a survival advantage for married versus single patients with pancreatic cancer. The mechanisms underlying the association of marital status and survival are likely multiple and complex and, therefore, may be obscured in analyses generated from large population-based databases. The goal of this research was to characterize this potential association of marital status with outcomes in patients with resected pancreatic cancer who underwent combined modality adjuvant therapy on a prospective clinical trial.