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Physica Medica : PM : An International... Mar 2024Classical radiation protocols are guided by physical dose delivered homogeneously over the target. Protocols are chosen to keep normal tissue complication probability...
BACKGROUND
Classical radiation protocols are guided by physical dose delivered homogeneously over the target. Protocols are chosen to keep normal tissue complication probability (NTCP) at an acceptable level. Organs at risk (OAR) adjacent to the target volume could lead to underdosage of the tumor and a decrease of tumor control probability (TCP). The intent of our study was to explore a biology-based dose escalation: by keeping NTCP for OAR constant, radiation dose was to be maximized, allowing to result in heterogeneous dose distributions.
METHODS
We used computed tomography datasets of 25 dogs with brain tumors, previously treated with 10x4 Gy (40 Gy to PTV D). We generated 3 plans for each patient: A) original treatment plan with homogeneous dose distribution, B) heterogeneous dose distribution with strict adherence to the same NTCPs as in A), and C) heterogeneous dose distribution with adherence to NTCP <5%. For plan comparison, TCPs and TCP equivalent doses (homogenous target dose which results in the same TCP) were calculated. To enable the use of the generalized equivalent uniform dose (gEUD) metric of the tumor target in plan optimization, the calculated TCP values were used to obtain the volume effect parameter a.
RESULTS
As intended, NTCPs for all OARs did not differ from plan A) to B). In plan C), however, NTCPs were significantly higher for brain (mean 2.5% (SD±1.9, 95%CI: 1.7,3.3), p<0.001), optic chiasm (mean 2.0% (SD±2.2, 95%CI: 1.0,2.8), p=0.010) compared to plan A), but no significant increase was found for the brainstem. For 24 of 25 of the evaluated patients, the heterogenous plans B) and C) led to an increase in target dose and projected increase in TCP compared to the homogenous plan A). Furthermore, the distribution of the projected individual TCP values as a function of the dose was found to be in good agreement with the population TCP model.
CONCLUSION
Our study is a first step towards risk-adaptive radiation dose optimization. This strategy utilizes a biologic objective function based on TCP and NTCP instead of an objective function based on physical dose constraints.
Topics: Humans; Dogs; Animals; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Neoplasms; Radiotherapy, Intensity-Modulated; Brain; Probability; Biology
PubMed: 38430675
DOI: 10.1016/j.ejmp.2024.103317 -
BMC Ophthalmology Mar 2024Acute retinal pigment epitheliitis (ARPE) is a rare, idiopathic and self-limiting disease. The article aims to present ARPE in a patient using D2 dopamine receptor...
BACKGROUND
Acute retinal pigment epitheliitis (ARPE) is a rare, idiopathic and self-limiting disease. The article aims to present ARPE in a patient using D2 dopamine receptor agonists for the treatment of hyperprolactinemia.
CASE PRESENTATION
A 28-year-old female during hyperprolactinaemia treatment suffered from a dyschromatopsia and a central visual field defect in the left eye. She noticed a deterioration of vision and discontinued the cabergoline administration. The woman had not been diagnosed with other chronic conditions and exhibited no symptoms of infection. Upon admission, the patient was subjected to a test for COVID-19, which was negative. The ophthalmological examination revealed a decrease in visual acuity to distance in the left eye, which amounted to 18/20 on the Snellen chart. A central scotoma was noted on the Amsler chart and a loss of pigment epithelium was visible on the fundus of the left eye. Fluorescein angiography showed a discrete window defect in the left one, with no signs of leakage. Optical coherence tomography (OCT) scans of the maculae revealed a characteristic change in the photoreceptor layer and retinal pigment epithelium (RPE) in the fovea in the left eye. The electrophysiological tests revealed decreased function of cells in macular region. A magnetic resonance imaging (MRI) of the head and orbits demonstrated an asymmetric pituitary gland without chiasm compression and discrete signal enhancement from the left optic nerve. The patient underwent observation during hospitalisation. She reported improved colour vision and a decreased scotoma in the centre of her visual field. In regular outpatient follow-ups, successive improvements in visual acuity, as well as a decreased RPE damage and outer photoreceptor layer loss during an OCT test were observed.
CONCLUSIONS
A case of ARPE is reported in a patient taking medications for hyperprolactinemia. The role of dopamine receptor antagonists in the photoreceptor function and causation of ARPE needs further evaluation.
Topics: Humans; Female; Adult; Hyperprolactinemia; Retinitis; Visual Fields; Scotoma; Retinal Pigments
PubMed: 38429692
DOI: 10.1186/s12886-024-03366-0 -
Journal of Neurosurgery. Case Lessons Feb 2024A cavernous malformation of the optic nerve (CMON) is a rare condition that often presents with an abrupt decline in vision. Acute management of ruptured optic nerve...
BACKGROUND
A cavernous malformation of the optic nerve (CMON) is a rare condition that often presents with an abrupt decline in vision. Acute management of ruptured optic nerve cavernous malformations is generally surgical, although the timing of surgery is controversial.
OBSERVATIONS
A 47-year-old female experienced the sudden loss of vision in her left eye. Examination showed that this eye was nearly blind, and her right eye had a temporal field defect. Neuroimaging showed hemorrhage in her left optic nerve and optic chiasm. She was taken to the operating room on an emergent basis where the optic canal was decompressed, the hemorrhage was evacuated, and a vascular malformation with features of a cavernoma was removed from the optic nerve. Over the next 2 days, the vision in her right eye significantly recovered.
LESSONS
CMONs remain rare, and it is unlikely that enough cases can be gathered to form a larger trial to compare the role and timing of surgery. On the basis of our experience with this case, the authors recommend that acute CMON-related hematomas should be treated as a surgical emergency and managed with acute optic nerve decompression, hematoma evacuation, and cavernoma resection to improve chances of vision recovery and prevent further vision loss.
PubMed: 38408352
DOI: 10.3171/CASE23746 -
Alternative Therapies in Health and... Feb 2024To assess the role of miR-30c-5p in subarachnoid hemorrhage (SAH) and its possible mechanism.
OBJECTIVE
To assess the role of miR-30c-5p in subarachnoid hemorrhage (SAH) and its possible mechanism.
METHODS
We established a SAH model by injecting fresh arterial non-heparinized blood into the anterior cistern of the optic chiasm of healthy Sprague-Dawley rats. Next, we treated the rats with a miR-30c-5p inhibitor or miR-30c-5p mimics. We then assessed behavior, serum lactate dehydrogenase levels, albumin expression, neuronal degeneration, neuronal apoptosis, neuronal survival, and the cerebral edema index in the SAH model rats. We identified downstream target genes of miR-30c-5p using the Targetscan database and confirmed them via luciferase reporter assay. Finally, we assessed the effect of these targeted genes on brain injury in SAH rats through a recovery assay.
RESULTS
Our results showed that the overexpression of miR-30c-5p in brain tissue 24h after SAH prevented brain injury, reduced inflammation levels and nerve function scores, inhibited neuronal apoptosis, and improved neuronal survival. Meanwhile, inhibiting miR-30c-5p yielded opposite effects. Two genes related to the autophagy pathway, ATG5 and ATG12, were identified as miR-30c-5p downstream target genes. Silencing ATG5 and ATG12 alleviated brain injury induced by knocking down miR-30c-5p.
CONCLUSION
Our findings suggest that miR-30c-5p protects from SAH-induced brain injury by inhibiting the ATG5/ATG12 pathway and it may serve as a new diagnostic maker or target for treatment of SAH patients.
PubMed: 38401106
DOI: No ID Found -
The Veterinary Quarterly Dec 2024A 16-year-old warmblood mare was referred with a progressive history of behavioral changes and left-sided blindness. Following neuroanatomical localization to the...
A 16-year-old warmblood mare was referred with a progressive history of behavioral changes and left-sided blindness. Following neuroanatomical localization to the forebrain, magnetic resonance imaging of the head revealed a well-delineated, 4.5 cm in diameter, round pituitary mass causing marked compression of the midbrain and optic chiasm. Euthanasia was recommended but declined by the owners. Veterinary specialists and a human neurosurgeon collaboratively prepared for surgical case management. A novel navigated transmandibular lateral transsphenoidal approach was developed to access the region of the sella turcica and practiced on cadaver specimens. The horse was anesthetized and placed in sternal recumbency with the head above the heart line. Using a cone beam computed tomography (CBCT)-coupled navigation system, a navigated pin traversing the vertical ramus of the mandible and the lateral pterygoid muscle was placed in a direct trajectory to the predetermined osteotomy site of the basisphenoid bone. A safe corridor to the osteotomy site was established using sequential tubular dilators bypassing the guttural pouch, internal and external carotid arteries. Despite the use of microsurgical techniques, visualization of critical structures was limited by the long and narrow working channel. Whilst partial resection of the mass was achieved, iatrogenic trauma to the normal brain parenchyma was identified by intraoperative imaging. With consent of the owner the mare was euthanized under the same general anesthesia. Post-mortem magnetic resonance imaging and gross anatomical examination confirmed partial removal of a pituitary adenoma, but also iatrogenic damage to the surrounding brain parenchyma, including the thalamus.
Topics: Horses; Humans; Female; Animals; Pituitary Neoplasms; Adenoma; Sella Turcica; Iatrogenic Disease; Magnetic Resonance Imaging; Horse Diseases
PubMed: 38393300
DOI: 10.1080/01652176.2023.2300947 -
Cureus Jan 2024Optic pathway gliomas (OPGs) are rare pediatric tumors that pose significant challenges in management due to their location and clinical manifestations. Traditional...
Optic pathway gliomas (OPGs) are rare pediatric tumors that pose significant challenges in management due to their location and clinical manifestations. Traditional transcranial approaches have been the mainstay for surgical intervention, but recent advancements in endoscopic endonasal transsphenoidal surgery offer a less invasive alternative. Here, we present a case of a 10-year-old female child with neurofibromatosis type-1 and an aggressive OPG who underwent endoscopic endonasal transsphenoidal debulking surgery. The pre-operative evaluation confirmed complete vision loss, and imaging revealed tumor progression. The surgery was successful, resulting in a subtotal resection and a diagnosis of pilocytic astrocytoma, WHO grade 1. Post-operative assessments showed no complications. This case highlights the feasibility of the endoscopic endonasal transsphenoidal approach for OPGs and emphasizes the importance of careful patient selection and multidisciplinary collaboration in achieving successful outcomes for these challenging tumors.
PubMed: 38380221
DOI: 10.7759/cureus.52649 -
International Journal of Ophthalmology 2024To evaluate the predictive value of superficial retinal capillary plexus (SRCP) and radial peripapillary capillary (RPC) for visual field recovery after optic cross...
AIM
To evaluate the predictive value of superficial retinal capillary plexus (SRCP) and radial peripapillary capillary (RPC) for visual field recovery after optic cross decompression and compare them with peripapillary nerve fiber layer (pRNFL) and ganglion cell complex (GCC).
METHODS
This prospective longitudinal observational study included patients with chiasmal compression due to sellar region mass scheduled for decompressive surgery. Generalized estimating equations were used to compare retinal vessel density and retinal layer thickness pre- and post-operatively and with healthy controls. Logistic regression models were used to assess the relationship between preoperative GCC, pRNFL, SRCP, and RPC parameters and visual field recovery after surgery.
RESULTS
The study included 43 eyes of 24 patients and 48 eyes of 24 healthy controls. Preoperative RPC and SRCP vessel density and pRNFL and GCC thickness were lower than healthy controls and higher than postoperative values. The best predictive GCC and pRNFL models were based on the superior GCC [area under the curve (AUC)=0.866] and the tempo-inferior pRNFL (AUC=0.824), and the best predictive SRCP and RPC models were based on the nasal SRCP (AUC=0.718) and tempo-inferior RPC (AUC=0.825). There was no statistical difference in the predictive value of the superior GCC, tempo-inferior pRNFL, and tempo-inferior RPC (all >0.05).
CONCLUSION
Compression of the optic chiasm by tumors in the saddle area can reduce retinal thickness and blood perfusion. This reduction persists despite the recovery of the visual field after decompression surgery. GCC, pRNFL, and RPC can be used as sensitive predictors of visual field recovery after decompression surgery.
PubMed: 38371253
DOI: 10.18240/ijo.2024.02.21 -
Acta Endocrinologica (Bucharest,... 2023Dopamine agonists (DA) are first line treatment for prolactinomas. Optic chiasm herniation can rarely occur during therapy, while brain herniation is very uncommon.
BACKGROUND
Dopamine agonists (DA) are first line treatment for prolactinomas. Optic chiasm herniation can rarely occur during therapy, while brain herniation is very uncommon.
CASE REPORTS
A 34 yo woman presented with headaches and vision changes. Prolactin (PRL) was 4300 ng/mL. MRI showed a 4.5 cm pituitary adenoma with chiasm compression. After 3 months, PRL decreased to 201 ng/mL while patient was taking CAB 0.75 mg twice a week. MRI showed ~30% tumor reduction with medial temporal lobe herniation and encephalocele. CAB was stopped and she underwent surgical debulking and encephalocele repair. Histopathology confirmed prolactin tumor. CAB 0.75 mg twice a week was resumed.A 50 yo man had incidental detection of a sellar mass after trauma. MRI showed 3.6 cm tumor with minimal contact of right optic nerve, and PRL 3,318 ng/ml. He received CAB 0.5mg twice a week with PRL improvement to 26 ng/mL after 1 month. After 2 months ophthalmology exam showed new left superotemporal depression. PRL was 68 ng/mL and MRI showed 35% mass reduction and new inferior displacement tethering of the chiasm. CAB dose was decreased to 0.25 mg twice a week.
CONCLUSION
Our cases illustrate that rapid biochemical and radiographic response to DA therapy in large prolactinomas warrants close clinical and neuro-ophthalmologic follow-up. We recommend repeating the MRI 3 months after initiation of DA therapy or sooner in case of new mass effect manifestations. Decision regarding DA dose reduction or chiasmopexy for visual field deficits needs to be multi-disciplinary and on a case-to-case basis.
PubMed: 38356985
DOI: 10.4183/aeb.2023.339 -
Cureus Jan 2024We present a case of an adult patient experiencing progressive visual loss. An initial presentation was concerning for neuromyelitis optica with optic chiasm...
We present a case of an adult patient experiencing progressive visual loss. An initial presentation was concerning for neuromyelitis optica with optic chiasm involvement. However, persistent contrast enhancement observed in follow-up brain and orbit images raised suspicion for optic tract malignant neoplasm. Histopathological evolution of optic nerve biopsy confirmed the diagnosis of an optic chiasm glioma. The patient was then referred to oncology for chemotherapy.
PubMed: 38313959
DOI: 10.7759/cureus.51614