Tumor localization of 16beta-18F-fluoro-5alpha-dihydrotestosterone versus 18F-FDG in patients with progressive, metastatic prostate cancer.

This trial was an initial assessment of the feasibility, in vivo targeting, and biokinetics of 16beta-(18)F-fluoro-5alpha-dihydrotestosterone ((18)F-FDHT) PET in patients with metastatic prostate cancer to assess androgen receptor expression. METHODS: Seven patients with progressive clinically metastatic prostate cancer underwent (18)F-FDG and (18)F-FDHT PET scans in addition to conventional imaging methods. Three patients had their studies repeated 1 mo later, 2 while on testosterone therapy, and the third after treatment with 17-allylamino-17-demethoxygeldanamycin (17-AAG). High-pressure liquid radiochromatography was used to separate (18)F-FDHT from radiolabeled metabolites. Lesion-by-lesion comparisons between the (18)F-FDHT, (18)F-FDG, and conventional imaging methods were performed. RESULTS: Metabolism of (18)F-FDHT was rapid, with 80% conversion within 10 min to radiolabeled metabolites that circulated bound to plasma proteins. Tumor uptake was rapid and tumor retention was prolonged. Fifty-nine lesions were identified by conventional imaging methods. (18)F-FDG PET was positive in 57 of 59 lesions (97%), with an average lesion maximum standardized uptake value (SUV(max)) = 5.22. (18)F-FDHT PET was positive in 46 of 59 lesions (78%), with the average positive lesion SUV(max) = 5.28. Treatment with testosterone resulted in diminished (18)F-FDHT uptake at the tumor site. CONCLUSION: (18)F-FDHT localizes to tumor sites in patients with progressive clinically metastatic prostate cancer and may be a promising agent to analyze antigen receptors and their impact on the clinical management of prostate cancer.     

Clinical implications of different image reconstruction parameters for interpretation of whole-body PET studies in cancer patients.

The standardized uptake value (SUV) is the most commonly used parameter to quantify the intensity of radiotracer uptake in tumors. Previous studies suggested that measurements of (18)F-FDG accumulation in tissue might be affected by the image reconstruction method, but the clinical relevance of these findings has not been assessed. METHODS: Phantom studies were performed and clinical whole-body (18)F-FDG PET images of 85 cancer patients were analyzed. All images were reconstructed using either filtered backprojection (FBP) with measured attenuation correction (MAC) or iterative reconstruction (IR) with segmented attenuation correction (SAC). In a subset of 15 patients, images were reconstructed using all 4 combinations of IR+SAC, IR+MAC, FBP+SAC, and FBP+MAC. For phantom studies, a sphere containing (18)F-FDG was placed in a water-filled cylinder and the activity concentration of that sphere was measured in FBP and IR reconstructed images using all 4 combinations. Clinical studies were displayed simultaneously and identical regions of interest (ROIs, 50 pixels) were placed in liver, urinary bladder, and tumor tissue in both image sets. SUV max (maximal counts per pixel in ROI) and SUV avg (average counts per pixel) were measured. RESULTS: In phantom studies, measurements from FBP images underestimated the true activity concentration to a greater degree than those from IR images (20% vs. 5% underestimation). In patient studies, SUV derived from FBP images were consistently lower than those from IR images in both normal and tumor tissue: Tumor SUV max with IR+SAC was 9.6 +/- 4.5, with IR+MAC it was 7.7 +/- 3.5, with FBP+MAC it was 6.9 +/- 3.0, and with FBP+SAC it was 8.6 +/- 4.1 (all P < 0.01 vs. IR+SAC). Compared with IR+SAC, SUV from FBP+MAC images were 25%-30% lower. Similar discrepancies were noted for liver and bladder. Discrepancies between measurements became more apparent with increasing (18)F-FDG concentration in tissue. CONCLUSION: SUV measurements in whole-body PET studies are affected by the applied methods for both image reconstruction and attenuation correction. This should be considered when serial PET studies are done in cancer patients. Moreover, if SUV is used for tissue characterization, different cutoff values should be applied, depending on the chosen method for image reconstruction and attenuation correction.     

Design of respiration averaged CT for attenuation correction of the PET data from PET/CT

Our previous patient studies have shown that the use of respiration averaged computed tomography (ACT) for attenuation correction of the positron emission tomography (PET) data from PET/CT reduces the potential misalignment in the thorax region by matching the temporal resolution of the CT to that of the PET. In the present work, we investigated other approaches of acquiring ACT in order to reduce the CT dose and to improve the ease of clinical implementation. Four-dimensional CT (4DCT) data sets for ten patients (17 lung/esophageal tumors) were acquired in the thoracic region immediately after the routine PET/CT scan. For each patient, multiple sets of ACTs were generated based on both phase image averaging (phase approach) and fixed cine duration image averaging (cine approach). In the phase approach, the ACTs were calculated from CT images corresponding to the significant phases of the respiratory cycle: ACT(050phs) from end-inspiration (0%) and end-expiration (50%), ACT(2070phs) from mid-inspiration (20%) and mid-expiration (70%), ACT(4phs) from 0%, 20%, 50% and 70%, and ACT(10phs) from all ten phases, which was the original approach. In the cine approach, which does not require 4DCT, the ACTs were calculated based on the cine images from cine durations of 1 to 6 s at 1 s increments. PET emission data for each patient were attenuation corrected with each of the above mentioned ACTs and the tumor maximum standard uptake value (SUVmax), average SUV (SUVavg), and tumor volume measurements were compared. Percent differences were calculated between PET data corrected with various ACTs and that corrected with ACT(10phs). In the phase approach, the ACT(10phs) can be approximated by the ACT(4phs) to within a mean percent difference of 2% in SUV and tumor volume measurements. In cine approach, ACT(10phs) can be approximated to within a mean percent difference of 3% by ACTs computed from cine durations > or =3 s. Acquiring CT images only at the four significant phases for the ACT can reduce radiation dose to 1/3 of the current 4DCT dose; however, the implementation of this approach requires additional hardware that is not standard equipment on PET/CT scanners. In the cine approach, we recommend a duration of 6 +/- 1 s in order to include variations of respiratory patterns in a larger population. This approach can be easily implemented because cine acquisition mode is available on all GE PET/CT scanners. The CT dose in the cine approach can be reduced to approximately 5 mGy by using the lowest mA setting (10 mA), while still maintaining good quality CT data for PET attenuation correction. In our scanning protocol, the ACT is only acquired if respiration-induced misregistration is observed (determined before the PET scan is completed), and therefore patients do not receive unnecessary CT radiation dose.     

The Cost and Consequences of Failed Osteosynthesis of Intertrochanteric Femur Fractures: A Matched Cohort Study

BackgroundWe aimed to evaluate the cost and consequences of failed osteosynthesis of intertrochanteric femur fracture (ITFF) patients and compare with primary ITFF patients.MethodsWe retrospectively evaluated 689 patients who underwent surgery due to ITFF via cephalomedullary nail. 31 patients (5.8%) had revision surgery because of osteosynthesis failure of ITFF. Each revision case included in the study was matched with four primary ITFF cases as control group based on age, gender, year of operation, type of fracture and American Society of Anesthesiologists (ASA) grade. Total cost for the admission that patients underwent surgery, mortality rate at first year, infection rate, length of stay at hospital, length of stay at intensive care unit, and erythrocyte transfusion amounts were recorded from hospital registry records. Tip apex distances (TAD) were noted.ResultsThe mean total cost of the revision cases and primary cases was 10,027 ± 6387 and 5261 ± 1773 Turkish Liras, respectively (p < 0.001). TAD was ≥ 20 mm in 32.3% (10/31) of patients in revision group while 2.4% (3/124) of the patients in control group (p < 0.001). The mean length of stay at hospital, length of stay at intensive care unit, erythrocyte transfusion amounts, infection rate and mortality rate at first year were significantly higher in revision cases compared to matched primary control cases (p < 0.05).ConclusionRevision surgeries due to failed osteosynthesis of ITFFs with cephalomedullary nail have at least two times higher mean total cost than primary cases. The awareness of the cost, morbidity and mortality of the revision surgeries may reduce the modifiable risk factors of osteosynthesis failure including maintenance of TAD below 20 mm, obtaining optimal lag screw position and reduction quality.Level of EvidenceLevel 3, retrospective cohort study.     

Interaction of commonly used emollients with photochemotherapy

BACKGROUND/AIM: Even though emollients are commonly used in combination with photochemotherapy, we still lack guidance for the selection of the appropriate emollient to be used in combination with photochemotherapy. The purpose of our study was to determine the interaction of commonly used emollients with photochemotherapy. METHODS: The study was carried on 75 healthy volunteers. In order to assess the effects of five different emollients--white petrolatum, 3% salicylic acid in white petrolatum, Balmandol, Decubal and Urederm hydro--the subjects were divided into five groups. Minimal phototoxic dose (MPD) was determined by irradiating two rows of six circular test fields on the back of the subjects with increasing doses of UVA. One of the emollients listed above was applied to the skin under the upper rows alternatively, whereas the lower rows served as control. RESULTS: Application of Urederm hydro and Decubal before exposure to UVA resulted in a statistically significant decrease in the MPD in all subjects. Even though application of white petrolatum and white petrolatum containing 3% salicylic acid decreased the MPD in most of the subjects and Balmandol application slightly increased the MPD, the results did not reach statistical significance. CONCLUSIONS: According to our findings, it is probable that the total dose of UVA needed to cause clearing of psoriasis would be decreased by application of Urederm hydro and Decubal prior to photochemotherapy. We noted a slight photoprotective effect of Balmandol in the UVA range, but this finding has to be further studied. Clinical studies are needed to clarify the effects of these emollients on the course and outcome of photochemotherapy.     

CSF hydrothorax after ventriculoperitoneal shunt without catheter migration: a case report

Ventriculoperitoneal (VP) shunting is the most common procedure performed for the management of hydrocephalus. VP shunt related complications remain a persistent problem in current clinical practice. Five-year-old female patient was admitted to our hospital with persistent dyspnea complaint. The patient was operated at the age of 3 months and a VP shunt established in a different clinic due to hydrocephalus associated with Dandy-Walker malformation. The patient’s chest X-ray revealed right sided pleural effusion. Thorasentesis was performed and the effusion was drained with a chest tube. The discharged liquid was consistent with CSF. Scintigraphic radionuclide shunt analyses were performed and CSF passage from abdomen to chest and lower mediastinal region was determined in the late static images. The patient was operated and the incorporated ventriculoperitoneal shunt was removed. Hydrothorax was completely resolved after early postoperative stage. CSF hydrothorax especially without catheter migration is an unusual but potentially serious-clinical complication.     

The Surgical Management of Traumatic C6-C7 Spondyloptosis

A case of traumatic spondyloptosis of the cervical spine at the C6-C7 level is reported. The patient was treated succesfully with a anterior-posterior combined approach and decompression. The patient had good neurological outcome after surgery. A-51-year-old female patient was transported to our hospital''s emergency department after a vehicle accident. The patient was quadriparetic (Asia D, MRC power 4/5) with severe neck pain. Plain radiographs, computerize tomography and spinal magnetic resonance imaging (MRI) showed C6-7 spondyloptosis and C5, C6 posterior element fractures. Gardner-Wells skeleton traction was applied. Spinal alignment was reachived by traction and dislocation was decreased to a grade 1 spondylolisthesis. Then the patient was firstly operated by anterior approach. Anterior stabilization and fusion was firstly achieved. Seven days after first operation the patient was operated by a posterior approach. The posterior stabilization and fusion was achieved. Postoperative lateral X-rays and three-dimensional computed tomography showed the physiological realignment and the correct screw placements. The patient''s quadriparesis was improved significantly. Subaxial cervical spondyloptosis is a relatively rare clinical entity. In this report we present a summary of the clinical presentation, the surgical technique and outcome of this rarely seen spinal disorder.     

Electrophysiology of papillary muscle in SAH: changes and N-acetylcysteine protection

Background  

Although subarachnoid hemorrhage (SAH) serves as a good model to study heart–brain interactions, neither the changes on the single ventricular action potential (SVAP) and contraction nor the effects of possible cardioprotective agents have been investigated.