Application of positron emission tomography in gynecological malignancies

Use of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging has gained an increasing importance in oncological applications. PET/computerized tomography (CT) scan provides both anatomic and functional imaging. FDG-PET/CT is used for staging of gynecological tumors, evaluating response to treatment and detecting relapses. It has been proven that FDG-PET/CT is useful for both early and advanced stages of cervical cancer. It gives promising results in determining prognoses and demonstrating recurrence foci in the case of indefinable increased tumor markers existing after treatment. As a diagnostic tool, PET/CT provides an important benefit in patients with ovarian cancer with an increase in the specific biomarker, CA-125, and negative findings on conventional imaging. It has been emphasized that PET/CT has an important role in endometrial cancer. Alternative PET tracers are used for diagnosis of genital system cancers. In this paper, we review the literature on the current role and future contributions of PET imaging in gynecologic tumor imaging, with particular attention on PET/CT

Significance of increased scrotal Tc-99m MDP uptake in patients with prostate cancer

Objective We observed an unusually increased scrotal uptake as an interesting finding in some patients with prostate cancer who were scanned for any possible metastatic disease. This study was designed to investigate the significance of this incidental finding in the technetium-99m methylene diphosphonate scintigraphies

The value of different washout parameters in the evaluation of renal transplants by technetium-99m-ethylene-I-I-dicysteine

Technetium-99m-ethylene-I-I-dicysteine (Tc-99m-EC) is an agent with a potential for renal imaging. It is reported that EC uses the same tubular transporter system as ortho-hippurate (OIH) and mercaptoacetyltriglycine (MAG3) and that this agent has good imaging properties and higher renal clearance than MAG3. In this study we used Tc-99m-EC to compare different washout parameters in renal transplanted patients. Sixty nine scans in 55 patients (38 males, 17 females) were performed with Tc-99m-EC during the follow-up period after kidney transplantation. After bolus injection of 280MBq Tc-99m-EC, 60x1sec and 29x1min images were taken in anterior position. Perfusions of transplanted kidneys were examined visually and perfusion indices (PI) were calculated according to Hilson's method. The semiquantitative washout parameters such as 20 and 30min to peak activity ratios and 20 and 30min to 3min activity ratios were calculated. The patients were clinically evaluated by nephrologists experienced in renal transplantation cases and followed-up by serum creatinine and blood urea nitrogen determinants which were checked every postoperative day until stabilized to a optimal level for each patient. Two standard deviations above the mean values derived from all cases with normal functioning transplanted kidneys were calculated for each method. Then, these values served as the threshold to differentiate the pathological cases respectively. Of the 69 total studies performed, we found 34 normal kidneys, 14 rejections, 19 acute tubular necrosis (ATN) and 2 cyclosporin A toxicity cases. The number of abnormal cases detected with 30/3min, 30/max, 20/3min and 20/max indices were 27, 26, 24, and 18, respectively. In conclusion, we strongly recommend in studying renal transplants to consider the activity at the 3(rd) min post injection as a reference point instead of the time to maximum activity for washout index calculation. If, for any reason the time to maximum counts using Tc-99m-(peak activity) is prefered, then the period of study should not be performed for less than 30min to achieve reliable results