Old and new facts about hyperthermia-induced modulations of the immune system

Combined Radiotherapy and Hyperthermia: A Systematic Review of Immunological Synergies for Amplifying Radiation-Induced Abscopal Effects

INTRODUCTION

The abscopal effect is a systemic immune response characterized by metastases regression at sites distant from the irradiated lesion. This systematic review aims to explore the immunological mechanisms of action underlying the abscopal effect and to investigate how hyperthermia (HT) can increase the chances of radiotherapy (RT) triggering systemic anti-tumor immune responses.

METHODS

This review is created in accordance with the PRISMA guidelines.

RESULTS AND CONCLUSION

HT and RT have both complementary and synergistic immunological effects. Both methods trigger danger signal release, promoting cytokine and chemokine secretion, which increases T-cell infiltration and facilitates cell death. Both treatments upregulate extracellular tumor HSP70, which could amplify DAMP recognition by macrophages and DCs, leading to stronger tumor antigen presentation and CTL-mediated immune responses. Additionally, the combined increase in cell adhesion molecules (VCAM-1, ICAM-1, E-selectin, L-selectin) could enhance leukocyte adhesion to tumors, improving lymphocyte trafficking and boosting systemic anti-tumor effects. Lastly, HT causes vasodilation and improves blood flow, which might exacerbate those distant effects. We suggest the combination of local radiotherapy with fever-range whole-body hyperthermia to optimally enhance the chances of triggering the abscopal effect mediated by the immune system.

Effects of RF Electric Currents on Hair Follicle Growth and Differentiation: A Possible Treatment for Alopecia

Androgenic alopecia (AGA) is the most common type of alopecia and its treatments involve drugs that have various adverse effects and are not completely effective. Radiofrequency-based therapies (RF) are an alternative for AGA treatment. Although there is increasing clinical evidence of the effectiveness of RF for alopecia, its effects at the tissue and cellular level have not been studied in detail. The objective of this study was to analyze ex vivo the potential effect of RF currents used in capacitive resistive electrical transfer (CRET) therapy on AGA. Hair follicles (HFs) were donated by patients with AGA and treated with CRET. AGA-HFs were exposed in vitro to intermittent 448 kHz electric current in subthermal conditions. Cell proliferation (Ki67), apoptosis (TUNEL assay), differentiation (β-catenin), integrity (collagen and MMP9), thickness of the epidermis surrounding HF, proportion of bulge cells and melanoblasts in AGA-HF were analyzed by immunohistochemistry. CRET increased proliferation and decreased death of different populations of AGA-HF cells. In addition, the melanoblasts increased in bulge and the epidermis surrounding the hair follicle thickened. These results support the effectiveness of RF-based therapies for the treatment of alopecia. However, clinical trials are necessary to know the true effectiveness of CRET therapy and other RF therapies for AGA treatment.

Multifunctional hydrogels based on photothermal therapy: A prospective platform for the postoperative management of melanoma

Preventing the recurrence of melanoma after surgery and accelerating wound healing are among the most challenging aspects of melanoma management. Photothermal therapy has been widely used to treat tumors and bacterial infections and promote wound healing. Owing to its efficacy and specificity, it may be used for postoperative management of tumors. However, its use is limited by the uncontrollable distribution of photosensitizers and the likelihood of damage to the surrounding normal tissue. Hydrogels provide a moist environment with strong biocompatibility and adhesion for wound healing owing to their highly hydrophilic three-dimensional network structure. In addition, these materials serve as excellent drug carriers for tumor treatment and wound healing. It is possible to combine the advantages of both of these agents through different loading modalities to provide a powerful platform for the prevention of tumor recurrence and wound healing. This review summarizes the design strategies, research progress and mechanism of action of hydrogels used in photothermal therapy and discusses their role in preventing tumor recurrence and accelerating wound healing. These findings provide valuable insights into the postoperative management of melanoma and may guide the development of promising multifunctional hydrogels for photothermal therapy.

Recurrent Glioblastoma-Molecular Underpinnings and Evolving Treatment Paradigms

Glioblastoma is the most common and lethal central nervous system malignancy with a median survival after progression of only 6-9 months. Major biochemical mechanisms implicated in glioblastoma recurrence include aberrant molecular pathways, a recurrence-inducing tumor microenvironment, and epigenetic modifications. Contemporary standard-of-care (surgery, radiation, chemotherapy, and tumor treating fields) helps to control the primary tumor but rarely prevents relapse. Cytoreductive treatment such as surgery has shown benefits in recurrent glioblastoma; however, its use remains controversial. Several innovative treatments are emerging for recurrent glioblastoma, including checkpoint inhibitors, chimeric antigen receptor T cell therapy, oncolytic virotherapy, nanoparticle delivery, laser interstitial thermal therapy, and photodynamic therapy. This review seeks to provide readers with an overview of (1) recent discoveries in the molecular basis of recurrence; (2) the role of surgery in treating recurrence; and (3) novel treatment paradigms emerging for recurrent glioblastoma.

Gold nanoparticles-mediated photothermal and photodynamic therapies for cancer

Cancer remains one of the major causes of death globally, with one out of every six deaths attributed to the disease. The impact of cancer is felt on psychological, physical, and financial levels, affecting individuals, communities, and healthcare institutions. Conventional cancer treatments have many challenges and inadequacies. Nanomedicine, however, presents a promising solution by not only overcoming these problems but also offering the advantage of combined therapy for treatment-resistant cancers. Nanoparticles specifically engineered for use in nanomedicine can be efficiently targeted to cancer cells through a combination of active and passive techniques, leading to superior tumor-specific accumulation, enhanced drug availability, and reduced systemic toxicity. Among various nanoparticle formulations designed for cancer treatment, gold nanoparticles have gained prominence in the field of nanomedicine due to their photothermal, photodynamic, and immunologic effects without the need for photosensitizers or immunotherapeutic agents. To date, there is no comprehensive literature review that focuses on the photothermal, photodynamic, and immunologic effects of gold nanoparticles. In this review, significant attention has been devoted to examining the parameters pertaining to the structure of gold nanoparticles and laser characteristics, which play a crucial role in influencing the efficacy of photothermal therapy (PTT) and photodynamic therapy (PDT). Moreover, this article provides insights into the success of PTT and PDT mediated by gold nanoparticles in primary cancer treatment, as well as the immunological effects of PTT and PDT on metastasis and recurrence, providing a promising strategy for cancer therapy. In summary, gold nanoparticles, with their unique properties, have the potential for clinical application in various cancer therapies, including the treatment of primary cancer, recurrence and metastasis.

Laser interstitial thermal therapy for recurrent glioblastomas: a systematic review and meta-analysis

We aim to investigate the efficacy and safety of laser interstitial thermal therapy (LITT) in treating recurrent glioblastomas (rGBMs). A comprehensive search was conducted in four databases to identify studies published between January 2001 and June 2022 that reported prognosis information of rGBM patients treated with LITT as the primary therapy. The primary outcomes of interest were progression-free survival (PFS) and overall survival (OS) at 6 and 12 months after LITT intervention. Adverse events and complications were also evaluated. Eight eligible non-comparative studies comprising 128 patients were included in the analysis. Seven studies involving 120 patients provided data for the analysis of PFS. The pooled PFS rate at 6 months after LITT was 25% (95% CI 15-37%, I2 = 53%), and at 12 months, it was 9% (95% CI 4-15%, I2 = 24%). OS analysis was performed on 54 patients from six studies, with an OS rate of 92% (95% CI 84-100%, I2 = 0%) at 6 months and 42% (95% CI 13-73%, I2 = 67%) at 12 months after LITT. LITT demonstrates a favorable safety profile with low complication rates and promising tumor control and overall survival rates in patients with rGBMs. Tumor volume and performance status are important factors that may influence the effectiveness of LITT in selected patients. Additionally, the combination of LITT with immune-based therapy holds promise. Further well-designed clinical trials are needed to expand the application of LITT in glioma treatment.

Nanoparticles integrated with mild photothermal therapy and oxaliplatin for tumor chemotherapy and immunotherapy

Aims: Preparation and evaluation of nanoparticles for tumor chemotherapy and immunotherapy mild photothermal therapy and oxaliplatin. Methods: The double emulsion method was used for nanoparticle preparations. Polydopamine was deposited on the surface, which was further modified with folic acid. Cytotoxicity assays were carried out by cell counting kit-8. In vivo antitumor assays were carried out on 4T1 tumor-bearing mice. Results: The nanoparticles exhibited a 190 nm-diameter pomegranate-like sphere, which could increase temperature to 43-46°C. In vivo distribution showed enhanced accumulation. The nanoparticles generated stronger immunogenic cell death effects. By stimulating the maturation of dendritic cells, mild photothermal therapy combined with oxaliplatin significantly increased the antitumor effect by a direct killing effect and activation of immunotherapy. Conclusion: This study provided a promising strategy of combination therapy for tumors.

Application of Nanoparticles for Magnetic Hyperthermia for Cancer Treatment-The Current State of Knowledge

Hyperthermia (HT) is an anti-cancer therapy commonly used with radio and chemotherapies based on applying heat (39-45 °C) to inhibit tumor growth. However, controlling heat towards tumors and not normal tissues is challenging. Therefore, nanoparticles (NPs) are used in HT to apply heat only to tumor tissues to induce DNA damage and the expression of heat shock proteins, which eventually result in apoptosis. The aim of this review article is to summarize recent advancements in HT with the use of magnetic NPs to locally increase temperature and promote cell death. In addition, the recent development of nanocarriers as NP-based drug delivery systems is discussed. Finally, the efficacy of HT combined with chemotherapy, radiotherapy, gene therapy, photothermal therapy, and immunotherapy is explored.

Recent advances in light-triggered cancer immunotherapy

Light-triggered phototherapies, such as photodynamic therapy (PDT) and photothermal therapy (PTT), have shown strong therapeutic efficacy with minimal invasiveness and systemic toxicity, offering opportunities for tumor-specific therapies. Phototherapies not only induce direct tumor cell killing, but also trigger anti-tumor immune responses by releasing various immune-stimulating factors. In recent years, conventional phototherapies have been combined with cancer immunotherapy as synergistic therapeutic modalities to eradicate cancer by exploiting the innate and adaptive immunity. These combined photoimmunotherapies have demonstrated excellent therapeutic efficacy in preventing tumor recurrence and metastasis compared to phototherapy alone. This review covers recent advancements in combined photoimmunotherapy, including photoimmunotherapy (PIT), PDT-combined immunotherapy, and PTT-combined immunotherapy, along with their underlying anti-tumor immune response mechanisms. In addition, the challenges and future research directions for light-triggered cancer immunotherapy are discussed.

Gene and Photothermal Combination Therapy: Principle, Materials, and Amplified Anticancer Intervention

Gene therapy (GT) and photothermal therapy (PTT) have emerged as promising alternatives to chemotherapy and radiotherapy for cancer treatment, offering noninvasiveness and reduced side effects. However, their efficacy as standalone treatments is limited. GT exhibits slow response rates, while PTT is confined to local tumor ablation. The convergence of GT and PTT, known as GT-PTT, facilitated by photothermal gene nanocarriers, has attracted considerable attention across various disciplines. In this integrated approach, GT reciprocates PTT by sensitizing cellular response to heat, while PTT benefits GT by improving gene translocation, unpacking, and expression. Consequently, this integration presents a unique opportunity for cancer therapy with rapid response and improved effectiveness. Extensive efforts over the past few years have been dedicated to the development of GT-PTT, resulting in notable achievements and rapid progress from the laboratory to potential clinical applications. This comprehensive review outlines recent advances in GT-PTT, including synergistic mechanisms, material systems, imaging-guided therapy, and anticancer applications. It also explores the challenges and future prospects in this nascent field. By presenting innovative ideas and insights into the implementation of GT-PTT for enhanced cancer therapy, this review aims to inspire further progress in this promising area of research.

Ex vivo photothermal treatment-induced immunogenic cell death for anticancer vaccine development

Photothermal therapy is an anti-cancer strategy that induce cell death by converting light energy into heat energy. During photothermal therapy, cancer cells were treated with photothermal agents, such as indocyanine green, and irradiated with a laser. Heat stress in cancer cells results in cellular death and inflammatory responses. In the present study, we demonstrated how ex vivo photothermal (PT)-treated cells underwent immunogenic cell death. PT treatment caused significant expression of heat shock protein (HSP) 27, HSP70, and HSP90 in murine tumor cells. To evaluate the immunogenicity of heat-stressed cells, lysate from PT-treated tumor cells or water-based heated cells was pulsed to syngeneic bone-marrow-derived dendritic cells (DCs) to generate a DC-based vaccine. Administration with PT-treated tumor lysates-pulsed DC vaccine resulted in significant inhibition of tumor growth in BALB/c and C57BL/6 syngeneic tumor-bearing mice. The immunogenicity of PT-treated cancer cells was reduced in the presence of HSP inhibitors, J2, VER-155008 or 17-AAG. Our study elucidates how PT techniques have distinct mechanisms from water-based heating and might be a potentially robust and efficient solution to developing an anti-cancer vaccine.

The Curie temperature: a key playmaker in self-regulated temperature hyperthermia

The Curie temperature is an important thermo-characteristic of magnetic materials, which causes a phase transition from ferromagnetic to paramagnetic by changing the spontaneous re-arrangement of their spins (intrinsic magnetic mechanism) due to an increase in temperature. The self-control-temperature (SCT) leads to the conversion of ferro/ferrimagnetic materials to paramagnetic materials, which can extend the temperature-based applications of these materials from industrial nanotechnology to the biomedical field. In this case, magnetic induction hyperthermia (MIH) with self-control-temperature has been proposed as a physical thermo-therapeutic method for killing cancer tumors in a biologically safe environment. Specifically, the thermal source of MIH is magnetic nanoparticles (MNPs), and thus their biocompatibility and Curie temperature are two important properties, where the former is required for their clinical application, while the latter acts as a switch to automatically control the temperature of MIH. In this review, we focus on the Curie temperature of magnetic materials and provide a complete overview beginning with basic magnetism and its inevitable relation with Curie's law, theoretical prediction and experimental measurement of the Curie temperature. Furthermore, we discuss the significance, evolution from different types of alloys to ferrites and impact of the shape, size, and concentration of particles on the Curie temperature considering the proposed SCT-based MIH together with their biocompatibility. Also, we highlight the thermal efficiency of MNPs in destroying tumor cells and the significance of a low Curie temperature. Finally, the challenges, concluding remarks, and future perspectives in promoting self-control-temperature based MIH to clinical application are discussed.

Harnessing Hyperthermia: Molecular, Cellular, and Immunological Insights for Enhanced Anticancer Therapies

Hyperthermia, the raising of tumor temperature (≥39°C), holds great promise as an adjuvant treatment for cancer therapy. This review focuses on 2 key aspects of hyperthermia: its molecular and cellular effects and its impact on the immune system. Hyperthermia has profound effects on critical biological processes. Increased temperatures inhibit DNA repair enzymes, making cancer cells more sensitive to chemotherapy and radiation. Elevated temperatures also induce cell cycle arrest and trigger apoptotic pathways. Furthermore, hyperthermia modifies the expression of heat shock proteins, which play vital roles in cancer therapy, including enhancing immune responses. Hyperthermic treatments also have a significant impact on the body's immune response against tumors, potentially improving the efficacy of immune checkpoint inhibitors. Mild systemic hyperthermia (39°C-41°C) mimics fever, activating immune cells and raising metabolic rates. Intense heat above 50°C can release tumor antigens, enhancing immune reactions. Using photothermal nanoparticles for targeted heating and drug delivery can also modulate the immune response. Hyperthermia emerges as a cost-effective and well-tolerated adjuvant therapy when integrated with immunotherapy. This comprehensive review serves as a valuable resource for the selection of patient-specific treatments and the guidance of future experimental studies.

Protocol of the HISTOTHERM study: assessing the response to hyperthermia and hypofractionated radiotherapy in recurrent breast cancer

Introduction

Breast cancer is globally the leading cancer in women, and despite the high 5-year survival rate the most frequent cause of cancer related deaths. Surgery, systemic therapy and radiotherapy are the three pillars of curative breast cancer treatment. However, locoregional recurrences frequently occur after initial treatment and are often challenging to treat, amongst others due to high doses of previous radiotherapy treatments. Radiotherapy can be combined with local hyperthermia to sensitize tumor cells to radiation and thereby significantly reduce the required radiation dose. Therefore, the combination treatment of mild local hyperthermia, i.e. locally heating of the tissue to 39-43°C, and re-irradiation with a reduced total dose is a relevant treatment option for previously irradiated patients. The mechanisms of this effect in the course of the therapy are to date not well understood and will be investigated in the HISTOTHERM study.

Methods and analyses

Patients with local or (loco)regional recurrent breast cancer with macroscopic tumors are included in the study. Local tumor control is evaluated clinically and histologically during the course of a combination treatment of 60 minutes mild superficial hyperthermia (39 - 43°C) using water-filtered infrared A (wIRA) irradiation, immediately followed by hypofractionated re-irradiation with a total dose of 20-24 Gy, administered in weekly doses of 4 Gy. Tumor and tumor stroma biopsies as well as blood samples will be collected prior to treatment, during therapy (at a dose of 12 Gy) and in the follow-up to monitor therapy response. The treatment represents the standard operating procedure for hyperthermia plus re-irradiation. Various tissue and blood-based markers are analyzed. We aim at pinpointing key mechanisms and markers for therapy response which may help guiding treatment decisions in future. In addition, quality of life in the course of treatment will be assessed and survival data will be evaluated.

Registration

The study is registered at the German Clinical Trials Register, Deutsches Register Klinischer Studien (DRKS00029221).

Combination cancer imaging and phototherapy mediated by membrane-wrapped nanoparticles

Cancer is a devastating health problem with inadequate treatment options. Many conventional treatments for solid-tumor cancers lack tumor specificity, which results in low efficacy and off-target damage to healthy tissues. Nanoparticle (NP)-mediated photothermal therapy (PTT) is a promising minimally invasive treatment for solid-tumor cancers that has entered clinical trials. Traditionally, NPs used for PTT are coated with passivating agents and/or targeting ligands, but alternative coatings are being explored to enhance tumor specific delivery. In particular, cell-derived membranes have emerged as promising coatings that improve the biointerfacing of photoactive NPs, which reduces their immune recognition, prolongs their systemic circulation and increases their tumor accumulation, allowing for more effective PTT. To maximize treatment success, membrane-wrapped nanoparticles (MWNPs) that enable dual tumor imaging and PTT are being explored. These multifunctional theranostic NPs can be used to enhance tumor detection and/or ensure a sufficient quantity of NPs that have arrived in the tumor prior to laser irradiation. This review summarizes the current state-of-the-art in engineering MWNPs for combination cancer imaging and PTT and discusses considerations for the path toward clinical translation.

Amplifying cancer treatment: advances in tumor immunotherapy and nanoparticle-based hyperthermia

In the quest for cancer treatment modalities with greater effectiveness, the combination of tumor immunotherapy and nanoparticle-based hyperthermia has emerged as a promising frontier. The present article provides a comprehensive review of recent advances and cutting-edge research in this burgeoning field and examines how these two treatment strategies can be effectively integrated. Tumor immunotherapy, which harnesses the immune system to recognize and attack cancer cells, has shown considerable promise. Concurrently, nanoparticle-based hyperthermia, which utilizes nanotechnology to promote selective cell death by raising the temperature of tumor cells, has emerged as an innovative therapeutic approach. While both strategies have individually shown potential, combination of the two modalities may amplify anti-tumor responses, with improved outcomes and reduced side effects. Key studies illustrating the synergistic effects of these two approaches are highlighted, and current challenges and future prospects in the field are discussed. As we stand on the precipice of a new era in cancer treatment, this review underscores the importance of continued research and collaboration in bringing these innovative treatments from the bench to the bedside.

Iron Oxide Nanoparticles in Cancer Treatment: Cell Responses and the Potency to Improve Radiosensitivity

The main concept of radiosensitization is making the tumor tissue more responsive to ionizing radiation, which leads to an increase in the potency of radiation therapy and allows for decreasing radiation dose and the concomitant side effects. Radiosensitization by metal oxide nanoparticles is widely discussed, but the range of mechanisms studied is not sufficiently codified and often does not reflect the ability of nanocarriers to have a specific impact on cells. This review is focused on the magnetic iron oxide nanoparticles while they occupied a special niche among the prospective radiosensitizers due to unique physicochemical characteristics and reactivity. We collected data about the possible molecular mechanisms underlying the radiosensitizing effects of iron oxide nanoparticles (IONPs) and the main approaches to increase their therapeutic efficacy by variable modifications.

Hyperthermia promotes M1 polarization of macrophages via exosome-mediated HSPB8 transfer in triple negative breast cancer

PURPOSE

To investigate the mechanism underlying the modulation of M1 macrophage polarization by exosomes released from hyperthermia-treated triple-negative breast cancer (TNBC) cells.

MATERIALS AND METHODS

In this study, the effects of hyperthermia on TNBC cells were examined using cell counting kit-8, apoptosis, and cell cycle assays. Transmission electron microscopy was used to identify the structure of exosomes, while bicinchoninic acid and nanoparticle tracking analysis were used to detect particle size and amounts of exosomes released after hyperthermia. The polarization of macrophages incubated with exosomes derived by hyperthermia-pretreated TNBC cells were assessed by RT-qPCR and flow cytometry analysis. Next, RNA sequencing was performed to determine the targeting molecules changed in hyperthermia-treated TNBC cells in vitro. Finally, the mechanism underlying the modulation of macrophage polarization by exosomes derived from hyperthermia-treated TNBC cells was examined by using RT-qPCR, immunofluorescence and flow cytometry analysis.

RESULTS

Hyperthermia markedly reduced cell viability in TNBC cells and promoted the secretion of TNBC cell-derived exosomes. The hub genes of hyperthermia-treated TNBC cells were significantly correlated with macrophage infiltration. Additionally, hyperthermia-treated TNBC cell-derived exosomes promoted M1 macrophage polarization. Furthermore, the expression levels of heat shock proteins, including HSPA1A, HSPA1B, HSPA6, and HSPB8, were significantly upregulated upon hyperthermia treatment, with HSPB8 exhibiting the highest upregulation. Moreover, hyperthermia can induce M1 macrophage polarization by promoting exosome-mediated HSPB8 transfer.

CONCLUSION

This study demonstrated a novel mechanism that hyperthermia can induce M1 polarization of macrophages via exosome-mediated HSPB8 transfer. These results will help with future development of an optimized hyperthermia treatment regime for clinical application, especially for combination treatment with immunotherapy.

Engineered Organic Nanorockets with Light-Driven Ultrafast Transportability for Antitumor Therapy

Nanomedicines confront various complicated physiological barriers limiting the accumulation and deep penetration in the tumor microenvironment, which seriously restricts the efficacy of antitumor therapy. Self-propelled nanocarriers assembled with kinetic engines can translate external energy into orientated motion for tumor penetration. However, achieving a stable ultrafast permeability at the tumor site remains challenging. Here, sub-200 nm photoactivated completely organic nanorockets (NRs), with asymmetric geometry conveniently assembled from photothermal semiconducting polymer payload and thermo-driven macromolecular propulsion through a straightforward nanoprecipitation process, are presented. The artificial NRs can be remotely manipulated by 808 nm near-infrared light to trigger the photothermal conversion and Curtius rearrangement reaction within the particles for robustly pushing nitrogen out into the solution. Such a two-stage light-to-heat-to-chemical energy transition effectively powers the NRs for an ultrafast (≈300 µm s^-1 ) and chemical medium-independent self-propulsion in the liquid media. That endows the NRs with high permeability against physiological barriers in the tumor microenvironment to directionally deliver therapeutic agents to target lesions for elevating tumor accumulation, deep penetration, and cellular uptake, resulting in a significant enhancement of antitumor efficacy. This work will inspire the design of advanced kinetic systems for powering intelligent nanomachines in biomedical applications.

Harnessing immunotherapy to enhance the systemic anti-tumor effects of thermosensitive liposomes

Chemotherapy plays an important role in debulking tumors in advance of surgery and/or radiotherapy, tackling residual disease, and treating metastatic disease. In recent years many promising advanced drug delivery strategies have emerged that offer more targeted delivery approaches to chemotherapy treatment. For example, thermosensitive liposome-mediated drug delivery in combination with localized mild hyperthermia can increase local drug concentrations resulting in a reduction in systemic toxicity and an improvement in local disease control. However, the majority of solid tumor-associated deaths are due to metastatic spread. A therapeutic approach focused on a localized target area harbors the risk of overlooking and undertreating potential metastatic spread. Previous studies reported systemic, albeit limited, anti-tumor effects following treatment with thermosensitive liposomal chemotherapy and localized mild hyperthermia. This work explores the systemic treatment capabilities of a thermosensitive liposome formulation of the vinca alkaloid vinorelbine in combination with mild hyperthermia in an immunocompetent murine model of rhabdomyosarcoma. This treatment approach was found to be highly effective at heated, primary tumor sites. However, it demonstrated limited anti-tumor effects in secondary, distant tumors. As a result, the addition of immune checkpoint inhibition therapy was pursued to further enhance the systemic anti-tumor effect of this treatment approach. Once combined with immune checkpoint inhibition therapy, a significant improvement in systemic treatment capability was achieved. We believe this is one of the first studies to demonstrate that a triple combination of thermosensitive liposomes, localized mild hyperthermia, and immune checkpoint inhibition therapy can enhance the systemic treatment capabilities of thermosensitive liposomes.

Elevated temperatures and longer durations improve the efficacy of oxaliplatin- and mitomycin C-based hyperthermic intraperitoneal chemotherapy in a confirmed rat model for peritoneal metastasis of colorectal cancer origin

Introduction

In patients with limited peritoneal metastasis (PM) originating from colorectal cancer, cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is a potentially curative treatment option. This combined treatment modality using HIPEC with mitomycin C (MMC) for 90 minutes proved to be superior to systemic chemotherapy alone, but no benefit of adding HIPEC to CRS alone was shown using oxaliplatin-based HIPEC during 30 minutes. We investigated the impact of treatment temperature and duration as relevant HIPEC parameters for these two chemotherapeutic agents in representative preclinical models. The temperature- and duration- dependent efficacy for both oxaliplatin and MMC was evaluated in an in vitro setting and in a representative animal model.

Methods

In 130 WAG/Rij rats, PM were established through i.p. injections of rat CC-531 colon carcinoma cells with a signature similar to the dominant treatment-resistant CMS4 type human colorectal PM. Tumor growth was monitored twice per week using ultrasound, and HIPEC was applied when most tumors were 4-6 mm. A semi-open four-inflow HIPEC setup was used to circulate oxaliplatin or MMC through the peritoneum for 30, 60 or 90 minutes with inflow temperatures of 38°C or 42°C to achieve temperatures in the peritoneum of 37°C or 41°C. Tumors, healthy tissue and blood were collected directly or 48 hours after treatment to assess the platinum uptake, level of apoptosis and proliferation and to determine the healthy tissue toxicity.

Results

In vitro results show a temperature- and duration- dependent efficacy for both oxaliplatin and MMC in both CC-531 cells and organoids. Temperature distribution throughout the peritoneum of the rats was stable with normothermic and hyperthermic average temperatures in the peritoneum ranging from 36.95-37.63°C and 40.51-41.37°C, respectively. Treatments resulted in minimal body weight decrease (<10%) and only 7/130 rats did not reach the endpoint of 48 hours after treatment.

Conclusions

Both elevated temperatures and longer treatment duration resulted in a higher platinum uptake, significantly increased apoptosis and lower proliferation in PM tumor lesions, without enhanced normal tissue toxicity. Our results demonstrated that oxaliplatin- and MMC-based HIPEC procedures are both temperature- and duration-dependent in an in vivo tumor model.

Regional hyperthermia with cisplatin added to gemcitabine versus gemcitabine in patients with resected pancreatic ductal adenocarcinoma: The HEAT randomised clinical trial

BACKGROUND

Regional hyperthermia (RHT) with cisplatin added to gemcitabine showed efficacy in gemcitabine-pre-treated patients with advanced pancreatic ductal adenocarcinoma. We conducted a randomised clinical trial to investigate RHT with cisplatin added to gemcitabine (GPH) compared with gemcitabine (G) in the adjuvant setting of resected pancreatic ductal adenocarcinoma.

METHODS

This randomised, multicentre, open-label trial randomly assigned patients to either GPH (gemcitabine 1000 mg/m² on day 1, 15 and cisplatin 25 mg/m² with RHT on day 2, 3 and 15,16) or to G (gemcitabine 1000 mg/m² on day 1,8,15), four-weekly over six cycles. Disease-free survival (DFS) was the primary end-point. Secondary end-points included overall survival (OS) and safety.

RESULTS

A total of 117 eligible patients (median age, 63 years) were randomly allocated to treatment (57 GPH; 60 G). With a follow-up time of 56.6 months, the median DFS was 12.7 compared to 11.2 months for GPH and G, respectively (p = 0.394). Median post-recurrence survival was significantly prolonged in the GPH-group (15.3 versus 9.8 months; p = 0.031). Median OS reached 33.2 versus 25.2 months (p = 0.099) with 5-year survival rates of 28.4% versus 18.7%. Excluding eight patients who received additional capecitabine in the G-arm (investigators choice), median OS favoured GPH (p = 0.052). Adverse events CTCAE (Common Terminology Criteria for Adverse Events) grade ≥3 occurred in 61.5% (GPH) versus 63.6% (G) of patients. Two patients in the G-group died because of treatment-related toxic effects.

CONCLUSIONS

The randomised controlled Hyperthermia European Adjuvant Trial study failed to demonstrate a significant difference in DFS. However, it suggests a difference in post-recurrence survival and a trend for improved OS.

CLINICALTRIALS

gov, number NCT01077427.

Temperature management during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

In addition to attaining complete or near complete cytoreduction, the instillation of select heated chemotherapeutic agents into the abdominal cavity has offered a chance for cure or longer survival inpatients with peritoneal surface malignancies. While the heating of chemotherapeutic agents enhances cytotoxicity, the resulting systemic hyperthermia has been associated with an increased risk of severe hyperthermia and its associated complications. Factors that have been associated with an increased risk of severe hyperthermia include intraoperative blood transfusions and longer perfusion duration. However, the development of severe hyperthermia still remains largely unpredictable. Thus, at several institutions, cooling protocols are employed during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Cooling protocols for CRS-HIPEC are not standardized and may be associated with episodes of severe hyperthermia or alternatively hypothermia. In theory, excessive cooling could result in a decreased effectiveness of the intraperitoneal chemotherapeutic agents. This presumption has been supported by a recent study of 214 adults undergoing CRS-HIPEC, where failure to attain a temperature of 38° C at the end of chemo-perfusion was associated with worse survival. Although not statistically significant, failure to maintain a temperature of 38° C for at least 30 minutes was associated with worse survival. Although studies are limited in this regard, the importance of maintaining a steady state of temperature during the hyperthermic phase of intraperitoneal chemotherapy administration cannot be disregarded. The following article describes the processes and physiological mechanisms responsible for hyperthermia during CRS-HIPEC. The challenges associated with temperature management during CRS-HIPEC and methods to avoid severe hypothermia and hyperthermia are also described.

The Emerging Evidence Supporting Integration of Deep Regional Hyperthermia With Chemoradiation in Bladder Cancer

For decades, the antineoplastic potential of hyperthermia alone or in combination with radiotherapy and/or chemotherapy has been subject of intensive preclinical and clinical research in various tumor entities. The clinical evidence on the beneficial effects of additional hyperthermia in combination with intravesical Mitomycin C for superficial non-muscle-invasive bladder cancer as well as for deep regional microwave hyperthermia techniques applied during an external beam radiotherapy or chemoradiation treatment for more advanced tumors are summarized. In some series, deep regional hyperthermia in combination with an initial transurethral resection and Cisplatin-based chemoradiation increased the 5-year overall survival rates up to 20%. The presented data justifies a fresh irrespective chance for mild regional hyperthermia in the context of new progressive prospective trials on multimodality treatment for bladder preservation.

A Multicenter Study of 2-year Outcomes Following Hyperthermia Therapy with Mitomycin C in Treating Non-Muscle Invasive Bladder Cancer: HIVEC-E

INTRODUCTION

High grade, non-muscle invasive bladder cancer (NMIBC) is usually treated with intravesical Bacillus Calmette-Guérin. Chemohyperthermia therapy (CHT) may be a novel alternative therapy for the treatment of NMIBC.

OBJECTIVE

To evaluate the recurrence-free survival (RFS) of patients treated with CHT using the Combat bladder recirculation system (BRS) for NMIBC.

METHODS

This was a prospective multi-institutional study of 1,028 consecutive patients with NMIBC undergoing CHT between 2012 and 2020. A total of 835 patients were treated with CHT with Mitomycin C (MMC). Disease was confirmed on transurethral resection of bladder tumor (TURBT) prior to starting CHT. Follow-up included cystoscopy and subsequent TURBT if recurrence/progression was suspected. The primary endpoint was RFS. Secondary endpoints were progression-free survival (PFS) and adverse events from CHT.

RESULTS AND LIMITATIONS

Median follow up was 22.4 months (Interquartile range (IQR): 12.8 -35.8). Median age was 70.4 years (IQR: 62.1 -78.6). A total of 557 (66.7%), 172 (20.6) and 74 (8.9%) of patients were classified to BCG naïve, BCG unresponsive and BCG failure, respectively. The RFS at 12 months and 24 months for BCG naïve was 87.6% (95% CI 85.0% - 90.4%) and 75.0% (95% CI 71.3% - 78.8%), respectively. The RFS at 12 months and 24 months for BCG unresponsive cohort was 78.1% (95% CI 72.0% - 84.7%) and 57.4% (95% CI 49.7% - 66.3%), respectively. The RFS at 24 months for the BCG unresponsive cohort for CIS with/without papillary disease and papillary only disease were 43.6% (95% CI 31.4% -60.4%) and 64.5% (95% CI 55.4% - 75.1%), respectively. Minor adverse events occurred in 216 (25.6%) patients and severe events occurred in 17 (2.0%) patients.

CONCLUSIONS

CHT with MMC using the Combat BRS is effective in the medium term and has a favorable adverse event profile.

Nanoplasmonics Enabling Cancer Diagnostics and Therapy

In this paper, we highlight several advances our laboratory has developed in the pursuit of cancer diagnostics and therapeutics by integrating plasmonics, photonics, and nanotechnology. We discuss the development and applications of plasmonics-active gold nanostar (GNS), a uniquely shaped nanoparticle with numerous branches that serve to greatly amplify the thermal generation at resonant wavelengths. GNS has also been successfully used in tumor imaging contexts from two-photon fluorescence to surface-enhanced Raman scattering (SERS) sensing and imaging. Finally, GNS has been coupled with immunotherapy applications to serve as an effective adjuvant to immune checkpoint inhibitors. This combination of GNS and immunotherapy, the so called synergistic immuno photo nanotherapy (SYMPHONY), has been shown to be effective at controlling long-lasting cancer immunity and metastatic tumors.

Interaction of Radiotherapy and Hyperthermia with the Immune System: a Brief Current Overview

Purpose of Review

This review focuses on the opposing effects on the immune system of radiotherapy (RT) and the consequences for combined cancer treatment strategies of RT with immunotherapies, including hyperthermia (HT). How RT and HT might affect cancer stem cell populations is also briefly outlined in this context.

Recent Findings

RT is one of the crucial standard cancer therapies. Most patients with solid tumors receive RT for curative and palliative purposes in the course of their disease. RT achieves a local tumor control by inducing DNA damage which can lead to tumor cell death. In recent years, it has become evident that RT does not only have local effects, but also systemic effects which involves induction of anti-tumor immunity and possible alteration of the immunosuppressive properties of the tumor microenvironment. Though, often RT alone is not able to induce potent anti-tumor immune responses since the effects of RT on the immune system can be both immunostimulatory and immunosuppressive.

Summary

RT with additional therapies such as HT and immune checkpoint inhibitors (ICI) are promising approaches to induce anti-tumor immunity effectively. HT is not only a potent sensitizer for RT, but it might also improve the efficacy of RT and certain chemotherapeutic agents (CT) by additionally sensitizing resistant cancer stem cells (CSCs).

Graphical abstract

Global Stability and Thermal Optimal Control Strategies for Hyperthermia Treatment of Malignant Tumors

Malignant tumor (cancer) is the leading cause of death globally and the annual cost of managing cancer is trillions of dollars. Although, there are established therapies including radiotherapy, chemotherapy and phototherapy for malignant tumors, the hypoxic environment of tumors and poor perfusion act as barriers to these therapies. Hyperthermia takes advantage of oxygen deficiency and irregular perfusion in the tumor environment to destroy malignant cells. Despite successes recorded with hyperthermia, there are concerns with the post-treatment condition of patients as well as the required thermal dose to prevent harm. The investigation of the dynamics of tumor-induced immune suppression with hyperthermia treatment using mathematical analysis and optimal control theory is potentially valuable in the development of hyperthermia treatment. The role of novel tumor-derived cytokines in counterattacking immune cells is considered in this study as a mechanism accounting for the aggressiveness of malignant tumors. Since biological processes are not instantaneous, a discrete time delay is used to model biological processes involved in tumor inhibitory mechanisms by secretion, the elaboration of suppressive cells, and effector cell differentiation to produce suppressive cells. Analytical results obtained using Lyapunov’s function indicate the conditions required for global stability of the tumor-present steady-state. A thermal optimal control strategy is pursued based on optimal control theory, and the best strategy to avoid adverse outcomes is obtained. We validate the analytical results numerically and demonstrate the impact of both inadequate and excessive heat on the dynamics of interactive cell functioning.

Potential use of microwave technology in dermatology

BACKGROUND

Microwaves are used in medicine for diagnostics, and treatment of cancer. Recently, novel microwave devices (Swift^®, Emblation Ltd, UK and miraDry^®, Miramar Labs Inc., CA) have been cleared by the FDA and Health Canada for various dermatological conditions.

OBJECTIVE AND METHODS

To review the dermatological use of microwave-based treatments (plantar warts, corns, actinic keratosis, dermatophytosis, axillary hyperhidrosis, osmidrosis, and hidradenitis suppurativa). Clinical trials, case reports, or in vitro studies for each condition are summarized.

RESULTS AND CONCLUSION

Microwaves are a promising alternative therapy for cutaneous warts, actinic keratosis, axillary hyperhidrosis, and osmidrosis, with favorable safety profiles. However, patients with hidradenitis suppurativa have had negative clinical outcomes. Limited treatment of corns showed good pain reduction but did not resolve hyperkeratosis. A preliminary in vitro study indicated that microwave treatment inhibits the growth of T. rubrum. We present the first case of toenail onychomycosis successfully treated with microwaves. Despite the advancements in the use of microwaves, the mechanism of action in non-ablative treatment is not well understood; further research is needed. More high-quality randomized clinical trials with larger groups and long follow-up periods are also required to evaluate the clinical benefits and possible adverse effects of microwaves in treating dermatological conditions.

Detailed in vitro analyses of the impact of multimodal cancer therapy with hyperthermia and radiotherapy on the immune phenotype of human glioblastoma cells

PURPOSE

Improvements of heat-delivery systems have led to hyperthermia (HT) being increasingly recognized as an adjunct treatment modality also for brain tumors. But how HT affects the immune phenotype of glioblastoma cells is only scarcely known.

MATERIALS AND METHODS

We therefore investigated the effect of in vitro HT, radiotherapy (RT), and the combination of both (RHT) on cell death modalities, immune checkpoint molecule (ICM) expression and release of the danger signal HSP70 of two human glioblastoma cell lines (U87 and U251) by using multicolor flow cytometry and ELISA. Hyperthermia was performed once or twice for 60-minute sessions reaching temperatures of 39 °C, 41 °C, and 44 °C, respectively. RT was administered with 5 x 2 Gy.

RESULTS

A hyperthermia chamber for cell culture t-flasks regulating the temperature via a contact sensor was developed. While the glioblastoma cells were rather radioresistant, particularly in U251 cells, the combination of RT with HT significantly increased the percentage of apoptotic and necrotic cells for all temperatures examined and for both, single and double HT application. In line with that, an increased release of HSP 70 was seen only in U251 cells, mainly following treatment with HT at temperatures of 44 °C alone or in combination with RT. In contrast, immune suppressive (PD-L1, PD-L2, HVEM) and immune stimulatory (ICOS-L, CD137-L and Ox40-L) ICMs were significantly increased mostly on U87 cells, and particularly after RHT with 41 °C.

CONCLUSIONS

Individual assessment of the glioblastoma immune cell phenotype with regard to the planned treatment is mandatory to optimize multimodal radio-immunotherapy protocols including HT.

Mild phototherapy mediated by manganese dioxide-loaded mesoporous polydopamine enhances immunotherapy against colorectal cancer

One of the main challenges in applying the immune checkpoint blockade to treat colorectal cancer (CRC) is the immunosuppressive tumor microenvironment. Owing to its excellent cancer cell killing ability and immune activation, mild photothermal therapy (PTT) has shown bright promise to sensitize tumors to immune checkpoint inhibition through turning the immunologically "cold" tumors into "hot" ones. Herein, a mild photothermal effect-assisted theragnostic nanodrug (MnO₂@MPDA-PEG NPs) is developed by incorporating MnO₂ into PEGylated-mesoporous polydopamine nanoparticles (MPDA-PEG NPs). The presence of PEG endows the theragnostic nanodrug with high biostability. After accumulation in colorectal tumor, the theragnostic nanodrug responds to the tumor microenvironment, leading to the simultaneous release of Mn²⁺ which serves as a magnetic resonance imaging (MRI) contrast agent for tumor imaging. The released Mn²⁺ could also promote mild photothermal treatment-induced immune response, including the maturation of BMDC cells. In vivo antitumor studies on a CT26 model demonstrate that MnO₂@MPDA-PEG NPs could be a promising dual-imaging theragnostic nanodrug to potentiate the systemic antitumor immunities.

Photoactivated Organic Nanomachines for Programmable Enhancement of Antitumor Efficacy

Limited permeability in solid tumors significantly restricts the anticancer efficacy of nanomedicines. Light-driven nanomotors powered by photothermal converting engines are appealing carriers for directional drug delivery and simultaneous phototherapy. Nowadays, it is still a great challenge to construct metal-free photothermal nanomotors for a programmable anticancer treatment. Herein, one kind of photoactivated organic nanomachines is reported with asymmetric geometry assembled by light-to-heat converting semiconducting polymer engine and macromolecular anticancer payload through a straightforward nanoprecipitation process. The NIR-fueled polymer engine can be remotely controlled to power the nanomachines for light-driven thermophoresis in the liquid media and simultaneously thermal ablating the cancer cells. The great manipulability of the nanomachines allows for programming of their self-propulsion in the tumor microenvironment for effectively improving cellular uptake and tumor penetration of the anticancer payload. Taking the benefit from this behavior, a programmed treatment process is established at a low drug dose and a low photothermal temperature for significantly enhancing the antitumor efficacy.

Advances in local therapy for glioblastoma - taking the fight to the tumour

Despite advances in neurosurgery, chemotherapy and radiotherapy, glioblastoma remains one of the most treatment-resistant CNS malignancies, and the tumour inevitably recurs. The majority of recurrences appear in or near the resection cavity, usually within the area that received the highest dose of radiation. Many new therapies focus on combatting these local recurrences by implementing treatments directly in or near the tumour bed. In this Review, we discuss the latest developments in local therapy for glioblastoma, focusing on recent preclinical and clinical trials. The approaches that we discuss include novel intraoperative techniques, various treatments of the surgical cavity, stereotactic injections directly into the tumour, and new developments in convection-enhanced delivery and intra-arterial treatments.

The roles of thermal and mechanical stress in focused ultrasound-mediated immunomodulation and immunotherapy for central nervous system tumors

BACKGROUND

Focused ultrasound (FUS) is an emerging technology, offering the capability of tuning and prescribing thermal and mechanical treatments within the brain. While early works in utilizing this technology have mainly focused on maximizing the delivery of therapeutics across the blood-brain barrier (BBB), the potential therapeutic impact of FUS-induced controlled thermal and mechanical stress to modulate anti-tumor immunity is becoming increasingly recognized.

OBJECTIVE

To better understand the roles of FUS-mediated thermal and mechanical stress in promoting anti-tumor immunity in central nervous system tumors, we performed a comprehensive literature review on focused ultrasound-mediated immunomodulation and immunotherapy in brain tumors.

METHODS

First, we summarize the current clinical experience with immunotherapy. Then, we discuss the unique and distinct immunomodulatory effects of the FUS-mediated thermal and mechanical stress in the brain tumor-immune microenvironment. Finally, we highlight recent findings that indicate that its combination with immune adjuvants can promote robust responses in brain tumors.

RESULTS

Along with the rapid advancement of FUS technologies into recent clinical trials, this technology through mild-hyperthermia, thermal ablation, mechanical perturbation mediated by microbubbles, and histotripsy each inducing distinct vascular and immunological effects, is offering the unique opportunity to improve immunotherapeutic trafficking and convert immunologically "cold" tumors into immunologically "hot" ones that are prone to generate prolonged anti-tumor immune responses.

CONCLUSIONS

While FUS technology is clearly accelerating concepts for new immunotherapeutic combinations, additional parallel efforts to detail rational therapeutic strategies supported by rigorous preclinical studies are still in need to leverage potential synergies of this technology with immune adjuvants. This work will accelerate the discovery and clinical implementation of new effective FUS immunotherapeutic combinations for brain tumor patients.

Clinical Evidence for Thermometric Parameters to Guide Hyperthermia Treatment

Hyperthermia (HT) is a cancer treatment modality which targets malignant tissues by heating to 40-43 °C. In addition to its direct antitumor effects, HT potently sensitizes the tumor to radiotherapy (RT) and chemotherapy (CT), thereby enabling complete eradication of some tumor entities as shown in randomized clinical trials. Despite the proven efficacy of HT in combination with classic cancer treatments, there are limited international standards for the delivery of HT in the clinical setting. Consequently, there is a large variability in reported data on thermometric parameters, including the temperature obtained from multiple reference points, heating duration, thermal dose, time interval, and sequence between HT and other treatment modalities. Evidence from some clinical trials indicates that thermal dose, which correlates with heating time and temperature achieved, could be used as a predictive marker for treatment efficacy in future studies. Similarly, other thermometric parameters when chosen optimally are associated with increased antitumor efficacy. This review summarizes the existing clinical evidence for the prognostic and predictive role of the most important thermometric parameters to guide the combined treatment of RT and CT with HT. In conclusion, we call for the standardization of thermometric parameters and stress the importance for their validation in future prospective clinical studies.

Hyperthermia: A Potential Game-Changer in the Management of Cancers in Low-Middle-Income Group Countries

Loco-regional hyperthermia at 40-44 °C is a multifaceted therapeutic modality with the distinct triple advantage of being a potent radiosensitizer, a chemosensitizer and an immunomodulator. Risk difference estimates from pairwise meta-analysis have shown that the local tumour control could be improved by 22.3% (p < 0.001), 22.1% (p < 0.001) and 25.5% (p < 0.001) in recurrent breast cancers, locally advanced cervix cancer (LACC) and locally advanced head and neck cancers, respectively by adding hyperthermia to radiotherapy over radiotherapy alone. Furthermore, thermochemoradiotherapy in LACC have shown to reduce the local failure rates by 10.1% (p = 0.03) and decrease deaths by 5.6% (95% CI: 0.6-11.8%) over chemoradiotherapy alone. As around one-third of the cancer cases in low-middle-income group countries belong to breast, cervix and head and neck regions, hyperthermia could be a potential game-changer and expected to augment the clinical outcomes of these patients in conjunction with radiotherapy and/or chemotherapy. Further, hyperthermia could also be a cost-effective therapeutic modality as the capital costs for setting up a hyperthermia facility is relatively low. Thus, the positive outcomes evident from various phase III randomized trials and meta-analysis with thermoradiotherapy or thermochemoradiotherapy justifies the integration of hyperthermia in the therapeutic armamentarium of clinical management of cancer, especially in low-middle-income group countries.

A Review of In Vitro Instrumentation Platforms for Evaluating Thermal Therapies in Experimental Cell Culture Models

Thermal therapies, the modulation of tissue temperature for therapeutic benefit, are in clinical use as adjuvant or stand-alone therapeutic modalities for a range of indications, and are under investigation for others. During delivery of thermal therapy in the clinic and in experimental settings, monitoring and control of spatio-temporal thermal profiles contributes to an increased likelihood of inducing desired bioeffects. In vitro thermal dosimetry studies have provided a strong basis for characterizing biological responses of cells to heat. To perform an accurate in vitro thermal analysis, a sample needs to be subjected to uniform heating, ideally raised from, and returned to, baseline immediately, for a known heating duration under ideal isothermal condition. This review presents an applications-based overview of in vitro heating instrumentation platforms. A variety of different approaches are surveyed, including external heating sources (i.e., CO2 incubators, circulating water baths, microheaters and microfluidic devices), microwave dielectric heating, lasers or the use of sound waves. We discuss critical heating parameters including temperature ramp rate (heat-up phase period), heating accuracy, complexity, peak temperature, and technical limitations of each heating modality.

Laser interstitial thermal therapy for brain metastases

Laser interstitial thermal therapy (LITT) is a minimally invasive treatment for intracranial lesions entailing thermal ablation via a stereotactically placed laser probe. In metastatic disease, it has shown the most promise in the treatment of radiographically progressive lesions after initial stereotactic radiosurgery, whether due to recurrent metastatic disease or radiation necrosis. LITT has been demonstrated to provide clinical benefit in both cases, as discussed in the review below. With its minimal surgical footprint and short recovery period, LITT is further advantaged for patients who are otherwise high-risk surgical candidates or with lesions in difficult to access locations. Exploration of the current data on its use in metastatic disease will allow for a better understanding of the indications, benefits, and future directions of LITT for these patients.

Hyperthermia ablation combined with transarterial chemoembolization versus monotherapy for hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND AND AIMS

The existing evidence has indicated that hyperthermia ablation (HA) and HA combined with transarterial chemoembolization (HATACE) are the optimal alternative to surgical resection for patients with hepatocellular carcinoma (HCC) in the COVID-19 crisis. However, the evidence for decision-making is lacking in terms of comparison between HA and HATACE. Herein, a comprehensive evaluation was performed to compare the efficacy and safety of HATACE with monotherapy.

MATERIALS AND METHODS

Worldwide studies were collected to evaluate the HATACE regimen for HCC due to the practical need for global extrapolation of applicative population. Meta-analyses were performed using the RevMan 5.3 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark).

RESULTS

Thirty-six studies involving a large sample of 5036 patients were included finally. Compared with HA alone, HATACE produced the advantage of 5-year overall survival (OS) rate (OR:1.90; 95%CI:1.46,2.46; p < 0.05) without increasing toxicity (p ≥ 0.05). Compared with TACE alone, HATACE was associated with superior 5-year OS rate (OR:3.54; 95%CI:1.96,6.37; p < 0.05) and significantly reduced the incidences of severe liver damage (OR:0.32; 95%CI:0.11,0.96; p < 0.05) and ascites (OR:0.42; 95%CI:0.20,0.88; p < 0.05). Subgroup analysis results of small (≤3 cm) HCC revealed that there were no significant differences between the HATACE group and HA monotherapy group in regard to the OS rates (p ≥ 0.05).

CONCLUSIONS

Compared with TACE alone, HATACE was more effective and safe for HCC. Compared with HA alone, HATACE was more effective for non-small-sized (>3 cm) HCC with comparable safety. However, the survival benefit of adjuvant TACE in HATACE regimen was not found for the patients with small (≤3 cm) HCC.

A combination strategy based on an Au nanorod/doxorubicin gel via mild photothermal therapy combined with antigen-capturing liposomes and anti-PD-L1 agent promote a positive shift in the cancer-immunity cycle

The antitumor immune response involves a cascade of cancer-immunity cycles. Developing a combination therapy aimed at the cancer-immunity cycle is of great importance. In this research, we designed and tested a combined therapeutic-Au nanorod (AuNR)/doxorubicin (DOX) gel (AuNR/DOX gel)-in which the sustained release of DOX was controlled by Pluronic gel. DOX served as an immunogenic tumor cell death (ICD) inducer, triggering the production of damage-associated molecular patterns (DAMPs). Mild photothermal therapy (Mild PTT) produced by 880 nm laser-irradiated AuNRs also generated tumor-associated antigens. Maleimide-modified liposomes (L-Mals), as antigen capturing agents, promoted tumor antigen uptake by DCs. Ultimately, more CD8+ T cells and fewer regulatory T cells (Tregs) infiltrated the tumor, eliciting antitumor responses from the PD-L1 antibody. Our results indicate that this combination strategy promotes a positive shift in the cancer-immunity cycle and holds much promise for combination strategy will lead to development of an antitumor drug delivery system. STATEMENT OF SIGNIFICANCE: Developing a combination therapy for cancer-immunity cycle is of great importance due to antitumor immune response involving a cascade of cancer-immunity cycles. Cancer-immunity cycle usually includes tumor antigen release, antigen presentation, immune activation, trafficking, infiltration, specific recognition of tumor cells by T cells, and finally cancer cell killing. In this research, we designed a combination strategy based on Au nanorod/doxorubicin gel via mild photothermal therapy combined with antigen-capturing liposomes and anti-PD-L1 agent promoting a positive shift in the cancer-immunity cycle. Our results indicate that this combination strategy promotes a positive shift in the cancer-immunity cycle and holds much promise for combination strategy will lead to development of an antitumor drug delivery system.

Immune infiltrates in patients with localised high-risk soft tissue sarcoma treated with neoadjuvant chemotherapy without or with regional hyperthermia: A translational research program of the EORTC 62961-ESHO 95 randomised clinical trial

BACKGROUND

The EORTC 62961-ESHO 95 randomised trial showed improved long-term survival of patients with high-risk soft-tissue sarcoma by adding regional hyperthermia to neoadjuvant chemotherapy. We hypothesised that immune infiltrate of patients treated with neoadjuvant therapy associate with clinical outcome.

METHODS

Tumour infiltrating lymphocytes (TILs) and CD8, FOXP3, PD-1, and PD-L1 were evaluated in sequential biopsies of patients after four cycles of therapy.

RESULTS

From a subgroup of 109 patients who had been randomised between July 1997 and November 2006 to neoadjuvant chemotherapy (53 patients) or neoadjuvant chemotherapy with regional hyperthermia (56 patients), 137 biopsies were obtained. TILs increased in paired second biopsies independent of treatment allocation (p < 0.001). FOXP3 regulatory T cells decreased (p = 0.002), and PD-L1 expression of tumours became undetectable. In the multivariate analysis, post-treatment high TILs correlated to LPFS (HR: 0.34; 95% CI 0.15-0.75; p = 0.008) and DFS (HR: 0.38; 95% CI 0.17-0.82; p = 0.015). In comparing post-treatment immune infiltrate between treatment arms, tumour response was associated with neoadjuvant chemotherapy with regional hyperthermia (p = 0.013) and high TILs (p = 0.064). High CD8 cell infiltration was associated with improved LPFS (HR: 0.27; 95% CI 0.09-0.79; Log-rank p = 0.011) and DFS (HR: 0.25; 95% CI 0.09-0.73; Log-rank p = 0.006). Improved survival at 10 years was associated with immune infiltrate after neoadjuvant chemotherapy with regional hyperthermia.

CONCLUSION

Preoperative therapy re-programs a non-inflamed tumour at baseline into an inflamed tumour. The post-treatment immune infiltrate became predictive for clinical outcomes. The combination with regional hyperthermia primes the tumour microenvironment, enabling enhanced anti-tumour immune activity in high-risk soft tissue sarcomas.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00003052.

Supplementation with Serum-Derived Extracellular Vesicles Reinforces Antitumor Immunity Induced by Cryo-Thermal Therapy

Effective cancer therapies should reshape immunosuppression and trigger antitumor immunity. Previously, we developed a novel cryo-thermal therapy through applying local rapid cooling followed by rapid heating of tumor tissue. It could not only ablate local tumors, but also, subsequently, induce systemic long-term antitumor immunity. Hyperthermia can induce the release of extracellular vesicles (EVs) to stimulate antitumor immunity. We examine whether EVs are released after cryo-thermal therapy and whether they could improve the efficacy of cryo-thermal therapy in the 4T1 model. In this study, serum extracellular vesicles (sEVs) are isolated and characterized 3 h after cryo-thermal therapy of subcutaneous tumors. sEV phagocytosis is observed in vitro and in vivo by using laser confocal microscopy and flow cytometry. After cryo-thermal therapy, sEVs are administered to mice via the tail vein, and changes in immune cells are investigated by using flow cytometry. After cryo-thermal therapy, a large number of sEVs are released to the periphery carrying danger signals and tumor antigens, and these sEVs could be phagocytosed by peripheral blood monocytes and differentiated macrophages. After cryo-thermal therapy, supplementation with sEVs released after treatment promotes the differentiation of myeloid-derived suppressor cells (MDSCs), monocytes into macrophages and CD4⁺ T cells into the Th1 subtype, as well as prolonging the long-term survival of the 4T1 subcutaneous tumor-bearing mice. sEVs released after cryo-thermal tumor treatment could clinically serve as an adjuvant in subsequent cryo-thermal therapy to improve the therapeutic effects on malignant tumors.

Hyperthermia-mediated changes in the tumor immune microenvironment using iron oxide nanoparticles

Iron oxide nanoparticles (IONPs) have often been investigated for tumor hyperthermia. IONPs act as heating foci in the presence of an alternating magnetic field (AMF). It has been shown that hyperthermia can significantly alter the tumor immune microenvironment. Typically, mild hyperthermia invokes morphological changes within the tumor, which elicits a secretion of inflammatory cytokines and tumor neoantigens. Here, we focused on the direct effect of IONP-induced hyperthermia on the various tumor-resident immune cell subpopulations. We compared direct intratumoral injection to systemic administration of IONPs followed by application of an external AMF. We used the orthotopic 4T1 mouse model, which represents aggressive and metastatic breast cancer with a highly immunosuppressive microenvironment. A non-inflamed and 'cold' microenvironment inhibits peripheral effector lymphocytes from effectively trafficking into the tumor. Using intratumoral or systemic injection, IONP-induced hyperthermia achieved a significant reduction of all the immune cell subpopulations in the tumor. However, the systemic delivery approach achieved superior outcomes, resulting in substantial reductions in the populations of both innate and adaptive immune cells. Upon depletion of the existing dysfunctional tumor-resident immune cells, subsequent treatment with clinically approved immune checkpoint inhibitors encouraged the repopulation of the tumor with 'fresh' infiltrating innate and adaptive immune cells, resulting in a significant decrease of the tumor cell population.

Plasmonic Gold Nanostar-Mediated Photothermal Immunotherapy

Cancer is among the leading cause of death around the world, causing close to 10 million deaths each year. Significant efforts have been devoted to developing novel technologies that can detect and treat cancer early and effectively to reduce cancer recurrences, treatment costs, and mortality. Gold nanoparticles (GNP) have been given particular attention for its use with photo-induced hyperthermia coupled with novel immunotherapy methods to provide a new platform for highly selective and less invasive cancer treatment. Among the various GNP platforms, gold nanostars (GNS) have a unique star-shaped geometric structure that allows superior light absorption and photothermal heating. This photothermal effect have also been found to amplify the anti-tumor immune response and can be exploited with adjuvant treatments using immune checkpoint inhibitors. This combination treatment known as Synergistic Immuno Photo Nanotherapy (SYMPHONY) has been shown to reverse tumor-mediated immunosuppression and has led to effective and long-lasting immunity against not only primary tumors but also cancer metastasis. This overview highlights the development and applications of GNS-mediated therapy developed in our laboratory for cancer treatment. This paper also presents recent results of experimental studies to illustrate the superior performance of GNS for photothermal treatment applications.

Characterization of Ferromagnetic Composite Implants for Tumor Bed Hyperthermia

Hyperthermia therapy (HT) is becoming a well-recognized method for the treatment of cancer when combined with radiation or chemotherapy. There are many ways to heat a tumor and the optimum approach depends on the treatment site. This study investigates a composite ferromagnetic surgical implant inserted in a tumor bed for the delivery of local HT. Heating of the implant is achieved by inductively coupling energy from an external magnetic field of sub-megahertz frequency. Implants are formed by mechanically filling a resected tumor bed with self-polymerizing plastic mass mixed with small ferromagnetic thermoseeds. Model implants were manufactured and then heated in a 35 cm diameter induction coil of our own design. Experimental results showed that implants were easily heated to temperatures that allow either traditional HT (39-45°C) or thermal ablation therapy (>50°C) in an external magnetic field with a frequency of 90 kHz and amplitude not exceeding 4 kA/m. These results agreed well with a numerical solution of combined electromagnetic and heat transfer equations solved using the finite element method.

Plasmonic gold nanostars for synergistic photoimmunotherapy to treat cancer

Cancer is the second leading cause of death and there is an urgent need to improve cancer management. We have developed an innovative cancer therapy named Synergistic Immuno Photothermal Nanotherapy (SYMPHONY) by combining gold nanostars (GNS)-mediated photothermal ablation with checkpoint inhibitor immunotherapy. Our previous studies have demonstrated that SYMPHONY photoimmunotherapy not only treats the primary tumor but also dramatically amplifies anticancer immune responses in synergy with checkpoint blockade immunotherapy to treat remote and unresectable cancer metastasis. The SYMPHONY treatment also induces a 'cancer vaccine' effect leading to immunologic memory and prevents cancer recurrence in murine animal models. This manuscript provides an overview of our research activities on the SYMPHONY therapy with plasmonic GNS for cancer treatment.

Hyperthermia with Chemotherapy for Unresectable Gastric Cancer in a Patient with a Vagus Nerve Stimulator Implant: A Case Report

BACKGROUND Radiofrequency (RF) hyperthermia is commonly used as an adjunct to established treatment modalities such as chemotherapy and radiotherapy for the management of cancer patients. This case report aims to introduce the use of hyperthermia, in combination with chemotherapy, for the treatment of unresectable gastric cancer in a patient implanted with a vagus nerve stimulator (VNS). CASE REPORT A 55-year-old man with dermatomyositis, laryngeal squamous cell carcinoma in situ and double synchronous gastric cancer was found to have unresectable gastric disease during surgery despite neoadjuvant chemotherapy. Postoperatively, he received chemotherapy with RF hyperthermia. The patient had a VNS implant to treat epileptic seizures. VNS failure due to RF hyperthermia was an area of significant concern, and the procedures were completed with a full preparation to manage epileptic seizures in the event of its anticipated occurrence. Twenty-one thermotherapies were performed over 21 weeks. After 3 courses of S-1 chemotherapy (12 weeks) with RF hyperthermia without any adverse events, the regimen was changed to S-1+ CDDP combination chemotherapy (SP) and RF hyperthermia. The patient continued to receive treatment with a decrease in the size of the primary gastric tumors as well as lymph node metastases, without major adverse events, until he died due to disseminated disease. CONCLUSIONS We report the first case of unresectable gastric cancer with VNS implants in which chemo-hyperthermal therapy was safe and successful. This case report highlights the importance of providing a multidisciplinary treatment with appropriate measures for patients with intractable cancer who have received special treatments for underlying comorbidities.

A unifying model to estimate the effect of heat stress in the human innate immunity during physical activities

Public health is threatened by climate change and extreme temperature events worldwide. Differences in health predispositions, access to cooling infrastructure and occupation raises an issue of heat-related health inequality in those vulnerable and disadvantaged demographic groups. To address these issues, a comprehensive understanding of the effect of elevated body temperatures on human biological systems and overall health is urgently needed. In this paper we look at the inner workings of the human innate immunity under exposure to heat stress induced through exposure to environment and physical exertion. We couple two experimentally validated computational models: the innate immune system and thermal regulation of the human body. We first study the dynamics of critical indicators of innate immunity as a function of human core temperature. Next, we identify environmental and physical activity regimes that lead to core temperature levels that can potentially compromise the performance of the human innate immunity. Finally, to take into account the response of innate immunity to various intensities of physical activities, we utilise the dynamic core temperatures generated by a thermal regulation model. We compare the dynamics of all key players of the innate immunity for a variety of stresses like running a marathon, doing construction work, and leisure walking at speed of 4 km/h, all in the setting of a hot and humid tropical climate such as present in Singapore. We find that exposure to moderate heat stress leading to core temperatures within the mild febrile range (37, 38][Formula: see text], nudges the innate immune system into activation and improves the efficiency of its response. Overheating corresponding to core temperatures beyond 38[Formula: see text], however, has detrimental effects on the performance of the innate immune system, as it further induces inflammation, which causes a series of reactions that may lead to the non-resolution of the ongoing inflammation. Among the three physical activities considered in our simulated scenarios (marathon, construction work, and walking), marathon induces the highest level of inflammation that challenges the innate immune response with its resolution. Our study advances the current state of research towards understanding the implications of heat exposure for such an essential physiological system as the innate immunity. Although we find that among considered physical activities, a marathon of 2 h and 46 min induces the highest level of inflammation, it must be noted that construction work done on a daily basis under the hot and humid tropical climate, can produce a continuous level of inflammation triggering moieties stretched at a longer timeline beating the negative effects of running a marathon. Our study demonstrates that the performance of the innate immune system can be severely compromised by the exposure to heat stress and physical exertion. This poses significant risks to health especially to those with limited access to cooling infrastructures. This is due in part to having low income, or having to work on outdoor settings, which is the case for construction workers. These risks to public health should be addressed through individual and population-level measures via behavioural adaptation and provision of the cooling infrastructure in outdoor environments.

Magnetic systems for cancer immunotherapy

Immunotherapy is a rapidly developing area of cancer treatment due to its higher specificity and potential for greater efficacy than traditional therapies. Immune cell modulation through the administration of drugs, proteins, and cells can enhance antitumoral responses through pathways that may be otherwise inhibited in the presence of immunosuppressive tumors. Magnetic systems offer several advantages for improving the performance of immunotherapies, including increased spatiotemporal control over transport, release, and dosing of immunomodulatory drugs within the body, resulting in reduced off-target effects and improved efficacy. Compared to alternative methods for stimulating drug release such as light and pH, magnetic systems enable several distinct methods for programming immune responses. First, we discuss how magnetic hyperthermia can stimulate immune cells and trigger thermoresponsive drug release. Second, we summarize how magnetically targeted delivery of drug carriers can increase the accumulation of drugs in target sites. Third, we review how biomaterials can undergo magnetically driven structural changes to enable remote release of encapsulated drugs. Fourth, we describe the use of magnetic particles for targeted interactions with cellular receptors for promoting antitumor activity. Finally, we discuss translational considerations of these systems, such as toxicity, clinical compatibility, and future opportunities for improving cancer treatment.

Photodynamic Therapy and Hyperthermia in Combination Treatment-Neglected Forces in the Fight against Cancer

Cancer is one of the leading causes of death in humans. Despite the progress in cancer treatment, and an increase in the effectiveness of diagnostic methods, cancer is still highly lethal and very difficult to treat in many cases. Combination therapy, in the context of cancer treatment, seems to be a promising option that may allow minimizing treatment side effects and may have a significant impact on the cure. It may also increase the effectiveness of anti-cancer therapies. Moreover, combination treatment can significantly increase delivery of drugs to cancerous tissues. Photodynamic therapy and hyperthermia seem to be ideal examples that prove the effectiveness of combination therapy. These two kinds of therapy can kill cancer cells through different mechanisms and activate various signaling pathways. Both PDT and hyperthermia play significant roles in the perfusion of a tumor and the network of blood vessels wrapped around it. The main goal of combination therapy is to combine separate mechanisms of action that will make cancer cells more sensitive to a given therapeutic agent. Such an approach in treatment may contribute toward increasing its effectiveness, optimizing the cancer treatment process in the future.