Page 84 - Fluorescence-guided cancer surgery

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Chapter 5
orientation was di cult in some procedures and surgery under uorescence guidance could only be performed when su cient uorescent signal was present. This would also allow a more detailed analysis of the optimal window between administration of ICG and peak uorescence measurements, and gives a better insight in the decrease of uorescent signal over time, as uorescent signal can be measured all procedure long. In addition, to improve visual contrast, the uorescence images displayed by the endoscopy system as blue on black could be converted to white on black. Further technical developments of endoscopic NIR uorescence imaging systems are in progress and aim to improve the real-time intraoperative display of NIR uorophores17;21;22.
One limitation in the study was that only one endoscope and light cable suitable for NIR uorescence imaging was available. Therefore only one patient could be included daily, potentially leading to selection bias. An aselect procedure was used to prevent this bias: always the rst patient of the day was included, the order of cases was determined by chance.
CONCLUSION
NIR uorescence imaging using intraoperative intravenous administration of low-dose ICG, can safely and easily be implemented in daily clinical practice. A useful di erentiation between adenoma and pituitary gland was possible with NIR uorescence.
Timing of the ICG administration warrants future study to optimize this technique. Better discrimination of tumor versus normal pituitary tissue, will likely facilitate improved surgical remission rates and reduced surgical morbidity after endoscopic transnasal transsphenoidal selective adenomectomy. With improved techniques and imaging protocols, we advocate that the potential additional value has to be evaluated prospectively in a randomized study design.