Tolerability of long-term temperature controlled whole-body thermal treatment in advanced cancer-bearing dogs

A modular, human body-mimicking phantom with active thermoregulation capabilities for validation and verification of convective hyperthermia devices

OBJECTIVES

This study aims to design and fabricate a modular phantom for hyperthermia applications, addressing interpatient variability in thermal regulation mechanisms like sweating rate, metabolic heat production, and blood redistribution.

MATERIALS & METHODS

The phantom can be constructed in various weights and dimensions by connecting identical units. Each unit consists of an agar-based block, an ethyl cellulose-based top layer, a heat source, deep and superficial water circulation, and a sweating mechanism. Agar and ethyl cellulose gels mimic the thermal properties of human tissues and fat respectively. The blocks are wrapped in PVC foil to prevent water evaporation. A heating wire, coiled around an embedded aluminum tubing simulates metabolic heat production. A superficial water circulation mimics skin capillaries. A water pump ensures a steady flow rate throughout the tubing system. Sweat production is simulated using a water pump and perforated tubing. A programmed controller maintains core temperature in a normal operating mode and simulates an anesthetized patient in anesthesia mode.

RESULTS

Temperature uniformity and regulation were assessed under varying environmental conditions. The phantom effectively regulated its core temperature at 37.0 °C +/- 0.7 °C with an ambient temperature ranging between 21 °C and 30 °C. Activating the water circulation reduced the maximum temperature gradient within the phantom from 4.70 °C to 1.92 °C.

CONCLUSION

The versatile phantom successfully models heat exchange processes. Its thermal properties, dimensions, and heat exchange rates can be tuned to mimic different patient models. These are promising results as an effective tool for hyperthermia device validation and verification, representing human physiological responses.

Neoadjuvant Hyperthermia Combined with Hybrid Nanoarchitectures Enhances Chemoradiotherapy Efficacy in Head and Neck Carcinoma

Head and neck squamous cell carcinomas are characterized by a high incidence of recurrence, especially in patients with locally advanced disease. Standard treatment strategies can be associated with severe side effects to healthy tissues that can negatively impact the patient's quality of life. Hyperthermia (HT) is a noninvasive treatment modality that has improved the effectiveness of chemotherapy (CT) and/or radiotherapy (RT) for the management of some solid neoplasms. In this context, the association of this approach with rationally designed nanomaterials may further enhance the treatment outcome. In this study, we demonstrate the enhanced effect of neoadjuvant HT in combination with hybrid nanoarchitectures enclosing a cisplatin prodrug (NAs-CisPt) and RT. All the treatments and their combinations have been fully evaluated by employing standardized chorioallantoic membrane tumor models of HPV-negative head and neck carcinoma. An improved tumor-shrinking effect was observed by the administration of the trimodal treatment (HT/NAs-CisPt/RT), which also highlighted a significant increase in apoptosis. Our findings demonstrate that the combination of HT with nanotechnology-based CT and RT in a certain order enhances the in vivo treatment outcome. On a broader basis, this study paves the way for the next exploration of noninvasive treatment approaches for the clinical management of oral cancer based on innovative strategies.

Hyperthermia Reduces Irradiation-Induced Tumor Repopulation in an In Vivo Pancreatic Carcinoma Model

Pancreatic cancer has a poor prognosis due to its aggressive nature and ability to metastasize at an early stage. Currently, its management is still a challenge because this neoplasm is resistant to conventional treatment approaches, among which is chemo-radiotherapy (CRT), due to the abundant stromal compartment involved in the mechanism of hypoxia. Hyperthermia, among other effects, counteracts hypoxia by promoting blood perfusion and thereby can enhance the therapeutic effect of radiotherapy (RT). Therefore, the establishment of integrated treatments would be a promising strategy for the management of pancreatic carcinoma. Here, the effects of joint radiotherapy/hyperthermia (RT/HT) on optimized chick embryo chorioallantoic membrane (CAM) pancreatic tumor models are investigated. This model enables a thorough assessment of the tumor-arresting effect of the combined approach as well as the quantitative evaluation of hypoxia and cell cycle-associated mechanisms by both gene expression analysis and histology. The analysis of the lower CAM allows to investigate the variation of the metastatic behaviors of the cancer cells associated with the treatments. Overall, this study provides a potentially effective combined strategy for the non-invasive management of pancreatic carcinoma.

Safety and Efficacy of an Oncolytic Adenovirus as an Immunotherapy for Canine Cancer Patients

Simple Summary

The use of oncolytic virus is an innovative approach that has shown promising results as a treatment in oncology. Epithelial-derived tumors are the most frequent neoplasms in dogs, but gold standard therapies can be highly invasive procedures. Due to the accessible localization of these tumors, the intratumoral administration is feasible. Therefore, we propose to determine the safety and efficacy of intratumoral administration of oncolytic adenovirus ICOCAV15, in canine patients with epithelial-derived tumors. Eight dogs with carcinoma/adenocarcinoma were intratumorally treated with ICOCAV15. No clinically relevant changes were observed in the blood count, biochemistry and coagulation test analyzed during follow-up. The survival time of the 6/8 dogs exceeded the median survival time with chemotherapy, showing a partial response rate of 25% and 75% of stable disease. ICOCAV15 was detected in the target lesion by qPCR and immunohistochemistry. Also, some of the non-treated metastasis showed an infiltration of ICOCAV15 by immunohistochemistry. The immune populations were evaluated, and an increase of CD8+, MAC387+, CD3+ and CD20+ cells was reported in some of the patients after the inoculation. These results show that intratumoral ICOCAV15 is safe and well tolerated by dogs. Also, they suggest ICOCAV15 could be a new tool in veterinary oncology for accessible carcinomas/adenocarcinomas.

Abstract

The use of oncolytic viruses is an innovative approach to lyse tumor cells and induce antitumor immune responses. Eight dogs diagnosed with carcinoma/adenocarcinoma were intratumorally treated with ICOCAV15, an oncolytic canine adenovirus (CAV). To evaluate the treatment’s safety, a blood count, biochemistry, and coagulation test were performed before treatment and during follow-up. Immune populations were analyzed by flow cytometry. Anti-adenovirus antibodies were also determined. The immune infiltration, vascularization, and viral presence in the tumor were determined by CD3, CD4, CD20, CD31 and CAV by immunohistochemistry. All the dogs maintained a good quality of life during follow-up, and some had increased median survival time when compared with dogs treated with chemotherapy. No treatment-related adverse effects were detected. The Response Evaluation Criteria In Solid Tumors criteria were also assessed: two patients showed a partial response and the rest showed stable disease at various times during the study. ICOCAV15 was detected inside the tumor during follow-up, and antiviral antibodies were detected in all patients. Furthermore, the tumor-infiltrating immune cells increased after viral administration. Therefore, we suggest that intratumorally administered ICOCAV15 could represent as a new tool for the treatment of canine carcinoma because it is safe, well-tolerated by dogs, and shows promising results.

Hyperthermia Enhances Efficacy of Chemotherapeutic Agents in Pancreatic Cancer Cell Lines

Chemotherapy (CT) is the standard care for advanced pancreatic ductal adenocarcinoma (PDAC); however, with limited efficacy. Hyperthermia (HT) treatment has been suggested as a sensitizer to improve outcomes. However, the direct effect of the HT and CT combination is not fully understood. Therefore, we aim to assess the direct cytotoxic effect of HT in PDAC cells as monotherapy or in combination with chemotherapeutics. Different temperatures (37-, 40.5-, 41-, and 41.5 °C) and durations (6-, 12-, and 24 h) were tested in PDAC cell lines (BxPC-3, Capan-1, Capan-2, PANC-1, and MIA-PaCa-2). Different concentrations of gemcitabine, 5-fluorouracil, and cisplatin were also tested in these conditions. The impact on cell metabolic activity was determined by an MTS assay. Enhancement of chemosensitivity was assessed by a reduction in half-maximal inhibitory concentration (IC50). HT and chemotherapeutics interactions were classified as antagonistic, additive, or synergistic using the combination index. HT inhibited cell proliferation in a cell type, temperature, and duration-dependent manner. The induction of apoptosis was seen after 6 h of HT treatment, eventually followed by secondary necrosis. The HT and CT combination led to an IC50 reduction of the tested CT. At 12 h of HT, this effect was between 25 to 90% and reached a 95% reduction at 24 h. The additive or synergistic effect was demonstrated in all cell lines and chemotherapeutics, although, again, this depended on cell type, duration, and temperature. HT is cytotoxic and enhances the therapeutic effectiveness of gemcitabine, 5-fluorouracil, and cisplatin on PDAC cells. This result was further confirmed by the decrease in the expression of RRM2, TS, and ERCC1 in BxPC-3 and Capan-2 cells. These observations warrant further study in specific subsets of PDAC patients to improve their clinical outcomes.