Safety and efficacy of image-guided enzyme-targeting radiosensitization and intraoperative radiotherapy for locally advanced unresectable pancreatic cancer

Radiosensitization treatment using hydrogen peroxide for inoperable rectal cancer

The treatment outcomes of patients with unresectable rectal cancer are complex, and concurrent chemoradiation therapy is the main treatment option. Radiosensitizers can enhance the effect of localized intratumoral hypoxia, contributing to local control and symptomatic relief. The present study evaluated the feasibility and safety of radiosensitization using hydrogen peroxide combined with radiation therapy (RT) in patients with unresectable rectal cancer. A total of 13 patients with rectal cancer were recruited in the present study. Radiosensitization was performed twice weekly in combination with RT. Gauze soaked in 3% hydrogen peroxide solution was inserted into the anus, ensuring firm contact with the lesion. In total, 45-65 Gy was delivered in 25-33 fractions to the whole pelvis from four directions using 10 MV X-rays 5 days per week. Acute and late adverse events were evaluated 1 and 6 months after the completion of RT. Treatment was well tolerated, with no acute grade 3 or worse events noted, and no patient developed rectal fistula, necrosis, obstruction, perforation, stenosis, ulcer or retroperitoneal hemorrhage. No notable late adverse events, beyond 6 months, were observed at the end of the analysis. All patients experienced pain relief, hemostatic effects and tumor shrinkage. Therefore, the use of a hydrogen peroxide solution-soaked gauze in the rectum may be a promising option for patients with inoperable rectal tumors. The limitations of the present study are that the patient population was small and the observation time was relatively short. This study was retrospectively registered with the University Hospital Medical Information Network Center (trial registration no. R000061902) on April 21, 2024.

Focus on current and emerging treatment options for glioma: A comprehensive review

This comprehensive review delves into the current updates and challenges associated with the management of low-grade gliomas (LGG), the predominant primary tumors in the central nervous system. With a general incidence rate of 5.81 per 100000, gliomas pose a significant global concern, necessitating advancements in treatment techniques to reduce mortality and morbidity. This review places a particular focus on immunotherapies, discussing promising agents such as Zotiraciclib and Lerapolturev. Zotiraciclib, a CDK9 inhibitor, has demonstrated efficacy in glioblastoma treatment in preclinical and clinical studies, showing its potential as a therapeutic breakthrough. Lerapolturev, a viral immunotherapy, induces inflammation in glioblastoma and displays positive outcomes in both adult and pediatric patients. Exploration of immunotherapy extends to Pembrolizumab, Nivolumab, and Entrectinib, revealing the challenges and variabilities in patient responses. Despite promising preclinical data, the monoclonal antibody Depatuxizumab has proven ineffective in glioblastoma treatment, emphasizing the critical need to understand resistance mechanisms. The review also covers the success of radiation therapy in pediatric LGG, with evolving techniques, such as proton therapy, showing potential improvements in patient quality of life. Surgical treatment is discussed in the context of achieving a balance between preserving the patient's quality of life and attaining gross total resection, with the extent of surgical resection significantly influencing the survival outcomes. In addition to advancements in cancer vaccine development, this review highlights the evolving landscape of LGG treatment, emphasizing a shift toward personalized and targeted therapies. Ongoing research is essential for refining strategies and enhancing outcomes in the management of LGG.

KORTUC, a novel hydrogen peroxide‑based radiosensitizer for the enhancement of brachytherapy in patients with unresectable recurrent uterine cervical cancer

Kochi Oxydol Radiation Therapy for Unresectable Carcinoma (KORTUC) is a novel radiosensitizer invented by Professor Ogawa at Kochi University (Japan) in 2006. The current study aimed to report the experience of the present authors with the use of KORTUC treatment in combination with interstitial brachytherapy (ISBT), with or without external beam (EB) radiotherapy (RT), in patients with locally recurrent cervical cancer (LRCC), who were likely to have a high risk of poor prognosis. Between April 2012 and January 2020, 14 female patients (15 tumoral lesions) with LRCC underwent KORTUC with ISBT. Their previous treatments included surgery (n=4), radiation therapy (n=8) and surgery plus RT (n=3). The primary lesions were located in the vaginal stump (n=5), pelvic wall (n=3), cervix (n=3), vaginal wall (n=2) and lymph nodes (n=2). At 2 h before RT, KORTUC was injected intratumorally via direct colposcopy. The dose of KORTUC ranged from 4-12 ml, adjusted for the tumor size. For patients who underwent ISBT, KORTUC was administered before and after insertion of the applicator before irradiation. Intratumoral injection of KORTUC was completed without any technical or safety issues in all 15 patients; it was well tolerated with no adverse events observed. KORTUC also showed preferable efficacy; a clinical complete response was observed in 87% of patients and the initial response rate was 100%. The 2-year local control rate in patients who underwent ISBT + KORTUC was 79%, whereas it was 63% in the re-irradiation group which was significantly lower (P=0.02) than that in the non-irradiation group (100%). Based on this finding, KORTUC with external irradiation is considered to be an optimal treatment strategy for patients with newly diagnosed LRCC this disease. Additionally, KORTUC may be an effective radiation response enhancer in multiple cancer types in which locoregional control after RT alone remains poor.

The Efficacy and Safety of Intraoperative Radiotherapy in the Treatment of Recurrent High-Grade Glioma: A Single-Center Prospective Study

BACKGROUND

High-grade gliomas are treated following a standard protocol; however, tumor recurrence is almost inevitable. Recurrent high-grade gliomas have an extremely poor prognosis, and there are no clear treatment guidelines. In this stud, we evaluated the safety and effectiveness of intraoperative radiotherapy (IORT) for recurrent high-grade glioma.

METHODS

In this prospective randomized study begun in April 2018, patients ≥18 years of age with a Karnofsky Performance Status >50 and recurrent high-grade glioma were randomly assigned in a 1:1 ratio to tumor resection and IORT or tumor resection alone.

RESULTS

Twenty-two patients were allocated to the IORT group and 21 to receive surgery only (operation group). Clinical data of 42 enrolled patients were involved in the analysis. The progression-free survival of the IORT group was 9.6 months and of the operation group was 7.3 months (P = 0.018), and the overall survival of the 2 groups was 13.5 months and 10.2 months, respectively (P = 0.054). Univariate and multivariate analysis indicated that preoperative Karnofsky Performance Status >70 and IORT were protective factors for patients with recurrent high-grade glioma. A patient who underwent conventional fractionated radiotherapy within 6 months of receiving IORT died on the ninth day after undergoing tumor resection and IORT because of severe cerebral edema. The total operation time was longer in the IORT group, but there were no differences in intraoperative bleeding or adverse events between the 2 groups.

CONCLUSIONS

IORT with low-energy radiography at a dose of 30-40 Gy is generally safe and effective for patients with recurrent glioma. However, IORT should not be performed for patients who have received conventional fractionated radiotherapy within 6 months.

Radiosensitization using hydrogen peroxide in patients with cervical cancer

The purpose of the present study was to analyze the feasibility and safety of radiosensitization using hydrogen peroxide for cervical cancer. In superficial tumors, breast cancer and hepatocellular carcinoma, the safety and effectiveness of radiosensitization has been reported; to the best of our knowledge, however, there are no reports on cervical cancer. A total of 20 patients with cervical cancer were recruited. Inclusion criteria were as follows: Patients who required radical external beam radiotherapy (RT); ineligible for or refused brachytherapy; age, ≥20 years; no hematogenous metastasis; Eastern Cooperative Oncology Group Performance Status up to 2; and had not undergone prior treatment. Hydrogen peroxide was used twice a week in combination with RT. A 3% hydrogen peroxide solution-soaked gauze was inserted into the vagina during RT. A total of 45 Gy was delivered in 25 fractions to the whole pelvis with a boost of 10 Gy in 5 fractions if pelvic or para-aortic metastatic lymph nodes were observed. Ultimately, 18 patients were evaluated. Among the 17 patients (excluding one patient with tumor in situ), the one- and two-year overall survival rates were both 90% in patients with stage I/II and 86% in stage III/IV cervical cancer. The adverse events were well tolerated with no severe acute or late adverse events. Although limited by small sample size, short observation time and low radiation dose, the present study demonstrated that radiosensitization treatment may be an option for patients who cannot undergo brachytherapy. The study was retrospectively registered at the university hospital medical information network center (no. UMIN000039045) on January 6, 2020.

Endoscopic Ultrasound-Guided Fine-Needle Injection of Hydrogen Peroxide into the Pancreas: Feasibility and Tolerability Study Using a Survival Porcine Model

Hydrogen peroxide (H₂O₂) has been reported to be an effective radiation sensitizer for various cancers. A combination therapy comprising fine-needle injection (FNI) of H₂O₂ under endoscopic ultrasound (EUS) guidance and chemoradiation might improve treatment outcomes of pancreatic cancer; however, there have been no reports thus far. The aims of this study were to evaluate the feasibility and safety of EUS-FNI of H₂O₂ into the pancreas using a porcine survival model. EUS-FNI was performed in the pancreas of six pigs, which were randomly divided into three groups based on the solution injected: group 1, 2 mL of sodium hyaluronate (control); group 2, 0.5 mL of H₂O₂; group 3, 2 mL of H₂O₂. To evaluate any adverse events, blood tests and computed tomography (CT) were performed before and after FNI, as well as days 3 and 7 subsequently. The pigs were necropsied on day 7. Histologic evaluation was performed according to the criteria for experimental acute pancreatitis. EUS-FNI was successful in all pigs. CT immediately after FNI revealed gas formation in the FNI area in groups 2 and 3. No adverse events were revealed by blood tests and CT. Histologic evaluations revealed pancreatitis scores of 5 and 5 in group 1, 7 and 7 in group 2 and 14 and 15 in group 3. EUS-FNI of H₂O₂ into the pancreas is feasible; however, it could cause pancreatitis. FNI of H₂O₂ into only the pancreatic tumor might be ideal in minimizing possible adverse events.

Biological effects of hydrogen peroxide administered intratumorally with or without irradiation in murine tumors

Despite insufficient laboratory data, radiotherapy after intratumoral injection of hydrogen peroxide (H₂O₂) is increasingly being used clinically for radioresistant tumors. Especially, this treatment might become an alternative definitive treatment for early and advanced breast cancer in patients who refuse any type of surgery. The purpose of this study was to investigate the biological effects and appropriate combination methods of irradiation and H₂O₂in vivo. SCCVII tumor cells transplanted into the legs of C3H/HeN mice were used. Chronological changes of intratumoral distribution of oxygen bubbles after injection of H₂O₂ were investigated using computed tomography. The effects of H₂O₂ alone and in combination with single or five‐fraction irradiation were investigated using a growth delay assay. The optimal timing of H₂O₂ injection was investigated. Immunostaining of tumors was performed using the hypoxia marker pimonidazole. Oxygen bubbles decreased gradually and almost disappeared after 24 h. Administration of H₂O₂ produced 2–3 days’ tumor growth delay. Tumor regrowth was slowed further when H₂O₂ was injected before irradiation. The group irradiated immediately after H₂O₂ injection showed the longest tumor growth delay. Dose‐modifying factors were 1.7–2.0 when combined with single irradiation and 1.3–1.5 with fractionated irradiation. Pimonidazole staining was weaker in tumors injected with H₂O₂. H₂O₂ injection alone had modest antitumor effects. Greater tumor growth delays were demonstrated by combining irradiation and H₂O₂ injection. The results of the present study could serve as a basis for evaluating results of various clinical studies on this treatment.

Computed Tomography Demonstration of the Production and Distribution of Oxygen Gas Following Intratumoral Injection of a New Radiosensitizer (KORTUC) for Patients with Breast Cancer-Is Intratumoral Injection Not an Ideal Approach to Solve the Major Problem of Tumor Hypoxia in Radiotherapy?

We previously developed a new enzyme-targeting radiosensitization treatment named Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II), which contains hydrogen peroxide and sodium hyaluronate for injection into various types of tumors. For breast cancer treatment, the radiosensitization agent was injected into the tumor tissue twice a week under ultrasonographic guidance, immediately prior to each administration of radiation therapy. At approximately three hours after the second or third injection, computed tomography (CT) was performed to confirm the production and distribution of oxygen gas generated from the KORTUC radiosensitization agent by catalysis of peroxidases contained mainly in tumor tissue. The purpose of this study was to demonstrate that tumor hypoxia could be overcome by such a procedure and to evaluate the method of intratumoral injection in terms of confirming oxygen distribution in the target tumor tissue and around the tumor to be visualized on dedicated CT imaging. Three-dimensional reconstructed maximum intensity projection imaging of contrast-enhanced breast magnetic resonance imaging was used to compare the position of the tumor and that of the generated oxygen. Distributed oxygen gas was confirmed in the tumor tissue and around it in all 10 patients examined in the study. A region of oxygen gas was measured as an average value of −457.2 Hounsfield units (HU) as a region of interest. A slightly increased HU value compared to the density of air or oxygen was considered due to the presence of tumor tissue in the low-density area on 5-mm-thick reconstructed CT imaging. The results of this study showed that intratumoral oxygen was successfully produced by intratumoral KORTUC injection under ultrasonographic guidance, and that tumor hypoxia, which is considered a main cause of radioresistance in currently used Linac (linear accelerator) radiation therapy for malignant neoplasms, could be resolved by this method.

Paradigm Shift in Radiation Biology/Radiation Oncology-Exploitation of the "H₂O₂ Effect" for Radiotherapy Using Low-LET (Linear Energy Transfer) Radiation such as X-rays and High-Energy Electrons

Most radiation biologists/radiation oncologists have long accepted the concept that the biologic effects of radiation principally involve damage to deoxyribonucleic acid (DNA), which is the critical target, as described in "Radiobiology for the Radiologist", by E.J. Hall and A.J. Giaccia [1]. Although the concepts of direct and indirect effects of radiation are fully applicable to low-LET (linear energy transfer) radioresistant tumor cells/normal tissues such as osteosarcoma cells and chondrocytes, it is believed that radiation-associated damage to DNA does not play a major role in the mechanism of cell death in low-LET radiosensitive tumors/normal tissues such as malignant lymphoma cells and lymphocytes. Hall and Giaccia describe lymphocytes as very radiosensitive, based largely on apoptosis subsequent to irradiation. As described in this review, apoptosis of lymphocytes and lymphoma cells is actually induced by the "hydrogen peroxide (H₂O₂) effect", which I propose in this review article for the first time. The mechanism of lymphocyte death via the H₂O₂ effect represents an ideal model to develop the enhancement method of radiosensitivity for radiation therapy of malignant neoplasms. In terms of imitating the high radiosensitivity of lymphocytes, osteosarcoma cells (representative of low-LET radioresistant cells) might be the ideal model for indicating the conversion of cells from radioresistant to radiosensitive utilizing the H₂O₂ effect. External beam radiation such as X-rays and high-energy electrons for use in modern radiotherapy are generally produced using a linear accelerator. We theorized that when tumors are irradiated in the presence of H₂O₂, the activities of anti-oxidative enzymes such as peroxidases and catalase are blocked and oxygen molecules are produced at the same time via the H₂O₂ effect, resulting in oxidative damage to low-LET radioresistant tumor cells, thereby rendering them highly sensitive to irradiation. In this review, this potential paradigm shift in modern radiation biology/radiation oncology is discussed in detail in terms of overcoming drug/radiation resistance in radiation therapy and/or anti-cancer chemotherapy.

Pancreatic Cancer Epidemiology, Detection, and Management

PC (pancreatic cancer) is the fourth most common cause of death due to cancer worldwide. The incidence and mortality rates have been increasing year by year worldwide, and this review has analyzed the most recent incidence and mortality data for pancreatic cancer occurrence in China. Several possible risk factors have been discussed here, involving known established risk factors and novel possible risk factors. The development of this cancer is a stepwise progression through intraepithelial neoplasia to carcinoma. Though early and accurate diagnosis is promising based on a combination of recent techniques including tumor markers and imaging modalities, lacking early clinical symptoms makes the diagnosis late. Correct staging is critical because treatment is generally based on this parameter. Treatment options have improved throughout the last decades. However, surgical excision remains the primary therapy and efficacy of conventional chemoradiotherapy for PC is limited. Recently, some novel new therapies have been developed and will be applied in clinics soon. This review will provide an overview of pancreatic cancer, including an understanding of the developments and controversies.

Development of a Novel Enzyme-Targeting Radiosensitizer (New KORTUC) Using a Gelatin-Based Hydrogel Instead of a Sodium Hyaluronate

We recently developed Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas (KORTUC) as a strategy to increase intratumoral oxygen concentrations and degrade antioxidant enzymes such as peroxidase and catalase. We then developed KORTUC II, which uses sodium hyaluronate containing hydrogen peroxide as a radiosensitizer. KORTUC II requires twice-weekly administration to sustain its effects, but decreasing the frequency of radiosensitizer injections to once-weekly would reduce the burden on the patients and the physicians. The goal of this study was thus to develop a new formulation of KORTUC (New KORTUC) that only requires once-weekly administration. We performed experimental studies using a mouse tumor model and biodegradable hydrogel. C3H/He mice were allocated to control, KORTUC, or hydrogel groups. At 72 h after injection, each tumor was irradiated with a 6 MeV electron beam to a total dose of 30 Gy. During a 62-day observation period, changes in tumor volume and survival rates were assessed in each group. Tumor growth rate was slowest in the hydrogel groups. These data suggest that hydrogel could represent a useful adjunct as a long-acting radiosensitizer in place of sodium hyaluronate. New KORTUC, which contains hydrogen peroxide and hydrogel, exerted a radiosensitizing effect that persisted beyond 72 h following injection of the agent. Use of this new formulation allows radiosensitizer injections to be performed once-weekly with good effect.

Prospective small bowel mucosal assessment immediately after chemoradiotherapy of unresectable locally advanced pancreatic cancer using capsule endoscopy: a case series

In this case series, three consecutive patients with unresectable locally advanced pancreatic cancer (ULAPC) underwent capsule endoscopy (CE) before and after chemoradiotherapy (CRT) to evaluate duodenal and jejunal mucosa, and to examine the relationship between CE findings and dose distribution. CE after CRT showed duodenitis and proximal jejunitis in all three patients. The most inflamed region was the third part of the duodenum, and in dose distribution, this was the closest region to the center of irradiation. This case series shows that CE can safely diagnose acute duodenitis and proximal jejunitis caused by CRT for ULAPC, and that dose distribution is possible to predict the degree of duodenal and jejunal mucosal injuries.