Page 83 - Fluorescence-guided cancer surgery

Furthermore, surgical remission is not always achieved after resection of a functional adenoma and recurrence of a pituitary adenoma after apparent cure is also frequently reported5. Mean remission values and ranges of 68.8% (27-100) in prolactinoma, 47.3% (3-92) in NFA, 61.2% (37-88) in acromegaly, and 71.3% (41-98) in Cushing’s disease, are reported. Overall remission rates of 53–64% for macroadenomas and 84-88% for microadenomas are reported4.
Patients can su er from recurrent disease, with the incidence peaking between 1 and 5 years after surgery. It is suggested that recurrence originates from small postoperative tumor remnants5. Consequently, there is a clear unmet need for improved peri-operative identi cation of pituitary adenomas, normal gland and surrounding structures, so as to improve surgical outcomes. A more aggressive attempt to attain complete adenoma resection will increase the number of patients achieving biochemical remission but will also increase the likelihood of postoperative complications such as DI and hypopituitarism. Thus, it is plausible to postulate that improved optical guidance during surgery could assist in resecting the adenoma in total while minimizing iatrogenic injury.
Only a limited number of imaging techniques during surgery, are described to improve completeness of tumor resection; for example intraoperative MRI19 and intraoperative transcranial-transdural real-time ultrasonography20. Both techniques are reported as complementary imaging techniques and require the use of di erent, additional imaging devices that until now, interfere with the normal surgical procedure. Moreover, both techniques do not allow real-time merging of the surgical eld and additional tumor imaging. NIR uorescence imaging, as we describe here, has shown the ability to overcome these constraints.
We noticed several limitations to the described technique. Firstly, NIR uorescence imaging identi cation was based on the principle that the normal gland stained after ICG administration, whereas tumor tissue stains to a lesser degree and with a time delay. For high-sensitive identi cation of adenomas and especially microadenomas, uorescence signal in tumor tissue instead of healthy tissue would be of greater value. Should tumor tissue be stained, only uorescent tissue has to be resected. The development of tumor-speci c contrast agents targeting speci c ligands could potentially facilitate this. Secondly, the imaging system used in the current study did not allow real-time overlay of color (white light) and NIR (blue light) images. Therefore, anatomical
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