Contrast-enhanced computed tomography does not improve the diagnostic value of parathyroid dual-phase MIBI SPECT/CT.

OBJECTIVE: The aim of this study was to investigate the contribution of contrast-enhanced computed tomography (CE-CT) to the localization of parathyroid adenomas compared with the dual-phase Tc-99m MIBI SPECT with low-dose CT (LD-CT). PATIENTS AND METHODS: This retrospective study included consecutive patients with primary hyperparathyroidism who underwent a preoperative dual-phase MIBI SPECT/CT followed by surgical resection. The standard of care was dual-phase MIBI SPECT/CT, acquired with LD-CT in the early phase and CE-CT in the late phase (SPECT/CE-CT). The presence and localization of positive sites were extracted from study reports. To examine the role of CE-CT, patient cases were independently re-reviewed, with the early LD-CT fused with early and late SPECT (SPECT/LD-CT). The two SPECT/CT methods were compared for sensitivity, and the positive predictive value and histopathology were used as a reference. RESULTS: In total, 138 patients were included. The investigation was positive for suspected adenomas in 124 patients using SPECT/CE-CT and in 122 patients using SPECT/LD-CT. The per-patient sensitivity was 87.5% [95% confidence interval (CI): 80.7-92.6%] for SPECT/CE-CT and was not statistically significantly different from SPECT/LD-CT (85.3%; 95% CI: 78.2-90.8%) (P=0.39). The positive predictive value was 95.2% (95% CI: 95.4-99.9%) with SPECT/CE-CT versus 100% (95% CI: 96.8-100%) with SPECT/LD-CT. For small adenomas (≤500 mg), the sensitivity was low with SPECT/CE-CT (67%) as well as with SPECT/LD-CT (64%). CONCLUSION: Late CE-CT, compared with late LD-CT, did not significantly improve the sensitivity of dual-phase Tc-99m MIBI parathyroid SPECT/CT in a population of patients with primary hyperparathyroidism. These findings were consistent regardless of the size, location, or histology of the adenomas.

Bone Scan Index Is an Independent Predictor of Time to Castration-resistant Prostate Cancer in Newly Diagnosed Prostate Cancer: A Prospective Study.

OBJECTIVE: To prospectively determine the prognostic value of the bone scan index (BSI) for time to development of castration-resistant prostate cancer (CRPC) in consecutive, hormone-naïve patients with newly diagnosed prostate cancer. PATIENTS AND METHODS: Eligible patients participated in a prospective, observational, multicenter study of the value of bone scintigraphy (BS) at staging. BSI was determined using the EXINI BoneBSI software in 208 consecutive patients undergoing androgen deprivation therapy. The presence or absence of bone metastases at staging was classified by BS with or without supplementary imaging. Follow-up was performed >5 years after including the last patient. RESULTS: During follow-up, 149 of the 208 patients (72%) were diagnosed with CRPC. Median time to CRPC was 20 months. Median follow-up time was 4.4 years in patients without CRPC. In univariate analyses, presence of bone metastases (M1) (hazard ratio [HR] 3.00, 95% confidence interval [CI] 2.10-4.30), Gleason grade (HR 1.53, 95% CI 1.31-1.79), and BSI (HR 1.17, 95% CI 1.12-1.23) but not PSA significantly predicted time to CRPC (all, P < .001). The predictive values of M1 (HR 2.06), Gleason grade (HR 1.47), and BSI (HR 1.10) were confirmed in multivariate analyses. Log-rank test for equality of time to CRPC showed the significant predictive value of BSI (BSI = 0 vs 0 < BSI ≤ 1 vs BSI > 1, P < .001). In addition to routine assessment of M1 vs M0 status, BSI contributed to the predictive power. CONCLUSIONS: BSI is an independent risk factor for the time from initiation of androgen deprivation therapy to CRPC in hormone-naïve patients. The significant prognostic factors, in rank order, were M1 status, Gleason grade, and BSI.

Sex estimation from modern American humeri and femora, accounting for sample variance structure.

OBJECTIVES: A new procedure for skeletal sex estimation based on humeral and femoral dimensions is presented, based on skeletons from the United States. The approach specifically addresses the problem that arises from a lack of variance homogeneity between the sexes, taking into account prior information about the sample's sex ratio, if known. MATERIAL AND METHODS: Three measurements useful for estimating the sex of adult skeletons, the humeral and femoral head diameters and the humeral epicondylar breadth, were collected from 258 Americans born between 1893 and 1980 who died within the past several decades. RESULTS: For measurements individually and collectively, the probabilities of being one sex or the other were generated for samples with an equal distribution of males and females, taking into account the variance structure of the original measurements. The combination providing the best estimates correctly classifies 88.3% of the skeletons, with 10.8% considered unknown and 0.9% assigned to the wrong sex. DISCUSSION: Probabilities of correct assignments are a better means of categorizing individuals as male or female than the sectioning points commonly used in skeletal studies. That is because it is possible to estimate the observer's certainty that the individual represented by measured bones was one sex or the other. A computer program is available that simultaneously considers samples of unequal sex composition. It is useful when there is contextual information available about the nature of skeletal samples (e.g., a mass burial from a battle or genocide).