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PubMed2026

Linking MRI radiomics to transcriptomics-based radiosensitivity in lower-grade glioma: A radiogenomic framework.

BACKGROUND: RSI is a transcriptomics-based biomarker associated with radiotherapy outcomes, but its clinical application is constrained by the requirement for tumor tissue and RNA sequencing. This study investigates whether MRI-derived radiomic features can reflect RSI-defined intrinsic radiosensitivity in lower-grade glioma.This addresses a critical gap arising from the limited availability of matched imaging and genomic data in routine clinical practice. METHODS: MRI-derived radiomic features were extracted from FLAIR images of lower-grade glioma patients obtained from TCIA and matched with transcriptomic data from TCGA. A total of 107 patients with both MRI and RNA sequencing data were included in the radiogenomic analysis. Radiomic features were ranked using a Borda-based ensemble feature selection strategy. Five supervised machine-learning classifiers were trained to predict RSI-based radiosensitivity classification, and model interpretability was assessed using SHAP within radiogenomic framework. RESULTS: Classification performance increased with feature number and stabilized at compact subset of 13 radiomic features. Logistic regression showed stable performance with an AUC of 0.82 (95 % CI: 0.71-0.93). SHAP analysis indicated that heterogeneity-related texture features were dominant contributors to model predictions, with many associated with the RR phenotype, while others were linked to the RS phenotype. CONCLUSION: An MRI-based radiomic signature enables non-invasive prediction of RSI-defined radiosensitivity in lower-grade glioma. Rather than offering an immediately deployable clinical tool, this study establishes a proof-of-concept radiogenomic framework demonstrating that intrinsic radiosensitivity, traditionally assessed through invasive molecular assays, can be approximated using quantitative imaging features. These findings highlight the potential of imaging-based radiosensitivity assessment and provide a foundation for future radiogenomic investigations.

Lower-grade glioma↗

PubMed1979

Spinal metastasis: current status and recommended guidelines for management.

An overview of the current status of various aspects of spinal metastasis, including pathology, diagnosis, and management is presented. The cell type of the tumor, particularly with reference to its radiosensitivity, seems to be positively correlated with treatment outcome, regardless of the treatment modality. Because pretreatment neurological status also seems to influence prognosis, early identification of spinal involvement in patients at risk is important; therefore, a high index of suspicion in patients known to have cancer is necessary. The most useful warning of impending spinal cord or nerve root compression is spinal or radicular pain, which usually precedes neurological deficit by days to years. An aggressive diagnostic evaluation of pain symptoms is therefore warranted; this should include plain spine films and, in questionable cases, radioisotope bone scan. Myelography should also be considered in any cancer patient with persistent spinal or radicular pain, even in the absence of neurological deficit and certainly if there is any neurological impairment. Therapeutically, radiation and surgery continue as the mainstays of management, whereas steroids and chemotherapy serve as adjuvants. The guidelines for management recommended in this paper are to be viewed as tentative because the ideal treatment for spinal metastasis has not been established. The proposed guidelines are based on an analysis of retrospective studies that suggest that radiotherapy should be the primary mode of treatment and that surgery should be reserved for situations in which radiotherapy fails or where there is bony compression or spinal instability. Cases are presented to illustrate the application of these guidelines. (Neurosurgery, 5: 726--746, 1979).

Adolescent↗

PubMed2026

Evaluation of the clinical and mechanistic role of MCM2 expression in the prediction of meningioma recurrence after radiotherapy.

OBJECTIVE: Postoperative radiotherapy is an effective treatment for meningiomas; however, treatment response varies among patients. In addition, practical methods for predicting tumor recurrence after radiotherapy have not been well established. Minichromosome maintenance protein 2 (MCM2), a key regulator of DNA replication licensing, was recently implicated in highly proliferative molecular subtypes of meningioma. In this study, the authors evaluated whether MCM2 immunohistochemical expression predicts response to radiotherapy in patients with meningiomas. METHODS: The authors retrospectively analyzed the records of patients with WHO grade 1-3 meningiomas treated with resection followed by radiotherapy at a single institution between July 2003 and November 2023. The MCM2 labeling index was assessed immunohistochemically, and patients were stratified into MCM2-high and -low groups using a cutoff of 35%. Progression-free survival (PFS) was defined as the interval from the completion of radiation therapy to postoperative radiological tumor recurrence or regrowth. Patients who showed no progression were censored at their last follow-up. PFS was estimated using Kaplan-Meier analysis and subsequently evaluated with Cox proportional hazards models. To further investigate the biological mechanisms associated with MCM2 expression, comprehensive transcriptomic analyses, including gene set enrichment analysis, was performed to elucidate the molecular processes that occur within MCM2-high tumors. RESULTS: The study population included 15 men (42%) and 21 women (58%), with a mean age of 63 years. Ten tumors (28%) were classified as MCM2-high meningiomas and 26 (72%) as MCM2-low meningiomas. High MCM2 expression was significantly associated with WHO grades 2-3 histology and higher Ki-67 labeling indices. During a median follow-up of 2.52 years, tumor progression after radiotherapy occurred in 47% of the patients. High MCM2 expression (HR 8.34, p = 0.03) was significantly associated with shorter PFS and remained an independent predictor of recurrence after adjustment for WHO grade, tumor size, and Ki-67 labeling index. Transcriptomic analyses of MCM2-high tumors revealed upregulation of cell proliferation-related pathways, accompanied by increased signaling through the E2F8-CHEK1 axis associated with radiation resistance and suppression of the TNF-α signaling pathway implicated in radiosensitivity. CONCLUSIONS: In meningiomas, high MCM2 expression is associated with early recurrence following radiotherapy. The study findings suggest that this association is driven by diverse biological mechanisms related to cell cycle regulation and radioresistance. Immunohistochemical assessment of MCM2 expression may serve as a practical and accessible biomarker for risk stratification and may support the future development of individualized postoperative radiotherapy strategies.

Humans↗

PubMed1979

Changes in repair of potentially lethal damage with culture age in EMT6 cells.

We have investigated the changes in the amplitude of repair of potentially lethal damage (PLD) in EMT6 cells with increasing culture age and determined the delay necessary to achieve this repair. This experimental system presents all intermediaries between the exponential growth type and a plateau with a cell turnover nearly nil. The radiosensitivity was studied by the colony method. When the percentage of surviving cells was tested immediately after irradiation it was observed that their radiosensitivity increased with culture age. This percentage fell only slightly when the cells were tested for viability 6 hours after irradiation. Therefore, the amplitude of repair increases with culture age. Repair was found to terminate 1, 1.75, 3 and 6 hours after irradiation of cultures aged respectively 2, 4, 6 and 9 days. The delay and the amplitude of repair did not vary significantly for cultures of 9, 11 and 13 days.

Animals↗