PRF1 and neoplasm: According to the results, FA-FRT-PFP had the following advantages: (1) PFP could be easily loaded into FRT by changing the pH from acidic to neutral; (2) under low-intensity focused ultrasound (LIFU, 2 W/cm2, 3 min) and pH = 5.0, FA-FRT-PFP releases PFP and undergoes phase changes to enhance US imaging signals through acoustic droplet vaporization (ADV); 3) Under long-term LIFU irradiation (4 min) and pH = 5.0, the PFP released from FA-FRT-PFP exploded and produced a physical shock wave that could effectively destroy tumor cells through necrosis.