Cold Caps and Cooling Sytems
Scalp cooling is achieved by wearing a specially lined cap designed to fit snugly (Table 1). The cap lining is filled with a gel that stays flexible even when frozen. Prior to each chemotherapy session several caps are chilled to between –15°F to –40°F either manually (the patient stores the caps in a cooler filled with dry ice) or mechanically (placed in a mechanical cooler at the infusion center). A home freezer will not bring the caps down to the proper temperature; the cold cap process requires using a freezer that can maintain a temperature of –30°C (–22°F).
TABLE 1. Cold Caps and Cooling Systems.
|Manual Cold Caps|
|Arctic Cold Caps
|Penguin Cold Caps
|Computerized Cooling Systems|
|Dignicap — Intelligent Scalp Cooling System
|Paxman Scalp Cooling System
Some infusion centers have special biomedical freezers that freeze and maintain the caps at the ideal temperature. Patients bring their caps to the infusion center the day before their treatment and put the caps in the biomedical freezer so they will be ready for the next day’s chemotherapy session. The caps are worn for approximately 1 hour before and up to 4 hours after each infusion session, depending on the type of chemotherapy administered.5
Manual caps are uncomfortably cold when first placed on the patient’s head. However, the discomfort resolves after several minutes as the scalp becomes numb. Computerized scalp cooling systems offer an advantage for patients in that the caps are at room temperature when the patients put them on and then they are brought down to treatment temperature. Two currently available computer-controlled scalp cooling units are DigniCap and the Paxman Scalp Cooling System (Paxman Coolers Limited; Huddersfield, England). Both devices were developed in Europe.
The US FDA recently granted clearance to the DigniCap system for use in the United States. The cap is connected to a cooling control unit. Channels in the cap circulate coolant, while sensors monitor scalp temperature. The system automatically regulates the cap’s temperature throughout the treatment.7
Clinical trials for the Paxman system are underway in the United States. The Paxman system was developed by a family-owned company that had developed a beer cooling system for breweries. Their cold cap prototype was conceived when a family member with breast cancer faced chemotherapy-induced alopecia. Although the cooling product did not work for her, the company continued to refine its product. The device is similar to other automatic cooling cap systems; each cap is connected to a unit that controls the circulating coolant in the cap for up to 2 patients at a time.6