Hyperthermia

What is hyperthermia?

Hyperthermia therapy involves heating the tumor(s) to temperatures up to 112 F for a short time with a medical device known as the I-wave.   The extreme heat makes cancer cells more sensitive to radiation and chemotherapy, helping these treatments work better without any risk of burning the skin or other side effects.

How does it help?

Studies have compared radiation alone versus radiation plus hyperthermia (sometimes also with chemotherapy). Here’s what they found:

• Better tumor shrinkage and control
• In one large study, adding hyperthermia more than doubled the chance of the cancer completely disappearing (about 82% vs 37% with radiation alone).
• When all studies were pooled together, about 6 out of 10 patients had their tumor completely disappear with heat + radiation, compared to 4 out of 10 with radiation alone.
• Stronger results in tough cases
• For patients whose head and neck cancer came back after earlier treatment, combining chemo + radiation + heat still gave very good results:
• Tumors shrank in about 8 out of 10 patients, and in more than half, the tumor disappeared completely.
• About 57% of patients were still alive two years later, which is encouraging compared to typical survival rates in this difficult situation.
• Tongue and oral cavity cancers with large neck nodes
• In a Japanese study of patients with very advanced disease in the neck, using chemotherapy delivered directly into the tumor’s blood supply, plus radiation and heat, led to about half of patients living 5 years or longer. Most of those patients had excellent local control of the cancer in the neck.

• Many clinical studies have shown that Local Hyperthermia can:

• • Favorably Alter the Tumor Microenvironment
  • Improve Chemotherapy Efficacy up to 500%
  • Improve Radiation Efficacy up to 300%
  • Reduce Cancer Pain
  • Induce Cancer Cells Apoptosis (cell death) 
  • Improve Tumor Control and double Survival rate

What about side effects?

• Adding heat therapy did not increase the usual side effects of radiation or chemotherapy, such as mouth soreness, skin irritation, or swallowing problems.
• Burns from the heat treatment rarely occur (1 in 10,000 patient treatments) due to computer controlled sensors that prevent excessive surface skin temperatures.
• Some patients reported more comfort-related issues (warmth, temporary skin redness), but these were generally mild.

What are treatments like?  How many?  How long?

Treatments are comfortable for the patients.  The treatment applicator is placed over the target tissue and secured with an elastic band.  Patients report a gentle warmth, often described as relaxing.  Treatments take 60 minutes and recommended to be performed 2-3 times per week for 8 weeks. 

Why I-wave?  For the intellectually curious and technical types (nerds)

Older technology hyperthermia devices had many limitations and fell out of favor for cancer treatments. The BSD-500 Pyrexar is still utilized in a few US clinics and was previously considered state-of-the-art technology.  This device emits energy from outside the body.  This provides only a portion of the electromagnetic wave to reach the tumor because most of it is reflected by the skin.  When the reflected and the transmitted waves combine, they create a high current density at the skin’s surface which will burn the skin. 

To compensate for this technological limitation, the Purexar device requires a cooled water bolus that is placed between the radio applicator and the skin.  This improves skin contact and reduces the heat from the reflected wave, but the water absorbs a significant amount of energy.  The reduced energy delivery obviously reduces the efficacy of the therapeutic heating of the target tissue making the process very inefficient. 

This system requires high-power levels (200 – 500 W) to compensate for the power loss and still cannot achieve temperatures above 42.5 C without burning the skin.  The temperature sensors must be surgiccally inserted into the tumor and constantly monitored by a skilled operator to adjust the phase and amplitude of the antennas to maintain the desired temperature.  The depth of penetration of the therapy is up to 1 inch.

Why I-Wave vs. Traditional Heat Therapy?

The I-Wave Medical device utilizes dual frequency phased array technology and a direct contact applicator that projects a deep energy field inside the body.  This technological advancement provides a more consistent and safer energy delivery that bypasses the skin so almost all the power is delivered to the targeted tumor tissue. 

The efficiency of the I-wave technology allows for an internal tumor temperature of up to 112 F with the maximum skin surface temperature of only 104 F.  This system can deliver thermal doses 8 to 16 times more than the older BSD technology.  The application pad contains 5 temperature sensors which provide constant skin temperature data in order to automatically adjust the power delivery to maintain a safe surface temperature and the maximal internal tumor temp.  The depth of penetration of therapy varies from 6 inches in soft tissue (muscle and fat) and 3 for more bony treatment areas such as the knee. 

The I-wave is not yet FDA approved for the treatment of any condition. There are no guarantees of benefit or treatment response.

Hannon, Gary & Tansi, Felista & Hilger, Ingrid & Prina-Mello, Adriele. (2021). The Effects of Localized Heat on the Hallmarks of Cancer. Advanced Therapeutics. 2000267.10.1002/adtp.202000267.   This review discusses the evidence associated with the effects of localized heat on the hallmarks of cancer. Key literature describing modulations to vasculature, cell viability, DNA damage and repair, metabolism, immune system, and tumor metastasis in response to heat will be reviewed along with considerations for its optimal implementation in the clinic to enhance the efficacy of conventional treatments.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adtp.202000267