Page 119 - Effects of radiotherapy and hyperbaric oxygen therapy on oral microcirculation Renee Helmers

Effects of HBOT on late irradiation injury
HBOT
Hyperbaric treatment sessions were carried out in a multiple person hyperbaric chamber and had a total duration of 110 min; 100% oxygen was administered through an oronasal mask during 75 min total at 2.4 ATA.34 HBOT was planned on weekdays from Monday to Friday. Patients receiving HBOT sessions concerning pre-extraction osteoradionecrosis prophylaxis (20 sessions prior and 10 sessions postoperative, total of 30 sessions) and patients receiving HBOT therapeutically (>20 sessions) were pooled.
Microvascular imaging
To visualize the oral microcirculation a CytoCam (CC) Microscope System (Braedius Medical, Huizen, The Netherlands) was used; details on this vital handheld imaging instrument are described elsewhere.1,15,20 In brief, a clear and high-resolution image (14-megapixel, 25 fps) with a field of view (FOV) equal to 1.55x1.16mm (1.80 mm2) is created of the microcirculation displaying the lumen of blood vessels filled with dark circulating erythrocytes contrasted by a bright background. A medical PC (Braedius Medical, Huizen, The Netherlands) is connected with the CC which is set with the CCTools software (CytoCamTools Camera Manager v1.7.12, Braedius Medical, Huizen, The Netherlands) for camera operation and video data processing.
Measurement procedures 6 Microcirculation measurements were performed at baseline (T0), 4 weeks
after start of HBOT (T4) and 24 weeks (6 months) after start of HBOT (T24).
The measurement procedures followed protocolled patient instruction
and microscope handling as described in a previous study of our group.12 An allocated examination room maintained at a constant 20±2°C was used for performing the microcirculation measurements at all time points. A trained investigator (RH) performed all measurements together with an assistant (NFS) who controlled the CC PC to adjust contrast, focus and focal depth (Fd; mm) and recorded the images. Four regions of interest (ROIs) were measured: the left and right cheek parallel to the upper premolar region and the left and right gingiva in the lower premolar region. In each region 4 different clips of 4 s each were recorded of adjacent sites. The average of the 4 clips represented the ROI.
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