Fluorine-18 fluorodeoxyglucose positron emission tomography in the follow-up of differentiated thyroid cancer

Whole-body fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging was performed during the follow-up of 33 patients suffering from differentiated thyroid cancer. Among them there were 26 patients with papillary and seven with follicular tumours. Primary tumour stage (pT) was pT1 in six cases, pT2 in eight cases, pT3 in three cases and pT4 in 14 cases. FDG PET was normal in 18 patients. In three patients a slightly increased metabolism was observed in the thyroid bed, assumed to be related to remnant tissue. In one case local recurrence, in ten cases lymph node metastases (one false-positive, caused by sarcoidosis) and in three cases distant metastases were found with FDG PET. In comparison with whole-body scintigraphy using iodine-131 (WBS) there were a lot of discrepancies in imaging results. Whereas three patients had distant metastases (proven with¹³¹I) and a negative FDG PET, in four cases¹³¹I-negative lymph node metastases were detectable with PET. Even in the patients with concordant staging, differences between¹³¹I and FDG were observed as to the exact lesion localization. Therefore, a coexistence of¹³¹I-positive/FDG-negative,¹³¹I-negative/FDG-positive and¹³¹I-positive/FDG-positive malignant tissue can be assumed in these patients. A higher correlation of FDG PET was observed with hexakis (2-methoxyisobutylisonitrile) technetium-99m (I) (MIBI) scintigraphy (performed in 20 cases) than with WBS. In highly differentiated tumours¹³¹I scintigraphy had a high sensitivity, whereas in poorly differentiated carcinomas FDG PET was superior. The clinical use of FDG PET can be recommended in all cases of suspected or proven recurrence and/or metastases of differentiated thyroid cancer and is particularly useful in cases with elevated serum thyroglobulin levels and negative WBS.     

Tissue mean transit time from dynamic computed tomography by a simple deconvolution technique

In order to calculate the mean transit time of tissue, such as brain, from dynamic computed tomography performed after a bolus injection of intravenous contrast material, the time dependence of the input of contrast material to the tissue must be "deconvolved" from the observed time course of the tissue contrast enhancement. If the approximate shape of the curve of the response of the tissue to an instantaneous injection of contrast material is assumed, the width of this curve that gives the best fit to the observed tissue response can be used to find a value for the tissue mean transit time. Applying this technique to dynamic CT scans of two normal volunteers yielded values comparable to those in the literature by other techniques. The method has the advantages of being simple to implement, relatively insensitive to noise and the details of the assumed curve shape, and not requiring any curve fitting to correct for recirculation.     

Mitral valve repair in patients with end stage cardiomyopathy: who benefits?

Objective: Patients with end stage cardiomyopathy frequently present with additional severe mitral regurgitation. We analyzed the outcome of mitral valve reconstruction in this high risk patient group. Methods: Sixty-six patients with significant mitral regurgitation and an ejection fraction (EF) below 30% (dilated CARDIOMYOPATHY=53, ischemic cardiomyopathy (ICM)=13) were retrospectively evaluated from 07/96 and 02/02. All received annuloplasty ring implantation and additional repair (n=4) if required. Mean follow-up was 28±18 months. Results: Mitral valve repair (MVR) was technically feasible in all patients. Intraoperative transesophageal echocardiography (TEE) revealed none (n=60) or only trivial (n=6) residual mitral regurgitation. Thirty day mortality was 6.1%. Actuarial survival after 1 and 5 years was 86±4 and 66±8%, respectively. During follow-up seven patients were transplanted due to lack of clinical improvement after 10±7 months (range 1–23). Echocardiography revealed a significant improvement in EF (25±10.5% pre-op, 34±15% post-op) and a slight decrease in left ventricular end-diastolic diameter (69±10 mm pre-op, 67±13 mm follow up). Patients were in NYHA functional -class 3 (median) preoperatively and in class 2 at long term-follow-up. Gender, left ventricular enddiastolic diameter, preoperative ejection fraction or type of surgical approach (sternotomy, right lateral minithoracotomy) had no significant influence on patient outcome. Patients with ICM or patients older than 60 years showed an increased risk for clinical events both early post-operatively and at long-term follow-up. Conclusion: MVR can be performed with low perioperative morbidity and mortality even in patients with advanced heart failure, modifying selection criteria for potential candidates may further improve long term outcome.     

Structural basis of neurogenic bladder dysfunction. II. Myogenic basis of detrusor hyperreflexia

PURPOSE: We describe the ultrastructure of detrusor smooth muscle in long-standing neurogenic bladder dysfunction in the human. MATERIALS AND METHODS: Detrusor biopsies were obtained from (15 female and 31 male) patients 7 to 96 years old with neurogenic bladder dysfunction for less than 1 to 43 years. Of the patients 9 had meningomyelocele, 25 spinal cord injury and 12 brain disorder. Urodynamically, all patients had detrusor hyperreflexia (neurogenic detrusor overactivity) in addition to bladder outlet obstruction in 4, impaired detrusor contractility in 19, decreased bladder compliance in 4, and detrusor-sphincter dyssynergia in 24. Ultrastructural changes in detrusor, including those associated with detrusor overactivity, impaired detrusor contractility and bladder outlet obstruction, were evaluated qualitatively and quantitatively. RESULTS: Intermediate junctions of muscle cells were absent or reduced in 45 biopsies, which instead had dominant intimate cell appositions with much narrower junctional gaps. A greater than 2 intimate cell apposition-to-intermediate junction ratio was present in 45 biopsies (98%), and intimate cell apposition linked chains of 5 muscle cells or greater in all biopsies (100%). Muscle cell degeneration was observed in 34 biopsies from 20 of 27 patients (74%) with normal contractility and 14 of 19 (74%) with impaired detrusor contractility. No particular changes were associated with functional bladder outlet obstruction due to detrusor-sphincter dyssynergia. CONCLUSIONS: The ultrastructural complete dysjunction pattern is a feature of hyperreflexia as well as nonneuropathic detrusor overactivity of various etiology. A greater than 2 intimate cell apposition-to-intermediate junction ratio had 98% sensitivity but its specificity remains to be determined. The lack of relationship between muscle cell degeneration and detrusor contractility probably reflects limitations of urodynamic measurement of contractility in patients with spinal cord injury and meningomyelocele.     

Conspicuity of zones of ablation after radiofrequency ablation in porcine livers: comparison of an extracellular and an SPIO contrast agent

PURPOSE: To compare conspicuity of zones of ablation on nonenhanced, gadopentetate dimeglumine-(Gd-DTPA) and ferucarbotran-(SPIO)-enhanced magnetic resonance (MR) images. MATERIALS AND METHODS: In all, 33 radiofrequency ablations (RFA) were performed in 17 healthy porcine livers at 1.5T MR imaging 1 day and 2 and 4 weeks after RFA: T2-weighted (w) ultra turbo spin echo (UTSE), proton density (PD)-w UTSE, T1-w gradient echo (GRE) pre- and 5 minutes postcontrast administration, dynamic T1-w GRE during Gd-DTPA (Magnevist) or SPIO (Resovist) administration, T2-w UTSE, and PD-w UTSE sequences 10 minutes after SPIO administration. Regions of interest (ROIs) for contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were drawn in consensus by two radiologists. RESULTS: PD-w SPIO-enhanced images (23.5 +/- 5.5) showed higher liver-to-lesion CNR than T1-w GRE Gd-DTPA-enhanced images (13.5 +/- 6.1) 1 day after RFA (P < or = 0.05). At all other timepoints, liver-to-lesion CNR of PD-w and T2-w SPIO-enhanced images did not differ significantly from T1-w GRE Gd-DTPA-enhanced images (P > or = 0.05). Nonenhanced T2-w images revealed lower liver-to-lesion CNR (7.0 +/- 7.5/6.5 +/- 5.9/6.8 +/- 5.0, 1 day/2 weeks/4 weeks, respectively) than T2-w SPIO-enhanced (17.4 +/- 4.8/15.3 +/- 4.5/14.2 +/- 5.7), PD-w SPIO-enhanced (23.5 +/- 5.5/16.9 +/- 3.6, 1 day/2 weeks), and T1-w Gd-DTPA-enhanced (15.3 +/- 3.6/12.7 +/- 3.5, 2/4 weeks) images (P < or = 0.05). Liver-to-lesion CNR of SPIO-enhanced dynamic T1-w GRE images after 30, 80, 150, and 240 seconds did not change significantly over time (P > or = 0.05). CONCLUSION: One day after RFA lesion conspicuity on PD-w ferucarbotran-enhanced images is better than on T1-w GRE Gd-DTPA-enhanced images. At all other timepoints, ferucarbotran is not superior to gadolinium. Ferucarbotran- and gadolinium-enhanced images improve lesion conspicuity compared with nonenhanced T2-w images at all timepoints.     

Histological verification of 11C-choline-positron emission/computed tomography-positive lymph nodes in patients with biochemical failure after treatment for localized prostate cancer

OBJECTIVES

To evaluate the potential of ¹¹C‐choline‐positron emission tomography (PET)/computed tomography (CT) for planning surgery in patients with prostate cancer and prostate‐specific antigen (PSA) relapse after treatment with curative intent.

PATIENTS AND METHODS

We retrospectively reviewed the charts of 10 patients with PSA recurrence after either external beam radiation (two) or radical retropubic prostatectomy (eight) for prostate cancer, and who had a laparoscopic lymphadenectomy for suspicious lymph nodes detected on ¹¹C‐choline‐PET/CT. The histological results and PET/CT findings were compared.

RESULTS

In all, 22 suspicious lymph nodes were found on PET/CT, and 14 on conventional CT or magnetic resonance imaging. Comparing the conventional imaging showed concordance in 13 lymph nodes. Three of the 10 patients had no metastatic lymph node disease on definitive histology. The mean (sd ) PSA level for these patients was 1.0 (0.4) ng/mL, whereas that in patients with lymph node metastases was 15.1 (9.2) ng/mL (statistically significant difference, P < 0.05). The positive predictive value was seven of 10. All of the patients initially regressed, with PSA increases after lymphadenectomy. Two of the patients are being managed by watchful waiting, two had radiotherapy of the prostate fossa and two had chemotherapy with docetaxel. Four patients were treated by hormone‐deprivation therapy. After a mean (sd ) follow up of 11 (7) months, one patient died, one has PSA progression, but none of those with negative histology has clinical signs of local recurrence.

CONCLUSIONS

¹¹C‐choline‐PET is a valuable tool for detecting recurrent prostate cancer, but the limited positive predictive value should lead to a critical interpretation of the results.     

Kissing melanoma or kissing nevus of the penis?

Divided, or so-called kissing nevi of the penis, which are separated during embryogenesis, are very rare, with only seven studies reported to date. We present a case of a 30-year-old patient with a divided nevus located at the penis that rapidly changed in size and color within 4 months. These clinical features and the histopathologic appearance of both parts led to the diagnosis of malignant melanoma. Melanoma of the penis is very rare, and the prognosis is poor. This could be the first case of a "kissing melanoma" of the penis reported in published studies.     

Improved right heart function after myocardial preservation with 2,3-butanedione 2-monoxime in a porcine model of allogenic heart transplantation.

BACKGROUND: Right heart dysfunction is a major cause for early morbidity and mortality after heart transplantation. Experiments were designed to evaluate the influence of the calcium-desensitizing drug 2,3-butanedione 2-monoxime (BDM) on right heart function in a porcine model of heart transplantation. METHODS: Donor hearts of domestic pigs were arrested with BDM in Krebs solution (n = 7) and with BDM in Bretschneider's histidine-tryptophan-ketoglutarate (HTK) solution (n = 6). There were 2 control groups: University of Wisconsin (UW, n = 6) and HTK (n = 6). An isovolumic model was used in which the right ventricular volume was precisely controlled in vivo with an intracavitary high-compliance balloon. After 4 hours of ischemia, hearts were transplanted into recipients. After 1 and 2 hours of reperfusion, the right ventricular balloon volume was increased in 10-mL increments until right ventricular failure occurred and the developed pressures were recorded. RESULTS: Maximal right ventricular developed pressures were significantly different after 2 hours of reperfusion (UW: 35 +/- 13 mm Hg; HTK: 47 +/- 8 mm Hg; Krebs+BDM: 49 +/- 9 mm Hg; HTK+BDM: 50 +/- 6 mm Hg; P =.04). Hearts subjected to BDM could be loaded with a significantly increased volume after 1 hour and after 2 hours (UW: 57 +/- 10 mL vs HTK: 43 +/- 8 mL vs Krebs+BDM: 70 +/- 10 mL vs HTK+BDM: 67 +/- 15 mL; P =.002). Postischemic right ventricular enddiastolic compliance was significantly increased in groups treated with BDM after 1 hour (P =.02) and after 2 hours (P =.039). CONCLUSIONS: The drug BDM significantly improves right ventricular function in a heart transplantation model. The increase in volume load and developed right ventricular pressure achieved by BDM application would translate into a decreased risk of right ventricular failure after clinical transplantation.     

Selective COX-2 inhibitor versus indomethacin for the prevention of heterotopic ossification after hip replacement: a double-blind randomized trial of 100 patients with 1-year follow-up

Introduction Recent reports have suggested that selective COX-2 inhibition may be sufficient for the prevention of heterotopic ossification.

Methods We performed a randomized controlled study to evaluate the effect of the selective COX-2 inhibitor rofecoxib compared to that of indomethacin on the incidence and extent of heterotopic ossification in patients who had undergone hip replacement surgery. 50 patients received a daily dose of 25 mg rofecoxib and 50 patients received a daily dose of 100 mg indomethacin (25, 25, and 50 mg).

Results No ossifications were found in 48 patients. Grade-II ossifications were seen in 5/46 patients in the rofecoxib group and in 6/50 patients in the indomethacin group. Grade-III and grade-IV ossifications were seen in 3/46 patients in the rofecoxib group only. The differences were not statistically significant. The study medication had to be discontinued in 2 patients in the indomethacin group, due to dyspepsia.

Interpretation After short-term administration, the selective COX-2 inhibitor rofecoxib was effective in preventing heterotopic ossification after total hip arthroplasty.