The discovery of radiation has enabled great healthcare advances as well as catastrophic injury. This paper reviews major historical incidents of public radiation exposure and the evolution of standards affecting today's public and health care workers. Current patient care and response assessment to radiation exposure are reviewed. The strengths of modern radiation therapy and the need for continuous process improvements to ensure optimal patient care and secure safe environments are identified. The discovery of radiation has brought significant scientific achievements as well as catastrophic injury.
Radiation therapy continues to be an important treatment application in pediatric oncology.There have been significant improvements in the application of radiation therapy in the past decade which can be directly applied to children and improve patient outcome relative to tumor control and ameliorate the late effects of management imposed on normal tissue.In this paper we present an application of radiation therapy using volume modulation arc therapy in a unique presentation of Ewing sarcoma.Multiple body segments were treated in a simultaneous manner with conformal avoidance of critical normal tissues including cardiac structures, hepatic parenchyma, and the remaining left kidney.
Abstract INTRODUCTION Radiation induced cerebral vasculopathy encompasses a complex and broad range of effects such as ischemia, hemorrhage, vascular malformation, capillary telangiectasias, and large vessel stenosis caused by pathological reorganization of tissue after radiation exposure. Necrosis and inflammation induce damage and demyelinating changes to other vessels over the corresponding areas that may occur months to years after brain irradiation. Here we report an unusual case of hemorrhagic basal ganglia/internal capsule glioblastoma followed by contralateral basal ganglia/internal capsule acute infarct with resulting acute transient global amnesia followed by chronic memory impairment. CASE REPORT A 58-year old man was diagnosed with a hemorrhagic left basal ganglia/internal capsule mass after presenting with severe headaches, agitation, and vomiting. Glioblastoma (IDH wild type by sequencing, MGMT unmethylated) was identified on resection. He underwent radiotherapy and concurrent and adjuvant (12 cycles) temozolomide. Serial surveillance brain MRI scans demonstrated multiple incidental vascular abnormalities including subacute right basal ganglia/internal capsule ischemic infarct, right temporal cavernoma, and right temporal intra-parenchymal hemorrhage approximately 1, 2, and 3 years after diagnosis, respectively. Approximately 4 years after diagnosis, he presented with transient global amnesia and imaging demonstrated right basal ganglia/internal capsule ischemic stroke. DISCUSSION Bilateral basal ganglia/internal capsule damage from stroke has been reported as causing memory impairment (Tatemichi TK et al, Neurology 1992;42:1966-79; PMID 1407580). Here we report memory impairment from unilateral basal ganglia/internal capsule tumor and contralateral infarct following brain radiotherapy as another mechanism of neurocognitive injury. Our case highlights the significance of continuing to surveil for these findings as new neurologic symptoms may mimic tumor progression.
Abstract INTRODUCTION Papillary tumor of the pineal region (PTPR) is a very rare tumor comprising < 1% of all intracranial neoplasms. It was first included as a distinct tumor entity in the 2007 World Health Organization classification. Due to its rarity, only anecdotal data is currently available to guide management. However, with these tumors being recognized more frequently, further molecular observations and therapeutic experiences are necessary. Herein, we report an unusual case of PTPR with a previously treated leptomeningeal metastasis (LM) whom we successfully managed with Gamma Knife Radiosurgery (GKRS) and adjuvant temozolomide at time of distant brain parenchymal tumor progression. CASE REPORT: A 41-year-old man presented with headache and diplopia in 2015, MRI brain revealed a large cystic enhancing lesion in the pineal region protruding into the third ventricle and causing obstructive hydrocephalus. He had a ventriculoperitoneal shunt placed and underwent partial tumor resection. He then transferred care to our institution and a gross total resection was achieved. Pathology confirmed PTPR. A repeat MRI 15 months later showed evidence of radiographic LM in the cerebellum and he underwent craniospinal proton radiation therapy. He remained stable until January 2020 when a new left temporal heterogeneously enhancing multicystic lesion was identified on surveillance MRI. He underwent subtotal resection of this intra-axial lesion. Histological features of the tumor were similar to his initial tumor. Somatic tumor mutation testing using FoundationOne®CDx did not reveal targetable molecular alterations. Following surgery, he received GKRS and six cycles of adjuvant temozolomide. At 21-month follow up, patient continues to do well. CONCLUSION To our knowledge, this is the first case to describe a metastatic brain intraparenchymal PTPR. We also describe a first case of successful therapeutic strategy for a distant recurrence of PTPR.
Laura Anselmi, Victor Ruiz-Velasco, Sean D. Stocker, Shannon P. Higgins, Guillaume P. Ducrocq and Marc P. Kaufman. The role played by the transient receptor potential vallinoid-1 (TRPV1) on the endings of thin fiber muscle afferents in evoking the exercise pressor reflex is controversial. To shed light on this controversy, we used TRPV1-/- rats that were made by a CRISPR-Cas9 deletion to introduce a 26-bp frameshift deletion in exon 3. We compared the magnitude of the reflex between TRPV1 +/+ wild-type rats (WT), TRPV1+/- heterozygous rats (HET), and TRPV1-/- knockout rats (KO). The exercise pressor reflex was evoked by stimulating the tibial nerve (40Hz, 0.01ms, 1.5 times motor threshold) in precollicular decerebrated unanesthetized rats whose femoral arteries were either freely perfused or were occluded for 30 sec before the start of contraction. We found that there was no difference between the magnitude of the reflex in the three groups of rats with freely perfused hindlimbs (p=0.61). Specifically, the exercise pressor reflex averaged 16.4 ± 2.2 mmHg in WT rats (n=9), 21.1 ± 5 mmHg in HET rats (n=9), and 17.7 ± 2.3 mmHg in KO rats (n=9). No difference was also observed among the three groups of rats that received acute femoral artery occlusion (p=0.79). Specifically, the peak exercise pressor reflex averaged 15.3 ± 2.2 mmHg in WT rats (n=4), 19.8 ± 4.7 mmHg in HET rats (n=6), and 19 ± 8 mmHg in KO rats (n=3). Stimulation of the tibial nerve after paralysis of the rats with pancuronium (iv) had trivial effects on arterial pressure indicating that the pressor responses to contraction were not caused by electrical stimulation within the axon of the tibial nerve. Intra-carotid arterial injection of the TRPV1 agonist, capsaicin (0.5 mg), evoked a significant pressor response in the WT rats (34.7 ± 9.2 mmHg) and in the HET rats (36.3 ± 7.2 mmHg), but not in the KO rats (3.2 ± 0.4 mmHg). In electrophysiological studies of dorsal root ganglion cells innervating the gastrocnemius muscles, capsaicin evoked inward currents in the WT and HET rats, but not in the KO rats. Moreover, immunofluorescence revealed the presence of TRPV1 in the DRG of WT, but not in the DRG of KO rats. We conclude that TRPV1 is not needed to evoke the exercise pressor reflex either in rats whose femoral arteries were either freely perfused or were occluded. These results are consistent with our previous finding that pharmacological antagonism of TRPV1 had no effect on the exercise pressor reflex. Supported by HL156594 and HL 156513 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Technology and computational analytics are moving forward at an extraordinary rate with changes in patient care and department workflows. This rapid pace of change often requires initiating and maintaining the educational support at multiple levels to introduce technology to radiation oncology staff members. Modern physics quality assurance and dosimetry treatment planning now require expertise beyond traditional skill based in computational algorithms and image management including quality assurance of the process of image acquisition and fusion of image datasets. Expertise in volumetric anatomy and normal tissue contouring are skills now performed by physics/dosimetry in collaboration with physicians and these skills are required in modern physics dosimetry training programs. In this chapter, challenges of modern radiation planning are reviewed for each disease site. Skills including future applications of image integration into planning objects and the future utility of artificial intelligence in modern radiation therapy treatment planning are reviewed as these issues will need to be added to modern training programs.
