Disclaimer: Consult with a doctor before deciding on a treatment plan for cancer or any other disease.
Resonant frequencies operate according to principles that are similar to other treatment modalities such as the Rife Machine. Resonant frequency treatments seek to find vibrational frequencies that resonate with the patients cancer and exploit these to destroy the cancer cell. A variety of treatment centers offer resonant frequencies therapies across the world.
Resonant frequencies occur when one object with a particular frequency takes on the vibration of another object vibrating at the same frequency. In his 2013 TED Talk, Anthony Holland demonstrates resonance with the use of two tuning forks, both tuned to 440hz. When one tuning fork is hit in pulses, the other tuning fork starts vibrating as well. The best comparison for the curing of cancer is in the common cartoon situation where a singer hits a note and shatters resonant windows or glasses in the area. In curing cancer, the cancer cells would be like the glass/windows and the singer’s voice the electric frequencies that surround the patient to effect a cure. 
Resonant frequencies aren’t readily available as a cancer treatment in the United States, nor are they noted as an effective treatment, but they are not actively scandalized either. In contrast, the Rife Machine (a similar treatment based on the same concepts) is often said to be “quackery” despite its huge success with treating cancer.
Safety and Effectiveness
Patients who are receiving RFT generally don’t experience any pain during or after the treatment. They may experience minor discomfort or a tingling sensation during the treatment itself, which is a sign that the treatment is doing what it’s supposed to do. The discomfort/tingling sensation is often experienced as being in or around the area where the patient is sick or has an issue.  
In leukemia, RFT has been shown to work to kill 25-40% of cancer cells on average (in some cases, it worked to kill up to 60% of cancer cells). Of those remaining, the frequencies released with RFT slowed the growth of the cancer cells by up to 60%. Ovarian and pancreatic cancers showed similar success. 
How Resonant Frequency Therapy is Administered
When receiving RFT, patients are advised to drink plenty of water to assist in cleansing the body of waste during and after the treatment. The liver is responsible for filtering the dead cancer cells and their fragments from the body, and in order to do its job properly it must have plenty of water. The Natural Healing Center recommends that patients drink 8-12 (8oz.) glasses of “clean, filtered water” during the treatment to assist in eliminating toxins from the body. 
RFT utilizes electronic signal pulses of particular frequencies to burst cancer cells. The use of pulses ensures that cells in the vicinity of cancer cells don’t overheat from the vibrations, but that the cancer cells are still being targeted with the frequency at intervals that causes cancer cell death. These frequencies are often referred to as oscillating pulsed electronic field (OPEF) technology. 
Other Important Information
The following healing/cancer centers offer resonant frequency therapies:
- The Natural Healing Center in Myrtle Beach, SC. (http://naturalhealingcentermb.com/resonant-therapy/)
- Dr. Greg Ling, D.C. – Alternative Healing Therapies in Grand Haven, MI. (http://www.drgregling.com/Resonant-Frequency-Therapy.html )
- The Medical Frequency Centre with locations in Hyderabad (India), Karachi (Pakistan), Kuala Lumpur (Malaysia), and Singapore. (https://medicalfrequencycentre.com/)
RFT is similar to the Rife Machine. There is much overlap between these two methods of treating cancer, since they both make use of vibrational frequencies to kill cancer cells. The difference is that with RFT the resonant frequencies used are emitted into the air, and aren’t necessarily directed in any particular direction. In other words, RFT uses “far field” tools. In contrast, the Rife Machine is often aimed at a particular area of the body or is directed toward a particular individual (it is a “near field” tool). Another difference between the two therapies is that RFT is capable of treating many people at once, but the Rife Machine works to treat only one person at a time. However, despite their differences, the concept between the two modalities remains the same. 
 Holland, Anthony (2013). Shattering cancer with resonant frequencies: Anthony Holland at TEDxSkidmoreCollege. Retrieved April 17, 2018 from: https://www.youtube.com/watch?v=1w0_kazbb_U
 Natural Healing Center (2016). Resonant Therapy. Retrieved April 17, 2018 from: http://naturalhealingcentermb.com/resonant-therapy/
 N.A. (2015). Shattering Cancer With Resonant Frequencies. Retrieved April 23, 2018 from: https://www.gatewaycr.org/gateway-blog/posts/2015/october/shattering-cancer-with-resonant-frequencies/
 Dr. Zayed, Ahmed (2016). Bioresonance Frequency Explained. Retrieved April 23, 2018 from: https://bioresonance.com/bioresonance-frequency-explained/
 Bare, James E., D.C. (2010). A Brief Introduction to Resonant Frequency Therapy. Retrived April 23 from: http://www.rexresearch.com/bare/bare.htm