Rapid growth hormone measurement during transsphenoidal surgery: analysis of 252 acromegalic patients

The usefulness of rapid growth hormone (GH) measurement was retrospectively evaluated as an indicator of total tumor removal during surgery and compared with several reported criteria in 252 acromegalic patients who underwent transsphenoidal surgery at Toranomon Hospital between 2006 and 2008. GH levels were measured in blood samples obtained before surgery, at the start of tumor removal, and every 20 minutes thereafter until 20 minutes after total tumor removal as judged by the operator. Intraoperative GH dynamics were compared between 201 patients fulfilling the Cortina consensus criteria (successful group) and 37 patients who did not (unsuccessful group). Among several criteria indicating total tumor removal, only the ratio of serum GH level 20 minutes after the end of tumor removal to GH level at the end of tumor excision was significantly different between the groups; a reduction ratio of 65% was the most appropriate cut-off value based on sensitivity (59.2%) and specificity (59.5%). The ratio of GH level 20 minutes after the end of tumor removal/GH level at the end of tumor excision was the most reliable index to judge tumor removal during surgery, but this index is neither necessary nor sufficient and should be used as one of the indicators to judge complete tumor removal during surgery.