Several cytotoxic drugs are known to cause moderate to severe alopecia . Chemotherapy-induced alopecia (CIA) usually occurs 7–14 days after infusion. The incidence and severity of alopecia depend both on the type and dose of chemotherapy . CIA is a distressing adverse event associated with the use of systemic chemotherapy in patients with cancer. Hair loss impacts self-esteem, is a visible reminder of the disease, affects the patient’s privacy, and negatively impacts social and work interactions [2, 3]. In a patient survey, the impact of CIA on patients ranks highest, ahead of fatigue, nausea, trouble sleeping, and early hot flashes .
The theory as to why inducing scalp hypothermia limits CIA is twofold. First, cooling constricts blood vessels in the scalp, thereby decreasing the amount of chemotherapy that reaches the hair follicles. Second, the cold decreases the proliferative activity of hair follicles and makes them less sensitive to cytotoxic drugs, which target rapidly dividing cells. Consequently, there is less of a chemotherapeutic effect on hair follicle cells which limits hair loss from the scalp, without impacting overall treatment efficacy .
Scalp cooling (SC) devices are US Food and Drug Administration (FDA)-cleared and indicated to reduce the likelihood of CIA in patients with solid tumors such as ovarian, breast, colorectal, bowel, and prostate cancer . These systems allow the scalp to be cooled by circulating cold fluid through channels in the inner cap specifically fitted to the patient. The temperature of the coolant is monitored and kept within a specified temperature range (23–25 °F).
SC efficacy is dependent on several factors, the most significant being the chemotherapy regimen (drugs, dose, frequency, number of cycles). While individual factors such as hair type can play a role in efficacy, the extent to which these factors affect outcome remains anecdotal. The National Comprehensive Cancer Network (NCCN) Guidelines® recommend SC as a category 2A treatment option for patients with invasive breast cancer and ovarian cancer [6, 7].
Efficacy of SC is based on a visual inspection of the patient’s scalp by a clinician during physical exam, or on a patient’s alopecia self-report. SC significantly reduces the risk of CIA from taxane-based and anthracycline-based chemotherapy regimens [8,9,10,11,12]. The majority of studies have been conducted in patients with early-stage breast cancer receiving neoadjuvant or adjuvant chemotherapy with curative intent [13, 14]. However, one prospective trial and one large registry analysis performed in patients with breast, lung, prostate, gastrointestinal/colorectal, and female genital solid tumors demonstrated the potential for broader use, including in the palliative setting [15, 16].
SC has minimal adverse events, is a generally well-tolerated intervention, and contributes to patient well-being [3, 17]. The most common SC-related adverse events are grade 1 and include chills, “heavy head”, headache, pain (scalp, forehead, or sinus), nausea, dizziness, pruritus, and skin ulceration [9, 12, 13]. No serious adverse events have been reported from the device and participants find the SC device to be reasonably comfortable . In general, very few patients discontinue SC because of intolerance or side effects from the intervention [11, 14,15,16].
Initially there was concern that SC could increase the risk of scalp metastases. This concern created a barrier to incorporation of the technology into standard cancer care; however, subsequent studies did not show this to be a significant risk. In a study of Dutch patients with cancer and 5 years of follow-up, no scalp metastases occurred in patients receiving the SC intervention. A review of 58 publications including 533 women with breast cancer reported that only 0.36% of patients receiving SC developed scalp metastases  and that overall mortality was not affected in women who received SC (HR 0.89, 95% CI 0.68–1.17, p = 0.40) . Another meta-analysis including 1959 patients reported that the incidence rate of scalp metastasis in the scalp cooling group versus the no scalp cooling group was 0.61% (95% CI 0.32–1.1%) versus 0.41% (95% CI 0.13–0.94%); p = 0.43 . Therefore, the fear of increased risk of scalp metastases has not been demonstrated in research or practice and should not limit the use of SC technology.
SC technology has been around for over a quarter of a century. At this time, the Paxman System and the DigniCap Scalp Cooling System have been cleared by the FDA and are marketing in the USA. The Paxman SC system operates in over 1156 locations and has helped over 100,000 patients with cancer worldwide in over 50 countries to retain their hair during chemotherapy [20, 21]. Study results have demonstrated a high degree of patient satisfaction using SC and that a majority of patients reported not needing to wear a head covering during the time course of chemotherapy [8, 13, 14]. Dignitana markets an SC system called the DigniCap that is available in 39 countries. A second system called DigniCap Delta received clearance from the FDA in June 2019 and CE Marking in March 2019. More than 120 DigniCap Deltas are operating in the USA and around the globe .
Using a SC system will extend the patient’s time at the treatment center or clinic. SC starts at least 30 min before the infusion of cytotoxic chemotherapy. Cooling continues throughout the infusion of chemotherapeutic agents and for up to 20–120 min after the infusion is completed, dependent on the chemotherapy regimen [14, 23]. Treatment centers must incorporate the logistics of SC into facility workflows by coordinating physician general supervision of the patient, as defined by the 2020 Hospital Outpatient Prospective Payment System (HOPPS) final rule , scheduling additional chair time, planning for incremental nursing staff effort, and modifying the physical infusion suite to accommodate cooling machines (e.g., space, power requirements) .
Physicians play an important role in the decision to offer SC to patients, the education that must be provided to patients, and the general management of SC for CIA before, during, and after delivery of chemotherapy. The hands-on roles of the chemotherapy nurse and nurse manager in the process are also critical. Interaction and proper communication between physicians, advanced practitioners, and allied health professionals are needed to provide this supportive care service to patients at risk for CIA.