Hyperthermia doubles cancer response rate

Munich, March 9, 2017: Clinical data has already demonstrated that adding superficial hyperthermia to radiation in the treatment of recurrent breast cancer and malignant melanoma can double the complete response rate (1). Now a new report published in the "International Journal of Hyperthermia" proves that radiated hyperthermia is the superior method for the treatment of these superficial cancerous tumors.

Hyperthermia, i.e. the heating of tumors to temperatures of 41-45 °C for one hour, is a proven radiosensitizer and chemosensitizer. The superficial form of hyperthermia is applied to tumors infiltrating up to four centimeters into the tissue. Locally recurrent breast cancer (LRBC) is one example of superficial tumor sites for which the effectiveness and safety of combined radiotherapy and hyperthermia has been proven. Only last April, a systematic review and meta-analysis of the results from 34 studies, totaling 2,110 patients, revealed that the overall complete response (tumor eliminated) rate for LRBC increases by 22% to over 60% after adding hyperthermia to radiotherapy. Moreover, in those patients who had been previously irradiated a complete response rate of 66.6% was achieved by combining hyperthermia with reirradiation, without any additional significant treatment morbidity (2).

This increase in clinical outcome as a result of adjuvant hyperthermia is related to the quality of the hyperthermia treatment, i.e. the thermal dose realized in the target region, the goal being 43 °C. Unfortunately, not all methods of hyperthermia are equal.

There are basically two heat delivery methodologies – capacitive and radiated electromagnetic fields. In a recent study at the Department of Radiation Oncology, AMC Academisch Medisch Centrum Amsterdam, Dr. H.P. Kok and Dr. J. Crezee compared the two methods to determine which technique offers the more effective heating characteristics. Not only are there differences between the two heating methods, not all the systems on the market are capable of achieving the required results. For instance, of the five radiated and capacitive hyperthermia systems specifically named in the report, Pyrexar’s BSD-500 system is the only one to have earned FDA approval. This is a portable, fully self-contained radiated system for the treatment of superficial tumors within a few centimeters of the skin surface. It features temperature probes for accurate thermal dosing and monitoring, as well as interchangeable superficial applicators in multiple configurations for treating a range of tumor sizes and locations.

Using their own hyperthermia treatment planning software, the Dutch researchers computed the heat delivery in terms of the specific absorption rate (SAR) and with regard to the temperature distribution. They performed their comparative simulations on a perfused muscle-equivalent phantom and phantoms with a superficial fat layer, assuming a cylindrical superficial target region. Subsequently, they examined a real patient model with a breast cancer recurrence derived from a CT data set, with the target assumed to have muscle-like properties, fat properties or heterogeneous properties in each case.

The results showed that capacitive heating techniques are limited by the fat layer, often resulting in hot spots that cause patient discomfort and prevent the tumor from attaining the temperature necessary for a therapeutic effect. The Pyrexar BSD-500 system uses radiated microwaves at a frequency of 434 MHz to transmit the energy into the body which is absorbed by the tissue as heat, thus reaching the cancer tumor instead of being trapped in the fat layer.

In fact, the researchers observed that radiative hyperthermia yields a temperature in at least 90% of the target volume that is 0.4–1.1 °C higher compared to capacitive heating. This corresponds approximately to a factor 2–4 difference in the thermal dose. Due to the higher tumor temperatures that can be achieved before treatment-limiting hot spots occur, Drs. Kok and Crezee concluded that radiative heating will benefit the clinical outcome.

View the entire report here: http://www.tandfonline.com/doi/abs/10.1080/02656736.2016.1268726?journalCode=ihyt20

(1) Based on published Phase III Clinical Studies
(2) Datta, Niloy R. et al. Hyperthermia and Radiation Therapy in Locoregional Recurrent Breast Cancers: A Systematic Review and Meta-analysis. Int J Radiation Oncol Biol Phys, Vol. 94, No. 5, pp. 1073–1087, 2016

About Dr. Sennewald Medizintechnik:
Dr. Sennewald Medizintechnik GmbH was founded in 1985 by Dr. Gerhard Sennewald in Munich with the goal of discovering trendsetting electro-medical systems providing innovative and beneficial medical treatments and introducing them in Europe. From the beginning, cancer therapy was at the forefront of the company, with a focus on regional and local hyperthermia.

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This release was published on openPR.