S.A. Sohaib

Evaluation of endometrial carcinoma on magnetic resonance imaging

Our aims were to assess diagnostic performance of T2-weighted (T2W) and dynamic gadolinium-enhanced T1-weighted (T1W) magnetic resonance imaging (MRI) in the preoperative assessment of myometrial and cervical invasion by endometrial carcinoma and to identify imaging features that predict nodal metastases. Two radiologists retrospectively reviewed MR images of 96 patients with endometrial carcinoma. Tumor size, depth of myometrial and cervical invasion, and nodal enlargement were recorded and then correlated with histology. The sensitivity, specificity, positive and negative predictive values (PPV and NPV) for the identification of any myometrial invasion (superficial or deep) were 0.94, 0.50, 0.93, 0.55 on T2W and 0.92, 0.50, 0.92, 0.50 on dynamic T1W, and for deep myometrial invasion were 0.84, 0.78, 0.65, 0.91 on T2W and 0.72, 0.88, 0.72, 0.88 on dynamic T1W. The sensitivity, specificity, PPV and NPV for any cervical invasion (endocervical or stromal) were 0.65, 0.87, 0.57, 0.90 on T2W and 0.50, 0.90, 0.46, 0.92 on dynamic T1W, and for cervical stromal involvement were 0.69, 0.95, 0.69, 0.95 on T2W and 0.50, 0.96, 0.57, 0.95 on dynamic T1W. Leiomyoma or adenomyosis were seen in 73% of misdiagnosed cases. Sensitivity and specificity for the detection of nodal metastases was 66% and 73%, respectively. Fifty percent of patients with cervical invasion on MRI had nodal metastases. In conclusion, MRI has a high sensitivity for detecting myometrial invasion and a high NPV for deep invasion. MRI has a high specificity and NPV for detecting cervical invasion. Dynamic enhancement did not improve diagnostic performance. MRI may allow accurate categorization of cases into low- or high-risk groups ensuring suitable extent of surgery and adjuvant therapy

MRI appearances of borderline ovarian tumours.

This review was performed to describe the range of magnetic resonance imaging (MRI) appearances of borderline ovarian tumours. The MRI findings in 26 patients with 31 borderline ovarian tumours (mean age: 40.1 years, range: 14-85 years) were retrospectively reviewed. For each tumour, site, size, MRI characteristics, and enhancement following gadolinium administration were recorded. There were 20 serous and 11 mucinous borderline ovarian subtypes. Nine of 26 patients demonstrated bilateral disease on MRI; synchronous contralateral ovarian disease included three benign, five serous borderline, and one serous invasive tumour. A history of a metachronous mucinous borderline tumour was identified in one patient. MRI appearances were classified into four morphological categories: group 1 (6/31, 19%), unilocular cysts; group 2 (6/31, 19%), minimally septate cysts with papillary projections; group 3 (14/31, 45%), markedly septate lesions with plaque-like excrescences; and group 4 (5/31, 16%), predominantly solid with exophytic papillary projections, all of serous subtype. There was a significant difference in mean volume between serous (841.5 cm(3)) and mucinous (6358.2 cm(3)) subtypes (p=0.009). All tumours demonstrated at least one MRI feature suggestive of malignancy. The present review demonstrates the variable MRI appearances of borderline ovarian tumours along with imaging features suggestive of tumour subtype. In patients in whom the clinical features are suggestive of a borderline ovarian tumour (young age and normal or minimally elevated CA125), the ability to predict a borderline disease using morphological features observed on MRI would be extremely helpful in surgical planning, with the potential to offer fertility or ovary-preserving surgery. Future studies are required to further this aim.

Testicular microlithiasis as a familial risk factor for testicular germ cell tumour

Testicular microlithiasis (TM) is characterised by small intratesticular calcifications, which can be visualised by ultrasound. Men with testicular germ cell tumour (TGCT) have a higher frequency of TM than men without TGCT. To clarify the association between TGCT and TM and to investigate the relationship between TGCT susceptibility and TM, we recruited TGCT patients with and without family history of TGCT, unaffected male relatives and healthy male controls from the UK. Testicular ultrasound data were analysed from 328 men. Testicular microlithiasis was more frequent in TGCT cases than controls (36.7 vs 17.8%, age adjusted P<0.0001) and in unaffected male relatives than controls (34.5 vs 17.8%, age adjusted P=0.02). Testicular germ cell tumour case and matched relative pairs showed greater concordance for TM than would be expected by chance (P=0.05). We show that TM is present at a higher frequency in relatives of TGCT cases than expected by chance indicating that TM is a familial risk factor for TGCT. Although the familiality of TM could be due to shared exposures, it is likely that there exists a genetic susceptibility to TM that also predisposes to TGCT. We suggest that TM is an alternative manifestation of a TGCT susceptibility allele.

Whole-body magnetic resonance imaging in the detection of skeletal metastases in patients with prostate cancer.

Whole‐body MRI is an effective method for evaluating the entire skeletal system in patients with metastatic disease. This study aimed to compare whole‐body MRI and radionuclide bone scintigraph in the detection of skeletal metastases in patients with prostate cancer. Patients with prostate cancer at high risk of skeletal metastasis with (i) prostate‐specific antigen of ≥50 ng/mL; (ii) composite Gleason score of ≥8 with prostate‐specific antigen of >20 ng/mL; or (iii) node‐positive disease were enrolled in this prospective study before systemic treatment was initiated. Whole‐body MR images and bone scans of 39 patients were analysed. Seven patients had bone metastases on bone scans, while seven patients had skeletal metastases by whole‐body MRI, with concordant findings only in four patients. Compared with the ‘gold standard’, derived from clinical and radiological follow‐up, the sensitivity for both bone scans and MRI was 70%, and the specificity for both was 100%. Magnetic resonance imaging detected 26 individual lesions compared with 18 lesions on bone scans. Only eight lesions were positive on both. Bone scans detected more rib metastases, while MRI identified more metastatic lesions in the spine. Whole‐body MRI and radionuclide bone scintigraphy have similar specificity and sensitivity and may be used as complementary investigations to detect skeletal metastases from prostate cancer.

Prospective assessment of MRI for imaging retroperitoneal metastases from testicular germ cell tumours

AIM To determine the sensitivity of magnetic resonance imaging (MRI) in the detection of retroperitoneal lymph nodes in patients with testicular germ cell tumours (TGCT). METHODS AND MATERIALS A prospective study of 52 patients (mean age 34 years, range 18-54 years) was performed. Imaging of the retroperitoneum was performed using multidetector computed tomography (CT) and 1.5 T MRI systems. The CT and MRI images were read independently by three observers. The number, size, and site of enlarged nodes (> or =10 mm maximum short axis diameter) were recorded. Retroperitoneal nodal detection on MRI was compared to CT. RESULTS Twenty-two (42%) of the 52 patients had no retroperitoneal disease; in remaining 30 patients 51 enlarged nodes were identified. On a per patient basis readers 1, 2, and 3 identified nodal disease in 28 of 29, 29 of 30, and 24 of 30 patients, respectively, using MRI compared to CT. Thus for experienced radiologists (readers 1 and 2) MRI is comparable to CT for nodal detection (i.e., this study excludes MRI being inferior to CT with 80% power and 5% type 1 error). CONCLUSION MRI offers an alternative method for staging the retroperitoneum in young patients being followed for TGCT and has the major advantage of avoiding exposure to ionizing radiation.

Correlation of diffusion-weighted MRI with whole mount radical prostatectomy specimens

The purpose of this study was to compare the apparent diffusion coefficient (ADC) of benign central gland (bCG), benign peripheral zone (bPZ) and cancer using diffusion-weighted MRI and whole mount specimens. 11 patients with biopsy-proven prostate cancer underwent diffusion-weighted MRI prior to radical prostatectomy. A single-shot echo planar image technique was used with b-values of 0 s mm(-2), 300 s mm(-2), 500 s mm(-2) and 800 s mm(-2). Whole mount specimens were compared with ADC maps. Areas of cancer, bCG and bPZ were identified, and regions of interest were drawn on ADC maps. Mean ADC values were recorded for all regions of interest, and paired t-tests were performed to compare mean values. Cancer was outlined in nine patients. In two patients, the tumours were too small to correlate with images; bCG was identified in 11 patients and bPZ was identified in 10 patients. Mean ADC values for bCG, bPZ and cancer were, 1.5 x 10(-3) mm(2) s(-1) (standard error (SE) = 0.04), 1.7 x 10(-3) mm(2) s(-1) (SE = 0.1), and 1.3 x 10(-3) mm(2) s(-1) (SE = 0.09), respectively. The most significant difference between benign tissue and cancer existed at b-values of 0-300 s mm(-2) (bCG vs cancer: mean difference = 0. 29, p = 0.001, 95% confidence interval (CI) = 0.17-0.41; bPZ vs cancer: mean difference = 0.34, p = 0.003, 95% CI = 0.18-0.61). In conclusion, we have confirmed, using whole mount verification, a significant difference in the ADC between benign tissue and cancer.

Nine-year Follow-up for a Study of Diffusion-weighted Magnetic Resonance Imaging in a Prospective Prostate Cancer Active Surveillance Cohort

BACKGROUND In active surveillance (AS) for prostate cancer there are few data on long-term outcomes associated with novel imaging markers. OBJECTIVE To determine long-term outcomes with respect to the apparent diffusion coefficient (ADC) derived from diffusion-weighted magnetic resonance imaging (DW-MRI) in a prospective AS cohort. Early results have already been published; we now present findings with long-term follow-up. DESIGN, SETTING, AND PARTICIPANTS A subset of patients (n=86) underwent pre-enrolment DW-MRI in a prospective AS study between 2002 and 2006. Inclusion criteria were untreated prostate cancer, clinical T1/T2a/N0M0, Gleason ≤ 3+4, and prostate-specific antigen (PSA) <15 ng/ml. Protocol follow-up was by biopsy at 18-24 mo and then every 24 mo, with regular PSA measurement. INTERVENTION Men underwent baseline DW-MRI in addition to standard sequences. ADC was measured from the index lesion on T2-weighted images. To avoid influencing treatment decisions, DW-MRI sequence results were not available to the AS study investigators. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Baseline ADC was analysed with respect to time to radical treatment (TRT) and time to adverse histology (TAH). Kaplan-Meier analysis and univariate and multivariate regression analyses were performed. RESULTS AND LIMITATIONS The median follow-up was 9.5 yr (interquartile range 7.9-10.0 yr). On univariate analysis, ADC below the median was associated with shorter TAH (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.17-3.89; p<0.014) and TRT (HR 2.54, 95% CI 1.49-4.32; p<0.001). Median TRT was 9.3 yr (95% CI 7.0-11.6 yr) for patients with ADC above the median and only 2.4 yr (95% CI 1.5-6.0 yr) for ADC below the median. For TRT, addition of ADC to a multivariate model of baseline variables resulted in a significant improvement in model fit (HR 1.33, 95% CI 1.14-1.54; p<0.001). Receiver operating characteristic analysis for TRT revealed an area under the curve of 0.80 (95% CI 0.70-0.88). The number of variables included in the multivariate model was limited by sample size. CONCLUSIONS Long-term follow-up for this study provides strong evidence that ADC is a useful marker when selecting patients for AS. Routine DW-MRI is now being evaluated in our ongoing AS study for initial assessment and as an alternative to repeat biopsy. PATIENT SUMMARY Before entering a study of close monitoring for the initial management of prostate cancer, patients had a type of magnetic resonance imaging scan that looks at the movement of water within cancers. These scans may help in predicting whether patients should receive close monitoring or whether immediate treatment should be given.

Imaging of testicular germ cell tumours.

In testicular germ cell tumour (GCT), imaging plays a central role in assessment of tumour bulk, sites of metastases, monitoring response to therapy, surgical planning and accurate assessment of disease at relapse. The primary modality used for imaging patients with GCT is computed tomography (CT) but plain film radiography, ultrasound, magnetic resonance imaging (MRI) and positron emission tomography (PET) may all have roles to play. This article reviews the role of imaging of testicular germ cell tumours.

Frequency of Screening Magnetic Resonance Imaging to Detect Occult Spinal Cord Compromise and to Prevent Neurological Deficit in Metastatic Castration-resistant Prostate Cancer

AIMS Neurological deficit from malignant spinal cord compression (SCC) is a major complication of metastatic castration-resistant prostate cancer (CRPC). The aims of the present study were to determine the incidence of neurological deficit in metastatic prostate cancer patients and to determine the optimal frequency of screening magnetic resonance imaging (MRI) spine required to detect clinically occult radiological SCC (rSCC). MATERIALS AND METHODS A retrospective analysis of the clinical data of 130 consecutive patients with CRPC, with no functional neurological deficit, who had screening MRI spine from January 2001 to May 2005, was undertaken. Patients found to have rSCC received radiotherapy. All patients were followed-up to document the incidence of neurological deficit. RESULTS Thirty-seven (28.4%) patients had rSCC on MRI. The proportion of patients free from neurological deficit at 3, 6, 12, 18 and 24 months was 94, 80, 59 and 43%, respectively, in patients who had rSCC on initial MRI and 97.5, 89, 75 and 63%, respectively, in patients who had no rSCC. A high prostate-specific antigen (PSA) level at initial MRI (P = 0.035) and a short PSA doubling time < 3 months (P = 0.009) significantly predicted for neurological deficit on univariate analysis, whereas back pain (P = 0.059), although an important predictive factor, did not attain statistical significance. On multivariate analysis, only rapid PSA doubling time (<3 months) independently predicted for future neurological deficit (P = 0.042). CONCLUSION MRI spine can be used to detect asymptomatic rSCC in patients with CRPC and serial estimations are required to maintain a low incidence of clinical SCC. If serial screening MRI spine is used to detect rSCC in 90% of patients before the development of neurological signs, the optimum frequency depends on the subset of patients studied. The results of our study suggest that the optimum frequency would be every 4-6 months for patients with previous SCC, rapid or high PSA or back pain and annually for asymptomatic patients.

Baseline results from the UK SIGNIFY study: a whole-body MRI screening study in TP53 mutation carriers and matched controls

In the United Kingdom, current screening guidelines for TP53 germline mutation carriers solely recommends annual breast MRI, despite the wide spectrum of malignancies typically seen in this group. This study sought to investigate the role of one-off non-contrast whole-body MRI (WB MRI) in the screening of asymptomatic TP53 mutation carriers. 44 TP53 mutation carriers and 44 population controls were recruited. Scans were read by radiologists blinded to participant carrier status. The incidence of malignancies diagnosed in TP53 mutation carriers against general population controls was calculated. The incidences of non-malignant relevant disease and irrelevant disease were measured, as well as the number of investigations required to determine relevance of findings. In TP53 mutation carriers, 6 of 44 (13.6, 95% CI 5.2–27.4%) participants were diagnosed with cancer during the study, all of which would be considered life threatening if untreated. Two were found to have two primary cancers. Two participants with cancer had abnormalities on the MRI which were initially thought to be benign (a pericardial cyst and a uterine fibroid) but transpired to be sarcomas. No controls were diagnosed with cancer. Fifteen carriers (34.1, 95% CI 20.5–49.9%) and seven controls (15.9, 95% CI 6.7–30.1%) underwent further investigations following the WB MRI for abnormalities that transpired to be benign (p = 0.049). The cancer detection rate in this group justifies a minimum baseline non-contrast WB MRI in germline TP53 mutation carriers. This should be adopted into national guidelines for management of adult TP53 mutation carriers in addition to the current practice of contrast enhanced breast MRI imaging.