Therapeutic applications of radioactive sources: from image-guided brachytherapy to radio-guided surgical resection

Advances in the regulation of radiation-induced apoptosis by polysaccharides: A review

Polysaccharides are biomolecules composed of monosaccharides that are widely found in animals, plants and microorganisms and are of interest for their various health benefits. Cumulative studies have shown that the modulation of radiation-induced apoptosis by polysaccharides can be effective in preventing and treating a wide range of radiation injuries with safety and few side effects. Therefore, this paper summarizes the monosaccharide compositions, molecular weights, and structure-activity relationships of natural polysaccharides that regulate radiation-induced apoptosis, and also reviews the molecular mechanisms by which these polysaccharides modulate radiation-induced apoptosis, primarily focusing on promoting cancer cell apoptosis to enhance radiotherapy efficacy, reducing radiation damage to normal tissues, and inhibiting apoptosis in normal cells. Additionally, the role of gut microbiota in mediating the interaction between polysaccharides and radiation is discussed, providing innovative ideas for various radiation injuries, including hematopoiesis, immunity, and organ damage. This review will contribute to a better understanding of the value of natural polysaccharides in the field of radiation and provide guidance for the development of natural radioprotective agents and radiosensitizers.

Brachytherapy is an effective and safe salvage option for re-irradiation in recurrent glioblastoma (rGBM): A systematic review

PURPOSE

To evaluate the clinical efficacy and toxicity of brachytherapy as a salvage therapy for patients with recurrent glioblastoma (rGBM).

METHODS AND MATERIALS

We searched the PubMed, Embase, and Cochrane libraries from its inception to June 2023, for eligible studies in which patients underwent brachytherapy for rGBM. Outcomes of interest were mOS, mPFS, OS, PFS, and adverse events (AEs). For individual clinical survival outcomes and common AEs, weighted-mean descriptive statistics were calculated as a summary measure using study sample size as the weight. The calculation formula is as follows: weighted-mean = Σwx/Σw (w is the sample size and x is the outcome).

RESULTS

This review included 29 studies with a total of 1202 rGBM patients, including 22 retrospective and 7 prospective studies. The results showed that from the time of brachytherapy, the mOS and mPFS were 6.8 to 24.4 months and 3.7 to 11.7 months. The OS of 6 months, 1 year, 18 months, 2 years, and 3 years after brachytherapy were 58.3 % to 85.2 % (weighted-mean 76.2 %), 26 % to 66 % (weighted-mean 41.9 %), 20 % to 37 % (weighted-mean 27.6 %), 11 % to 23 % (weighted-mean 14.8 %), and 8 % to 15 % (weighted-mean 12.1 %), respectively. The PFS of 6 months and 1 year after brachytherapy were 26.7 % to 86 % (weighted-mean 53.4 %) and 14 % to 81 % (weighted-mean 24.1 %). Most patients with rGBM will experience treatment failure again during the follow-up period, mainly local (10.7 % to 79.4 %) or marginal(3.6 % to 22.2 %) recurrence, followed by distant failure (6.7 % to 57.7 %). Although therapeutic AEs had not been uniformly reported, the overall toxicity rate was considered to be low. The common AEs reported included progressive neurologic deterioration, seizures, CSF leak, brain necrosis, hemorrhage, and infection/meningitis, with a weighted-mean incidence of 1.9 %, 2.4 %, 4.1 %, 5.4 %, 2.1 %, and 3.8 %, respectively.

CONCLUSIONS

The evidence summarized above, albeit mostly level III, suggests that brachytherapy has acceptable safety and good post-treatment clinical efficacy for selected patients with rGBM. Well-designed, high-quality, large-sample randomized controlled and prospective studies are needed to further validate these findings.

Intraoperative Gamma Cameras: A Review of Development in the Last Decade and Future Outlook

Portable gamma cameras suitable for intraoperative imaging are in active development and testing. These cameras utilise a range of collimation, detection, and readout architectures, each of which can have significant and interacting impacts on the performance of the system as a whole. In this review, we provide an analysis of intraoperative gamma camera development over the past decade. The designs and performance of 17 imaging systems are compared in depth. We discuss where recent technological developments have had the greatest impact, identify emerging technological and scientific requirements, and predict future research directions. This is a comprehensive review of the current and emerging state-of-the-art as more devices enter clinical practice.

The Proper Administration Sequence of Radiotherapy and Anti-Vascular Agent-DMXAA Is Essential to Inhibit the Growth of Melanoma Tumors

Vascular disrupting agents (VDAs), such as DMXAA, effectively destroy tumor blood vessels and cause the formation of large areas of necrosis in the central parts of the tumors. However, the use of VDAs is associated with hypoxia activation and residues of rim cells on the edge of the tumor that are responsible for tumor regrowth. The aim of the study was to combine DMXAA with radiotherapy (brachytherapy) and find the appropriate administration sequence to obtain the maximum synergistic therapeutic effect. We show that the combination in which tumors were irradiated prior to VDAs administration is more effective in murine melanoma growth inhibition than in either of the agents individually or in reverse combination. For the first time, the significance of immune cells' activation in such a combination is demonstrated. The inhibition of tumor growth is linked to the reduction of tumor blood vessels, the increased infiltration of CD8⁺ cytotoxic T lymphocytes and NK cells and the polarization of macrophages to the cytotoxic M1 phenotype. The reverse combination of therapeutic agents showed no therapeutic effect and even abolished the effect of DMXAA. The combination of brachytherapy and vascular disrupting agent effectively inhibits the growth of melanoma tumors but requires careful planning of the sequence of administration of the agents.