• Book : 158()
• Pub. Date : 2025
• Page : pp.109906
• Keyword :

Atypical teratoid/rhabdoid tumor (ATRT) is an aggressive, malignant embryonal tumor with dismal long-term survival despite aggressive multimodal therapy. While this tumor typically presents in infancy or early childhood, there are published case reports of adult-onset ATRT. Making prognostic conclusions or therapeutic decisions for this older patient population remains challenging due to the paucity of these reports. A 25-year-old female with Down syndrome presented with dysphagia and facial droop and was found to have an avidly enhancing, cerebellopontine angle mass. Histology demonstrated sheets of rhabdoid cells with loss of INI1 expression, pathognomonic for ATRT. Further sequencing detected a frameshift SMARCB1 mutation and methylation profiling matched with high confidence to the MYC subclass of ATRT. The patient was treated with subtotal surgical resection and focal proton beam irradiation, followed by chemotherapy on a modified regimen due to concern for heightened risk of treatment-related toxicity. On most recent follow-up 22 months from diagnosis, the patient remains without evidence of disease. This report represents the first known case of ATRT in a young adult patient with Down syndrome, offering unique mechanistic insight into the tumorigenesis of ATRT. Further studies are needed to define an appropriate risk-adapted and standardized therapeutic approach for this patient population.

• Book : 47(1)
• Pub. Date : 2025
• Page : pp.e52-e57
• Keyword :

Abstract

The β-decay properties of ⁶⁷⁻⁸⁰As nuclei have been investigated within the framework of the proton-neutron quasi-particle random phase approximation (pn-QRPA) model. The nuclear deformation obtained from the finite range droplet model is used as an input parameter in the pn-QRPA model for the analysis of β-decay properties including Gamow-Teller strength distributions, log ft, β-decay half-lives and stellar β^± decay rates. The predicted log ft values were fairly consistent with the observed data. The computed β-decay half-lives matched the measured values by a factor of 10. The stellar rates were compared with the shell model outcomes. At high densities and temperatures, the β⁺ and electron capture rates had a finite contribution. However, the β⁻ and positron capture rates are only significant at high temperatures and low densities. The pn-QRPA rates outperformed the shell model rates by a factor of 22 or more.

• Book : 77(3)
• Pub. Date : 2025
• Page : pp.035302
• Keyword :

Abstract

This article presents the design and experimental validation of a uniform circular array (UCA) of circularly polarized (CP) slot patch antennas for generating orbital angular momentum (OAM) beams at 2.4 GHz. The proposed UCA configuration enables high-purity OAM beam generation with azimuthal symmetry, which is critical for vehicular communication applications. Using left-hand circularly polarized elements and a series-fed network, the UCA achieves precise phase control and minimal side-lobe levels. The antenna was optimized to produce the OAM mode with a topological charge l = 1. Numerical simulations and experimental measurements show that the design offers strong impedance matching and high mode purity, making it suitable for applications requiring conical beam radiation, such as vehicle-to-vehicle communications. The 3D measurements further validate the prototype’s effectiveness in generating OAM beams with symmetric radiation patterns, demonstrating significant azimuthal symmetry and confirming its applicability for dynamic vehicular environments.

• Book : 27(1)
• Pub. Date : 2025
• Page : pp.015606
• Keyword :

• Book : 605()
• Pub. Date : 2025
• Page : pp.155568
• Keyword :

• Book : 605()
• Pub. Date : 2025
• Page : pp.155592
• Keyword :

Purpose:

The objective of this study was to better understand the onset of radiation retinopathy and secondary orbital tumors in the setting of retinoblastoma treated with radiation and chemotherapy.

Methods:

This was a case report.

Results:

Here, the authors present a 48-year-old woman with a history of bilateral hereditary retinoblastoma after enucleation of the left eye and radiation therapy to the right eye along with systemic chemotherapy. She underwent bladder leiomyosarcoma resection at the age of 24 years. In 2020, she presented with significantly delayed radiation retinopathy complicated by cystoid macular edema, and bevacizumab injections were initiated. An incidental benign lymphoproliferative tumor in the right lacrimal gland was found on B-scan ultrasound and was successfully excised.

Conclusion:

It is rare for radiation retinopathy to present with significant delay after local radiation treatment, with only two other cases found in the literature describing a similar late onset. In addition, there have been no other published cases of a secondary benign lymphoproliferative tumor in the setting of retinoblastoma treated with radiation and chemotherapy.

• Book : 19(1)
• Pub. Date : 2025
• Page : pp.19-22
• Keyword :

• Book : 605()
• Pub. Date : 2025
• Page : pp.155590
• Keyword :

Abstract

Objective. The objective is to generate reliable Ki parametric images from ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) total-body positron emission tomography (PET) with clinically acceptable scan durations using Patlak and shallow machine learning algorithms, under conditions of limited computational and data resources. Approach. We proposed a robust and fast algorithm named Patlak-KX^D to generate Ki images from dynamic PET images with shortened scan durations. In the training phase, K-means is employed to generate a Ki-balanced training dataset. Subsequently, XGBoost is utilized to learn the mapping relationship between the tissue-to-blood standardized uptake ratio (SUR) time curves and Patlak-based Ki values using this balanced dataset. In the prediction phase, the trained XGBoost can generate Ki images by calculating the Ki values from voxel-based SUR time curves obtained from the dynamic images. We compared the accuracy of Ki images generated by both the Patlak-KX^D and the traditional Patlak methods across a range of shortened scan durations, and the differences in Ki images generated by the XGBoost model using static (Patlak-KX^S) and dynamic PET inputs. Main results. The Ki images generated by the Patlak-KX^D from just a 4 min (56-60 min) dynamic ¹⁸F-FDG total-body PET scan are comparable to those generated by the traditional Patlak method using 40 min (20-60 min) dynamic PET images, as demonstrated by a normalized mean square error of 0.13 and a Pearson’s correlation coefficient of 0.94 on average. The Ki images generated by the Patlak-KX^D is robust to the scan duration, and the quality of Ki images generated from Patlak-KX^D is superior to those from Patlak-KX^S as scan duration >10 min. Significance. Reliable Ki images can be rapidly generated using shallow machine learning algorithms from dynamic ¹⁸F-FDG total-body PET scans with durations as short as four minutes. This total-body Ki parametric imaging method has potential to be used in clinical nuclear medicine and molecular imaging.

• Book : 70(1)
• Pub. Date : 2025
• Page : pp.015017
• Keyword :

• Book : 605()
• Pub. Date : 2025
• Page : pp.155574
• Keyword :