Publications by authors named "John Adler"

Article Synopsis
  • The ZAP-X system is an innovative radiosurgical option using a 3 MV linear accelerator and varying collimator cone sizes aimed at early-stage treatments, which minimizes harm to healthy tissue.
  • A new 3 mm collimator cone has been developed for the ZAP-X, and the study aimed to assess the effectiveness of a commercial diode detector, the microSilicon, for measuring dosimetric properties and understanding the small field effects.
  • Results indicate that the microSilicon detector accurately characterizes the 3 mm beam's dosimetric properties, with high correlation between measurements from the detector and films, confirming its suitability for small field conditions in radiosurgery.
View Article and Find Full Text PDF

Background The subgenual cingulate cortex (SGC) has been identified as a key structure within multiple neural circuits whose dysfunction is implicated in the neurobiology of depression. Deep brain stimulation in the SGC is thought to reduce and normalize local metabolism, causing normalization of circuit behavior and an improvement in depressive symptoms. We hypothesized that nonablative stereotactic radiosurgery (SRS) to the SGC would reduce local metabolism and reduce the severity of depression in patients with treatment-resistant bipolar depression.

View Article and Find Full Text PDF

Essential tremor (ET) is one of the most common adult movement disorders. As the worldwide population ages, the incidence and prevalence of ET is increasing. Although most cases can be managed conservatively, there is a subset of ET that is refractory to medical management.

View Article and Find Full Text PDF

Purpose: Irradiating the surgical bed of resected brain metastases improves local and distant disease control. Over time, stereotactic radiosurgery (SRS) has replaced whole brain radiotherapy (WBRT) as the treatment standard of care because it minimizes long-term damage to neuro-cognition. Despite this data and growing adoption, socio-economic disparities in clinical access can result in sub-standard care for some patient populations.

View Article and Find Full Text PDF

Purpose: In patients with newly diagnosed glioblastoma (GBM), tumor margins of at least 20 mm are the standard of care. We sought to determine the pattern of tumor progression in patients treated with 5-fraction stereotactic radiosurgery with 5-mm margins.

Methods And Materials: Thirty adult patients with newly diagnosed GBM were treated with 5-fraction stereotactic radiosurgery in escalated doses from 25 to 40 Gy with a 5-mm total treatment margin.

View Article and Find Full Text PDF

Background: Stereotactic radiosurgery (SRS) to the surgical bed of resected brain metastases is now considered the standard of care due to its advantages over whole brain radiation therapy (WBRT). Despite the upward trend in SRS adoption since the 2000s, disparities have been reported suggesting that socio-economic factors can influence SRS utilization.

Objective: To analyze recent trends in SRS use and identify factors that influence treatment.

View Article and Find Full Text PDF

Background: Modulation of pathological neural circuit activity in the brain with a minimum of complications is an area of intense interest.

Objective: The goal of the study was to alter neurons' physiological states without apparent damage of cellular integrity using stereotactic radiosurgery (SRS).

Methods: We treated a 7.

View Article and Find Full Text PDF

Objectives: We investigated differences in quality of life (QoL) in patients enrolled on a phase I/II dose-escalation study of 3-fraction resection cavity stereotactic radiosurgery (SRS) for large brain metastases.

Methods: Eligible patients had 1 to 4 brain metastases, one of which was a resection cavity 4.2 to 33.

View Article and Find Full Text PDF

The win odds is a distribution-free method of comparing locations of distributions of two independent random variables. Introduced as a method for analyzing hierarchical composite endpoints, it is well suited to be used in the analysis of ordinal scale endpoints in COVID-19 clinical trials. For a single outcome, we provide power and sample size calculation formulas for the win odds test.

View Article and Find Full Text PDF

When radiation is focally delivered to brain tissue at sub-ablative doses, neural activity may be altered. When done at a specific brain circuit node or connection, this is referred to as "radiomodulation." Radiation-induced effects on brain tissue, basic science, and clinical research that supports the radiomodulation hypothesis are reviewed in this article.

View Article and Find Full Text PDF

The ZAP-X® is a newly designed, self-contained, and first-of-its-kind self-shielded therapeutic radiation therapy device dedicated to brain and head and neck stereotactic radiosurgery (SRS). By using an S-band linear accelerator (linac) and employing integrated minimal but sufficient shielding, the ZAP-X does not typically require a radiation bunker. At the same time, the self-shielded features of the ZAP-X are designed for more consistency of radiation protection, reducing the risk to radiation workers and others potentially exposed from a poorly designed or constructed radiotherapy vault.

View Article and Find Full Text PDF

Objective: The CyberKnife (CK) has emerged as an effective frameless and noninvasive method for treating a myriad of neurosurgical conditions. Here, the authors conducted an extensive retrospective analysis and review of the literature to elucidate the trend for CK use in the management paradigm for common neurosurgical diseases at their institution.

Methods: A literature review (January 1990-June 2019) and clinical review (January 1999-December 2018) were performed using, respectively, online research databases and the Stanford Research Repository of patients with intracranial and spinal lesions treated with CK at Stanford.

View Article and Find Full Text PDF

Skin cancers are the most common malignancy and are especially common among light-skinned individuals in sun-exposed areas. While in many cases, a characteristic or classic appearance of the lesion is sufficient to make a definitive diagnosis, shave biopsy remains an important procedure when diagnosing many such raised lesions. Over the span of two months, a 66-year-old Caucasian male noted the appearance of a small, raised pruritic scaly lesion over his right upper chest.

View Article and Find Full Text PDF

Ionizing radiation is clinically used to treat neurological problems and reduce pathological levels of neural activity in the brain, but its cellular-level mechanisms are not well understood. Although spontaneous and stimulated synaptic activity has been produced in rodents by clinically and environmentally relevant doses of radiation, the effects on basic excitability properties of neurons have seldom been reported. This study examined the effects of focused ionizing radiation on synaptic transmission and action potential generation in the squid giant-fiber system, which includes the giant synapse between a secondary interneuron and the tertiary giant motor axons.

View Article and Find Full Text PDF

Objective: To determine the long-term normal tissue complication probability with stereotactic body radiation therapy (SBRT) treatments for targets that move with respiration and its relation with the type of respiratory motion management (tracking . compression or gating).

Methods: A PubMed search was performed for identifying literature regarding dose, volume, fractionation, and toxicity (grade 3 or higher) for SBRT treatments for tumors which move with respiration.

View Article and Find Full Text PDF

Recording and manipulating neuronal ensemble activity is a key requirement in advanced neuromodulatory and behavior studies. Devices capable of both recording and manipulating neuronal activity brain-computer interfaces (BCIs) should ideally operate un-tethered and allow chronic longitudinal manipulations in the freely moving animal. In this study, we designed a new intracortical BCI feasible of telemetric recording and stimulating local gray and white matter of visual neural circuit after irradiation exposure.

View Article and Find Full Text PDF

Background And Importance: The Zap-X system (Zap Surgical Systems Inc, San Carlos, California) is a radically new surgical robot designed for brain and head and neck radiosurgery. It represents the first new dedicated brain stereotactic radiosurgery platform in almost half a century optimizing the goals of safety, speed, and accuracy. The Zap-X system was used in a required Chinese National Medical Products Administration clinical study.

View Article and Find Full Text PDF

Purpose: We sought to investigate the tumor control probability (TCP) of vestibular schwannomas after single-fraction stereotactic radiosurgery (SRS) or hypofractionated SRS over 2 to 5 fractions (fSRS).

Methods And Materials: Studies (PubMed indexed from 1993-2017) were eligible for data extraction if they contained dosimetric details of SRS/fSRS correlated with local tumor control. The rate of tumor control at 5 years (or at 3 years if 5-year data were not available) were collated.

View Article and Find Full Text PDF

The tsunami effect of the COVID-19 pandemic is affecting many aspects of scientific activities. Multidisciplinary experimental studies with international collaborators are hindered by the closing of the national borders, logistic issues due to lockdown, quarantine restrictions, and social distancing requirements. The full impact of this crisis on science is not clear yet, but the above-mentioned issues have most certainly restrained academic research activities.

View Article and Find Full Text PDF
Article Synopsis
  • * Researchers developed a porcine model to test the effects of high radiation doses (40-100 Gy) on small brain areas to understand how radiation affects neuronal activity.
  • * After 6 months of monitoring, they found that higher radiation doses led to damage in brain tissue: grey matter showed necrosis at 100 Gy, while white matter did so at 60 Gy, along with changes in blood vessels and brain cell structures.
View Article and Find Full Text PDF

Vestibular schwannoma (VS) is associated with dizziness and vertigo during all stages of treatment. This report describes a patient who presented with a one-year history of intermittent motion sickness, dizziness, headache, imbalance, and nausea. MRI showed a right-side VS in the cerebellopontine angle and internal auditory canal.

View Article and Find Full Text PDF

Introduction The treatment of trigeminal neuralgia (TN) is one of the most demanding of all radiosurgery procedures, requiring accurate delivery and sharp dose fall off. ZAP-X®, a new, innovative frameless radiosurgical device, maybe an attractive platform for the treatment of TN and other functional brain disorders. Here, we compared the dosimetry of ZAP-X plans for a single patient to that generated by a well-established dedicated radiosurgery device, the CyberKnife.

View Article and Find Full Text PDF