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Mark D. Krieger

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Tord D. Alden and Mark D. Krieger

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Mark D. Krieger, William T. Couldwell and Martin H. Weiss

Object. The criteria for remission of acromegaly following transsphenoidal adenoma resection are in evolution. In the present study the authors evaluate the utility of predicting long-term remission by reference to a single fasting growth hormone (GH) level on the 1st postoperative day.

Methods. A retrospective analysis was conducted on 181 patients with acromegaly who underwent transsphenoidal resection between 1973 and 1990 and completed a 5-year follow-up period. Fasting serum GH levels were obtained in all patients on the 1st postoperative day in the absence of exogenous glucocorticoids. All patients participated in a follow-up evaluation lasting at least 5 years, which included measurements of serum insulin-like growth factor—I (IGF-I) levels as an index of acromegalic activity.

Among the 181 patients, GH levels ranged from 0 to 8 ng/ml in 131 (72%) on the 1st postoperative day, suggesting biochemical remission. This group included 107 (84%) of the 127 patients with microadenomas, but only 24 (44%) of the 54 with macroadenomas. Nevertheless, 15 (11%) of the 131 patients who initially had attenuated GH levels displayed recurrent acromegaly within the first 2 years (with elevated levels of IGF-I in all cases, and abnormalities appearing on magnetic resonance images in nine cases). Only one of 116 patients in whom the initial postoperative GH level was lower than 2 ng/ml experienced a recurrence, whereas 14 (93%) of the 15 patients with postoperative GH levels between 2.2 and 8 ng/ml subsequently displayed biochemical evidence of acromegaly.

Conclusions. The findings indicate that a fasting morning serum GH level lower than 2 ng/ml on the 1st postoperative day portends long-term biochemical remission of acromegaly, whereas higher levels are a significant marker for recurrent disease.

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Laurence Davidson, Mark D. Krieger and J. Gordon McComb

Object

The purpose of this study was to evaluate the posterior interhemispheric retrocallosal approach (PIRA) for its safety and efficacy in the resection of pineal region and posterior fossa lesions in children.

Methods

Twenty-nine PIRAs were performed in 26 children between March 1997 and March 2009, and these cases were retrospectively reviewed. There were 15 girls and 11 boys in the series. The median age at the time of surgery was 7 years (range 7 months–17 years). Twenty-seven cases were treated for tumor, 1 for loculated hydrocephalus, and 1 for an aneurysm.

Results

Of the 27 cases treated for tumor, there were 20 (74%) gross-total resections, 5 (19%) subtotal resections, and 2 (7%) biopsies. One bridging vein was sacrificed in 6 cases and 2 bridging veins were divided in 1 case, whereas in 3 cases there was sacrifice of a single deep cerebral vein. No patient developed radiographic evidence of venous infarction. Approach-related complications were low, and included 2 cases of transient homonymous hemianopia. There were no surgery-related deaths.

Conclusions

This approach allows for ample access to pineal region and posterior fossa lesions, with low postoperative morbidity.

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John A. Jane Jr., Mark D. Krieger and John Persing

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Sergei Terterov, Mark D. Krieger, Ira Bowen and J. Gordon McComb

Object

The objective of this study was to determine the role of intracranial CSF examination in detecting true cases of early tumor dissemination. Cerebrospinal fluid dissemination is an ominous feature of pediatric brain tumors, occurring in as many as 30% of medulloblastomas, 25% of supratentorial primitive neuroectodermal tumors (PNETs), and 5% of ependymomas at diagnosis. Detecting early dissemination is important for determining both treatment and prognosis. Dissemination can be detected by evaluating imaging of the full neuraxis and by examining CSF cytology. Neuraxis MR imaging and lumbar CSF cytology evaluation are widely accepted methods for determining dissemination. However, the value of examining intracranial CSF cytology in detecting early dissemination is uncertain.

Methods

Under an institutional review board–approved protocol, medical records, pathology reports, and radiology reports for 150 patients who had undergone resection of brain tumors (88 with medulloblastomas, 21 with supratentorial PNETs, and 41 with ependymomas) and who had been evaluated using neuraxis MR imaging studies in the last 15 years were retrospectively reviewed. Radiology results were compared with the CSF cytology results and long-term disease outcomes.

Results

Between lumbar and intracranial CSF cytology results, 7 of 40 were discordant: in 2 intracranial CSF was negative and lumbar CSF was positive, and in 5 the reverse was true. The discordance percentage was 18%, with a kappa statistic of 0.36. Between MR imaging and lumbar CSF cytology results, 11 of 65 were discordant: in 9 the lumbar CSF was negative and MR imaging was positive, and in 2 the reverse was true. The discordance percentage is 17%, with a kappa statistic of 0.27. Between MR imaging and intracranial CSF cytology results, 8 of 52 were discordant: in 3 intracranial CSF was negative and MR imaging was positive, and in 5 the reverse was true. The discordance rate was 15%, with a kappa statistic of 0.41. Patients with positive and negative results on perioperative neuraxis MR imaging studies had a median survival of 26.8 and 33.1 months, respectively (p = 0.02). Patients with positive and negative results on perioperative lumbar CSF cytology had a median survival of 20.1 and 31.4 months, respectively (p = 0.11). Patients with positive and negative results on intracranial CSF cytology had a median survival of 31 and 31.4 months, respectively (p = 0.84).

Conclusions

Discordance exists between the results of neuraxis MR imaging and lumbar and intracranial CSF cytology in perioperative detection of tumor dissemination for pediatric medulloblastoma, supratentorial PNETs, and ependymoma. In 1 case in this series, perioperative dissemination was detected by intracranial CSF cytology, but not by lumbar CSF cytology or neuraxis MR imaging. Isolated intracranial CSF cytology positivity may represent an earlier stage of disseminated disease. Complementary use of perioperative neuraxis MR imaging and lumbar and intracranial CSF cytology can reduce the incidence of missed diagnoses of dissemination. Survival analysis revealed that perioperative neuraxis MR imaging findings are correlated with survival, whereas perioperative lumbar and intracranial CSF cytology findings are not.

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John A. Jane Jr., Mark D. Krieger and Alan R. Cohen