99mTc-HDP bone scintigraphy and 18F-sodiumfluoride PET/CT in primary staging of patients with prostate cancer.

INTRODUCTION/AIM: Correct staging of patients with prostate cancer is important for treatment planning and prognosis. Although bone scintigraphy with 99mTc-phosphonates (BS) is generally advised for staging by guidelines in high risk prostate cancer, this imaging technique is hampered by a high rate of inconclusive results and moderate accuracy. Potentially better imaging techniques for detection of bone metastases such as 18F-sodiumfluoride PET/CT (NaF PET/CT) are therefore being evaluated. In this observational cohort study we evaluate the performance and clinical impact of both BS and NaF PET/CT in primary staging of patients with prostate cancer. METHODS: The first of two cohorts consisted of patients who received a BS while the second included patients who received a NaF PET/CT for primary staging of prostate cancer. For both cohorts the number of positive, negative and equivocal findings, calculated diagnostic performance of the imaging modality in terms of sensitivity and specificity, as well as the impact on clinical management were studied. The ranges of the diagnostic performance were calculated both assuming that equivocal findings were positive and assuming that they were negative for bone metastases. For the NaF PET/CT cohort the number of patients with signs of lymph node metastases on low dose CT were also recorded, including the impact of these findings on clinical management. RESULTS: One-hundred-and-four patients underwent NaF PET/CT, whereas 122 patients underwent BS. Sensitivities of 97-100 and 84-95% and specificities of 98-100 and 72-100% were found on a patient basis for detection of bone metastases with NaF PET/CT and BS, respectively. Equivocal findings warranted further diagnostic procedures in 2% of the patients in the NaF cohort and in 16% in the BS cohort. In addition NaF PET/CT demonstrated lymph node metastases in 50% of the included patients, of which 25% showed evidence of lymph node metastases only. CONCLUSION: Our data indicate better diagnostic performance of NaF PET/CT compared to BS for detection of bone metastases in primary staging of prostate cancer patients. Less equivocal findings are encountered with NaF PET/CT. Moreover, NaF PET/CT has additional value over BS since lymph node metastases are encountered frequently.

Meta-analysis and dose-response metaregression: circulating insulin-like growth factor I (IGF-I) and mortality.

CONTEXT: IGF-I plays a central role in metabolism and growth regulation. High IGF-I levels are associated with increased cancer risk and low IGF-I levels with increased risk for cardiovascular disease. OBJECTIVE: Our objective was to determine the relationship between circulating IGF-I levels and mortality in the general population using random-effects meta-analysis and dose-response metaregression. DATA SOURCES: We searched PubMed, EMBASE, Web of Science, and Cochrane Library from 1985 to September 2010 to identify relevant studies. STUDY SELECTION: Population-based cohort studies and (nested) case-control studies reporting on the relation between circulating IGF-I and mortality were assessed for eligibility. DATA EXTRACTION: Data extraction was performed by two investigators independently, using a standardized data extraction sheet. DATA SYNTHESIS: Twelve studies, with 14,906 participants, were included. Overall, risk of bias was limited. Mortality in subjects with low or high IGF-I levels was compared with mid-centile reference categories. All-cause mortality was increased in subjects with low as well as high IGF-I, with a hazard ratio (HR) of 1.27 (95% CI = 1.08-1.49) and HR of 1.18 (95% CI = 1.04-1.34), respectively. Dose-response metaregression showed a U-shaped relation of IGF-I and all-cause mortality (P = 0.003). The predicted HR for the increase in mortality comparing the 10th IGF-I with the 50th percentile was 1.56 (95% CI = 1.31-1.86); the predicted HR comparing the 90th with the 50th percentile was 1.29 (95% CI = 1.06-1.58). A U-shaped relationship was present for both cancer mortality and cardiovascular mortality. CONCLUSIONS: Both low and high IGF-I concentrations are associated with increased mortality in the general population.

Low incidence of adrenal insufficiency after transsphenoidal surgery in patients with acromegaly: a long-term follow-up study.

CONTEXT: The long-term prevalence of adrenal insufficiency after transsphenoidal surgery for GH-secreting pituitary adenomas is unknown. However, recently a single study reported a high prevalence of adrenal insufficiency in acromegalic patients after surgical and/or medical treatment without postoperative radiotherapy. OBJECTIVE: The objective of the study was to assess the prevalence and incidence rates of adrenal insufficiency in consecutive patients during long-term follow-up after successful transsphenoidal surgery for acromegaly. DESIGN: In 91 consecutive patients in remission after transsphenoidal surgery only, we retrospectively reviewed insulin tolerance tests, CRH stimulation tests, metyrapone tests, and ACTH stimulation tests used to assess corticotrope function. RESULTS: Early postoperatively, insufficient adrenal function was observed in 16 patients (18%), which was transient in eight and irreversible in eight other patients in the first year of postoperative follow-up. Therefore, after the first year, the prevalence of adrenal insufficiency was 9%. Late, new-onset adrenal insufficiency developed in only three patients 13, 18, and 24 yr after surgery. The incidence rate of late adrenal insufficiency after successful surgery was 2/1000 person-years. After long-term follow-up, a median of 8.1 (1-31 yr), the prevalence of secondary adrenal insufficiency was 12% in patients in remission after surgery for acromegaly. CONCLUSION: The prevalence of adrenal insufficiency 1 yr after surgery was 9%, whereas during prolonged follow-up, the incidence rate of adrenal insufficiency was only 2/1000 person-years in patients in remission after surgery. Therefore, development of late-onset adrenal insufficiency is a very infrequent complication in patients with acromegaly in remission after transsphenoidal surgery only.