Discussion
cancer, lymphoid malignancies, oral mucositis
CANCER, ORAL MUCOSITIS
Until recently, when a novel intraoral cooling device (ICD) was introduced, only modest resources had been devoted to further develop the modality of cooling in conjunction with chemotherapy. This is somewhat surprising since the superiority of OC for prevention of chemotherapy-induced oral mucositis (OM) has been demonstrated in several trials [Combined with existing evidence, it was reasonable to assume that cooling protocols in clinical settings should be further improved, especially with regards to when cooling should commence prior to chemotherapy infusion. Since it is believed that the lowest temperature achieved in the oral mucosa is the most protective, it was of importance to identify when along the course of cooling this is obtained, and if this is different depending on cooling modality and temperature. This was the rationale for conducting this study.The greatest drop in intraoral temperature was seen after 5 min of cooling. This was true for all the tested cooling methods, i.e., IC, ICDAlthough, intraoral temperatures seemed to reach a plateau phase after the first 5 min of cooling, the temperatures continued to decrease during the following 25 min for all the tested methods, leading to a significant temperature decrease of approximately 2–3 °C. It is however justified to question if this additional decrease in temperature is of relevance for prevention of OM, and whether it outweighs the disadvantages of exposing patients to longer cooling sessions. A retrospective study including 134 patients scheduled for chemotherapy due to lymphoid malignancies, investigated the preventive effect of 40 min of OC with IC. Cooling commenced ten minutes prior to the chemotherapy infusion and showed significantly less grade III-IV OM, i.e., severe OM according to WHO-scale, as compared to the controls [Considering this, 5 min of cooling prior to chemotherapy infusion appears to be enough to preserve the oral mucosa. This may be explained by the delicate histology of the intraoral mucosa [The main advantage of this study was that all images were analyzed by an observer blinded to the data sets. Thus, reducing the risk of bias. There are, however, some critical points of concern that should be acknowledged. First, this study was conducted on a limited number of healthy volunteers. Intraoral temperature reduction may be different in cancer patients subjected to cooling. A randomized controlled trial, including larger cohorts would be necessary to verify the results observed in this study. Second, the thermographic camera used in this study is not specifically designed for intraoral temperature recordings. Hence, the temperature recordings may not reflect actual intraoral temperatures. Nonetheless, as the same method was used throughout the study, the potential limiting factor may have affected all cooling methods equally.