Effect of Neoadjuvant Iodine-125 Brachytherapy Upon Resection of Glioma

Background: A more extensive surgical resection of glioma contributes to improved overall survival (OS) and progression-free survival (PFS). However, some of the patients lost the chance of surgical resection when the tumor involves critical structures. Purpose: The present study aimed to assess the feasibility of neoadjuvant 125I brachytherapy followed by total gross resection for initially inoperable glioma.Methods:Six patients diagnosed with inoperable glioma due to invasion of eloquent areas, bi-hemispheric diffusion, or large tumor volume received 125I brachytherapy. Surgical resection was performed when the tumor shrank, allowing a safe resection, assessed by the neurosurgeons. Patients were followed up after surgery.Results:Tumor shrinkage after adjuvant 125I brachytherapy enabled a total gross resection of all six patients. Four patients were still alive at the last follow-up, with the longest survival time of more than 50 months, two of which returned to a normal life with the KPS of 100. Another two patients got a neurological injury with the KPS of 80 and 50, respectively. One patient with grade Ⅱ glioma died 34 months, and another patient with grade Ⅳ glioma died 40 months later after the combined therapy.Conclusions: In the present study, the results demonstrated that 125I brachytherapy enabled a complete resection of patients with initially unresectable gliomas. 125I brachytherapy may offer a proper neoadjuvant therapy method for glioma.

Iodine-125 seed represses the growth and facilitates the apoptosis of colorectal cancer cells by suppressing the methylation of miR-615 promoter

Background Colorectal cancer (CRC) represents a common malignancy in gastrointestinal tract. Iodine-125 (125I) seed implantation is an emerging treatment technology for unresectable tumors. This study investigated the mechanism of 125I seed in the function of CRC cells. Methods The CRC cells were irradiated with different doses of 125I seed (0.4, 0.6 and 0.8 mCi). miR-615 expression in CRC tissues and adjacent tissues was detected by RT-qPCR. miR-615 expression was intervened with miR-615 mimic or miR-615 inhibitor, and then the CRC cells were treated with 5-AZA (methylation inhibitor). The CRC cell growth, invasion and apoptosis were measured. The methylation level of miR-615 promoter region was detected. The xenograft tumor model irradiated by 125I seed was established in nude mice. The methylation of miR-615, Ki67 expression and CRC cell apoptosis were detected. Results 125I seed irradiation repressed the growth and facilitated apoptosis of CRC cells in a dose-dependent manner. Compared with adjacent tissues, miR-615 expression in CRC tissues was downregulated and miR-615 was poorly expressed in CRC cells. Overexpression of miR-615 suppressed the growth of CRC cells. 125I seed-irradiated CRC cells showed increased miR-615 expression, reduced growth rate and enhanced apoptosis. The methylation level of miR-615 promoter region in CRC cells was decreased after 125I seed treatment. In vivo experiments confirmed that 125I seed-irradiated xenograft tumors showed reduced methylation of the miR-615 promoter and increased miR-615 expression, as well as decreased Ki67 expression and enhanced apoptosis. The target genes of miR-615 and its regulatory downstream pathway were further predicted by bioinformatics analysis. Conclusions 125I seed repressed the growth and facilitated the apoptosis of CRC cells by suppressing the methylation of the miR-615 promoter and thus activating miR-615 expression. The possible mechanism was that miR-615-5p targeted MAPK13, thus affecting the MAPK pathway and the progression of CRC.

Iodine-125 brachytherapy and robotic stereotactic radiotherapy — treatment options for patients with localized prostate cancer

Introduction. Modern radiological treatment options for patients with localized prostate cancer (PCa) have several advantages and allow achieving high rates of biochemical control.Purpose of the study. To compare immediate, proximate, and long-term results of low-dose Iodine-125 brachytherapy (I-125 BT) and robotic stereotactic radiotherapy (SBRT) in patients with localized low- and intermediate-risk PCa.Materials and methods. The study included 296 patients with localized low- and intermediate-risk PCa. I-125 BT and SBRT were performed in 208 and 88 patients, respectively. All patients with an intermediate-risk PCa were prescribed neoadjuvant androgen-deprivation therapy (NADT) with luteinizing hormone-releasing hormone analogues (LHRH) for 4-6 months. Only radiation treatment was used for low-risk PCa. As a result, two groups and four subgroups of patients were formed depending on the treatment method. The immediate, proximate, and long-term results of radiation treatment methods were studied in groups and subgroups.Results. No complications were recorded during brachytherapy I-125. Radiation cystitis grade 1 and radiation rectitis grade 1 were diagnosed after SBRT in 16.6% and 4.0% of cases, respectively. In the only I-125 BT subgroup, the PSA level during the year decreased from 8.3 to 1.1 ng/ml, in the SBRT subgroup — from 7.5 to 0.8 ng/ml. In the case of combined treatment, PSA decreased from 1.2 to 0.93 ng/ml and from 4.5 to 0.5 ng/ml, respectively. Changes in prostate volume, residual volume, and urinary quality (I-PSS) were comparable in all subgroups. Five-year cancer-specific survival and overall survival in the group of patients after SBRT was 100%, after I-125 BT — more than 90%.Conclusion. Radiation treatment options for patients with localized PCa are safe. Conducting NADT does not significantly reduce the prostate volume and does not affect the indicators of urodynamics. High rates of cancer-specific five-year survival rate testify to the effectiveness of the evaluated treatment options.

Bone pain from spinal metastases: Iodine-125 brachytherapy

ObjectivesThis study evaluated the analgesic efficacy and safety of CT-guided iodine-125 (125I) brachytherapy in patients with spinal metastasis-induced pain who were not suitable to receive radiotherapy.MethodsA cohort of 68 patients with spinal metastasis induced pain not fully relieved by opioids and did not receive external beam radiation therapy due to poor general status were enrolled and underwent CT-guided 125I brachytherapy for analgesic treatment.ResultsPatients were followed for 8 weeks after brachytherapy. Mean Numerical Rating Scale score before brachytherapy was 7.3±1.3 and decreased to 3.3±0.9, 2.6±0.8, 2.7±0.8, 2.9±0.9 and 3.3±1.1 at weeks 1, 2, 4, 6 and 8, respectively, after brachytherapy. Daily dose of morphine equivalent was 105.1±28.0 mg before brachytherapy and decreased to 45.3±13.7, 39.9±14.2, 40.4±14.9, 48.5±18.0 and 62.4±17.5 mg at weeks 1, 2, 4, 6 and 8, respectively, after brachytherapy. Patients had fewer daily episodes of breakthrough pain after brachytherapy (p<0.001). Patients had improvement in pain-related functional interference and in hospital anxiety and depression score after brachytherapy.ConclusionsCT-guided 125I brachytherapy is an effective and safe intervention for patients with spinal metastasis-induced pain who are not able to receive radiation therapy.

Development of A Decahedral Nanoenzyme Capable of Overcoming Hypoxia to Facilitate the Iodine-125 Radiosensitization of Esophageal Cancer

Radioisotopes have long been leveraged for internal radiotherapy-mediated cancer treatment. However, such therapeutic approaches are associated with serious side effects, and their efficacy is limited by intratumoral hypoxia. Herein, we prepared a folic acid-decorated palladium decahedral platform capable of enhancing the radiotherapeutic efficacy of iodine-125 (125I) seed treatment. This decahedral nanoenzyme was able to target tumor regions and catalyze the conversion of intracellular H2O2 to O2, thereby alleviating hypoxia within the tumor microenvironment. In addition, palladium was hypoxia can be alleviated, on the other hand, palladium was able to enhance the radiotherapeutic energy deposition within tumor tissues. The results of this analysis indicated that synthesized decahedral constructs can efficiently target and modify the hypoxic tumor microenvironment while simultaneously enhancing radiation energy deposition therein. Relative to palladium nanodots, the prolonged in vivo circulation of these decahedral constructs better enabled them to facilitate sustained radiosensitization. Overall, the results of this study highlight a novel approach to improving the therapeutic utility of 125I seed interstitial implantation, thus underscoring an important direction for future clinical research.