Predictive significance of intraprostatic volumetric parameters derived from early and standard time 68Ga-PSMA PET/CT images in newly diagnosed prostate cancer patients.

OBJECTIVE: To investigate the relationship between intraprostatic 68Ga-prostate-specific membrane antigen (PSMA) uptake values and volumetric parameters derived from early pelvic and standard-time whole-body 68Ga-PSMA PET/computed tomography (CT) images in untreated prostate cancer (PCa) patients, and to assess the predictive significance of these data in relation to disease prognosis, comparing them with the Gleason score, clinical risk classification and the presence of metastatic disease detected in 68Ga-PSMA PET/CT imaging. METHODS: Eighty-one newly diagnosed PCa patients underwent early phase pelvic imaging at the 5th minute and standard time whole-body imaging at the 60th minute. Various threshold values were used in intraprostatic delineations to compute maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), intraprostatic PSMA tumor volume and intraprostatic total lesion PSMA uptake. Correlations between early and standard time measurements, as well as changes in SUV parameters over time, were examined. The association of these values with Gleason score, clinical risk status (National Comprehensive Cancer Network), and metastatic disease was explored. RESULTS: SUVmax measurements from both early and standard time images distinguished all three groups (clinical risk scores, Gleason score and metastatic group), with standard imaging demonstrating statistical superiority in receiver operating characteristic analyses. Strong correlations were observed between early and standard-time PET parameters. Changes in intraprostatic SUVmax and SUVmean values over time did not exhibit predictive value. CONCLUSION: Although intraprostatic PSMA PET parameters generally aligned at both early and standard times, parameters obtained from standard time images showed more robust correlations with clinical risk scores, Gleason score and metastasis status in newly diagnosed, untreated PCa patients.

Investigation of Added Value of Imaging Performed in a Prone Position to Standard 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging for Staging in Patients with Breast Cancer.

OBJECTIVES: To investigate whether additional imaging in a prone position has any value to the supine whole-body 18fluorine-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) images by comparing the visual and quantitative data about a local disease in the breast and axilla for the initial staging of breast cancer (BC). METHODS: In this study, a total of 91 female patients with the BC were studied. Both the supine and prone images were examined based on the axial diameter, number and location of the primary tumor, local invasion signs of the tumor, the number of axillary lymph nodes with a suspected metastasis, metabolic parameters of the primary tumor and axillary lymph nodes, and registration artifacts of the PET and CT images were evaluated individually. These findings were compared with the histopathological data obtained after a surgery. RESULTS: In the evaluation of a supine and prone imaging, tumor diameter and metabolic tumor volume (MTV) values of the breast lesions were greater in the supine position than in the prone position. However, there was no significant difference found between the other metabolic parameters of a primary tumor and axilla in both positions. In the supine and prone images, accuracy for skin involvement was 84% and 91.3%, respectively. CONCLUSION: In our study, we observed that, obtaining additional images in the prone position does not significantly benefit the evaluation of a local disease. The average values of the primary tumor diameter and MTV in the prone position appear to be smaller than the one in the supine position. However, the prone imaging in the patients with a newly diagnosed BC may be beneficial in selected patients and may contribute to preventing the false-positive results especially in patients with a suspected skin involvement.

Synchronous Hepatocellular Carcinoma and Cholangiocellular Carcinoma on 18F-FDG PET/CT

A 43-year-old male patient presented with a mass lesion on the right liver lobe, segment 5, in radiological imaging and elevated alpha-fetoprotein levels (323 ng/mL) compatible with hepatocellular carcinoma (HCC). Positron emission tomography/computed tomography (PET/CT) images showed background level 18F-FDG uptake in the mass lesion. In addition, a secondary focus of increased 18F-FDG uptake was detected on the left liver lobe, segment 2, approximately 1,5 cm in diameter. Histopathological examination revealed HCC in the larger mass lesion with a lower 18F-FDG uptake, and cholangiocellular carcinoma in the smaller mass lesion with a higher 18F-FDG uptake. To our knowledge, this is the first case report of two histopathologically different primary malignant liver tumors in two distinct segments of the liver detected by PET/CT.

The role of PET and MRI in evaluating the feasibility of skin-sparing mastectomy following neoadjuvant therapy.

Objective To investigate the role of positron emission tomography (PET) and magnetic resonance imaging (MRI) in evaluating the feasibility of skin-sparing mastectomy in patients with locally-advanced breast cancer (LABC) who will undergo neoadjuvant chemotherapy (NAC) by evaluating the sensitivity and specificity of PET and MRI compared with skin biopsy results before and after NAC treatment. Methods Patients with LABC who were treated with NAC between November 2013 and November 2015 were included in this study. Demographic, clinical, radiological and histopathological features of the patients were recorded. Results A total of 30 patients were included in the study with a mean age of 52.6 years (range, 35-70 years). Sensitivity and specificity for detecting skin involvement in LABC was 100%/10% (62%/85%) with MRI and 60%/80% (12%/92%) with PET before (after) NAC, respectively. When radiological skin involvement was assessed in relation to the final histopathological results, the preNAC PET results and histopathological skin involvement were not significantly different; and there was no difference between postNAC MRI and histopathological skin involvement. Conclusions As preNAC PET and postNAC MRI more accurately determined skin involvement, it might be possible to use these two radiological evaluation methods together to assess patient suitability for skin-sparing mastectomy in selected patients.

Inflammatory Fibroid Polyp of the Stomach Mimics Malignancy on 18F FDG PET/CT Imaging.

Inflammatory fibroid polyps (IFPs) are rare non-neoplastic and proliferating submucosal lesions of the gastrointestinal tract. The classic IFP, which was first described by Vanek, consists of prominent blood vessels and is characterized by a heavy inflammatory infiltrate, which is rich in eosinophilic granulocytes. The clinical presentation depends on the size and location. Inflammatory fibroid polyps cannot be differentiated from malignancy without histological examination. We report a case of IFP in the stomach that mimicked a primary gastric malignancy showing an increased F-FDG uptake.

New Fetal Dose Estimates from 18F-FDG Administered During Pregnancy: Standardization of Dose Calculations and Estimations with Voxel-Based Anthropomorphic Phantoms.

Data from the literature show that the fetal absorbed dose from 18F-FDG administration to the pregnant mother ranges from 0.5E-2 to 4E-2 mGy/MBq. These figures were, however, obtained using different quantification techniques and with basic geometric anthropomorphic phantoms. The aim of this study was to refine the fetal dose estimates of published as well as new cases using realistic voxel-based phantoms. METHODS: The 18F-FDG doses to the fetus (n = 19; 5-34 wk of pregnancy) were calculated with new voxel-based anthropomorphic phantoms of the pregnant woman. The image-derived fetal time-integrated activity values were combined with those of the mothers' organs from the International Commission on Radiological Protection publication 106 and the dynamic bladder model with a 1-h bladder-voiding interval. The dose to the uterus was used as a proxy for early pregnancy (up to 10 wk). The time-integrated activities were entered into OLINDA/EXM 1.1 to derive the dose with the classic anthropomorphic phantoms of pregnant women, then into OLINDA/EXM 2.0 to assess the dose using new voxel-based phantoms. RESULTS: The average fetal doses (mGy/MBq) with OLINDA/EXM 2.0 were 2.5E-02 in early pregnancy, 1.3E-02 in the late part of the first trimester, 8.5E-03 in the second trimester, and 5.1E-03 in the third trimester. The differences compared with the doses calculated with OLINDA/EXM 1.1 were +7%, +70%, +35%, and -8%, respectively. CONCLUSION: Except in late pregnancy, the doses estimated with realistic voxelwise anthropomorphic phantoms are higher than the doses derived from old geometric phantoms. The doses remain, however, well below the threshold for any deterministic effects. Thus, pregnancy is not an absolute contraindication of a clinically justified 18F-FDG PET scan.

Evaluation of nasal mucociliary transport rate according to nasal septum deviation type.

BACKGROUND: Nasal septum deviation (NSD) may affect mucociliary activity (MCA) to varying degrees, depending upon the severity of the deviation. We used rhinoscintigraphy to determine the impact of the various NSD types on MCA. METHODS: A recent classification describing 6 different forms of NSD was used to standardize the study. Forty-eight subjects were enrolled. Eight patients for each form of NSD were accrued for further study. Rhinoscintigraphy was performed using technetium 99m macroaggregated albumin ((99m) Tc-MAA) before and 3 months after surgery. Nasal mucociliary transport rate (NMTR), the half-time of (99m) Tc-MAA activity, and clearance rate over a 20-minute period were compared between groups. RESULTS: Preoperative NMTR and clearance rates were significantly lower and half-time was significantly longer in types 4 and 6 than in the other groups. Although the postoperative NMTR and clearance rates increased compared with preoperative values in all groups, the increase was significant only in types 2, 4, and 6. The postoperative half-time increased significantly compared with the preoperative values in types 2, 4, and 6. The postoperative rhinoscintigraphy evaluation revealed no significant differences among groups in NMTR, half-time, or clearance rate. CONCLUSION: NSD types 4 and 6 had lower preoperative NMTR and clearance rates and a longer half-time compared with the other groups. However, the postoperative values of these parameters were not significantly different among groups. Our results indicate that NSD types 4 and 6 had the greatest impact on MCA, suggesting that these patients may receive the maximum benefit from septoplasty.

Epithelioid Myofibroblastoma in an Old-Male Breast: A Case Report with MRI Findings.

Myofibroblastoma of the breast (MFB) is a very rare benign stromal tumor. In recent years, increase in mammographic screenings has resulted in increased diagnosis of MFB. Most cases are old males and postmenopausal women. MFB may be confused as malignant, clinically, morphologically, or by imaging. Immunohistochemistry is essential for final diagnosis in these cases. We report a case of a pathologically diagnosed MFB in an 80-year-old male patient who had coexisting prostate cancer and describe its imaging characteristics, especially magnetic resonance imaging (MRI). In this paper, histopathological and MRI findings of the MFB were discussed.

Incidental detection of prostate-specific antigen-negative metastatic prostate cancer initially presented with solitary pulmonary nodule on fluorodeoxyglucose positron emission tomography/computed tomography.

A 71-year-old male patient with solitary pulmonary nodule underwent fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) showing slightly increased FDG uptake in this nodule. In addition, PET/CT detected hypermetabolic sclerotic bone lesions in the right second rib and 7(th) thoracic vertebrae, which were interpreted as possible metastases, and mildly increased FDG uptake in the prostate gland highly suspicious of malignancy. The patient's prostate-specific antigen (PSA) level was within normal range (3.8 ng/dL). The histopathological examination of the lung nodule and right second rib lesion proved metastases from prostate cancer, then the prostate biopsy-confirmed prostate adenocarcinoma. The unique feature of this case is to emphasize the importance of performing PET/CT for solitary pulmonary nodule in detecting PSA-negative metastatic prostate cancer. This case indicated that it should be kept in mind that, even if the PSA is negative, a lung metastasis of prostate cancer may be an underlying cause in patients evaluated for solitary pulmonary nodule by FDG PET/CT.

Use of PET-CT for the assessment of treatment results in patients with sarcoidosis.

BACKGROUND AND AIM: Sarcoidosis is a multisystem disease of unknown origin. Determining the involvement and the response to the treatment is important. The aim of this study was to identify the effects of methylprednisolone and indomethacine on metabolic activity and pulmonary function test parameters in patients with sarcoidosis. MATERIAL AND METHODS: A total of 24 pulmonary sarcoidosis patients were enrolled in the study. All the patients underwent spirometry and [(18)F]fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) scan before treatment and were divided into two groups according to the necessity of corticosteroid treatment or not. Patients who did not have corticosteroid indication were treated with indomethacine. Symptomatic patients and patients who did not respond to indomethacine treatment received methylprednisolone. Patients were followed up on a monthly basis to determine the response. FDG uptakes as the disease activity were re-evaluated before ending the treatment at the sixth month. RESULTS: Mean age of patients (16 male, 8 female) was 39.79 (9.3) years. Besides mediastinum and pulmonary parenchyma, extrapulmonary sites were also involved in patients with pulmonary sarcoidosis (distant lymph nodes (upper abdominal, supraclavicular, inguinal, and axillary), liver, and spleen). Although maximum standard uptake values of methylprednisolone group regressed significantly (p < 0.001) after treatment, indomethacine group did not have significant regression (p = 0.345). Despite metabolic regressions, spirometry values of patients did not significantly increase (p > 0.005). CONCLUSION: FDG PET-CT may be useful for determining activity and the efficacy of treatments. Methylprednisolone is effective in reducing metabolic activity but does not lead to improvement in functional parameters.

Assessment of multifocality and axillary nodal involvement in early-stage breast cancer patients using 18F-FDG PET/CT compared to contrast-enhanced and diffusion-weighted magnetic resonance imaging and sentinel node biopsy.

BACKGROUND: Non-invasive evaluation of the extent of axillary nodal involvement in early-stage breast cancer (ESBC) patients and accurate assessment of multifocality are both challenging. Few reports have explored whether 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) might be more useful than other diagnostic methods in these contexts. PURPOSE: To prospectively evaluate the diagnostic utility of FDG PET/CT, contrast-enhanced, and diffusion-weighted magnetic resonance imaging (DCE-MRI and DWI), and sentinel lymph node biopsy (SNB), in detection of axillary metastatic lymph nodes in ESBC patients; and to explore the utilities of FDG PET/CT and DCE-MRI for identification of multifocality. MATERIAL AND METHODS: Twenty-four female patients (mean age, 47 ± 9.9 years; range, 24-68 years) with ESBC underwent whole-body FDG PET/CT and breast MRI prior to operation. SNB and axillary lymph node dissection (ALND) were performed on all patients, as was mastectomy or wide local tumor excision. Histopathological findings served as the gold standard when evaluating either multifocality or axillary nodal involvement. RESULTS: The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, of PET/CT and DCE-MRI, used to detect multifocality, were as follows: 67% versus 78%, 100% versus 53%, 100% versus 50%, 83% versus 80%, and 88% versus 63%. SNB afforded the highest sensitivity (93%) in terms of detection of axillary metastasis. The sensitivity, NPV, and accuracy of PET/CT were 67%, 62%, and 75% respectively, thus higher than the equivalent values of either DCE-MRI or DWI. CONCLUSION: For assessment of multifocality in ESBC patients, highly specific results of PET/CT should be taken into account along with DCE-MRI findings. For evaluation of axillary nodal involvement, PET/CT has higher sensitivity, NPV, and accuracy values than DCE-MRI and DWI and may guide a surgical decision to proceed or not to SNB or ALND.

Appearance of recurrent cardiac myxofibrosarcoma on FDG PET/CT.

Primary cardiac sarcomas are extremely rare tumors. In this case report, we presented the condition of a 37-year-old male patient diagnosed with myxofibrosarcoma after histopathologic evaluation of the left atrium mass excision. FDG PET/CT was performed and showed recurrent hypermetabolic lesions in the left atrial wall and right anterior mediastinal region.