Different hyperthermia devices use different forms of energy. Common sources include radiofrequency (RF), microwave, ultrasound, and infrared, each with different penetration depth and energy distribution characteristics. This page compares only objective physical properties and does not address the relative efficacy of any specific product.
Comparing physical properties of common energy sources
(This table has several columns — on a mobile screen you may need to swipe left/right to see all of it.)
| Energy form | Typical operating frequency range | Penetration depth characteristics | Common use cases |
|---|---|---|---|
| Radiofrequency (RF) | Roughly hundreds of kHz to tens of MHz | Relatively able to reach deeper tissue | Local / regional hyperthermia |
| Microwave | Roughly hundreds of MHz to a few GHz | Relatively shallower penetration, energy more concentrated near the surface | Surface or near-surface lesions |
| Ultrasound | Energy focus point can be adjusted via focusing techniques | Can reach specific depths through focusing | Local focused heating |
| Infrared | Falls within the thermal-radiation range of the electromagnetic spectrum | Acts mainly at the body surface | Surface warming applications |
The table above describes physical properties at a general engineering level. Actual penetration depth, energy distribution, and treatment effect can vary significantly depending on individual device design, electrode or probe configuration, tissue characteristics, and parameter settings — physical properties alone should not be used to infer clinical efficacy differences between devices.
Why do devices use different energy forms?
Depending on the treatment purpose (surface vs. deep lesions), target area size, and clinical use case, engineering design chooses different energy forms and electrode configurations. This is a technical trade-off made during device development and is a separate question from whether a treatment is effective.
Any comparison between energy sources here is limited to objective physical properties (frequency, penetration depth, and similar engineering specifications) and does not constitute an efficacy comparison or superiority claim between different technologies or products.
Does deeper penetration always mean better treatment results?
Not necessarily. Penetration depth is just one of many technical parameters. Actual clinical suitability also depends on tumor location, size, surrounding tissue tolerance, and the overall treatment plan. It cannot be judged by penetration depth alone and should be comprehensively assessed by the care team.
Last updated: 2026-08-16 | Source: General publicly available medical engineering educational material. If content differs from the latest research, the latest publicly available information takes precedence — please also consult your care team.