Feasibility and diagnostic performance of hybrid PET/MRI compared with PET/CT for gynecological malignancies: a prospective pilot study

Purpose

The purpose of the study was to assess the feasibility and diagnostic performance of FDG-PET/MR imaging compared to PET/CT for staging of patients with a gynecological malignancy.

Methods

25 patients with a gynecological malignancy were prospectively enrolled into this pilot study. Patients underwent sequential full-body PET/CT and PET/MR of the abdomen and pelvis after administration of a single dose of F-18 FDG. PET/MRI and PET/CT images were independently reviewed by two expert radiologists. Readers were blinded to the results of the other imaging procedures. Clinical and pathologic information was abstracted from medical charts.

Results

18 patients were included in the final analysis with a median age of 62 years (range 31–88). 61% of patients (11/18) had cervical cancer, while the remaining patients had endometrial cancer. PET/MRI as compared to PET/CT detected all primary tumors, 7/7 patients with regional lymph nodes, and 1/1 patient with an abdominal metastasis. Two patients had additional lymph nodes outside of the abdominopelvic cavity detected on PET/CT that were not seen on PET/MRI, whereas 6 patients had parametrial invasion and one patient had invasion of the bladder seen on PET/MRI not detected on PET/CT. Five cervical cancer patients had discordant clinical vs. radiographic staging based on PET/MRI detection of soft tissue involvement. Management changed for two patients who had clinical stage IB1 and radiographic stage IIB cervical cancer.

Conclusions

PET/MRI is feasible and has at least comparable diagnostic ability to PET/CT for identification of primary cervical and endometrial tumors and regional metastases. PET/MRI may be superior to PET/CT for initial radiographic assessment of cervical cancers.

     

Early Hepatocellular Carcinoma: Pathology, Imaging, and Therapy

Background In 1987, Japanese researchers proposed to define the pathological concept of early hepatocellular carcinoma (HCC). However, there are some conceptual differences between the East and the West in the diagnosis and treatment of early HCC. Methods To provide up-to-date data for making a worldwide consensus, this article has collected six papers focused on the management of early HCC, which were presented in the Fifth International Meeting of “Hepatocellular Carcinoma: Eastern and Western Experiences” in Houston in January 2007. Results In the pathological perspective, the common criteria to discriminate early HCC from dysplastic nodule included hepatocytic invasion of portal triads and septa (stromal invasion). The current imaging modalities such as contrast-enhanced ultrasound (CEUS), computed tomography (CT), and magnetic resonance imaging (MRI) with the use of intravenous contrast material with multiphasic imaging could enhance their ability to accurately characterize early HCC. From the treatment perspective, a single early HCC had a high chance for cure by resection, ablation, or transplantation, which proved to be the earliest clinical entity (Stage 0 HCC). Conclusions Early HCC is characterized by its incipient malignant nature and by an extremely favorable clinical outcome, thereby justifying its definition. Proceedings of the Fifth International Meeting Hepatocellular Carcinoma: Eastern and Western Experiences held in Houston, TX, January 11–13, 2007.     

Intraductal papillary mucinous tumors of the pancreas: helical CT with histopathologic correlation

PURPOSE: To evaluate the accuracy of preoperative computed tomography (CT) in predicting the location and type of ductal involvement and malignant transformation in intraductal papillary mucinous (IPM) pancreatic tumors and to determine the predictive factors for malignancy at CT. MATERIALS AND METHODS: The helical CT scans obtained in 36 operated on patients with a diagnosis of IPM pancreatic tumor were retrospectively assessed. CT-histopathologic correlation was then performed. RESULTS: The final diagnoses of IPM tumor were combined type (n = 26) and branch duct type (n = 10) lesions. Histologic analysis revealed adenocarcinoma (n = 9), hyperplasia (n = 8), low-grade dysplasia (n = 12), and high-grade dysplasia (n = 7). The lesions were located mainly in the head or uncinate process (n = 20) or were diffuse or multifocal (n = 12). In 12 patients (13 cases), CT-histopathologic correlation was poor, including that in the evaluation of ductal involvement (n = 7), evaluation of lesion location (n = 2), and diagnosis of malignant transformation (n = 4). The most specific predictive signs of malignancy were presence of diabetes and, at CT, a solid mass, main pancreatic duct dilatation greater than 10 mm, diffuse or multifocal involvement, and attenuating or calcified intraluminal content. CONCLUSION: The main causes of poor CT-histopathologic correlation were related to evaluation of main pancreatic duct involvement and diagnosis of malignant transformation. The association between diabetes and specific CT criteria was highly suggestive of malignancy.     

Segment 4 and the left lateral segment regeneration pattern after resection of the middle hepatic vein in a living donor right hepatectomy

Background

Inclusion of the middle hepatic vein (MHV) with a right hepatectomy (RH) in live donor liver transplantation improves venous drainage of the anterior sector of the graft. Its long-term effects on donor left liver (LL) regeneration are not well described.

Methods

Donors who underwent RH with MHV (MHV+, n = 12) were compared with donors who underwent RH with preservation of the MHV (MHV–, n = 24). Peri-operative complications and volume of the entire liver and individual segments were evaluated at 1 year post-donation.

Results

There was a trend towards a higher complication rate in the MHV+ group (41% versus 25%), without reaching statistical significance (P = 0.3). Males, high body mass index (BMI) and a smaller residual liver volume (RLV) were predictors for greater LL regeneration. MHV+ donors had impaired regeneration of segment 4 (S4) at 1 year, and compensatory greater left lateral segment regeneration. The absence of venous drainage of S4 (V4) to left hepatic vein (LHV) was a predictor of impaired S4 regeneration.

Conclusions

Regeneration of S4 is impaired in MHV+ donors. Caution should be taken when considering MHV removal on donors with dominant S4, especially on those with potential increased demand for liver regeneration, such as males, higher BMI and a smaller RLV.     

Optimizing the detection of subclinical inguinal hernias in men undergoing open radical retropubic prostatectomy

Study Type – Diagnostic (exploratory cohort)
Level of Evidence 2b

OBJECTIVE

To evaluate the role of magnetic resonance imaging (MRI) and up‐standing ultrasonography (USUS) for the detection of inguinal hernias (IHs) before open radical retropubic prostatectomy (ORRP) and to assess factors associated with the presence of IHs in these men.

PATIENTS AND METHODS

From 1 July 2007 to 1 February 2009, 164 men underwent preoperative evaluation for ORRP by one surgeon. Of these men 113 (69%) were evaluated for IHs by physical examination (PE), USUS and MRI. In all 226 groins were examined. Any IH diagnosed by any method was considered a true positive. The sensitivity, negative predictive value (NPV), and concordance were calculated for the three diagnostic methods. Possible predictive factors of IHs were evaluated.

RESULTS

Of the 226 groins evaluated, 72 (32%) IHs were diagnosed. USUS had the greatest sensitivity (69.4%) and the highest NPV (87.5%). MRI had fair agreement with PE and USUS, while USUS and PE had moderate agreement with each other. No factor was associated with an increased likelihood of preoperative diagnosis of IH.

CONCLUSIONS

This study was limited by the lack of a reference standard to diagnose IH. USUS was the most sensitive method for the detection of IH. We recommend that all men undergoing ORRP should be evaluated for IHs by PE and at least one imaging method and that IHs be repaired at the time of ORRP, obviating the need for a second surgical procedure.