Hyperthermia for cancer treatment

Introduction

Hyperthermia is a treatment that involves heating body tissue up to 113 ° F to damage and destroy cancer cells without harming normal tissue. It is also called thermal therapy, thermal ablation, or thermotherapy.

Hyperthermia treatment is a non-invasive procedure of increasing tumor temperature to stimulate blood flow, increase oxygen supply, and make tumor cells more sensitive to radiation. By adding hyperthermia to radiation therapy, radiation oncologists can improve tumor control and minimize damage to healthy tissue. 

Hyperthermia also helps in approaching the limitations of radiation therapy by managing unwanted side effects of radiation due to an increase in dosage.

There are different techniques for generating the heat required for hyperthermia treatment. These include probes that make energy from microwaves, radio waves(radiofrequency), lasers, ultrasound, perfusion(putting heated fluids like blood or chemotherapy drugs into the body), placing the entire body in a heated chamber or wrapping the body with hot blankets or in a hot water bath.

Hypothermia and cancer

Hyperthermia is always used with other forms of cancer treatment. Many clinical studies indicates that hyperthermia combined with radiotherapy and chemotherapy can help shrink tumors and kill cancer cell easily.

During the treatment, the doctor anaesthetizes the area to be treated and inserts a tiny probe with a small thermometer into the tumor. Thermometers help doctors closely monitor the temperature of tumors and nearby tissues during treatment. Imaging methods such as computed tomography is used for verification.

Types of hyperthermia for cancer treatment

Hyperthermia may deal with small regions of the body, massive regions, or the complete body. Based on the region, different types of hyperthermia techniques are used.


For local hyperthermia, the doctor will administer heat to a small area. Radio waves, microwaves, ultrasound waves, and other forms of energy can heat the area. When ultrasound is used, the technique is known as high intensity focused ultrasound, or HIFU, sometimes referred to simply as focused ultrasound. The type of local hyperthermia used depends on the location of the tumor.
External hyperthermia is used to treat tumors on or under the skin. In this type of hyperthermia, the doctor will place heating devices around or near the treatment area.
Intraluminal or endocavitary hyperthermia treats tumors in or near body cavities, such as the oesophagus or rectum. In this hyperthermia, the doctor places heating probes in the cavity and inserts them into the tumor.

Interstitial hyperthermia is used to treat tumors that are deep in the body, such as the brain. This type of hyperthermia heats the tumor to a higher temperature than external methods. When you are under anesthesia, your doctor will insert a probe or needle into the tumor. Ultrasound is used to ensure that the transducer/probe is in the correct position.

Radiofrequency ablation(RFA) is a form of interstitial hyperthermia. RFA uses high energy radio waves for this technique. A thin, needle-like probe is inserted into the tumor for a short time, of 10 to 30 minutes. The probe is slowly guided into position by ultrasound or MRI or CT scans. a high-frequency current that generates very high levels of heat and destroys cells in a specific area. RFA is most usually used to deal with tumors that can’t be eliminated with surgical procedures or for sufferers who can’t undergo the stresses of surgical procedures. RFA can be repeated for tumors that come lower back or begin to grow. It also can be introduced to different remedies like surgical procedures, radiation therapy, chemotherapy, hepatic arterial infusion therapy, alcohol ablation, or chemoembolization.

Deep tissue strategy deals with cancers inside the body, inclusive of cervical or bladder cancer. During this procedure, instruments that produce heat are located across the hollow space/cavity or organ to be handled, and energy is concentrated at the region to elevate its temperature.

The regional perfusion method deals with cancers withinside the limbs which include melanoma, or in a few organs, like the liver or lung. Throughout this procedure, some of your blood is removed, heated, after which pumped returned into the limb or organ. Chemotherapy is regularly given all through this treatment.

Continuous hyperthermic peritoneal perfusion treats most cancers inside the peritoneal cavity; that is, the space inside the stomach includes the intestines, stomach, and liver. This treatment is given in the course of surgery. While you’re under anaesthesia, the heated chemotherapy pills/cancer drugs flow from a warming machine through the peritoneal cavity, inflicting the temperature withinside the vicinity to attain 106 to 108°F.

Whole-body hyperthermia treats most cancers that have diffused throughout the inside of the body. In this form of hyperthermia, you’re positioned in a thermal chamber or wrapped in warm water blankets that elevate your body temperature to 107 or 108 °F for brief intervals of time.

Cancers treated with hyperthermia

Hyperthermia therapy is not widely available to treat different cancer types. It is used for advanced cancers, includes appendix cancer, bladder cancer, brain cancer, breast cancer, cervical cancer, oesophagal cancer, head and neck cancer, liver cancer, lung cancer, melanoma, mesothelioma(tumor of tissue that lines lungs, stomach, heart and other organs called the mesothelium), sarcoma(soft tissue cancer), rectal cancer, thyroid cancer, leukaemia. 

Limitations and side effects

The hyperthermia is performed with specific and unique equipment and expertise, not extensively available.

Most of the time, healthy tissue is not damaged under 111oF, but due to different compositions of the tissue may cause burns, discomfort or pain.

Perfusion techniques may cause swelling, blood clots, bleeding, and cause other damage in the treated area to the normal, healthy tissues. But most of these side effects progress after the treatment.

Nausea, vomiting, diarrhoea can be common side effects after whole-body hyperthermia therapy. It may sometimes cause more severe side effects like heart and blood vessels problems.