Disclaimer: Consult with a doctor before deciding on a treatment plan for cancer or any other disease.
Sonodynamic Therapy is a technique that involves several components in tandem with ultrasound in order to sensitize, damage, and then kill cancer cells. Sonodynamic therapy may be used in tandem with photodynamic therapy. A variety of activators can be used to sensitize cancer cells to this treatment modality.
Sonodynamic therapy (SDT) use a series of chemical interactions along with ultrasound to damage and kill cancer cells. The treatment has shown success specifically with solid cancerous tumors that are seated deeper in the body, since the ultrasound frequencies used in SDT are capable of reaching further through tissue to target cancer cells than other similar methods like photodynamic therapy. 
The treatment consists of three primary components:
1) a sensitizing drug
3) molecular oxygen.
The combination of these components creates ROS (reactive oxygen species), which can in turn be used to kill cancer cells. The non-invasive nature of this treatment, in addition to the use of more affordable and safe ultrasound treatments make SDT an appealing treatment option for cancer. 
How Sonodynamic Therapy Is Administered
Sonodynamic therapy is a treatment that can be done at home or in a clinic (the Hope4Cancer clinic offers patients an at-home treatment). Twenty-four hours before each treatment, the patient takes an “activator,” which is a non-toxic chemical sono-sensitizing substance. The activator selectively attaches itself to cancer cells in the body, thus allowing the sound waves from the SDT treatment to effectively reach their target. SDT is designed to only target cancer cells, so healthy cells are unaffected and unharmed by the treatment. 
There are numerous activators that may be used in SDT, but they fall into three different groups:
1) porphyrin-based sensitizers (i.e. Photofrin)
2) xanthene-based sensitizers (Rose Bengal)
3) non-steroidal anti-inflammatory sensitizers (quinolone compounds, like ciprofloxacin and tenoxicam) 
4) sensitizers that don’t fit in any category (Curcumin, methylene blue, and acridine orange, and indocyanine green).
Because most of these activators are also used with photodynamic therapy, they can often result in the patient having some sensitivity to light immediately after the treatment. There are no other observed side effects of the treatment. 
The treatment is often used in combination with photodynamic therapy, a treatment that works similarly to SDT, except that it uses light instead of sound to activate sensitizers and cause chemical reactions to create the cancer fighting ROS (the combination treatment is known commonly as NGPDT (next generation photodynamic therapy) or SPDT). 
Other Important Information
The following clinics have listed on their websites as of March 2018 that they offer sonodynamic therapy treatment for patients:
∙ Hope4Cancer Clinic. Website: https://hope4cancer.com/
∙ The various Saisei Mirai Clinics (locations in Tokyo, Osaka, and Kobe). Website: https://www.saisei-mirai.or.jp/index_eng.html
∙ Resurrection Clinics Europe (associated with the above) with locations in Düsseldorf, Germany and Roermond, Netherlands. Website: http://www.resurrection-clinics.eu/index.php/de/
∙ Immunity Therapy Center in Tijuana, Mexico. Website: https://www.immunitytherapycenter.com/
 Atchison, Jordan; Callan F., John; Costley, David; Fowley, Colin; McEwan, Conor; McHale P., Anthony; Nomikou, Nikolitsa (2015). Treating cancer with sonodynamic therapy: A review. Retrieved March 16, 2018 from: https://www.researchgate.net/publication/270827937_Treating_cancer_with_sonodynamic_therapy_A_review
 Berrios, Karen (2017). Sono-Dynamic Therapy. Retrieved March 19, 2018 from: https://www.karenberrios.com/sono-dynamic-therapy/
 Wan, Guo-Yun; Liu, Yang; Chen, Bo-Wei; Liu, Yuan-Yuan; Wang, Yin-Song; Zhang, Ning (2016). Recent advances of sonodynamic therapy in cancer treatment. Retrieved March 19, 2018 from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5069838/