Hepatectomy for recurrent colorectal liver metastases after radiofrequency ablation.

BACKGROUND: The results of surgery for recurrent colorectal liver metastases (CLM) after radiofrequency ablation (RFA) have not been evaluated. METHODS: From 1993 to 2009, data on patients who underwent resection or RFA for recurrent CLM were collected prospectively. Inclusion criteria for this study were RFA as initial treatment for CLM and resection of recurrent CLM after RFA. Postoperative results and oncological outcomes were analysed. RESULTS: Twenty-eight patients (median number of tumours 1 (1-3), median size 2·8 (2·0-4·0) cm) met the inclusion criteria. Of these, 22 had recurrence at the site of RFA only, two developed new lesions, whereas four had both recurrent and de novo metastases. At the time of resection, patients had a median of 1 (1-13) CLM with a median maximum tumour diameter of 5·0 (1·8-11·0) cm, significantly larger than at the time of RFA (P = 0·021). Ninety-day postoperative morbidity and mortality rates were 46 per cent (13 of 28) and 7 per cent (2 of 28) respectively. After a median follow-up of 35 (0-70) months, 3-year overall and disease-free survival rates calculated by Kaplan-Meier analysis were 60 and 29 per cent respectively. Plasma carcinoembryonic antigen level over 5 ng/ml at the time of resection and a rectal primary tumour were associated with worse survival (P = 0·041 and P = 0·021 respectively). CONCLUSION: Resection for recurrence after RFA is associated with significant morbidity and modest long-term benefit.

Portal vein embolization before major hepatectomy and its effects on regeneration, resectability and outcome.

BACKGROUND: This study evaluated the safety of portal vein embolization (PVE), its impact on future liver remnant (FLR) volume and regeneration, and subsequent effects on outcome after liver resection. METHODS: Records of 112 patients were reviewed. Standardized FLR (sFLR) and degree of hypertrophy (DH; difference between the sFLR before and after PVE), complications and outcomes were analysed to determine cut-offs that predict postoperative hepatic dysfunction. RESULTS: Ten (8.9 per cent) of 112 patients had PVE-related complications. Postoperative complications occurred in 34 (44 per cent) of 78 patients who underwent hepatic resection and the 90-day mortality rate was 3 per cent. A sFLR of 20 per cent or less after PVE or DH of not more than 5 per cent (versus sFLR greater than 20 per cent and DH above 5 per cent) had a sensitivity of 80 per cent and a specificity of 94 per cent in predicting hepatic dysfunction. Overall, major and liver-related complications, hepatic dysfunction or insufficiency, hospital stay and 90-day mortality rate were significantly greater in patients with a sFLR of 20 per cent or less or DH of not more than 5 per cent compared with patients with higher values. CONCLUSION: DH contributes prognostic information additional to that gained by volumetric evaluation in patients undergoing PVE.

Staging of pancreatic cancer with multidetector CT in the setting of preoperative chemoradiation therapy.

BACKGROUND: Preoperative chemoradiation can potentially improve outcomes in patients with pancreatic cancer. This study addresses its effect on staging pancreatic cancer with multidetector computed tomography (MDCT). METHODS: Fifty-five patients underwent a dual-phase MDCT pancreas protocol for proved pancreatic cancer. Of these, 16 patients underwent preoperative chemoradiation. Three radiologists independently reviewed images to assess for locally advanced disease, liver and peritoneal metastases on baseline studies of all 55 patients, and on follow-up preoperative studies for the 16 patients receiving preoperative therapy. Overall score for resectability was graded on a scale from 1 to 5 (1, definitely resectable; 5. definitely unresectable). Receiver operating characteristic curves and weighted (kappa statistics were determined. RESULTS: The areas under the receiver operating characteristic curves for readers 1, 2, and 3 were 0.98, 0.96, and 0.90, respectively. Weighted kappa values for reader 1 versus reader 2, reader 1 versus reader 3, and reader 2 versus reader 3 were 0.90, 0.57, and 0.54, respectively. Interpreting scores of 1 to 3 for resectability as resectable disease, the mean values for sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were 0.92, 0.91, 0.74, 0.98, and 0.92 respectively. CONCLUSION: The negative predictive value for MDCT for identifying unresectable pancreatic cancer in the setting of preoperative therapy is comparable to that reported in the absence of neoadjuvant therapy.

Radio-frequency ablation of liver tumors: assessment of therapeutic response and complications.

An alternative to surgical resection of liver tumors, radio-frequency ablation induces in situ thermal coagulation necrosis through the delivery of high-frequency alternating current to the tissues. Imaging helps to detect treatable lesions, guide the placement of the probe, and assess the effect of therapy. Computed tomography (CT) is used most frequently to determine whether the ablation is complete and to screen for early recurrences that may benefit from reablation. Complete ablation creates an area of necrosis that, at CT, is of low attenuation compared with the surrounding liver tissue, is often homogeneous, and has smooth margins. The most important features are the size of the necrotic defect, which, immediately after treatment, should be larger than that of the pretreatment tumor, and the sharpness of the margins, which indicates an abrupt change in attenuation between the necrotic tissue and surrounding liver tissue. Enhancement, when present, is due to perfusion abnormality or granulation tissue and forms a regular rim or a homogeneous zone at the margin of the defect. It is seen immediately after ablation but may be prolonged. Enhancement is affected by the scanning technique. Over time, the size of the defect remains stable or decreases. Any variation from this general pattern is suggestive of incomplete ablation or recurrence.

Hepatocellular carcinoma and intrahepatic peripheral cholangiocarcinoma: enhancement patterns with quadruple phase helical CT--a comparative study.

PURPOSE: To define the hemodynamic features of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma by using quadruple phase helical computed tomography (CT) and determine the value of this information in characterizing tumors. MATERIALS AND METHODS: Helical CT of the liver was performed in 45 patients with newly diagnosed HCC or peripheral cholangiocarcinoma. Scans were obtained before and 25 seconds, 70 seconds, and 2-6 minutes after the start of the contrast material injection. The intensity and spatial distribution of contrast material uptake were evaluated during all phases. Time-attenuation curves were established for each lesion. Relative attenuation and lesion conspicuity were assessed. A diagnostic confidence level was assigned to each lesion. RESULTS: In the majority of HCC lesions, a single, early peak of enhancement followed by a continuous decrease in tumor attenuation over time was seen. The greatest tumor conspicuity occurred during the delayed phase. In cholangiocarcinoma, tumor attenuation increased during the delayed phase. In the majority of lesions, the greatest tumor conspicuity was seen during the portal venous phase. In both tumor types, the diagnostic confidence level improved when the delayed phase was used. CONCLUSION: The variation over time in the intensity of contrast enhancement in HCC and cholangiocarcinoma differs sufficiently to make this a useful diagnostic criterion. The delayed phase is particularly important because it amplifies this difference.

Metastases to the pancreas from renal cell carcinoma: findings on three-phase contrast-enhanced helical CT.

OBJECTIVE: Our goal was to define the lesion enhancement characteristics of renal cell carcinoma metastases to the pancreas using three-phase helical CT. MATERIALS AND METHODS: Thin-section three-phase contrast-enhanced CT scans of nine patients with renal cell carcinoma metastases to the pancreas were evaluated. The helical CT protocol included 3-mm collimation and a 2:1 pitch. Scans through the pancreas were obtained in three series beginning 25, 60, and 120 sec after the start of administration of i.v. contrast material delivered at 3 ml/sec. The Hounsfield densities of the pancreatic lesions and normal pancreatic parenchyma during each of the enhancement phases were recorded and compared. RESULTS: The enhancement patterns of the metastatic deposits and the normal pancreas differed. Thirty-four lesions ranging in size from 6 to 110 mm were identified. All metastases showed rapid enhancement during the early (arterial and portal) phases, resulting in differential attenuations (compared with normal pancreatic parenchyma) of approximately 50-100 H. The differential attenuations were approximately 5-45 H on delayed-phase scans, resulting in poorer conspicuity of the lesions. Multifocal metastases were clearly identified on the early-phase scans in seven patients. CONCLUSION: Renal cell carcinoma metastases to the pancreas enhance most conspicuously during the early phases of helical CT. Such metastases may fail to be appreciated in the delayed phase. In patients with suspected renal cell carcinoma metastases to the pancreas, early-phase scanning after i.v. contrast administration should be performed.

Patterns of uterine enhancement with helical CT.

OBJECTIVE: The purpose of this study was to evaluate the enhancement characteristics of the normal uterine body and cervix using dynamic contrast-enhanced helical CT. METHODS: Thirty-eight women scheduled for pelvic CT for non-gynecologic malignancies underwent dynamic contrast-enhanced helical CT of the pelvis. Data acquisition was during the arterial phase (30-45 s after the start of injection), the parenchymal phase (90-120 s after the start of injection), and delayed phase (3-9 min after the start of injection). The images were evaluated by four radiologists for the pattern of myometrial and cervical enhancement. Correlation was made with the age and menstrual status of the patients. RESULTS: In the uterine body, three types of enhancement were observed. Type 1 enhancement, seen in 16 patients (42%), was characterized by the visualization of a subendometrial zone of enhancement, 30-120 s after the start of injection. Eight of these patients also showed an enhancing zone in the outer myometrium. Both zones were transitory, and in all cases, the uterus became homogeneous in the delayed phase. This pattern was seen predominantly in premenopausal women with a mean age of 34 years. Type 2 enhancement, seen in 17 cases (45%), was defined by the absence of subendometrial enhancement in the early phase. Enhancement was either diffuse from the outset or originated in the outer myometrium. This pattern was seen nearly equally in premenopausal and postmenopausal women with a mean age of 40 years. Type 3 enhancement was seen in five postmenopausal patients (13%) with a mean age of 53 years and was characterized by faint diffuse enhancement. In the cervix, a zonal pattern of enhancement defining inner and outer stroma was seen in 23 patients (61%). Fifteen patients were premenopausal and eight were postmenopausal. CONCLUSION: In this study, we have shown a transitory zonal distribution of the contrast in the myometrium and cervix using dynamic contrast-enhanced helical CT. The demonstration of these patterns is not constant and depends on individual variables. Of these, the menopausal status and/or age of the patient appear to be most important. While CT is not the primary imaging modality to evaluate the uterus, knowledge of these normal findings might help when confronted with unusual uterine enhancement during routine studies obtained with spiral CT.

Vascular involvement in pancreatic adenocarcinoma: reassessment by thin-section CT.

We defined computed tomographic (CT) criteria of vascular involvement by pancreatic carcinoma and used these criteria to assess vascular involvement in 56 patients with pancreatic adenocarcinoma. CT of the pancreas was performed at 1.5-mm section thickness and 5-mm section intervals during a bolus phase of intravenous contrast enhancement. The type of vascular involvement was correlated with surgical and pathologic findings. When there was fat-plane (type A) or normal pancreatic parenchyma (type B) separating the tumor from adjacent vessels, the tumor could be resected without venous resection in 21 of 22 patients (95%). When the tumor was inseparable from the vessels but the points of contact formed a convexity against the vessel (type C), CT was not reliable in predicting whether or not the tumor was fixed against the vessel. When the tumor was partially encircling (type D) the vessel, the tumor was fixed against the vessels in most cases. The resectable rate was 47%, but resection would also require venous resection. When the tumor was completely encircling (type E) or occluding (type F) the vessel, all tumors were not resectable with a negative margin. Thin-section CT with bolus intravenous contrast enhancement improved the ability to assess vascular involvement in pancreatic adenocarcinoma.

Radiation change in normal organs: an overview of body imaging.

Radiotherapy causes changes in a treated malignancy and the surrounding normal tissue which must be included in the radiation fields. Awareness of the expected appearance of these changes frequently permits differentiation of them from superimposed infection, recurrent malignancy, radiation-induced tumors, and the other true complications of radiation therapy. Radiotherapy changes are a function of the tissue volume treated, field shape, total dose and how it was delivered, time from completion of therapy, and the possible effect of other therapies. Timing of radiation changes varies in the different organs. Acute radiation pneumonitis is generally seen approximately 2 months after completion of radiotherapy, but radiation pericarditis not until 6-9 months after therapy. Radiation-induced sarcomas do not develop on average until 10-15 years after radiation therapy. An overview of expected findings and complications in the lungs, heart, gastrointestinal tract, genitourinary tract, and bones is presented.

Imaging of superficial soft-tissue infections: sonographic findings in cases of cellulitis and abscess.

The variation in the sonographic appearances of superficial soft-tissue infections probably reflects a continuous process that leads from soft-tissue edema, seen in cellulitis, to a fully developed abscess and that depends on the type of infection or the immune status of the host. We describe the sonographic findings seen in this process and the variable appearance of abscesses, with emphasis on scanning techniques that facilitate the diagnosis of liquefaction.

The long-term effects of internal mammary chain irradiation and its role in the vascular supply of the pedicled transverse rectus abdominis musculocutaneous flap breast reconstruction.

With an increase in breast-sparing surgery and adjuvant radiotherapy, there has been a concomitant increase in the complexity of breast reconstruction. The effects of radiotherapy on the internal mammary artery were evaluated with respect to flap viability for conventional transverse rectus abdominis musculocutaneous breast reconstruction using the irradiated rectus muscle. Twenty-eight women who received postoperative irradiation for breast cancer were studied. All women had unilateral irradiation, and evaluation of the internal mammary arteries was performed at least 1 year after the completion of radiotherapy to allow for fibrosis and long-term vascular changes. Examination of the internal mammary artery (upper and lower chains) was performed using color Doppler sonography to assess vessel diameter, peak systolic velocity, and blood flow. The nonirradiated side was compared to the radiated internal mammary artery as an internal control. Based on the details of prior radiotherapy, the 28 women were designated into two groups. Group I included 14 women with radiation portals that specifically treated the internal mammary chain; the average dose to the internal mammary chain was 47.44 Gy. Group II comprised 14 patients that received tangential portals that did not directly target the internal mammary chain region; the average radiation dose was 48.21 Gy to the chest wall. No statistical difference was observed in group I between the irradiated and nonirradiated side for vessel diameter (p = .8631) or peak systolic velocity (p = .2646). However, an increase in blood flow on the irradiated side was significant (p = .0321).(ABSTRACT TRUNCATED AT 250 WORDS)

Importance of dynamic assessment of the soft tissues in the sonographic diagnosis of echogenic superficial abscesses.

Superficial abscesses evaluated by ultrasonography may occasionally be isoechoic relative to the surrounding inflamed tissues and without mass effect, preventing diagnosis by morphologic criteria alone. We present a simple and effective method to detect such abscesses. In three cases, gentle repetitive pressure of the inflamed tissue revealed the liquefied nature of abscesses that otherwise would have been overlooked.

Mammographic and CT findings after breast reconstruction with a rectus abdominis musculocutaneous flap.

This essay illustrates the radiologic appearance of the reconstructed breast and the abdominal wall after breast reconstruction with a transverse rectus abdominis musculocutaneous (TRAM) flap. The findings are based on a retrospective study of 42 mammograms, 17 abdominal CT scans, and two CT scans each of the chest and pelvis of patients who underwent this procedure.