Citations

Abstract Introduction Linear accelerators require a large amount of data to be collected daily, monthly and annually to verify safe deliveries for patients. Different detectors have been utilized to improve the simplicity, efficiency and accuracy of the various experimental setups required to collect the necessary data resulting in reduced data collection and evaluation time. Plastic scintillators are stable and energy independent radiation detectors with high spatial resolution that emit light proportional to the amount of radiation incident on them. With an appropriate photodetector and technique to measure and analyze the light that is emitted, scintillators can be utilized to measure dosimetric parameters necessary for various monthly quality assurance requirements. Methods A uniform cylindrical plastic scintillator imaged by a complementary metal oxide semiconductor (CMOS) camera is designed to act as a radiation detector to measure 2D projections of linear accelerator beams. Beams were delivered to the detector to evaluate machine quality assurance (QA) parameters, including beam energy, output, profile consistency and reproducibility as described by TG‐198. These measurements were compared to calculations from the Eclipse treatment planning system (TPS). Typical monthly quality assurance (QA) beams were delivered and 2D projections of the scintillation light were measured to validate the accuracy and reproducibility of this detector system for monthly QA. Results The plastic scintillator was able to accurately characterize the radiation beam. Energy and profile measurements were reproducible and within 2%/2mm of calculations in the TPS. Output measurements had maximum variations of up to 1.3% and average differences of 0.5%. Conclusion A simple cylindrical plastic scintillator and CMOS camera radiation detector setup was designed and tested for measuring monthly QA dosimetric parameters specified by TG‐198 with accurate and reproducible output, energy and profiles measurements. This method reduces the number of measurements required, allowing multiple parameters to be evaluated in a single beam delivery.

Reversible cerebral vasoconstriction syndrome (RCVS) represents a group of conditions that show reversible multifocal narrowing or constriction of the cerebral arteries that supply blood to the brain. The initial manifestation of RCVS often includes a “thunderclap” headache that is sudden, severe, and often disabling. Stimulants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and antipsychotics with serotonergic activity can alter the cerebral arterial tone, trigger vasoconstriction, and place patients at risk of a cerebrovascular accident. Thus, psychiatric medications are commonly discontinued on admission for RCVS, and psychiatry is often consulted for input on acute medication management and longitudinal treatment options. Currently, there is a dearth of literature on managing psychiatric medications in RCVS, resulting in variable practice patterns that place patients at risk of withdrawal, decompensation, and relapse. In this article, we provide a case example and aim to consolidate the limited data surrounding the management of psychiatric illness with comorbid RCVS in our discussion. There is a clear concern about worsening and even potentially lethal consequences due to serotonin or stimulant-induced vasospasm both during an acute episode and in long-term management of RCVS. We discuss the underlying pathophysiologic mechanisms proposed for serotonergic-, noradrenergic-, and dopaminergic-induced cerebral vasospasm and how this correlates with the clinical management of patients on psychiatric medications. These data will then be organized to create a risks versus benefits outline to equip psychiatrists to make decisions about when to stop and when to restart psychiatric medications in the setting of RCVS.