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Pathophysiological hallmarks of Alzheimer's disease (AD) include extracellular amyloid plaques and intracellular neurofibrillary tangles. Recent studies also demonstrated a role of neuroinflammation in the progression of the disease. Clinical trials and animal studies using low-dose radiation therapy (LDRT) have shown therapeutic potential for AD. This systematic review summarizes the current evidence on the use of LDRT for the treatment of AD, outlines potential mechanisms of action, and discusses current challenges in the planning of future trials. A systematic review of human and animal studies as well as registered clinical trials describing outcomes for RT in the treatment of AD was conducted. We followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles published until July 1, 2023, were included. The initial search yielded 993 articles. After the removal of duplicates and ineligible publications, a total of 16 (12 animal, 4 human) studies were included. Various dose regimens were utilized in both animal and human trials. The results revealed that LDRT reduced the number of amyloid plaques and neurofibrillary tangles, and it has a role in the regulation of genes and protein expression involved in the pathological progression of AD. LDRT has demonstrated reduced astro- and microgliosis, anti-inflammatory and neuroprotective effects, and an alleviation of symptoms of cognitive deficits in animal models. Most studies in humans suggested improvements in cognition and behavior. None of the trials or studies described significant (>grade 2) toxicity. Preclinical studies, animal studies, and early clinical trials in humans have shown a promising role for LDRT in the treatment of AD pathologies, although the underlying mechanisms are yet to be fully explored. Phase I/II/III trials are needed to assess the long-term safety, efficacy, and optimal treatment parameters of LDRT in AD treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • FLASH radiation therapy can reduce side effects in cancer therapy. • PITZ accelerator offers unique parameter range for electron FLASH studies. • Research plan to study electron FLASH radiation therapy at PITZ is presented. • International collaboration of research institutes was formed. • Preparations for realizing research platform are ongoing. At the P hoto I njector T est facility at DESY in Z euthen (PITZ), an R&D platform for electron FLASH and very high energy electron radiation therapy and radiation biology is being prepared (FLASH l a b @PITZ). The beam parameters available at PITZ are worldwide unique. They are based on experiences from 20 + years of developing high brightness beam sources and an ultra-intensive THz light source demonstrator for ps scale electron bunches with up to 5 nC bunch charge at MHz repetition rate in bunch trains of up to 1 ms length, currently 22 MeV (upgrade to 250 MeV planned). Individual bunches can provide peak dose rates up to 1014 Gy/s, and 10 Gy can be delivered within picoseconds. Upon demand, each bunch of the bunch train can be guided to a different transverse location, so that either a "painting" with micro beams (comparable to pencil beam scanning in proton therapy) or a cumulative increase of absorbed dose, using a wide beam distribution, can be realized at the tumor. Full tumor treatment can hence be completed within 1 ms, mitigating organ movement issues. With extremely flexible beam manipulation capabilities, FLASH l a b @PITZ will cover the current parameter range of successfully demonstrated FLASH effects and extend the parameter range towards yet unexploited short treatment times and high dose rates. A summary of the plans for FLASH l a b @PITZ and the status of its realization will be presented. [ABSTRACT FROM AUTHOR]

Craniopharyngiomas (CPs) are benign, dysontogenetic tumors associated with complex endocrinologic and neurologic symptoms and high morbidity. The aim of this study is to elucidate modifiable effectors of health-related quality of life (HrQoL) of adult patients with CP following neurosurgical intervention using standardized instruments as well as descriptive analysis. HrQoL (European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire C30 and BN20) was evaluated in 20 adult patients with CP. We examined pre- as well as postoperative radiologic, hormonal, and symptom-oriented data in a retrospective analysis. Surgical approach, postoperative complications, and extent of resection were recorded. Additional descriptive analysis was performed on case records of all patients with HrQoL results. Long-term follow-up of HrQoL (mean of 75 months) was lower than the in healthy reference group (CP = 58, reference = 75). The most common postoperative complaints were endocrinologic disturbances (88%). Overall, univariate and multivariate logistic regression analysis revealed no significant predictors of reduced postoperative HrQoL. Descriptive analysis did, however, reveal a cluster of patients among those with the lowest global HrQoL which reported new postoperative anosmia and ageusia. The global HrQoL of our cohort showed a substantial reduction compared with a healthy reference population. Postoperative hyposmia and ageusia is found in patients with the lowest postoperative HrQoL who otherwise had no new significant endocrinologic or neurologic complications. As these symptoms are not regularly accounted for in the HrQoL instruments used in this study, further analysis is needed to determine the possible significance of this complication in CP surgery, and it may affect the choice of surgical approach as well as the information patients receive before consenting to surgery. [ABSTRACT FROM AUTHOR]

• Patients with glioblastoma lesions in contact with the subventricular zone show worse overall survival. • Irradiation of the subventricular zone does not improve progression-free or overall survival. • Confirmatory prospective trials are needed. Current glioblastoma (GBM) therapies prolong survival, but overall prognosis is still poor. Irradiation of the subventricular zone (SVZ) has recently been discussed as a promising concept as this tissue harbors stem cells which seem to play a role in the initiation and recurrence of GBM. In this study, we retrospectively examined the relationship of SVZ irradiation dose and survival in a large, homogeneous GBM patient cohort. We included 200 GBM patients who had been treated at our institution with trimodal therapy (surgery, radiotherapy and chemotherapy) between 2009 and 2020. The SVZ was delineated, and dose-volume histograms were calculated and extracted. Tumors were classified according to their contact with the SVZ. The Kaplan-Meier method was used for survival analysis, and univariable and multivariable Cox regression (MVA) were used to determine prognostic effects on progression-free survival (PFS) and overall survival (OS). Median PFS of the study group was 7.2 months; median OS was 15.1 months. In MVA (with mean dose to the ipsilateral SVZ as a continuous covariable), PFS was significantly lower for patients with a Karnofsky performance status (KPS) < 70% and without MGMT promoter methylation. Factors prognostic for shorter OS were old age, lower KPS, unmethylated MGMT status, SVZ contact and biopsy instead of subtotal- or gross total resection. There was no significant correlation between survival and SVZ dose. In this cohort, an increased mean dose to the ipsilateral or contralateral SVZ did not correlate with improved survival in irradiated GBM patients in MVA. Patients whose tumor directly involved the SVZ showed worse OS in MVA. [ABSTRACT FROM AUTHOR]

Stereotactic radiosurgery (SRS) has been increasingly applied for malignant meningiomas as an alternative to conventionally fractioned radiation therapy. We performed a retrospective analysis of an institutional patient cohort with malignant meningiomas treated by image-guided SRS. All patients with atypical or anaplastic meningiomas who were treated by SRS using CyberKnife (CK) were identified. Local failure and regional and/or distant recurrences were evaluated together with toxicity and overall survival. We identified 127 treated lesions (105 atypical and 22 anaplastic) in 35 patients. The mean time interval between the last surgery and subsequent CK-SRS was 30.8 ± 24.5 months. Most lesions (83.5%) were treated using single-fraction CK-SRS. The median planning target volume of all 127 lesions was 1.71 cm3 (range, 0.06–22.5 cm3). The median follow-up period was 23 months (range, 2.1–60.3 months). The estimated local control rates were 97%, 77%, and 67% at 12, 36, and 60 months, respectively, in atypical meningiomas and 66% each at 12 and 24 months in anaplastic meningiomas. The regional progression-free survival was 93%, 73%, and 59% at 12, 36, and 60 months, respectively, in atypical lesions and 93% and 46% at 12 and 24 months in anaplastic lesions. The estimated distant tumor progression-free interval in atypical lesions was 80%, 44%, and 44% at 12, 36, and 60 months, respectively, and 49% and 24% at 12 and 24 months, respectively, in anaplastic lesions. Age was identified as a risk factor for local failure. Although the real boundaries of efficacy of SRS have to be further evaluated in a prospective trial, it seems that aggressive treatment by high-dose single or multisession SRS of recurring malignant meningiomas provides satisfactory local control rates. [ABSTRACT FROM AUTHOR]

Purpose: To assess ASIR (adaptive statistical iterative reconstruction) technique regarding dose reduction and its impact on image quality in evaluation CTs of potential kidney donors. Materials and Methods: Between May and November 2013, a prospective study of 53 assumingly healthy potential kidney donors was conducted. The subjects underwent abdominal evaluation CT prior to the planned explantation of a kidney and were randomly divided into 2 groups: Group A was examined with an ASIR 40 protocol (n=26), group B (n=27) was examined using a standard FBP (filtered back projection) protocol. Image quality was assessed both quantitatively (by obtaining attenuation values in different organ regions and calculating SNR and CNRs) and qualitatively (by two observers who evaluated image quality using a 5-point scale system). Applied dose was analyzed as CTDIvol (mGy), total DLP (mGy×cm) and effective dose (mSv). Results: Applied dose in group A was about 26% lower than in group B (p<0.05). Between both groups, dose determining parameters such as scan length and patients' body diameter showed no significant difference. SNR (signal-to-noise ratio) was significantly higher in group A (p<0.05). CNRs (contrast-to-noise ratios) for different tissues were not significantly different. Observer rated image quality showed no significant difference. Conclusion: ASIR can contribute to a relevant dose reduction without any loss of image quality in CT scans for evaluating potential kidney donors. [ABSTRACT FROM AUTHOR]