Diffusion-weighted MR imaging in gynecologic cancers

PET imaging of PARP expression using 68Ga-labelled inhibitors

PURPOSE

Imaging the PARP expression using 18F probes has been approved in clinical trials. Nevertheless, hepatobiliary clearance of both 18F probes hindered their application in monitoring abdominal lesions. Our novel 68Ga-labelled probes aim for fewer abdominal signals while ensuring PARP targeting by optimizing the pharmacokinetic properties of radioactive probes.

METHODS

Three radioactive probes targeted PARP were designed, synthesized, and evaluated based on the PARP inhibitor Olaparib. These 68Ga-labelled radiotracers were assessed in vitro and in vivo.

RESULTS

Precursors that did not lose binding affinity for PARP were designed, synthesized, and then labelled with 68Ga in high radiochemical purity (> 97%). The 68Ga-labelled radiotracers were stable. Due to the increased expression of PARP-1 in SK-OV-3 cells, the uptake of the three radiotracers by SK-OV-3 cells was significantly greater than that by A549 cells. PET/CT imaging of the SK-OV-3 models indicated that the tumor uptake of 68Ga-DOTA-Olaparib (0.5 h: 2.83 ± 0.55%ID/g; 1 h: 2.37 ± 0.64%ID/g) was significantly higher than that of the other 68Ga-labelled radiotracers. There was a significant difference in the T/M (tumor-to-muscle) ratios between the unblocked and blocked groups as calculated from the PET/CT images (4.07 ± 1.01 vs. 1.79 ± 0.45, P = 0.0238 < 0.05). Tumor autoradiography revealed high accumulation in tumor tissues, further confirming the above data. PARP-1 expression in the tumor was confirmed by immunochemistry.

CONCLUSION

As the first 68Ga-labelled PARP inhibitor, 68Ga-DOTA-Olaparib displayed high stability and quick PARP imaging in a tumor model. This compound is thus a promising imaging agent that can be used in a personalized PARP inhibitor treatment regimen.

Radiological Biomarkers for Brain Metastases Prognosis: Quantitative Magnetic Resonance Imaging (MRI) Modalities As Non-invasive Biomarkers for the Effect of Radiotherapy

Radiotherapy effect is achieved by its ability to cause DNA damage and induce apoptosis. In contrast, radiation can induce tumor cells' proliferation, invasiveness, and epithelial-mesenchymal transition (EMT). Besides developing radioresistance, this paradoxical effect of radiotherapy is considered a challenging problem in the field of radiotherapy. This highlights the importance of developing new modalities to diagnose radioresistance early to avoid any unnecessary exposure to radiation and differentiate between metastases recurrence versus post-radiation changes. Quantitative magnetic resonance imaging (MRI) techniques including diffusion-weighted imaging (DWI), dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast-enhanced (DCE) represent potential biomarkers to diagnose metastases recurrence and radioresistance. In this review, we will focus on recent studies discussing the possibility of using DWI, DSC, ASL, and DCE to diagnose radioresistance and recurrence in patients with brain metastases.

Added Value of Quantitative Analysis of Diffusion-Weighted Imaging in Ovarian-Adnexal Reporting and Data System Magnetic Resonance Imaging

BACKGROUND

The ovarian-adnexal reporting and data system-magnetic resonance imaging (O-RADS-MRI) score decreases the incidence of indeterminate adnexal masses from 18% to 31% with ultrasound till 10.8% to 12.5% with MRI. Further improvement of this score may be useful to improve patients' management.

PURPOSE

To evaluate the added value of quantitative diffusion-weighted imaging (DWI) in the diagnosis of adnexal masses classified according to the O-RADS-MRI score.

STUDY TYPE

Prospective cohort study with retrospective DWI analysis.

POPULATION

Among 402 recruited patients, surgery was done only in 163 women (median-age: 51 years) with 201 indeterminate adnexal masses, which were included in the final analysis.

FIELD STRENGTH/SEQUENCE

Standardized MRI (1.5 and 3-T) including diffusion and dynamic contrast-enhanced sequences (diffusion-weighted single-shot spin-echo echo-planar imaging) were used.

ASSESSMENT

Two radiologists classified the adnexal masses according to O-RADS-MRI and they were blinded to the pathology report. Two methods of quantitative analysis were applied using region-of-interest apparent-diffusion-coefficient (ROI-ADC) and whole-lesion ADC-histogram (WL-ADC).

STATISTICAL TESTS

Fisher's exact and Mann-Whitney-U tests were used to compare variables among malignant and benign lesions. Receiver-operating-characteristic (ROC) curves were constructed to examine the sensitivity/specificity of each parameter. ROI-ADC and WL-ADC of lesions with O-RADS-MRI score-4 were plotted to identify thresholds of malignant lesions. The improvement of the O-RADS-MRI score after adding these thresholds was assessed by two ROC-curves. A P < 0.05 was considered to be statistically significant.

RESULTS

Fifty-eight of the 201 lesions (28.9%) were malignant. The ROI-ADC and the WL-ADC means of malignant lesions were significantly lower than those of benign lesions. Forty-two lesions (20.9%) had an O-RADS-MRI score-4. In this subgroup, 76% of lesions with ROI-ADC < 1.7 × 10^-3  mm² /sec and WL-ADC < 2.6 × 10^-3  mm² /sec were malignant, whereas only 11.8% with ROI-ADC ≥ 1.7 × 10^-3  mm² /sec or a WL-ADC ≥ 2.6 × 10^-3  mm² /sec were malignant. The overall performance of the O-RADS-MRI score combined with these thresholds was improved.

DATA CONCLUSION

Integrating ADC-thresholds in O-RADS-MRI score-4 may discriminate low-to-intermediate and intermediate-to-high malignancy risk groups.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2.

Magnetic resonance scoring system for assessment of adnexal masses: added value of diffusion-weighted imaging including apparent diffusion coefficient map

OBJECTIVES

To validate prospectively the ADNEX magnetic resonance (MR) scoring system to assess adnexal masses and to evaluate a new, modified ADNEX MR scoring system that incorporates diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping.

METHODS

Between January 2015 and September 2018, 323 consecutive women with adnexal masses diagnosed on transvaginal ultrasound (TVS) underwent standardized MR imaging (MRI) including diffusion and dynamic contrast-enhanced sequences. Of these, 131 underwent subsequent surgery. For interpretation of the MRI examinations, we applied the five-category ADNEX MR scoring system, along with a modified scoring system including DWI with ADC mapping. For both scoring systems, a score was given for all adnexal masses. Histological diagnosis was considered as the gold standard and lesions were classified as benign or malignant. The difference between the predictive values for diagnosing malignancy of the classical and modified scoring systems was assessed on the basis of the areas under the receiver-operating-characteristics (AUC) curves. The sensitivity and specificity for diagnosing malignancy of each score were also calculated.

RESULTS

Among the 131 women with adnexal mass(es) diagnosed on TVS who underwent MRI and subsequent surgery, the surgery revealed 161 adnexal masses in 126 women; five women had no mass. Histological examination confirmed 161 adnexal masses, of which all had been detected on MRI: 32 malignant tumors, 15 borderline tumors, which were classified as part of the malignant group (n = 47), and 114 benign lesions. The AUC for prediction of a malignant lesion was 0.938 (95% CI, 0.902-0.975) using the classical ADNEX MR scoring system and 0.974 (95% CI, 0.953-0.996) using the modified scoring system. Pairwise comparison of these AUCs revealed a significant difference (P = 0.0032). The sensitivity and specificity for diagnosing malignancy with an ADNEX MR score of 4 or more were 95.5% and 86.6%, respectively, using the classic scoring system, and 95.7% and 93.3%, respectively, using the modified scoring system.

CONCLUSION

DWI with ADC mapping could be integrated into the ADNEX MR scoring system to improve specificity, thereby potentially optimizing clinical management by avoiding unnecessary surgery. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

2018 FIGO Staging Classification for Cervical Cancer: Added Benefits of Imaging

Cervical cancer is the fourth most common cancer in women of all ages worldwide. The disease is staged using the International Federation of Gynecology and Obstetrics (FIGO) system, which was updated in 2018. The authors explain the key changes from the 2009 version and the rationale behind them. The changes have been made to reflect common clinical practice, differentiate prognostic outcomes, and guide treatment stratification. Treatment options are dependent on the stage of disease and include fertility-sparing and non-fertility-sparing surgical options as well as chemoradiotherapy for locally advanced disease. The updated FIGO staging gives added importance to MRI as a method of accurately measuring tumor size and depicting the presence of parametrial involvement. With the inclusion of lymph node involvement in the updated 2018 FIGO staging, cross-sectional imaging-and in particular, fluorodeoxyglucose PET/CT-has an increasing role in the depiction of nodal disease. Understanding the radiologic techniques used, the literature supporting them, and common imaging pitfalls ensures accurate staging of disease and optimization of treatment. ^©RSNA, 2020 See discussion on this article by Javitt (pp 1823-1824).

Diffusion-Weighted Imaging in Oncology: An Update

To date, diffusion weighted imaging (DWI) is included in routine magnetic resonance imaging (MRI) protocols for several cancers. The real additive role of DWI lies in the "functional" information obtained by probing the free diffusivity of water molecules into intra and inter-cellular spaces that in tumors mainly depend on cellularity. Although DWI has not gained much space in some oncologic scenarios, this non-invasive tool is routinely used in clinical practice and still remains a hot research topic: it has been tested in almost all cancers to differentiate malignant from benign lesions, to distinguish different malignant histotypes or tumor grades, to predict and/or assess treatment responses, and to identify residual or recurrent tumors in follow-up examinations. In this review, we provide an up-to-date overview on the application of DWI in oncology.

Benign ovarian lesions with restricted diffusion

Developments in magnetic resonance imaging have expanded its role in the assessment of the female pelvis, including the diagnosis of ovarian lesions. In this setting, diffusion-weighted imaging has proven its diagnostic value, which is particularly important in differentiating between benign and malignant ovarian tumors. In general, the latter show restricted diffusion, whereas the former do not. Exceptions include teratomas, endometriomas, hemorrhagic cysts, ovarian abscesses, ovarian infarction, and some benign stromal tumors. The aim of this review is to draw attention to benign ovarian lesions with restricted diffusion, with a special focus on diffusion-weighted imaging pearls and pitfalls.

Imaging in the pre-operative staging of ovarian cancer

The main prognostic factor in ovarian cancer is the stage of disease at diagnosis. The staging system in use (FIGO classification, updated in 2014) is based on the surgical-pathological findings. Although surgical staging is the gold standard in ovarian cancer, the initial patient management depends on the imaging-based pre-surgical staging assessment, in order to identify unresectable or difficult to resect disease. Radiologists need to be aware of the strengths of the available imaging modalities, as well as the imaging pitfalls. Clear understanding of pattern of disease spread and review areas are critical for accurate staging and treatment planning. The current standard of care for pre-surgical staging is CT of the thorax, abdomen, and pelvis. This allows a rapid evaluation of disease extent and is fairly accurate in identifying bulky disease but has definite limitations in assessing the extent of small volume disease and in the confirmation of certain sites of disease beyond the abdomen. Functional MRI has been reported to be superior in detecting small peritoneal deposits. PET/CT may be used as a problem-solving tool in some patients where determination remains unclear, particularly in confirmation of advanced stage beyond the abdomen.

A histogram analysis of diffusion and perfusion features of cervical cancer based on intravoxel incoherent motion magnetic resonance imaging

OBJECTIVE

To evaluate the diagnostic potential based on histogram analysis of IVIM parameters between uterine cervical cancers (CC) - normal myometrium (Myo) versus CC - gluteus maximus muscle (GM) and to study the feasibility of histogram analysis of IVIM parameters to differentiate the early from locally advanced stage CCs.

METHODS

64 patients with pathologically confirmed CC were enrolled. Histogram indices mean, median, 25th, and ð 75th percentile of apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) value of entire tumor were statistically analyzed and compared between CC - GM versus CC - Myo, as well as between early and locally advanced stage CCs. A multivariate analysis was performed to identify indices that could best distinguish early from locally advanced stage CC. Receiver operating characteristic curves (ROC) were used to evaluate the diagnostic efficiency of every histogram parameter.

RESULTS

All the tested histogram indices significantly differed between the patients with CC - GM vs. CC - Myo, nonetheless, CC - GM yielded higher range area under the curve (AUC) value of 0.8-0.99 vs. 0.6-0.99. The additional significant difference was found among all the tested histogram indices of D*, mean, median, and 75th percentile of f, mean and 75th percentile of ADC, and 75th percentile of D discriminating early from locally advanced CCs. ROC curves indicated that the 75th percentile of D* value 28.17 × 10^-3 mm²/s could best differentiate early from locally advanced stage CCs, with AUC of 0.776. In the multivariate analysis, ROC indicated the 50th percentile of D* and f was the most significant with AUCs of 0.856.

CONCLUSIONS

The histogram analysis of IVIM parameters depicted that gluteus maximus served better reference tissue in comparison to myometrium. The histogram index 75th percentile of ADC, D, D*, and f may serve a diagnostic biomarker to differentiate the early from locally advanced stage CCs.

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.

PREOPERATIVE MAGNETIC RESONANCE IMAGING DIAGNOSTIC FEATURES OF UTERINE LEIOMYOSARCOMAS: A SYSTEMATIC REVIEW

Objectives: There are no current established pathognomonic diagnostic features for uterine leiomyosarcomas in the pre- or perioperative setting. Recent inadvertent upstaging of this rare malignancy during laparoscopic morcellation of a presumed fibroid has prompted widespread debate among clinicians regarding the safety of current surgical techniques for management of fibroids. This study aims to conduct a systematic review investigating significant diagnostic features in magnetic resonance imaging (MRI) of uterine leiomyosarcomas.

Methods: A comprehensive database search was conducted guided by PRISMA recommendations for peer-reviewed publications to November 2017. Parameters available in MRI were compared for reliability and accuracy of diagnosis of leiomyosarcomas. A decision tree algorithm classifier model was constructed to investigate whether T1 and T2 MRI signal intensities are useful indicators.

Results: Nine eligible studies were identified for analysis. There appears to be a significant relationship between histopathological type and T1 and T2 intensity signals (p < .05). A decision tree model analyzing T1 and T2 signal intensity readings supports this trend, with a diagnostic specificity of 77.78 percent for uterine leiomyosarcomas. The apparent diffusion coefficient (ADC) values were not observed to have a significant relationship with tumor pathology (p = .18).

Conclusions: Various studies have investigated pre- and perioperative techniques in differentiating uterine leiomyosarcoma from benign fibroids. Given the rarity of the malignancy and lack of pathognomonic diagnostic parameters, there is difficulty in establishing definitive criteria. A decision tree model is proposed to aid diagnosis based on MRI signal intensities.

Pitfalls of diffusion-weighted imaging of the female pelvis

Diffusion-weighted imaging (DWI) is widely used in protocols for magnetic resonance imaging (MRI) of the female pelvis. It provides functional and structural information about biological tissues, without the use of ionizing radiation or intravenous administration of contrast medium. High signal intensity on DWI with simultaneous low signal intensity on apparent diffusion coefficient maps is usually associated with malignancy. However, that pattern can also be seen in many benign lesions, a fact that should be recognized by radiologists. Correlating DWI findings with those of conventional (T1- and T2-weighted) MRI sequences and those of contrast-enhanced MRI sequences is mandatory in order to avoid potential pitfalls. The aim of this review article is the description of the most relevant physiological and benign pathological conditions of the female pelvis that can show restricted diffusion on DWI.

TRIM29 overexpression is associated with poor prognosis and promotes tumor progression by activating Wnt/β-catenin pathway in cervical cancer

Dysregulation of TRIM29 has been reported to be involved in tumorigenesis, but the role of TRIM29 in cervical cancer is unclear. In this study, we first examined TRIM29 expression and found that TRIM29 mRNA and protein expression was upregulated in cervical cancer tissues when compared with the matched adjacent cervical tissues. We further detected TRIM29 protein with immunohistochemistry in 150 paraffin-embedded samples from early-stage cervical cancer patients. The results showed that high expression of TRIM29 was significantly associated with pelvic lymph node metastasis (p=0.002), advanced FIGO stage (p=0.026) and post-operative recurrence (p<0.001). Patients with high expression of TRIM29 had a shorter overall survival (HR 5.042, p<0.001) and disease-free survival (HR 4.260, p<0.001). TRIM29 was proven to be an independent prognostic factor for cervical cancer patients. When endogenous TRIM29 expression was knocked down by siRNAs, cell proliferation, colony formation, migration and invasion in cervical cancer cell lines HeLa and SiHa were obviously inhibited. Meanwhile, TRIM29 knockdown increased E-cadherin expression but decreased the expression of N-cadherin and β-Catenin, which indicated that TRIM29 could promote epithelial-mesenchymal transition (EMT). Mechanically, knockdown of TRIM29 enhanced GSK-3β protein expression and inhibited the expression of β-Catenin and C-myc proteins. GSK-3β is a key upstream suppressor of β-Catenin and c-myc expression is an indicator of Wnt/β-Catenin activity. Therefore, these results demonstrate that TRIM29 promotes tumor progression by activating Wnt/β-Catenin signaling. In conclusion, TRIM29 is overexpressed and associated with survival of early-stage cervical cancer, indicating that TRIM29 may be a potential prognostic biomarker and therapeutic target for cervical cancer.

Diffusion-weighted imaging in gynaecological malignancy

Diffusion weighted imaging (DWI) has become an essential part of the gynaecological magnetic resonance imaging (MRI) protocol. DWI is used as an adjunct to conventional MRI sequences and has been shown to improve reporting accuracy in the imaging of gynaecological malignancy. In this review, we discuss the role of DWI in the diagnosis, staging, and assessment of treatment response of endometrial, cervical, and ovarian cancer. We also review the role of DWI in the assessment of the sonographically indeterminate ovarian lesion. Further, we highlight potential pitfalls that can beset the accurate interpretation of DWI in patients with gynaecological malignancy.

Functional MR imaging in gynecologic malignancies: current status and future perspectives

Using functional MR imaging techniques, we can approach the functional assessment of gynecologic malignancies. Among them, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MR imaging (DCE-MRI) are two important techniques. This article provides an overview of functional MR imaging techniques, focusing DWI and DCE-MRI on clinical application in gynecologic malignancies. Functional MR imaging techniques play an important role in detection, characterization, staging, treatment response, and outcome prediction, as well as providing conventional morphologic imaging. Familiarity with the characteristics and imaging features of functional MR imaging in gynecologic malignancies will facilitate prompt and accurate diagnosis and treatment.

Quantitative diffusion-weighted magnetic resonance imaging for the diagnosis of partial-thickness rotator cuff tears

BACKGROUND

This study investigated diffusion-weighted (DWI) magnetic resonance imaging (MRI) as an alternative to fat-suppressed T2-weighted imaging (FS-T2WI) for assessment of partial-thickness rotator cuff tears (RCTs).

METHODS

Patients with arthroscopy proven partial-thickness RCTs who also received MRI (FS-T2WI and DWI) before surgery were prospectively included. Receiver operating characteristic curves were used to compare DWI vs. FS-T2WI using lesion-to-muscle signal intensity ratios. A cutoff point for predicting partial-thickness tears was determined using the Youden index.

RESULTS

Included were 146 patients, with a mean age of 48.3 years (range, 19-86 years), of whom 43 had full-thickness RCTs, 67 had partial-thickness RCTs, and 36 had no tears. Areas under receiver operating characteristic curves for diagnosing partial-thickness tears were significantly higher for DWI (0.910) than for FS-T2WI (0.822, P = .016). Lesion-to-muscle signal intensity ratio cutoff values were 1.06 for DWI vs. 1.65 for FS-T2WI, respectively. The sensitivity and accuracy of DWI (89.1% [98 of 110] and 87.7% [128 of 146], respectively) for diagnosing partial-thickness and full-thickness tears were higher than for FS-T2WI (65.5% [72 of 110] and 72.6% [106 of 146], respectively). FS-T2WI, however, had higher specificity (94.4% [34 of 36]) than DWI (83.3% [30 of 36]).

CONCLUSIONS

DWI is more accurate and sensitive than FS-T2WI for diagnosing partial-thickness RCTs.

Use of enhanced T2 star-weighted angiography (ESWAN) and R2* values to distinguish ovarian cysts due to endometriosis from other causes

PURPOSE

To evaluate the feasibility of enhanced T2 star-weighted angiography (ESWAN) in differentiating endometrial from non-endometrial cysts.

METHODS

Forty-nine patients with 60 histopathologically proven ovarian cystic lesions underwent pelvic MRI including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), liver acquisition with volume acceleration, and ESWAN. Ovarian cystic lesions were divided into endometrial cysts (group 1; n = 28), pyosalpinx and hydrosalpinx (group 2; n = 13), and ovarian cystic and cystic-solid tumors (group 3; n = 19). R2* (effective transverse relaxation rate) values were measured and pairwise comparison of the R2* values among the three groups was made using Kruskal-Wallis test. Receiver operating characteristic curves were used to calculate cutoff values and performance of R2* values for distinguishing among groups. T1WI signal intensity and R2* value were also compared using area under curve values.

RESULTS

R2* values for group 1 were statistically higher than groups 2 and 3 (15.37, 1.40, and 1.79 Hz, respectively; P < 0.001). The cutoff value for R2* was 7.43 Hz with a sensitivity, specificity, PPV, NPV, and accuracy of 96.43, 87.50, 87.10, 96.55, and 91.67%, respectively. There was no significant difference between the R2* value and T1WI in diagnosing endometrial cysts.

CONCLUSIONS

The R2* value provides an effective way to discriminate endometrial cysts from other ovarian cystic lesions.

Significance of the ADC ratio in the differential diagnosis of breast lesions

BACKGROUND

Magnetic resonance imaging (MRI) has high sensitivity but low specificity for breast cancer, and consequently, new techniques to improve the specificity of breast MRI in diagnosing breast cancer are under development.

PURPOSE

To assess the ability of the apparent diffusion coefficient (ADC) compared with the ADC ratio (ADCr) to differentially diagnose benign compared with malignant breast lesions.

MATERIAL AND METHODS

Forty-eight women with breast lesions (average age, 45 years) underwent MRI scanning including T1-weighted dynamic contrast-enhanced (DCE) scanning and diffusion-weighted imaging (DWI). The average ADC and ADCr values for both lesions and pectoralis major muscles (ADCrmuscle and ADCrmuscle) were measured in patients with malignant (n = 25) and benign (n = 23) breast lesions. The ADCr of the contralateral breast (ADCr contralateral) was also evaluated. All histology was confirmed by pathological analysis of biopsied tissue. ADC and ADCr values were analyzed using receiver-operating characteristic (ROC) curves.

RESULTS

For benign lesions compared with malignant lesions, lesion-side ADC was 1.45 vs. 1.05, respectively (P < 0.001), normal-side ADC was 1.82 vs.1.64 (P = 0.002), ADCrmuscle was 1.35 vs. 0.9 (P < 0.001), and ADCrcontralateral was 0.79 vs. 0.64 (P = 0.001). ADCrmuscle showed higher sensitivity (82.61%) and specificity (96.00%) than ADCrcontralateral (60.87% and 92.00%, respectively) and ADC (69.57% and 96.00%) for discriminating malignant from benign lesions. The AUC using ADCrmuscle had higher discriminatory power (0.92, P < 0.001) for malignant versus benign breast lesions compared with either ADC (0.82, P < 0.001) or ADCrcontralateral (0.78, P = 0.001).

CONCLUSION

The ADCrmuscle value showed higher sensitivity and specificity and improved diagnostic accuracy compared with either ADC or ADCrcontralateral in differentiating benign from malignant breast lesions.

Use of diffusion tensor imaging in assessing superficial myometrial invasion by endometrial carcinoma: a preliminary study

BACKGROUND

Magnetic resonance imaging (MRI) remains the standard modality for local staging of gynecological malignancies, but it has several limitations, especially when differentiating a cancer limited to the endometrium from a cancer invading the superficial myometrium.

PURPOSE

To explore 1.5 T diffusion tensor imaging (DTI) in assessing superficial myometrial infiltration by endometrial carcinoma.

MATERIAL AND METHODS

We analyzed the sensitivity of apparent diffusion coefficient (ADC) versus fractional anisotropy (FA) in diagnosing superficial myometrial infiltration compared to DCE-MRI and T2-weighted imaging (T2WI) in 35 patients with endometrial cancer. For each patient, T2WI-DWI fusion images were generated, and five regions of interest (ROIs) were placed on corresponding DTI images. ADC and FA were calculated, and fiber tractography (FT) images for each level were obtained. ADC and FA values for the five ROIs were compared.

RESULTS

In distinguishing cancerous versus non-cancerous areas within superficial myometrium, median ADC values were significantly lower (1.16 vs. 1.48, respectively; P < 0.001) and median FA values were significantly higher (0.41 vs. 0.27; P < 0.001, respectively). ADC's versus FA's sensitivity, specificity, PPV, NPV, and accuracy for diagnosing superficial myometrial invasion were 74.3%, 88.6%, 86.7%, 77.5%, 81.4% versus 88.6%, 97.1%, 96.9%, 89.5%, 92.9%, respectively. T2WI and DCE-MR showed a sensitivity of 80.0% and 77.1%, respectively, in diagnosing myometrial invasion.

CONCLUSION

Both ADC and FA were able to distinguish between cancerous verss non-cancerous areas within superficial myometrium (although FA was more sensitive based on AUC values). In addition, FA was superior to ADC, and more sensitive than T2WI and DCE-MR, in evaluating myometrial invasion. FT images provided visual confirmation of irregular arrangement and direction of the fibers due to proliferation of stromal cells caused by superficial myometrial invasion.

Time-window of early detection of response to concurrent chemoradiation in cervical cancer by using diffusion-weighted MR imaging: a pilot study

Background

To investigate the feasibility of DWI in evaluating early therapeutic response of uterine cervical cancer to concurrent chemoradiation (CCR) and establish optimal time window for early detection of treatment response.

Methods

This was a prospective study and informed consent was obtained from all patients. Thirty-three patients with uterine cervical cancer who received CCR underwent conventional MRI and DWI examinations prior to therapy (base-line) and at 3 days (postT1), 7 days (postT2), 14 days (postT3), 1 month (postT4) and 2 months (postT5) after the therapy initiated. Tumor response was determined by comparing the base-line and postT5 MRI by using RECIST criterion.

Results

Percentage ADC change (γADC) of complete response (CR) group at each follow up time was greater than that of partial response (PR) group, and the differences were significant at postT3 (p = 0.007), postT4 (p = 0.001), and postT5 (p = 0.019). There was positive correlation between γADC at each follow-up time and percentage size reduction at postT5. The day of 14 after the therapy initiated can be considered as the optimal time for monitoring early treatment response of uterine cervical cancer to CCR, and the representative and sensitive index was γADC. With the cut-off value of 35.4 %, the sensitivity and specificity for prediction of CR group were 100 % and 73.1 %, respectively.

Conclusions

It is feasible to use DWI to predict and monitor early treatment response in patients with uterine cervical cancer that undergoing CCR, and optimal time window for early detection of tumor response is the day of 14 after therapy initiated.

Preoperative PET/CT FDG standardized uptake value of pelvic lymph nodes as a significant prognostic factor in patients with uterine cervical cancer

PURPOSE

Using integrated PET/CT, we evaluated the prognostic relevance in uterine cervical cancer of preoperative pelvic lymph node (LN) [(18)F]FDG uptake.

METHODS

Patients with FIGO stage IB to IIA uterine cervical cancer were imaged with FDG PET/CT before radical surgery. We used Cox proportional hazards regression to examine the relationship between recurrence and the FDG maximum standardized uptake value (SUV(max)) in the pelvic LN (SUVLN) on PET/CT.

RESULTS

Clinical data, treatment modalities, and results in 130 eligible patients were reviewed. The median postsurgical follow-up was 34 months (range 6 to 109 months). Receiver operating characteristic analysis identified SUVLN 2.36 as the most significant cut-off value for predicting recurrence. SUV(LN) was correlated with SUV(tumour) (P = 0.002), primary tumour size (P = 0.004), and parametrial invasion (P = 0.013). Univariate analyses showed significant associations between recurrence and SUV(LN) (P = 0.001), SUV(tumour) (P = 0.007), pelvic LN metastasis (P = 0.002), parametrial invasion (P < 0.001), primary tumour size (P = 0.007), suspected LN metastasis on MRI (P = 0.024), and FIGO stage (P = 0.026). Multivariate analysis identified SUV(LN) (P = 0.013, hazard ratio, HR, 4.447, 95 % confidence interval, CI, 1.379 – 14.343) and parametrial invasion (P = 0.013, HR 6.728, 95 % CI 1.497 – 30.235) as independent risk factors for recurrence. Patients with SUV(LN) ≥ 2.36 and SUV(LN) <2.36 differed significantly in terms of recurrence (HR 15.20, P < 0.001).

CONCLUSION

Preoperative pelvic LN FDG uptake showed a strong significant association with uterine cervical cancer recurrence.

Cotyledonoid dissecting leiomyoma of the uterus with intravascular luminal growth: a case study

Here, we report the case of a 43-year-old female who was diagnosed with a cotyledonoid dissecting leiomyoma (CDL) of the uterus. CDL is a recently described and extremely rare variant of a benign leiomyoma that can grossly masquerade as a malignancy. The 13-cm sized tumor was located primarily on the extrauterine surface as an intrauterine continuity, which showed dark red, congested, bulbous protuberances. It was multinodular appearance, encasing the bilateral adnexae and the left iliac vein. Microscopically, the nodules were separated by extensive hydropic degeneration. The nodules were composed of cigar-shaped spindle cells with no mitosis, cellular pleomorphism or coagulation necrosis. They also showed an intravascular luminal growth pattern. CDL with intravascular growth was diagnosed after excluding intravascular leiomyomatosis, disseminated peritoneal leiomyomatosis, and benign metastasizing leiomyoma. The present case is the second reported case of CDL in Korea. Recognition of this rare and bizarre, malignancy-mimicking leiomyoma is crucial to prevent inappropriate treatment.