Microvasculature and Perfusion in Normal Tissues and Tumors. In: Seegenschmiedt MH, Fessenden P, Vernon CC, editors. Thermoradiotherapy and Thermochemotherapy. Berlin: Springer Berlin Heidelberg; 1995. pp. 139-56. [DOI: 10.1007/978-3-642-57858-8_7]

Quo Vadis Oncological Hyperthermia (2020)?

Heating as a medical intervention in cancer treatment is an ancient approach, but effective deep heating techniques are lacking in modern practice. The use of electromagnetic interactions has enabled the development of more reliable local-regional hyperthermia (LRHT) techniques whole-body hyperthermia (WBH) techniques. Contrary to the relatively simple physical-physiological concepts behind hyperthermia, its development was not steady, and it has gone through periods of failures and renewals with mixed views on the benefits of heating seen in the medical community over the decades. In this review we study in detail the various techniques currently available and describe challenges and trends of oncological hyperthermia from a new perspective. Our aim is to describe what we believe to be a new and effective approach to oncologic hyperthermia, and a change in the paradigm of dosing. Physiological limits restrict the application of WBH which has moved toward the mild temperature range, targeting immune support. LRHT does not have a temperature limit in the tumor (which can be burned out in extreme conditions) but a trend has started toward milder temperatures with immune-oriented goals, developing toward immune modulation, and especially toward tumor-specific immune reactions by which LRHT seeks to target the malignancy systemically. The emerging research of bystander and abscopal effects, in both laboratory investigations and clinical applications, has been intensified. Our present review summarizes the methods and results, and discusses the trends of hyperthermia in oncology.

Consensus Perioperative Management Best Practices for Patients on Transdermal Fentanyl Patches Undergoing Surgery

PURPOSE OF REVIEW

The administration of a transdermal fentanyl patch can be complicated with different pharmacokinetics than other fentanyl preparations.

RECENT FINDINGS

The medical condition and baseline opioid requirements must all be carefully considered when dosing a fentanyl patch. An advantage of the fentanyl patch is its ability to bypass the gastrointestinal tract and in many patients, provide effective analgesia with minimal side effects. Fentanyl patches must be carefully administered since morbidity and/or mortality can result from the following: Giving higher doses than a patient needs, combining the medication with potent sedatives, or heating a fentanyl patch. The use of a transdermal fentanyl patch for the treatment of acute postoperative pain is not recommended and any patient undergoing a surgical procedure should have the fentanyl patch removed preoperatively. The current manuscript discusses the history of fentanyl and the fentanyl patch, as well as perioperative considerations, contraindications, current clinical efficacy, and clinical adversities related to the transdermal fentanyl patch. Regarding the heating of a transdermal fentanyl patch, which significantly increases blood levels of fentanyl, it is of the utmost importance that the patch be removed prior to surgery.

Microwave Ablation of Primary Malignant Pelvic Bone Tumors

Background: En bloc tumor resection followed by reconstruction is a widely used surgical treatment for malignant pelvic bone tumors. High rates of complications and mechanical instability often contribute to poor postoperative results. We attempted en bloc microwave ablation (MWA) in situ to improve the outcome.

Methods: From May 1995 to December 2015, 104 patients with primary pelvic malignancy received radical MWA in our department. After careful dissection of the tumor-bearing bone from surrounding normal tissues with safe margins, a microwave antenna array was inserted into the tumor mass to emit electromagnetic energy, inducing tumor cellular death via thermocoagulation. The loose, devitalized tumor tissues were removed by cutting or curettage, leaving a defective bone scaffold. Re-strengthening by autograft or allograft was needed in most patients.

Results: The over 3 years survival rate was 51.5% for high-grade malignancies (among them, 26.9% were osteosarcoma) and 94.8% for low-grade malignancies (chondrosarcoma). In most of the living patients, cosmetic and useful limbs were preserved. The mean functional score (Musculoskeletal Tumor Society) was 27 or 90% (range: 25–30, 75–100%). Among the 56 patients who belonged to the excellent function group, 11 were followed up for more than 10 years. The local recurrence rate was 8.6%. Among the 9 patients with recurrence, 5 died from disease, 2 were treated by hemipelvic amputation, and 2 underwent revision surgery with MWA and gained local control. The deep infection rate was 5.6%. All six patients with infection were healed by irrigation, debridement, and systemic antibiotic administration.

Conclusion: Local, microwave-induced hyperthermia for treating malignant pelvic bone tumors is an effective alternative method. The oncological and functional results are encouraging. The use of MWA should be continued to evaluate and improve this new therapeutic system.

Retrospective Clinical Study of Advanced Pancreatic Cancer Treated With Chemotherapy and Abdominal Hyperthermia

PURPOSE

Hyperthermia is a mechanistically plausible partner with chemotherapy, although many of the underlying molecular mechanisms of this combination treatment are not yet properly understood. Preclinical studies suggest that there is potential synergy with gemcitabine and that provides the basis for retrospective analysis of a clinical series combining these treatment modalities for patients with advanced pancreatic cancer.

PATIENTS AND METHODS

Twenty-nine chemotherapy-naive patients with locally advanced or metastatic pancreatic carcinoma with malignant ascites were treated with intraperitoneal cisplatin 30 mg/m² and gemcitabine 800 to 1,000 mg/m² intravenously on days 1, 8, and 15 every 28 days until tumor progression. Patients also received regional hyperthermia treatment (41 to 42°C) on the upper abdomen two times per week from days 1 to 21.

RESULTS

In all, 83 cycles of chemotherapy were administered and were generally well tolerated. No patients had a complete response, 13 had a partial response, seven had stable disease, and 9 had progressive disease. Mean progression-free survival and overall survival were 119 ± 61days and 195 ± 98 days, respectively.

CONCLUSION

This study provides preliminary evidence that the treatment approach of combined systemic and intraperitoneal chemotherapy plus hyperthermia is well tolerated, is active, and has an acceptable survival profile for patients with stage IV pancreatic cancer and ascites.

Hyperthermia: an effective strategy to induce apoptosis in cancer cells

Heat has been used as a medicinal and healing modality throughout human history. The combination of hyperthermia (HT) with radiation and anticancer agents has been used clinically and has shown positive results to a certain extent. However, the clinical results of HT treatment alone have been only partially satisfactory. Cell death following HT treatment is a function of both temperature and treatment duration. HT induces cancer cell death through apoptosis; the degree of apoptosis and the apoptotic pathway vary in different cancer cell types. HT-induced reactive oxygen species production are responsible for apoptosis in various cell types. However, the underlying mechanism of signal transduction and the genes related to this process still need to be elucidated. In this review, we summarize the molecular mechanism of apoptosis induced by HT, enhancement of heat-induced apoptosis, and the genetic network involved in HT-induced apoptosis.

Simulation techniques in hyperthermia treatment planning

Abstract Clinical trials have shown that hyperthermia (HT), i.e. an increase of tissue temperature to 39-44 °C, significantly enhance radiotherapy and chemotherapy effectiveness [1]. Driven by the developments in computational techniques and computing power, personalised hyperthermia treatment planning (HTP) has matured and has become a powerful tool for optimising treatment quality. Electromagnetic, ultrasound, and thermal simulations using realistic clinical set-ups are now being performed to achieve patient-specific treatment optimisation. In addition, extensive studies aimed to properly implement novel HT tools and techniques, and to assess the quality of HT, are becoming more common. In this paper, we review the simulation tools and techniques developed for clinical hyperthermia, and evaluate their current status on the path from 'model' to 'clinic'. In addition, we illustrate the major techniques employed for validation and optimisation. HTP has become an essential tool for improvement, control, and assessment of HT treatment quality. As such, it plays a pivotal role in the quest to establish HT as an efficacious addition to multi-modality treatment of cancer.

Miniature microwave applicator for murine bladder hyperthermia studies

PURPOSE

Novel combinations of heat with chemotherapeutic agents are often studied in murine tumour models. Currently, no device exists to selectively heat small tumours at depth in mice. In this project we modelled, built and tested a miniature microwave heat applicator, the physical dimensions of which can be scaled to adjust the volume and depth of heating to focus on the tumour volume. Of particular interest is a device that can selectively heat murine bladder.

MATERIALS AND METHODS

Using Avizo(®) segmentation software, we created a numerical mouse model based on micro-MRI scan data. The model was imported into HFSS™ (Ansys) simulation software and parametric studies were performed to optimise the dimensions of a water-loaded circular waveguide for selective power deposition inside a 0.15 mL bladder. A working prototype was constructed operating at 2.45 GHz. Heating performance was characterised by mapping fibre-optic temperature sensors along catheters inserted at depths of 0-1 mm (subcutaneous), 2-3 mm (vaginal), and 4-5 mm (rectal) below the abdominal wall, with the mid depth catheter adjacent to the bladder. Core temperature was monitored orally.

RESULTS

Thermal measurements confirm the simulations which demonstrate that this applicator can provide local heating at depth in small animals. Measured temperatures in murine pelvis show well-localised bladder heating to 42-43°C while maintaining normothermic skin and core temperatures.

CONCLUSIONS

Simulation techniques facilitate the design optimisation of microwave antennas for use in pre-clinical applications such as localised tumour heating in small animals. Laboratory measurements demonstrate the effectiveness of a new miniature water-coupled microwave applicator for localised heating of murine bladder.