Koon-Kwan Ng

Detection of lymph node metastasis in cervical and uterine cancers by diffusion‐weighted magnetic resonance imaging at 3T

To evaluate diffusion‐weighted imaging (DWI) for detection of pelvic lymph node metastasis in patients with cervical and uterine cancers.

Myometrial Invasion in Endometrial Cancer: Diagnostic Accuracy of Diffusion-weighted 3.0-T MR Imaging—Initial Experience

PURPOSE To assess the diagnostic accuracy of fused T2-weighted and high-b-value diffusion-weighted (DW) magnetic resonance (MR) images at 3 T for evaluation of myometrial invasion in patients with endometrial cancer. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained. From May 2006 to October 2007, 48 consecutive patients aged 25-80 years (mean age, 57 years) who had endometrial cancer were prospectively enrolled for preoperative evaluation by using a 3-T MR unit. Two radiologists interpreted the depth of myometrial invasion on T2-weighted images, dynamic contrast material-enhanced MR images, and fused T2-weighted and DW MR images (b = 1000 sec/mm(2)). Statistical methods included kappa statistics for reader agreement, Pearson analysis for pathologic correlation, accuracy assessment, and receiver operating characteristic analysis for diagnostic performance comparison. Surgical pathologic findings were the reference standard. RESULTS Reader agreement was excellent for fused T2-weighted and DW images (weighted kappa, 0.79), with a significant pathologic correlation regarding the depth of myometrial invasion (r = 0.94, P < .0001). For assessing any myometrial involvement, addition of fused T2-weighted and DW imaging to dynamic contrast-enhanced or dynamic contrast-enhanced and T2-weighted imaging was significantly better compared with dynamic contrast-enhanced imaging alone (P < .001) or dynamic contrast-enhanced and T2-weighted (P = .001) imaging; T2-weighted imaging combined with fused T2-weighted and DW imaging also was better than dynamic contrast-enhanced and T2-weighted imaging (P = .001). Tumor apparent diffusion coefficients were 0.60-1.32 x 10(-3) mm(2)/sec (median, 0.75 x 10(-3) mm(2)/sec), with no significant correlation with the depth of myometrial invasion (P = .31, r = -0.15). CONCLUSION Fused T2-weighted and high-b-value DW images at 3 T can provide accurate information for preoperative evaluation of myometrial invasion.

Randomized trial of surgical staging (extraperitoneal or laparoscopic) versus clinical staging in locally advanced cervical cancer

OBJECTIVE To define the role of pretreatment surgical staging for locally advanced cervical carcinoma. METHODS A two-step randomized trial was conducted to compare clinical staging (arm A) versus surgical staging (arm B) and to compare the laparoscopic (LAP) with the extraperitoneal (EXP) approach in previously untreated locally advanced cervical carcinoma. After the first randomization, those in arm B were randomly allocated to either LAP or EXP. An interim analysis was planned to evaluate the feasibility of LAP versus EXP, which led to the current report. RESULTS A total of 61 patients were eligible (arm A, 29; arm B, 32). The operation time, blood loss, and lymph node yield of LAP and EXP were not significantly different. Serious acute and late toxicity was not different between arm A and arm B, or LAP versus EXP. Para-aortic node metastasis was documented in 25% (95% confidence interval, 10% to 40%) of patients on arm B. An interim analysis was performed in January 2000. Patients on arm B had significantly worse progression-free survival than those on arm A. Hazard ratios of relapse/persistent or death were 3.13 (P = 0.005) and 1.76 (P = 0.150), respectively. Patient accrual was terminated according to the early stopping rules. With further follow-up till December 2001, the difference in progression-free survival remained significant (P = 0.003), and the difference in overall survival became significant (P = 0.024) as the data matured. CONCLUSION The benefit of pretreatment surgical staging for cervical carcinoma remained unproven. The detrimental effects of surgical staging observed in this study must be considered in the design of clinical guidelines or future trials.

Value of Dual-Phase 2-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography in Cervical Cancer

PURPOSE The role of positron emission tomography (PET) with fluorine-18-labeled fluoro-2-deoxy-d-glucose (FDG) in cervical cancer has not yet been well defined. We conducted a prospective study to investigate its efficacy in comparison with magnetic resonance imaging and/or computed tomography (MRI-CT). MATERIALS AND METHODS Patients with untreated locally advanced (35%) or recurrent (65%) cervical cancer were enrolled onto this study. In the first part of this study, 41 patients had a conventional FDG-PET (40 minutes after injection), and in the second part, 94 patients received dual-phase PET (at both 40 minutes and 3 hours after injection). The overall results of PET scans were compared with MRI-CT, and the two protocols of PET were also compared with each other. Lesion status was determined by pathology results or clinical follow-up. The receiver operating characteristic curve method with area under the curve (AUC) calculation was used to evaluate the discriminative power. RESULTS Overall (N = 135), FDG-PET was significantly superior to MRI-CT in identifying metastatic lesions (AUC, 0.971 v 0.879; P =.039), although the diagnostic accuracy was similar for local tumors. Dual-phase PET was also significantly better than the 40-minute PET (n = 94). The latter accurately recognized 70% of metastatic lesions and the former detected 90% (AUC, 0.943 v 0.951; P =.007). Dual-phase FDG-PET changed treatment of 29 patients (31%; upstaging 27% and downstaging 4%). CONCLUSION This study shows that dual-phase FDG-PET is superior to conventional FDG-PET or MRI-CT in the evaluation of metastatic lesions in locally advanced or recurrent cervical cancer.

Randomized Trial of Neoadjuvant Cisplatin, Vincristine, Bleomycin, and Radical Hysterectomy Versus Radiation Therapy for Bulky Stage IB and IIA Cervical Cancer

PURPOSE To compare the efficacy of neoadjuvant chemotherapy (NAC) followed by radical hysterectomy with that of radiotherapy (R/T) for bulky early-stage cervical cancer. PATIENTS AND METHODS Women with previously untreated bulky (primary tumor >/= 4 cm) stage IB or IIA non-small-cell carcinoma of the uterine cervix were randomly assigned to receive either cisplatin 50 mg/m(2) and vincristine 1 mg/m(2) for 1 day and bleomycin 25 mg/m(2) for 3 days for three cycles followed by radical hysterectomy (NAC arm) or receive primary pelvic radiotherapy only (R/T arm). The ratio of patient allocation was 6:4 for the NAC and R/T arms. Women with enlarged para-aortic lymph nodes on image study were ineligible unless results of cytologic or histologic studies were negative. RESULTS Of the 124 eligible patients, 68 in the NAC arm and 52 in the R/T arm could be evaluated. The median duration of follow-up was 39 months. Thirty-one percent of patients in the NAC arm and 27% in the R/T arm had relapse or persistent diseases after treatment, and 21% in each group died of disease. Estimated cumulative survival rates at 2 years were 81% for the NAC arm and 84% for the R/T arm; the 5-year rates were 70% and 61%, respectively. There were no significant differences in disease-free survival and overall survival. CONCLUSION NAC followed by radical hysterectomy and primary R/T showed similar efficacy for bulky stage IB or IIA cervical cancer. Further study to identify patient subgroups better suited for either treatment modality and to evaluate the concurrent use of cisplatin and radiation without routine hysterectomy is necessary.

Isolated paraaortic lymph node recurrence after definitive irradiation for cervical carcinoma.

PURPOSE To evaluate the clinical features of isolated paraaortic lymph node (PALN) recurrence after definitive radiotherapy, and analyze the prognostic factors and effect of salvage treatment. METHODS AND MATERIALS Of a total 876 patients who received pelvic radiotherapy after the diagnosis of primary cervical carcinoma, 26 were found to have isolated PALN recurrence as the first recurrent site, and these patients enrolled in this study. Only those with primary-site carcinoma controlled and who were free of other distant metastases were eligible. Nineteen of the 26 patients accepted salvage therapy. Fourteen patients accepted concurrent chemoradiation (CCRT), 1 accepted radiation to the paraaortic region, and 4 accepted chemotherapy alone. Clinical parameters evaluated included tumor markers (SCC and CEA) and image studies. RESULTS Seven of the 26 patients were alive and disease-free. All 7 survivors had salvage treatment with radiation to the paraaortic region and concurrent cisplatin-based chemotherapy. None of the patients receiving chemotherapy or radiation alone enjoyed long-term, disease-free survival. The 5-year survival rate for isolated PALN recurrence of the 14 patients who accepted salvage concurrent chemoradiation (CCRT) was 51.2%. The presence of a clinical symptom at the time of PALN recurrence was analyzed. Seven of the 12 asymptomatic patients and none of the 14 symptomatic patients survived without disease after salvage treatment. The SCC levels at recurrence showed a statistically significant relationship to disease-free survival. CONCLUSIONS An SCC level of < or = 4 ng/ml and a lack of symptoms at the time of recurrence were good prognostic factors in isolated PALN recurrence after primary radiation therapy. In addition to concurrent CCRT, periodical surveillance with tumor markers and imaging studies allowed early detection and salvage of those patients.

A Prospective Randomized Trial to Study the Impact of Pretreatment FDG-PET for Cervical Cancer Patients With MRI-Detected Positive Pelvic but Negative Para-Aortic Lymphadenopathy

PURPOSE This prospective randomized study was undertaken to determine the possible impact of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) on extrapelvic metastasis detection, radiation field design, and survival outcome for cervical cancer patients with enlarged pelvic nodes on MRI image. METHODS AND MATERIALS Inclusion criteria were patients with newly diagnosed Stage I-IVA cervical cancer and with positive pelvic but negative para-aortic lymph nodes (PALN) as detected by magnetic resonance image and good performance status for concurrent chemoradiotherapy. Eligible patients were randomized to receive either pretreatment FDG-PET (study group) or not (control group). Whole pelvis was the standard irradiation field for the control group and those with no extrapelvic findings on PET. The radiation fields for the rest of the study group were extended to include the PALN region or were modified according to the extrapelvic PET finding. RESULTS From January 2002 to April 2006, 129 patients were included, and 66 of them were randomized to receive FDG-PET. PET detected seven extrapelvic metastases (11%, 6 PALN and 1 omental node), and four of them remained disease-free after treatment modification. For patients who underwent PET compared with those who did not, there were no differences in the 4-year rates of overall survival (79% vs. 85%, p = 0.65), disease-free survival (75 % vs. 77%, p = 0.64), and distant metastasis-free survival (82% vs. 78%, p = 0.83). CONCLUSIONS Pretreatment FDG-PET in conjunction with magnetic resonance imaging can improve the detection of extrapelvic metastasis, mainly PALN, and help select patients for extended-field radiotherapy. However, the addition of FDG-PET may not translate into survival benefit, even though PALN relapses are reduced.

Functional MRI in the assessment of cortical activation during gait-related imaginary tasks.

Imaginary tasks can be used to investigate the neurophysiology of gait. In this study, we explored the cortical control of gait-related imagery in 21 healthy volunteers using functional magnetic resonance imaging. Imaginary tasks included gait initiation, stepping over an obstacle, and gait termination. Subjects watched a video clip that showed an actor in gait motion under an event-related design. We detected activation in the supplementary motor area during major gait-related imagery tasks, and especially during gait initiation. During gait termination and stepping over an obstacle, the amount of cortical resources allocated to the imaginary tasks included a large visuomotor network comprising the dorsal and ventral premotor areas. We conclude that our paradigm to study the cortical control of gait may help in elucidating the pathophysiology of higher-level gait disorders.

Comparative benefits and limitations of 18F-FDG PET and CT-MRI in documented or suspected recurrent cervical cancer.

PurposeThe purpose of this study was to assess the comparative benefits and limitations of 18F-fluorodeoxyglucose (FDG) PET and CT-MRI in documented or suspected recurrence of cervical cancer after primary treatment.MethodsThree patient groups were enrolled. Group A patients had biopsy-documented recurrent or persistent cervical cancer. Group B patients had suspicion of recurrent tumour on CT-MRI without biopsy proof and were potentially curable. Group C patients were in complete remission after previous definitive treatment for histologically confirmed cervical carcinoma but had elevated serum squamous cell carcinoma antigen (tumour marker) levels despite negative CT-MRI. Clinical management decisions were recorded with CT-MRI alone and with additional FDG PET. Discordances and concordances between CT-MRI and FDG PET results were identified and related to final diagnosis as based on histopathology or follow-up.ResultsA total of 150 patients (ten regions per patient) were eligible for analysis, with 58 in group A, 52 in group B and 40 in group C. For the 149 discordant regions, 126 (84.6%) had final diagnoses. Of these final diagnoses, there was additional benefit from FDG PET over CT-MRI in 73.8% (93/126), with FDG PET correcting false negatives (FNs) on CT-MRI in 74.2% (69/93) and correcting false positives (FPs) on CT-MRI in 25.8% (24/93). Among lesions confirmed by FDG PET, 75.4% (52/69) were extra-pelvic. There was additional benefit of CT-MRI compared with FDG PET in 26.2% (33/126): in nine (27.3%) CT-MRI results were shown to be true positive (TP) whereas FDG PET yielded FN results, while in 24 (72.7%) CT-MRI corrected FP results on FDG PET. Among the nine FNs on FDG PET that were identified by CT-MRI, four were extra-pelvic. Among the FPs on FDG PET that were excluded by CT-MRI, 79.2% (19/24) were extra-pelvic.ConclusionFor recurrent cervical cancer, the benefits of FDG PET exceed those of CT-MRI owing to the ability of FDG PET to identify extra-pelvic metastases and its higher sensitivity and specificity.

Biliary ascariasis: CT, MR cholangiopancreatography, and navigator endoscopic appearance—report of a case of acute biliary obstruction

A case of acute common bile duct obstruction caused by a roundworm in a 6-year-old girl is reported. Computed tomography (CT) and magnetic resonance imaging (MRI) showed “bulls-eye” and “eye-glass” appearances of the ascaris in the common bile duct. On reformation of the transverse CT and coronal MR images, the tubular Ascaris was better depicted. MRI and navigator endoscopic demonstrations of the common bile duct ascaris have not been described previously in the literature. These CT and MRI findings may be helpful in the diagnosis of Ascaris.