2-Hour Cryotherapy Effectively Reduces Severe Mucositis Associated with High-Dose Melphalan Followed By Stem Cell Rescue: Results from a Randomized Trial

Introduction: Severe mucositis in the autologous transplant setting has been correlated with adverse outcomes; longer febrile neutropenia duration, doubling of infectious risk, 2.7 additional days of total parenteral nutrition, 2.6 additional days of IV narcotics, increased length of stay (LOS), 3.9-fold increase in 100-day mortality, and US$25,405 increase in hospital charges (Sonis, JCO, 2001 19(8)). In a 40 patient randomized trial investigating cryotherapy (6 hours versus none) following high dose melphalan, grade 3/4 mucositis occurred in only 14% of patients using cryotherapy compared to 74% of patients using saline rinses (Lilleby, BMT, 2006 37). Prolonged cryotherapy is a significant hardship for patients and has resulted in nausea, vomiting, headache, toothache, and chills. We performed a randomized study investigating 2 versus 6 hours of cryotherapy in multiple myeloma (MM) patients undergoing autologous stem cell transplant (ASCT) with melphalan conditioning.

Hypothesis: We hypothesized that a 2-hour cryotherapy regimen would be non-inferior to 6-hours in severity of mucositis, LOS, and incidence of bacteremia.

Methods: We conducted a non-inferiority investigation of 146 sequential MM patients undergoing high dose melphalan with autologous stem cell rescue. Patients were consented and randomized to either 2 (n = 73) or 6 hours (n = 73) of cryotherapy via block randomization based on hemoglobin (less or greater than 11 g/dL), fat free mass (30-50, 50-70, >70 kg), or measured 24hr creatinine clearance (<30, 30-60, >60 mL/min). The cryotherapy process consisted of patients’ melting shaved ice inside their mouth for the designated period of time; flavoring with snow cone syrup was permitted. Inpatient nurse practitioners graded mucositis via WHO criteria. Patients received antifungal (fluconazole) and antiviral (acyclovir or valacyclovir) prophylaxis. Subset analyses investigated the incidence of bacteremia in all patients.

Results: Median age was 59 years (range 35 - 72) and 60 (range 38 – 71), and the median measured creatinine clearance was 90.6 mL/min (range 0.2 – 168.7) and 85.4 mL/min (range 21.5 – 196.5) for the 2 hour and 6 hour groups respectively.

Length of hospitalization (mean of 15 days) did not differ significantly between the 2 cohorts (p = 0.54). Mucositis was graded daily after melphalan infusion. In the 2-hour cohort, 59% of the patients had mucositis (31 patients with grade 1, 10 with grade 2, and 2 patients with grade 3). In the 6-hour cohort, 64% had mucositis (35 patients with grade 1, 9 with grade 2, and 3 patients with grade 3). These results suggest that 2-hour cryotherapy was not inferior to 6-hour therapy in decreasing mucositis grade. In the entire 146 patient group, approximately 30% developed a positive blood culture after transplant, including 25 (34%) and 20 (27%) in the 6-hour and 2-hour groups respectively. The three most common infectious organisms included gram negatives (n = 12 patients), polymicrobial (n = 7), and non-group A streptococcus (n = 7). In the cohort treated with 2-hour cryotherapy, positive blood cultures did not correlate with grade of mucositis (r = 0.05, p = 0.65).

Conclusions: In MM patients undergoing ASCT, 2-hour cryotherapy did not increase mucositis compared to 6-hours. The incidence of blood stream infection was not different between groups. In addition, having an infection did not correlate with grade of mucositis.These results suggest that a 2-hour cryotherapy regimen is not inferior to a 6-hour regimen, and may be considered a standard supportive care measure in patients receiving high dose melphalan.