A Retrospective Cohort Study of the Utility of Ultrasound, 99mTc-Sestamibi Scintigraphy, and Four-Dimensional Computed Tomography for Pre-Operative Localization of Parathyroid Disease To Facilitate Minimally Invasive Parathyroidectomy.

Background This study investigated the utility of ultrasound (US), 99mTc-Sestamibi scintigraphy (Sestamibi), and four-dimensional computed tomography (4DCT) for pre-operative localization of a single abnormal parathyroid gland prior to minimally invasive parathyroidectomy (MIP) to determine the optimum pre-operative scans to facilitate a MIP. Methods Patients with primary hyperparathyroidism who underwent curative parathyroidectomy at Broomfield Hospital, Mid and South Essex NHS Foundation Trust between 2009 and 2018 were included. Diagnostic performance parameters and the agreement between US, Sestamibi, and 4DCT were evaluated. Cohen's κ was used to assess the strength of agreement between imaging modalities. Results At localizing pathology to the correct side of the neck, Sestamibi had the highest sensitivity (87%), followed by US (76%) and 4DCT (64%). 4DCT had a positive predictive value (PPV) of 95%, similar to Sestamibi (96%), but higher than US (92%). Amongst patients who underwent both US and Sestamibi, the abnormal parathyroid gland was localized to the same area by both imaging modalities in 77% of patients (Cohen's κ: 0.383). Following an inconclusive US or Sestamibi scan, or discordance between the two modalities, 4DCT was correct at localization in 63% of patients. Conclusion Sestamibi has the highest sensitivity and PPV for accurately localizing parathyroid pathology. The addition of US to a positive Sestamibi scan adds little additional value. 4DCT is the preferred imaging modality following an inconclusive Sestamibi or US.

Effect of the abnormal bladder when full on upper tract drainage using a combined cystometrogram-(99m)Tc-mercapto-acetyltriglycine renogram: a prospective study.

OBJECTIVE: To examine the relevance of bladder volume in patients with chronic hydronephrosis and abnormal bladder function who lose renal function even though the bladder or reservoir pressure is normal (<40 cmH(2)0). PATIENTS AND METHODS: In all, 20 patients (16 male; age range 17-67 years) were studied prospectively; 12 had a reconstructed bladder. All had progressive loss of renal function with a glomerular filtration rate (GFR) of >15 mL/min. The study was in three parts: a baseline (99m)Tc-mercapto-acetyltriglycine (MAG3) scan was performed with an empty bladder, then a combined full bladder cystometrogram (CMG) with (99m)Tc-MAG3 study was done supine, and finally repeated in the sitting position. The pressure and volume changes together with the (99m)Tc-MAG3 scintigraphic variables with and without a full bladder were compared. RESULTS: Of the 17 patients with normotensive bladders, 13 (77%) had functional obstruction of the kidneys with a full bladder. In seven this was threshold dependent and occurred at a total mean (range) bladder volume of 348 (135-720) mL for both positions. In the other six patients there was minimal drainage of isotope from the kidneys even with the bladder empty. When the sitting position was compared with supine, gravity was more important for upper tract drainage in the reconstructed bladders. In five patients the detrusor pressure at which drainage began was close to zero. CONCLUSIONS: In 13 of 17 patients (77%) the kidneys failed to drain with a full bladder despite 'normal' detrusor pressures. It remains to be seen whether bladder emptying designed to keep the urine volume below the obstructing threshold volume will prevent further loss of renal function.

Detection of tumour thrombus by 18F-FDG-PET/CT imaging.

Tumour thrombus is a rare complication of many solid cancers including renal cell carcinoma, Wilms' tumour, testicular tumour, adrenal cortical carcinoma, lymphoma, pancreatic cancer, osteosarcoma and Ewing's sarcoma. We describe six patients who harboured occult tumour thrombus detected by fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography (PET)/X-ray computerized tomography (CT) imaging as part of the staging investigations. Recognition of this rare complication by PET/CT can change the management plan and prevent unnecessary long-term anti-coagulation treatment because of wrong diagnosis of cancer-related venous thrombus.

186Re-HEDP in the treatment of patients with inoperable osteosarcoma.

UNLABELLED: The aim of this study was to examine the safety and efficacy of (186)Re-hydroxyethylidene diphosphonate (HEDP) as an adjuvant to external-beam radiotherapy (EBRT) in the treatment of patients with osteosarcoma. METHODS: Thirteen patients (9 male, 4 female; age range, 12-42 y) were treated with combination chemotherapy (standard U.K. protocol) and (186)Re-HEDP therapy (18.5 MBq/kg, intravenously), followed by EBRT. A full blood count; liver function test; and measurements of urea and electrolytes, glomerular filtration rate, and left ventricular function were performed on all patients before and after therapy. Tumor volume and composition were obtained from CT or MRI data. Dosimetric calculations were performed using the MIRD formalism. RESULTS: Of the 13 patients, 1 is still under follow-up. The median survival time was 36 mo (range, 12-216 mo) from diagnosis and 5 mo (range, 1-60 mo) from the last (186)Re-HEDP treatment. The mean tumor dose delivered with (186)Re-HEDP was calculated to be 5.8 Gy (range, 0.5-16 Gy). CT and MRI revealed the tumors to have a complex structure, comprising "ossified," "partially calcified," and "soft-tissue" components. Posttherapy scans showed a heterogeneous distribution of (186)Re-HEDP in the tumor mass: Although the "soft-tissue" component showed minimal uptake of the therapeutic dose, the "ossified component" showed intense uptake. The 3 long-term survivors in whom tumor sterilization was achieved received calculated mean tumor doses in the range of 2.0-3.1 Gy, which was believed to be an underestimate of the actual tumor doses delivered. CONCLUSION: This study indicates that a simple approach to tumor dosimetry based on mean tumor dose is inappropriate because it may underestimate the dose delivered to these heterogeneous tumors. The data also indicate that EBRT combined with a standard dose of 18.5 MBq/kg of (186)Re-HEDP does not provide a sufficient dose to achieve tumor sterilization. A dose estimation technique is required that is based on the determination of tumor dose at the individual voxel level and that is able to represent the heterogeneous uptake observed in these complex tumor structures with highly nonuniform composition. This, coupled with individualized dose escalation, may then achieve the goal of tumor sterilization.