Exploring stereotactic radiosurgery for tremor using the Varian cone planning system.

Background: Stereotactic radiosurgery (SRS) is an effective treatment for essential tremor (ET) and Parkinsonian tremor (PT). However, current treatment methods can be time-consuming and expose patients to unnecessary radiation. This study investigates the use of the Varian TrueBeam system with FFF beam modes as a potential solution for these issues.

Dosimetric Advantage of Combined IMRT for Whole Lung and Abdomen Irradiation for Wilms Tumor.

Purpose: In patients with Wilms tumor with lung metastases, a cardiac-sparing intensity modulated radiation therapy (CS-IMRT) technique is increasingly being adopted for whole lung irradiation. However, the standard technique for flank and whole abdomen radiation remains 2-dimensional anterioposterior (AP), and overlap at the junction between the whole lung CS-IMRT and abdominal AP fields can result in overdose to normal organs. Here, we compared the dosimetry of patients who received whole lung irradiation and flank or abdominal radiation therapy with CS-IMRT with AP abdominal field (IMRT-AP) versus CS-IMRT with IMRT abdominal field (combined IMRT).

Triggering daily online adaptive radiotherapy in the pelvis: Dosimetric effects and procedural implications of trigger parameter-value selection.

Background: Online adaptive radiotherapy (ART) can address dosimetric consequences of variations in anatomy by creating a new plan during treatment. However, ART is time- and labor-intensive and should be implemented in a resource-conscious way. Adaptive triggers composed of parameter-value pairs may direct the judicious use of online ART.

Intravesical oncolytic virotherapy and immunotherapy for non-muscle-invasive bladder cancer mouse model.

Objectives: To test if intravesical instillation of both an anti-programmed cell death protein 1 (PD-1) inhibitor and an oncolytic reovirus would demonstrate a greater effect than either treatment alone, as non-muscle-invasive bladder cancer that is refractory to intravesical bacillus Calmette-Guérin can be treated by systemic anti-PD-1 immunotherapy and we previously demonstrated improved overall survival (OS) with six once-weekly instillations of intravesical anti-PD-1 in a murine model.

Materials And Methods: Using an orthotopic syngeneic C3H murine model of MBT2 urothelial bladder cancer, groups of 10 mice were compared between no treatment, intravesical anti-PD-1, intravesical oncolytic reovirus, or intravesical reovirus + anti-PD-1. A single intravesical treatment session was given.

Evaluation of 5 Fraction Stereotactic Body Radiation Therapy (SBRT) for Osseous Renal Cell Carcinoma Metastases.

Objectives: The best fractionation for stereotactic body radiotherapy (SBRT) in renal cell carcinoma (RCC) metastases has not been well defined. In addition, the literature on outcomes using 5-fraction SBRT in the setting of osseous metastases has not been well reported.

Materials And Methods: Thirty-nine patients with 69 RCC osseous metastases were treated using 5-fraction SBRT at a single institution using 2 dose-fractionation schemes.

Radiation Fibrosis After Stereotactic Body Radiation Therapy for Osseous Metastases: A Case Report.

Radiation-induced fibrosis is a potentially severe late complication after high-dose radiotherapy. Over the last decade, there has been increasing use of stereotactic body radiation therapy (SBRT) to treat both primary and metastatic malignancies. While there has been evolving evidence of appropriate dose constraints for certain organs receiving hypofractionated radiotherapy, the risk, and appropriate dose constraints to limit the risk of radiation-induced muscle fibrosis are poorly defined.

Academic patterns of practice regarding CT simulation scans and radiology review.

Objective: Currently, there are no consensus guidelines about handling incidental radiological findings on radiotherapy planning CT simulation scans. Retrospective studies analyzing incidental findings on CT simulations show a small, but not insignificant, rate of both oncologic and non-oncologic findings. These findings may have medico-legal, financial, and clinical implications.

Towards differentiation of brain tumor from radiation necrosis using multi-parametric MRI: Preliminary results at 4.7 T using rodent models.

Background: It remains a clinical challenge to differentiate brain tumors from radiation-induced necrosis in the brain. Despite significant improvements, no single MRI method has been validated adequately in the clinical setting.

Methods: Multi-parametric MRI (mpMRI) was performed to differentiate 9L gliosarcoma from radiation necrosis in animal models.

Radiopharmaceuticals as Novel Immune System Tracers.

Immune checkpoint inhibitors (ICIs) have transformed the treatment paradigms for multiple cancers. However, ICI therapy often fails to generate measurable and sustained antitumor responses, and clinically meaningful benefits remain limited to a small proportion of overall patients. A major obstacle to development and effective application of novel therapeutic regimens is optimized patient selection and response assessment.

Rodent Model of Brain Radionecrosis Using Clinical LINAC-Based Stereotactic Radiosurgery.

Purpose: Our purpose was to develop a rodent model of brain radionecrosis using clinical linear accelerator based stereotactic radiosurgery.

Methods And Materials: Single fraction maximum prescription points in the mouse's left hemisphere were irradiated using linear accelerator-based stereotactic radiosurgery with multiple arcs at 60 (n = 5), 100 (n = 5), and 140 (n = 5) Gy. Rats (n = 6) were similarly treated with 140 Gy.

Selective Cell Size MRI Differentiates Brain Tumors from Radiation Necrosis.

Unlabelled: Brain metastasis is a common characteristic of late-stage lung cancers. High doses of targeted radiotherapy can control tumor growth in the brain but can also result in radiotherapy-induced necrosis. Current methods are limited for distinguishing whether new parenchymal lesions following radiotherapy are recurrent tumors or radiotherapy-induced necrosis, but the clinical management of these two classes of lesions differs significantly.

The Use of Low-Dose Radiation Therapy in Osteoarthritis: A Review.

Despite its clinical use and investigation in other countries, low dose radiation therapy (LDRT) in the treatment of osteoarthritis (OA) is minimally used in the United States (US). Numerous recent studies published outside the US have shown moderate to long-term pain relief and improvement of mobility after treatment with LDRT for joints affected by OA. Here, we review the most recent literature published on the use of LDRT in OA.

Patient Reported Quality of Life Outcomes After Definitive Radiation Therapy With Absorbable Spacer Hydrogel for Prostate Cancer.

Purpose: SpaceOAR is a device approved for conventional radiation in prostate cancer. We sought to observe prospectively how SpaceOAR Hydrogel effected quality of life and dosimetry to organs at risk at our institution.

Methods And Materials: We prospectively enrolled patients with low risk or favorable-intermediate risk localized prostate cancer.

Targeting for stereotactic radiosurgical thalamotomy based on tremor treatment response.

Objective: Stereotactic radiosurgery (SRS) treats severe, medically refractory essential tremor and tremor-dominant Parkinson disease. However, the optimal target for SRS treatment within the thalamic ventral intermediate nucleus (VIM) is not clearly defined. This work evaluates the precision of the physician-selected VIM target, and determines the optimal SRS target within the VIM by correlation between early responders and nonresponders.

Noninvasive Thalamotomy for Refractory Tremor by Frameless Radiosurgery.

Purpose: We sought to determine whether a more widely accessible, noninvasive, frameless approach to radiosurgical thalamotomy would improve objective measures of refractory essential or parkinsonian tremor without added toxicity compared with reports of frame-based radiosurgery.

Methods And Materials: We conducted a single-arm pilot observational prospective trial of adult patients with essential or parkinsonian tremor from 2013 to 2019 and report results at 1-year follow-up. Patients were treated with frameless unilateral radiosurgical ablation of the thalamic ventral intermediate nucleus to a maximum dose of 160 Gy.

Monte Carlo study on dose distributions from total skin electron irradiation therapy (TSET).

Total skin electron therapy (TSET) has been used to treat mycosis fungoides since the 1950s. Practitioners of TSET rely on relatively crude, phantom-based point measurements for commissioning and treatment plan dosimetry. Using Monte Carlo simulation techniques, this study presents whole-body dosimetry for a patient receiving rotational, dual-field TSET.

Intravesical Anti-PD-1 Immune Checkpoint Inhibition Treats Urothelial Bladder Cancer in a Mouse Model.

Purpose: Nonmuscle-invasive bladder cancer is treated by resection within the bladder and bladder instillment with bacillus Calmette-Guérin or chemotherapy. For bacillus Calmette-Guérin-refractory disease, systemic anti-PD-1 (programmed cell death protein 1) immune checkpoint inhibition is a treatment. Our aim is to test whether intravesical instillment with anti-PD-1 inhibitor treats localized bladder cancer as effectively as systemic administration.

Intensity-Modulated Radiotherapy is Superior to Three-Dimensional Conformal Radiotherapy in the Trimodality Management of Muscle-Invasive Bladder Cancer with Daily Cone Beam Computed Tomography Optimization.

Objective: Intensity modulated radiation therapy (IMRT) using a volumetric-modulated arc therapy technique may offer dosimetric and clinical benefits compared to the historical standard of care 3D-conformal radiotherapy (3D-CRT) in definitive treatment of bladder cancer. We hypothesized that IMRT with CBCT would reduce dose to the rectum, bowel, and bladder compared to 3D-CRT.

Methods: We reviewed nineteen patients treated with maximal transurethral resection of bladder tumor followed by concurrent chemotherapy with IMRT.

Prospective observational trial of low-dose skin electron beam therapy in mycosis fungoides using a rotational technique.

Introduction: Low-dose total skin electron beam therapy provides a durable treatment response for skin lesions caused by cutaneous T-cell lymphoma. We prospectively assessed the durability of response and quality of life for patients receiving low-dose total skin electron beam therapy using a novel rotational technique and dosing regimen.

Methods: Patients completed baseline Skindex-29 quality-of-life surveys and had baseline Modified Severity-Weighted Assessment Tool score recorded.

An autoimmune-based, paraneoplastic neurologic syndrome following checkpoint inhibition and concurrent radiotherapy for merkel cell carcinoma: case report.

Purpose: Merkel cell carcinoma is highly sensitive to both radiation and immunotherapy. Moreover, concurrent radioimmunotherapy may capitalize on anti-tumor immune activity and improve Merkel cell treatment response, although an enhanced immune system may cross-react with native tissues and lead to significant sequelae.

Methods: Here we present a case study of a patient with metastatic Merkel cell carcinoma treated with radiotherapy concurrent with pembrolizumab.

Diffuse Primary Cutaneous Anaplastic Large Cell Lymphoma Treated by Rotational Total Skin Electron Beam Radiotherapy with Custom Shielding: Case Report.

Introduction: Primary cutaneous anaplastic large cell lymphoma (PCALCL) is a rare T-cell malignancy typically presenting as a solitary lesion treated with radiotherapy. Diffuse PCALCL is rare, and treatment paradigms of diffuse PCALCL are poorly defined.

Case And Outcomes: In this report, a 69-year-old male presented with progressive extensive truncal PCALCL resistant to brentuximab.

Radiosensitization by enzalutamide for human prostate cancer is mediated through the DNA damage repair pathway.

Radiation therapy is often combined with androgen deprivation therapy in the treatment of aggressive localized prostate cancer. However, castration-resistant disease may not respond to testosterone deprivation approaches. Enzalutamide is a second-generation anti-androgen with high affinity and activity that is used for the treatment of metastatic disease.

Radiation-associated epithelial-myoepithelial carcinoma among five secondary malignancies: A case report and review of literature.

Background: Epithelial-myoepithelial carcinoma (EMC) is a rare, low-grade, malignant tumor that constitutes less than one percent of all salivary gland tumors. To date, only one other case report has described radiation-associated EMC in the English language medical literature.

Case Summary: In this report, we describe the case of a 56-year-old male patient who presented with a neck mass diagnosed as EMC of the left submandibular gland approximately 30 years after mantle field radiation and chemotherapy for Hodgkin lymphoma.

Linear Accelerator-Based Stereotactic Radiosurgery for Cranial Intraparenchymal Metastasis of a Malignant Peripheral Nerve Sheath Tumor: Case Report and Review of the Literature.

Background: Malignant peripheral nerve sheath tumors (MPNSTs) are rare, aggressive soft tissue sarcomas. MPNST intracranial metastasis is exceedingly rare with only 22 documented cases in the literature and, to our knowledge, only 1 case with intraparenchymal brain metastasis. Most have been managed surgically; however, 2 documented cases were treated with Gamma Knife radiosurgery.