A comparison of the performance of ⁶⁸Ga-DOTATATE PET/CT and ¹²³I-MIBG SPECT in the diagnosis and follow-up of phaeochromocytoma and paraganglioma

PURPOSE

To compare the sensitivity of (123)I-metaiodobenzylguanidine (MIBG) SPECT and (68)Ga-DOTATATE PET/CT in detecting phaeochromocytomas (PCC) and paragangliomas (PGL) in the initial diagnosis and follow-up of patients with PCC and PGL disease.

METHODS

Retrospective analysis of 15 patients with PCC/PGL who had contemporaneous (123)I-MIBG and (68)Ga-DOTATATE imaging.

RESULTS

Of the 15 patients in the series, 8 were concordant with both modalities picking up clinically significant lesions. There were no patients in whom both modalities failed to pick up clinically significant lesions. There was discordance in seven patients: 5 had positive (68)Ga-DOTATATE and negative (123)I-MIBG, and 2 (12 and 14) had negative (68)Ga-DOTATATE and positive (123)I-MIBG. Utilizing (123)I-MIBG as the gold standard, (68)Ga-DOTATATE had a sensitivity of 80 % and a positive predictive value of 62 %. The greatest discordance was in head and neck lesions, with the lesions in 4 patients being picked up by (68)Ga-DOTATATE and missed by (123)I-MIBG. On a per-lesion analysis, cross-sectional (CT and MRI) and (68)Ga-DOTATATE was superior to (123)I-MIBG in detecting lesions in all anatomical locations, and particularly bony lesions.

CONCLUSION

First, (68)Ga-DOTATATE should be considered as a first-line investigation in patients at high risk of PGL and metastatic disease, such as in the screening of carriers for mutations associated with familial PGL syndromes. Second, if (123)I-MIBG does not detect lesions in patients with a high pretest probability of PCC or PGL, (68)Ga-DOTATATE should be considered as the next investigation. Third, (68)Ga-DOTATATE hould be considered in preference to (123)I-MIBG in patients in whom metastatic spread, particularly to the bone, is suspected.

Minireview: Glucagon in stress and energy homeostasis

Glucagon is traditionally thought of as an antihypoglycemic hormone, for example in response to starvation. However, it actually increases energy expenditure and has other actions not in line with protection from hypoglycemia. Furthermore, it is often found to be elevated when glucose is also raised, for example in circumstances of psychological and metabolic stress. These findings seem more in keeping with glucagon having some role as a hormone enhancing the response to stress.

Epidural analgesia for labour: maternal knowledge, preferences and informed consent

Epidural analgesia has become increasingly popular as a form of labour analgesia in Ireland. However obtaining true inform consent has always been difficult. Our study recruited 100 parturients who had undergone epidural analgesia for labour, aimed to determine the information they received prior to regional analgesia, and to ascertain their preferences regarding informed consent. Only 65 (65%) of patients planned to have an epidural. Knowledge of potential complications was variable and inaccurate, with less than 30 (30%) of women aware of the most common complications. Most women 79 (79%) believed that discomfort during labour affected their ability to provide informed consent, and believe consent should be taken prior to onset of labour (96, 96%). The results of this study helps define the standards of consent Irish patients expect for epidural analgesia during labour.

Effects of n-3 polyunsaturated fatty acids on hepatic tight junction after partial hepatectomy in rats

OBJECTIVE

To explore the effects of n-3 polyunsaturated fatty acid (PUFA) on the hepatic tight junction in rat liver after partial hepatectomy.

MATERIALS AND METHODS

Male Sprague-Dawley rats were divided into 4 groups: sham operation, 70% hepatectomy, 70% hepatectomy with administration of 1 mL/kg n-3 PUFA, and 70% hepatectomy with administration of 2 mL/kg n-3 PUFA. Morphologic features of the hepatic tight junction were observed at transmission electron microscopy, and expression of the tight junction proteins occludin, claudin-3, and ZO-1 was studied using Western blot analysis.

RESULTS

The hepatic tight junction structure became loosened 3 days after 70% hepatectomy. The levels of tight junction occludin decreased markedly, whereas claudin-3 and ZO-1 levels increased 2- or 3-fold over control levels. Supplementation of n-3 PUFA alleviated the changes in tight junction structure and occludin expression.

CONCLUSION

n-3 PUFA has protective effects on hepatic tight junction structure after 70% hepatectomy, which were attributed in part to modulation of occludin expression.

Mechanical properties of functionally graded hierarchical bamboo structures

This paper presents the results of a series of multi-scale experiments and numerical models concerning the mechanical properties of moso culm functionally graded bamboo structures. On the nano- and microscales, nanoindentation techniques are used to study the local variations in the Young's moduli of moso culm bamboo cross-sections. These are then incorporated into finite element models in which the actual variations in Young's moduli are used to model the deformation and fracture of bamboo during fracture toughness experiments. Similarly, the measured gradations in moduli are incorporated into crack bridging models that predict the toughening observed during resistance curve tests. The implications of the results are discussed for the bio-inspired design of structures that mimic the layered, functionally graded structure of bamboo.

Gefitinib, cisplatin, and concurrent radiotherapy for locally advanced head and neck cancer: EGFR FISH, protein expression, and mutational status are not predictive biomarkers

BACKGROUND

Gefitinib was demonstrated to be synergistic with cisplatin and radiotherapy (RT) in in vitro studies. Biomarkers predictive of response to gefitinib in squamous cell head and neck cancer is still lacking.

METHODS

Thirty-one patients with locally advanced and easily accessible primary tumor sites for biopsies were recruited. Gefitinib was started 3 weeks before the start of cisplatin/concurrent radiotherapy (CTRT) and continued during the CTRT phase and thereafter for 4 months as consolidation phase. Two baselines and a repeat tumor sample were taken after 2 weeks of gefitinib alone to study its impact on tumor gene expression. Epidermal growth factor receptor (EGFR) protein expression, FISH and mutational status, and matrix metallopeptidase 11 (MMP11) protein expression were correlated with response and survival outcome.

RESULTS

The overall response rate to gefitinib alone was 9.7%. The survival outcome is as follows: median disease free 1.3 years, median survival time 2.4 years, 3-year disease free 42.9%, and 3-year overall survival 48.4%. EGFR FISH, protein expression, and mutational status did not predict for response nor survival outcome of patients. Although MMP11 overexpression did not predict for response, it predicted significantly for a poorer survival outcome.

CONCLUSIONS

Gefitinib can be combined safely with cisplatin/RT. More studies are needed to uncover predictive biomarkers of benefit to gefitinib.

Proprioceptive deficits in Parkinson's disease patients with freezing of gait

Recent research has proposed that proprioceptive deficits may exist in Parkinson's disease (PD); however, proprioception has not been studied in those who experience freezing of gait (FOG). Proprioception was investigated through stimulation of proprioceptive receptors via patellar tendon vibration. In a force matching task to either 10% or 30% maximal voluntary contraction, response to vibration with and without vision of a force target was compared between 15 PD with FOG (PD-FOG), 16 PD without FOG (PD non-FOG), and 15 non-PD control participants (Controls). In a 15-s trial, vision of the target was provided for the first 10 s but in the last 5 s, four conditions were possible: (i) vision, no vibration; (ii) vision, vibration; (iii) no vision, no vibration; or (iv) no vision, vibration. The expected healthy response to vibration was an overshoot of the target. Controls and PD non-FOG did not perform significantly different with or without: vibration or vision. PD-FOG performed similarly to Controls and PD non-FOG in the baseline condition (i). Errors by PD-FOG on the other conditions (ii-iv) were significantly different from the baseline condition but were not significantly different from each other. The PD-FOG group significantly undershot the target when vibration was added [F((2,36))=4.8376, P<0.02] and when vision was removed [F((2,36))=4.8376, P<0.02]. It is suggested that any deviation from normal sensory availability contributes to severe deficits in PD-FOG.

Validation of the AJCC staging system (7th edition) in Asian patients with localized prostate cancer undergoing radical radiotherapy

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Background: The epidemiology of prostate cancer (PCa) varies widely internationally. Although prostate cancer is usually regarded as uncommon in Asia, dramatic rises in recent years have resulted in it being ranking third by incidence in Singapore. Conventional prognostic parameters derived from Western populations have been integrated into systems such as the new AJCC seventh edition staging system, the validity of which is unclear in Asia. We thus sought to validate its performance, alongside other prognostic factors in a large Asian series of radiotherapy patients.

Methods: A retrospective review of 404 consecutive Singaporean patients receiving radical radiotherapy between 1997 and 2005 at the National Cancer Centre was performed. The primary outcome was biochemical relapse free survival (BRFS), defined by the Phoenix criteria. Prognostic risk groups were defined using AJCC seventh edition. Univariate analysis (UVA) and multivariate analysis (MVA) was performed for other putative risk factors: age, race, Gleason score, prognostic risk grouping, tumour classification, radiation delivery technique, radiotherapy dose, hormonal therapy (HT) and initial PSA.

Results: Median age was 69; median BRFS was 55 months with 71 biochemical relapses. 4 risk factors showed univariate association with BRFS: AJCC risk groups (p=0.038), T-stage (p=0.018), RT dose (p=0.025) and initial PSA value (p=0.013) with AJCC risk groups and initial PSA value remaining significant after MVA ( Table ). Harrell's c-index for AJCC risk grouping was 0.56, with no significant difference seen in outcomes between AJCC risk group II and III.

Conclusions: Our results validate the new AJCC seventh edition prostate cancer prognostic risk grouping in an Asian radiotherapy population for the first time; the actual association however is relatively weak possibly due to differences in biology, screening or epidemiology.

[Table: see text]

No significant financial relationships to disclose.