The therapy was developed in close consultation with physicians at the Charité

WHAT ADVANTAGES DOES THERMOTHERAPY WITH NANOPARTICLES HAVE?

The cell-damaging effects of hyperthermia have been used therapeutically for a long time. Common hyperthermia procedures utilize various energy sources to generate a temperature increase within the tissue: externally radiated electromagnetic waves (such as radiofrequency or microwave hyperthermia), ultrasound (external or interstitial), current flow between two or more electrodes, electrical or magnetic fields between implanted antennas, electrically or magnetically activated thermoseeds or tubes fed with warm water. The greatest problem with the hyperthermia procedures used today is how to reach homogeneous heat distribution in the treated tissues. If this is not achieved, results may include an undersupply in tumor areas or organ damage due to excessively high temperatures in other regions.
NanoTherm® therapy is a special form of local deep thermotherapy. It has the advantage that for the first time, heat deposition specifically targets the tumor cells, thereby largely meeting the need for maximum deposition of the heat dosage in the target volume while sparing the surrounding healthy tissues as much as possible.

HOW DOES NanoTherm® THERAPY WORK IN DETAIL?

The treatment method is based on a defined energy transmission to biocompatible super paramagnetic nanoparticles in an alternating magnetic field. The resulting high heat production is determined by the particle type, the particle concentration, the frequency of the alternating magnetic field, and the magnetic field intensity. Depending on the duration of treatment and the achieved intratumoral temperatures, the tumor cells are either directly destroyed (thermal ablation) or sensitized for concomitant chemo or radiotherapy (hyperthermia).

Furthermore, thermotherapy with magnetic nanoparticles offers other fundamental advantages:

  • The magnetic fluid can be meted out amounts as small as necessary and therefore dispensed almost continuously in the target volume.
  • Due to the known energy absorption per nanoparticle, the energy transmission can be calculated from the density distribution, which is measured in the CT. This enables the three-dimensional calculation and simulation of the temperature distribution.
  • The ability to introduce a defined quantity into a target volume assures a controllability, not given in other interstitial procedures.
  • The nanoparticles remain in place at the treatment area, allowing repeated treatments and integration of multimodal therapy concepts.

WHAT ATTRIBUTES DO NANOPARTICLES POSSESS?

The magnetic fluid consists of super paramagnetic nano-scaled iron oxide particles in an aqueous solution with an iron concentration of approximately 112 mg/mL. The nanoparticles consist of an iron oxide core with a diameter of approximately 12 nm and a coating of aminosilanes. This covering allows the colloidal dispersion of the particles in an aqueous solution. The core, which consists of magnetite, has intrinsic magnetic energy which is activated by the externally applied alternating magnetic field. Due to relaxation processes, the particles release heat into their surroundings.

HOW ARE THE PARTICLES INTRODUCED INTO THE TUMOR?

In principle, the instillation of the nanoparticles can be done with any commercially available cannula (min. 19 Gauge). The dosage is 0.3 ml (± 0.1 ml) magnetic fluid per cm3 target volume. The distance between the injection canals should not be more than 8-10 mm. Through slow withdrawal of the cannula within the injection canal, the magnetic liquid is distributed in portions of 0.3 ml pro cm. The instillation of the nanoparticles is carried out either stereotactically (brain tumors), through transrectal ultrasound and X-ray guidance (prostate carcinoma), interoperatively (R1-Situation), or CT guided (other tumors).

HOW IS TREATMENT IN THE MAGNETIC FIELD APPLICATOR CARRIED OUT?

NanoTherm® therapy is carried out in a magnetic field applicator (NanoActivator®) which was developed specifically for this form of therapy. The alternating magnetic current has a frequency of 100kHz and produces a field strength between 2 and 15 kA/m. This magnetic current activates the iron oxide nanoparticles of the NanoTherm® magnetic liquid and therapeutic treatment temperatures are achieved within the tumor. The NanoActivator® can be used to treat tumors in all parts of the body. Patients are regularly treated six times with each session lasting around one hour. The treatment period lasts three weeks (two treatments per week).