Page 138 - Effects of radiotherapy and hyperbaric oxygen therapy on oral microcirculation Renee Helmers

Chapter 7
Oral microcirculatory response to HBOT in HN cancer patients
The effect of HBOT on previously established late IR alterations in oral microcirculation was subsequently monitored prospectively in vivo with the use of the CC microscope system. The results presented in Chapter 6 indicate that HBOT partially redirects microcirculation parameters towards healthy tissue values by increasing vessel density and reducing vessel diameter. Although these observations might confirm the angiogenic potential of HBOT, the clinical relevance remains undetermined. To which extent IR oral tissue quality needs to be revived to be resistant to further breakdown and to successfully endure future surgical events remains unclear. In other words: when will the tissue arrive to the point of equilibrium that facilitates undisturbed wound healing and that is beneficial for future tissue stability? When this injury resistant state of tissue quality is well-defined, therapy can be adapted to this need and the efficacy of a therapy can be determined.
FUTURE PERSPECTIVES
Although RT and HBOT induced microcirculatory changes can be measured, they have not yet been correlated to clinical findings. Future studies should be focused at grouping patients in categories based on clinical symptoms (for example: no clinical signs, soft tissue ulceration, stages of ORN) and total received RT dose and subsequently correlate these to observed microcirculatory parameters. Comparing the mean values of these microcirculatory parameters between groups and development of an additional scoring system could eventually aid in pinpointing stages of emerging disease and expose a transition phase between no clinical appearance and clinically visible IR pathology. Exposing a transition phase to clinical pathology could offer a window of opportunity for timely tissue supportive treatment (e.g., HBOT, pharmacologic management) and aid in the selection of patients that are in need of treatment. Furthermore, chairside monitoring of microcirculation tissue state (underlying vascular status) during therapy could enhance knowledge on treatment response and desired duration of treatment based on therapeutic efficacy (optimalization of treatment protocols). With accurate patient selection for HBOT the general patient population is alleviated from potential overtreatment with lengthy and expensive therapy (approx. €5,000 - €10,000
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