Publications by authors named "Robert D Timmerman"

We present a case of extensive and bulky pediatric metastatic melanoma originating in the head and neck which markedly responded to combination therapy with anti-programmed cell death (PD-1) inhibition and consolidative personalized ultra-fractionated stereotactic adaptive radiotherapy (PULSAR). After surgical debulking with neck dissection, the patient was initially treated with anti-PD-1 and anti-cytotoxic T-lymphocyte associated protein 4 (CTLA-4) dual checkpoint blockade immunotherapy, but quickly had disease progression. He was transitioned to a different anti-PD-1 immunotherapy in combination with tyrosine kinase inhibitors in conjunction with consolidative local therapy using PULSAR.

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IntroductionSCINTIX therapy, a form of biology-guided radiotherapy using real-time positron emission tomography (PET) imaging on the RefleXion X1 platform, recently received FDA clearance for FDG-guided treatment of lung and bone tumors. This study evaluates the feasibility and dosimetric quality of Biology-Guided Radiotherapy (BgRT) plans for FDG-avid lesions in anatomical sites beyond current indications using processed diagnostic PET (dPET) images.MethodsEleven previously treated FDG-avid lesions in ten patients (sites: liver, head and neck, pancreas, kidney, pelvic/abdominal nodes) were retrospectively analyzed.

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Purpose: Adaptive radiation therapy (RT) allows for smaller treatment volumes and adaptation to shrinking tumors, which is particularly intriguing in lymphomas that are radiosensitive and sometimes in difficult to target locations. We hypothesize that adaptive RT may be beneficial in a variety of lymphoma cases and describe our early experience to outline indications for adaptive RT in lymphomas.

Methods And Materials: An institutional review board-approved prospective registry was reviewed to identify patients with lymphoma who were treated with cone-beam computed tomography-based online adaptive RT (oART) at our institution from 2021 to 2024.

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Purpose: Radiation-induced cardiac dysfunction (RICD) is a competing cause of morbidity and mortality in patients receiving thoracic radiation therapy (RT). Currently, there are no clinically-validated approaches for early detection of RICD at a time point that affords the potential for mitigation. The goal of this study was to evaluate the potential of global longitudinal strain (GLS) derived from standard-of-care echocardiogram (ECHO) for the early detection of RICD and to assess the association between adverse GLS changes and survival in patients receiving thoracic RT.

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Lung cancer exhibits altered metabolism, influencing its response to radiation. To investigate the metabolic regulation of radiation response, we conducted a comprehensive, metabolic-wide CRISPR-Cas9 loss-of-function screen using radiation as selection pressure in human non-small cell lung cancer. Lipoylation emerged as a key metabolic target for radiosensitization, with lipoyltransferase 1 (LIPT1) identified as a top hit.

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Purpose: Despite easing of COVID-19 travel restrictions and social distancing, medical radiation oncology (RO) residency interviews for the 2023 Match remained exclusively virtual. Virtual interviews can be limited in providing program atmosphere, resident camaraderie, and city culture. Our institution offered a voluntary in-person (IP) second look (SL) to address these concerns and supplement the virtual interview.

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Purpose: We investigated the efficacy and toxicity of thoracic radiation therapy (RT) plus concurrent and consolidation carboplatin with either solvent-based paclitaxel (sb-paclitaxel) or solvent-free nanoparticle albumin-bound paclitaxel (nab-paclitaxel).

Methods And Materials: This multicenter phase 1/2 randomized trial included patients with inoperable stage IIIA/B nonsmall cell lung cancer (AJCC 7) and an Eastern Cooperative Oncology Group performance status of 0-1. In phase 1, 6 patients received weekly nab-paclitaxel (50 mg/m²) and carboplatin (AUC 2) with concurrent thoracic RT (60 Gy in 30 fractions), followed by nab-paclitaxel (100 mg/m²) on days 1, 8, and 15 and carboplatin (AUC 6) on day 1 for two 21-day cycles.

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Purpose: We report the financial toxicity and quality-of-life outcomes of our prospective phase 1 dose-escalation study of 5-fraction stereotactic partial breast irradiation (S-PBI) for early-stage breast cancer.

Materials And Methods: Women with unifocal in situ or invasive epithelial histologies, clinical stages 0, I, or II with tumor size < 3 cm treated with lumpectomy were enrolled in our phase 1 5-fraction S-PBI dose-escalation trial. Our institutionally generated questionnaire on the "Patient Perspective Cost and Convenience of Care" and the EuroQol 5-Dimension 5-level questionnaire were administered to patients treated at follow-up.

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Purpose: The phase 3 Veterans Affairs Lung Cancer Surgery Or Stereotactic Radiotherapy study implemented centralized quality assurance (QA) to mitigate risks of protocol deviations. This report summarizes the quality and compliance of the first 100 participants treated with stereotactic body radiation therapy (SBRT) in this study.

Methods And Materials: A centralized QA program was developed to credential and monitor study sites to ensure standard-of-care lung SBRT treatments are delivered to participants.

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Purpose: Consolidative durvalumab, an anti-programmed death ligand 1 (PDL1) immune checkpoint inhibitor, administered after concurrent chemoradiation improves outcomes of patients with locally advanced non-small cell lung cancer (NSCLC) without substantially increasing toxicities. We studied a chemotherapy-free regimen of thoracic radiation therapy (RT) with concurrent and consolidative durvalumab.

Methods And Materials: This single-arm phase 2 trial enrolled patients with stage III NSCLC (regardless of tumor PDL1 expression), Eastern Cooperative Oncology Group (ECOG) performance status 0-1, adequate pulmonary function, and RT fields meeting standard organ constraints.

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Importance: The optimal radiotherapy technique for unresectable locally advanced non-small cell lung cancer (NSCLC) is controversial, so evaluating long-term prospective outcomes of intensity-modulated radiotherapy (IMRT) is important.

Objective: To compare long-term prospective outcomes of patients receiving IMRT and 3-dimensional conformal radiotherapy (3D-CRT) with concurrent carboplatin/paclitaxel for locally advanced NSCLC.

Design, Setting, And Participants: A secondary analysis of a prospective phase 3 randomized clinical trial NRG Oncology-RTOG 0617 assessed 483 patients receiving chemoradiotherapy (3D-CRT vs IMRT) for locally advanced NSCLC based on stratification.

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Background And Purpose: Radiation oncology protocols for single fraction radiosurgery recommend setting dosing criteria based on assumed risk of radionecrosis, which can be predicted by the 12 Gy normal brain volume (V12). In this study, we show that tumor surface area (SA) and a simple power-law model using only preplan variables can estimate and minimize radiosurgical toxicity.

Materials And Methods: A 245-patient cohort with 1217 brain metastases treated with single or distributed Gamma Knife sessions was reviewed retrospectively.

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Purpose: Although hydrogel spacer placement (HSP) minimizes rectal dose during prostate cancer radiation therapy, its potential benefit for modulating rectal toxicity could depend on the achieved prostate-rectal separation. We therefore developed a quality metric associated with rectal dose reduction and late rectal toxicity among patients treated with prostate stereotactic body radiation therapy (SBRT).

Methods And Materials: A quality metric consisting of prostate-rectal interspace measurements from axial T2-weighted magnetic resonance imaging simulation images was applied to 42 men enrolled in a multi-institutional phase 2 study using HSP with prostate SBRT (45 Gy in 5 fractions).

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Importance: Spine metastasis can be treated with high-dose radiation therapy with advanced delivery technology for long-term tumor and pain control.

Objective: To assess whether patient-reported pain relief was improved with stereotactic radiosurgery (SRS) as compared with conventional external beam radiotherapy (cEBRT) for patients with 1 to 3 sites of vertebral metastases.

Design, Setting, And Participants: In this randomized clinical trial, patients with 1 to 3 vertebral metastases were randomized 2:1 to the SRS or cEBRT groups.

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Purpose: For patients with lung cancer, it is critical to provide evidence-based radiation therapy to ensure high-quality care. The US Department of Veterans Affairs (VA) National Radiation Oncology Program partnered with the American Society for Radiation Oncology (ASTRO) as part of the VA Radiation Oncology Quality Surveillance to develop lung cancer quality metrics and assess quality of care as a pilot program in 2016. This article presents recently updated consensus quality measures and dose-volume histogram (DVH) constraints.

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Introduction: Poor outcomes in glioblastoma patients, despite advancing treatment paradigms, indicate a need to determine non-physiologic prognostic indicators of patient outcome. The impact of specific socioeconomic and demographic patient factors on outcomes is unclear. We sought to identify socioeconomic and demographic patient characteristics associated with patient survival and tumor progression, and to characterize treatment options and healthcare utilization.

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Purpose: Poor outcomes in IDH wild-type (IDHwt) glioblastomas indicate the need to determine which genetic alterations can indicate poor survival and guidance of patient specific treatment options. We sought to identify the genetic alterations in these patients that predict for survival when adjusting particularly for treatments and other genetic alterations.

Methods: A cohort of 167 patients with pathologically confirmed IDHwt glioblastomas treated at our institution was retrospectively reviewed.

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Introduction: Poor outcomes in glioma patients indicate a need to determine prognostic indicators of survival to better guide patient specific treatment options. While preoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) have been suggested as prognostic systemic inflammation markers, the impact of post-radiation changes in these cell types is unclear. We sought to identify which hematologic cell measurements before, during, or after radiation predicted for patient survival.

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Purpose: Five-fraction stereotactic ablative radiotherapy (SABR) regimens are frequently used to treat centrally located early-stage non-small cell lung cancer or disease in the proximity of the chest wall as a means of optimizing tumor control and reducing treatment toxicity. However, increasing these SABR regimens to 5 fractions may reduce tumor control outcomes. We sought to identify the clinical parameters predictive of treatment failures with these 5-fraction courses.

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Purpose: The oligometastatic state is observed in patients across many malignancies, with increased recognition regarding improved outcomes after local therapies. However, there is limited data specifically regarding pancreatic ductal adenocarcinoma. We hypothesized that an oligometastatic pancreatic ductal adenocarcinoma (OPanc) phenotype would benefit from stereotactic ablative radiation therapy (SABR) to all active metastatic sites.

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Purpose: Functional lung avoidance (FLA) radiation therapy (RT) aims to minimize post-RT pulmonary toxicity by preferentially avoiding dose to high-functioning lung (HFL) regions. A common limitation is that FLA approaches do not consider the conducting architecture for gas exchange. We previously proposed the functionally weighted airway sparing (FWAS) method to spare airways connected to HFL regions, showing that it is possible to substantially reduce risk of radiation-induced airway injury.

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