Diffusion-weighted imaging in gynaecological malignancy

Magnetic Resonance Imaging of Endometriosis: The Role of Advanced Techniques

Endometriosis is a chronic inflammatory disease that affects about 10% of women, and it is characterized by the presence of endometrial tissue outside the uterine cavity. Associated symptoms are dyspareunia, chronic pelvic pain, and infertility. The diagnosis of endometriosis can be challenging due to various clinical and imaging presentations. Laparoscopy is the gold standard for the diagnosis, but it is an invasive procedure. The literature has increasingly promoted a switch to less invasive imaging techniques, such as ultrasound and magnetic resonance imaging (MRI). The latter, also in relation to the latest technological advances, allows a comprehensive and accurate assessment of the pelvis and it can also identify sites of endometriosis that escape laparoscopic evaluation. Furthermore, MRI has been found to be more accurate than other imaging techniques in relation to its improved sensitivity and specificity in identifying disease sites, also due to the role of new emerging sequences. This article aims to review the current role of advanced MRI applications in the assessment of endometriosis.

Utility of CT Scan in Detecting Bladder Involvement Among Patients With Cervical Carcinoma

Background Cervical cancer is a widespread health issue in India, particularly affecting women as the second most common cancer. The burden of cervical cancer in the country necessitates accurate staging for treatment optimization. The revised International Federation of Gynecology and Obstetrics (FIGO) staging system is vital for this purpose, emphasizing the extent of parametrial and pelvic sidewall involvement. Cervical cancer's propensity to infiltrate neighboring pelvic organs, including the bladder, necessitates precise staging. In India, traditional methods like cystoscopy have been relied upon, but they have limitations. Recent advancements in medical imaging, notably the increased use of computed tomography (CT) scans, provide a non-invasive alternative for staging and evaluating bladder involvement. This study aimed to evaluate the utility and accuracy of CT scans in assessing bladder involvement. Methods This cross-sectional study examined 127 newly diagnosed cervical carcinoma cases in women over a two-year period from August 2021 to July 2023. Patients underwent CT scans (plain) and cystoscopy, and bladder involvement was determined following the revised FIGO staging. Data collected comprised patient demographics, medical history, clinical symptoms, and FIGO staging. Cystoscopy was performed using an Olympus CYF-5 flexible cystoscope, and CT scans utilized a 64-slice multidetector CT scanner. Radiological reports detailed primary tumor characteristics and proximity to the bladder. Statistical analysis encompassed descriptive statistics, and calculation of sensitivity, specificity, positive predictive value, and negative predictive value for CT scans in comparison to cystoscopy. Statistical significance was considered at p < 0.05. Results In our study, the mean participant age was 45.3 years, with 61.4% falling in the 40-60 years age group. Socioeconomic status (SES) varied, with 37.8% classified as low SES, 48.8% as middle SES, and 13.4% as high SES. Parity data showed that 76.4% had three or more pregnancies. Among presenting symptoms, abnormal vaginal bleeding (65.4%) was the most prevalent, and squamous cell carcinoma (78.7%) was the predominant histological type. The prevalence of bladder involvement was 9.4% by cystoscopy and 30.7% by CT scans. CT scan demonstrated a high sensitivity (100%) but lower specificity (76.52%), with 78.80% overall accuracy. Conclusion A combined approach, using CT scans as a screening tool and cystoscopy as a confirmatory method, could provide the most comprehensive and reliable assessment of bladder involvement in cervical carcinoma patients, ultimately contributing to improved patient care and management.

Neoadjuvant chemotherapy induces an elevation of tumour apparent diffusion coefficient values in patients with ovarian cancer

OBJECTIVES

Multiparametric magnetic resonance imaging (mMRI) is the modality of choice in the imaging of ovarian cancer (OC). We aimed to investigate the feasibility of different types of regions of interest (ROIs) in the measurement of apparent diffusion coefficient (ADC) values of diffusion-weighted imaging in OC patients treated with neoadjuvant chemotherapy (NACT).

METHODS

We retrospectively enrolled 23 consecutive patients with advanced OC who had undergone NACT and mMRI. Seventeen of them had been imaged before and after NACT. Two observers independently measured the ADC values in both ovaries and in the metastatic mass by drawing on a single slice of (1) freehand large ROIs (L-ROIs) covering the solid parts of the whole tumour and (2) three small round ROIs (S-ROIs). The side of the primary ovarian tumour was defined. We evaluated the interobserver reproducibility and statistical significance of the change in tumoural pre- and post-NACT ADC values. Each patient's disease was defined as platinum-sensitive, semi-sensitive, or resistant. The patients were deemed either responders or non-responders.

RESULTS

The interobserver reproducibility of the L-ROI and S-ROI measurements ranged from good to excellent (ICC range: 0.71-0.99). The mean ADC values were significantly higher after NACT in the primary tumour (L-ROI p  < 0.001, S-ROIs p < 0.01), and the increase after NACT was associated with sensitivity to platinum-based chemotherapy. The changes in the ADC values of the omental mass were associated with a response to NACT.

CONCLUSION

The mean ADC values of the primary tumour increased significantly after NACT in the OC patients, and the amount of increase in omental mass was associated with the response to platinum-based NACT. Our study indicates that quantitative analysis of ADC values with a single slice and a whole tumour ROI placement is a reproducible method that has a potential role in the evaluation of NACT response in patients with OC.

TRIAL REGISTRATION

Retrospectively registered (institutional permission code: 5302501; date of the permission: 31.7.2020).

Greater increases in intratumoral apparent diffusion coefficients after chemoradiotherapy predict better overall survival of patients with cervical cancer

PURPOSE

To evaluate whether 1) the intratumoral apparent diffusion coefficients (ADCs) change during cervical cancer treatment and 2) the pretreatment ADC values or their change after treatment predict the treatment outcome or overall survival of patients with cervical cancer.

METHODS

We retrospectively enrolled 52 patients with inoperable cervical cancer treated with chemoradiotherapy, who had undergone diffusion weighted MRI before treatment and post external beam radiotherapy (EBRT) and concurrent chemotherapy. A subgroup of patients (n = 28) underwent altogether six consecutive diffusion weighted MRIs; 1) pretreatment, 2) post-EBRT and concurrent chemotherapy; 3-5) during image-guided brachytherapy (IGBT) and 6) after completing the whole treatment course. To assess interobserver and intertechnique reproducibility two observers independently measured the ADCs by drawing freehand a large region of interest (L-ROI) covering the whole tumor and three small ROIs (S-ROIs) in areas with most restricted diffusion.

RESULTS

Reproducibility was equally good for L-ROIs and S-ROIs. The pretreatment ADCs were higher in L-ROIs (883 mm2/s) than in S-ROIs (687 mm2/s, P < 0.001). The ADCs increased significantly between the pretreatment and post-EBRT scans (L-ROI: P < 0.001; S-ROI: P = 0.001). The ADCs remained significantly higher than pretreatment values during the whole IGBT. Using S-ROIs, greater increases in ADCs between pretreatment and post-EBRT MRI predicted better overall survival (P = 0.018).

CONCLUSION

ADC values significantly increase during cervical cancer treatment. Greater increases in ADC values between pretreatment and post-EBRT predicted better overall survival using S-ROIs. Standardized methods for timing and delineation of ADC measurements are advocated in future studies.

Utility of the Diffusion Weighted Sequence in Gynecological Imaging: Review Article

Simple Summary

Diffusion weighted imaging (DWI) is a magnetic resonance imaging sequence with diverse clinical applications in malignant and nonmalignant gynecological conditions. It provides vital supplemental information in the diagnosis and management of various gynecological conditions. Radiologists should be aware of fundamental concepts, clinical applications and pitfalls of DWI. Additionally we briefly discuss potential scope of newer advanced techniques based on DWI including diffusion tensor imaging and diffusion-weighted whole-body imaging with background signal suppression.

Abstract

Functional imaging with diffusion-weighted imaging (DWI) is a complementary tool to conventional diagnostic magnetic resonance imaging sequences. It is being increasingly investigated to predict tumor response and assess tumor recurrence. We elucidate the specific technical modifications of DWI preferred for gynecological imaging, including the different b-values and planes for image acquisition. Additionally, we discuss the problems and potential pitfalls encountered during DWI interpretation and ways to overcome them. DWI has a wide range of clinical applications in malignant and non-malignant gynecological conditions. It provides supplemental information helpful in diagnosing and managing tubo-ovarian abscess, uterine fibroids, endometriosis, adnexal torsion, and dermoid. Similarly, DWI has diverse applications in gynecological oncology in diagnosis, staging, detection of recurrent disease, and tumor response assessment. Quantitative evaluation with apparent diffusion coefficient (ADC) measurement is being increasingly evaluated for correlation with various tumor parameters in managing gynecological malignancies aiding in preoperative treatment planning. Newer advanced DWI techniques of diffusion tensor imaging (DTI) and whole body DWI with background suppression (DWIBS) and their potential uses in pelvic nerve mapping, preoperative planning, and fertility-preserving surgeries are briefly discussed.

The Diagnostic Performance of Maximum Uptake Value and Apparent Diffusion Coefficient in Differentiating Benign and Malignant Ovarian or Adnexal Masses: A Meta-Analysis

Objective

The purpose of this meta-analysis was to provide evidence for using maximum uptake value (SUVmax) and apparent diffusion coefficient (ADC) to quantitatively differentiate benign and malignant ovarian or adnexal masses, and to indirectly compare their diagnostic performance.

Material and Methods

The association between SUVmax, ADC and ovarian or adnexal benign and malignant masses was searched in PubMed, Cochrane Library, and Embase databases until October 1, 2021. Two authors independently extracted the data. Studies included in the analysis were required to provide data for the construction of a 2 × 2 contingency table to evaluate the diagnostic performance of SUVmax or ADC in differentiating benign and malignant ovarian or adnexal masses. The quality of the enrolled studies was evaluated by Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) instrument, and the meta-analysis was conducted using Stata software version 14.0. Forest plots were generated according to the sensitivity and specificity of SUVmax and ADC, and meta-regression analysis was further used to assess heterogeneity between studies.

Results

A total of 14 studies were finally included in this meta-analysis by gradually excluding duplicate literatures, conference abstracts, guidelines, reviews, case reports, animal studies and so on. The pooled sensitivity and specificity of SUVmax for quantitative differentiation of benign and malignant ovarian or adnexal masses were 0.88 and 0.89, respectively, and the pooled sensitivity and specificity for ADC were 0.87 and 0.80, respectively.

Conclusion

Quantitative SUVmax and ADC values have good diagnostic performance in differentiating benign and malignant ovarian or adnexal masses, and SUVmax has higher accuracy than ADC. Future prospective studies with large sample sizes are needed for the analysis of the role of SUVmax and ADC in the differentiation of benign and malignant ovarian or adnexal masses. 

Imaging in Carcinoma Cervix and Revised 2018 FIGO Staging System: Implications in Radiology Reporting

The International Federation of Gynecology and Obstetrics (FIGO) staging system of carcinoma cervix saw a radical change in 2018 with the inclusion of cross-sectional imaging tools for the assessment of disease extent and staging. One of the major revisions is the inclusion of lymph node status, detected either on imaging or pathological evaluation, in the staging system. The changes were based on long-term patient follow-up and survival rates reported in literature. Thus, it becomes imperative for a radiologist to be well versed with the recent staging system, its limitations, and implications on the patient management.

Combination Analysis of a Radiomics-Based Predictive Model With Clinical Indicators for the Preoperative Assessment of Histological Grade in Endometrial Carcinoma

BACKGROUND

Histological grade is one of the most important prognostic factors of endometrial carcinoma (EC) and when selecting preoperative treatment methods, conducting accurate preoperative grading is of great significance.

PURPOSE

To develop a magnetic resonance imaging (MRI) radiomics-based nomogram for discriminating histological grades 1 and 2 (G1 and G2) from grade 3 (G3) EC.

METHODS

This was a retrospective study included 358 patients with histologically graded EC, stratified as 250 patients in a training cohort and 108 patients in a test cohort. T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and a dynamic contrast-enhanced three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) were performed via 1.5-Tesla MRI. To establish ModelADC, the region of interest was manually outlined on the EC in an apparent diffusion coefficient (ADC) map. To establish the radiomic model (ModelR), EC was manually segmented by two independent radiologists and radiomic features were extracted. The Radscore was calculated based on the least absolute shrinkage and selection operator regression. We combined the Radscore with carbohydrate antigen 125 (CA125) and body mass index (BMI) to construct a mixed model (ModelM) and develop the predictive nomogram. Receiver operator characteristic (ROC) and calibration curves were assessed to verify the prediction ability and the degree of consistency, respectively.

RESULTS

All three models showed some amount of predictive ability. Using ADC alone to predict the histological risk of EC was limited in both the cohort [area under the curve (AUC), 0.715; 95% confidence interval (CI), 0.6509-0.7792] and test cohorts (AUC, 0.621; 95% CI, 0.515-0.726). In comparison with ModelADC, the discrimination ability of ModelR showed improvement (Delong test, P < 0.0001 for both the training and test cohorts). ModelM, established based on the combination of radiomic and clinical indicators, showed the best level of predictive ability in both the training (AUC, 0.925; 95% CI, 0.898-0.951) and test cohorts (AUC, 0.915; 95% CI, 0.863-0.968). Calibration curves suggested a good fit for probability (Hosmer-Lemeshow test, P = 0.673 and P = 0.804 for the training and test cohorts, respectively).

CONCLUSION

The described radiomics-based nomogram can be used to predict EC histological classification preoperatively.

Role of blood oxygenation saturation in ovarian cancer diagnosis using multi-spectral photoacoustic tomography

In photoacoustic tomography (PAT), a tunable laser typically illuminates the tissue at multiple wavelengths, and the received photoacoustic waves are used to form functional images of relative total haemoglobin (rHbT) and blood oxygenation saturation (%sO2 ). Due to measurement errors, the estimation of these parameters can be challenging, especially in clinical studies. In this study, we use a multi-pixel method to smooth the measurements before calculating rHbT and %sO2 . We first perform phantom studies using blood tubes of calibrated %sO2 to evaluate the accuracy of our %sO2 estimation. We conclude by presenting diagnostic results from PAT of 33 patients with 51 ovarian masses imaged by our co-registered PAT and ultrasound system. The ovarian masses were divided into malignant and benign/normal groups. Functional maps of rHbT and %sO2 and their histograms as well as spectral features were calculated using the PAT data from all ovaries in these two groups. Support vector machine models were trained on different combinations of the significant features. The area under ROC (AUC) of 0.93 (0.95%CI: 0.90-0.96) on the testing data set was achieved by combining mean %sO2 , a spectral feature, and the score of the study radiologist.

The adjunctive value of diffusion weighted imaging in diagnosis and follow up of uterovaginal diffuse B-cell lymphoma: A case report and literature review

BACKGROUND

Lymphoma of the female gynecologic tract is extremely rare. Typically, lymphoma is managed non surgically unlike other non-lymphomatous malignant tumors raising the importance to differentiate between both entities.

CASE REPORT

We describe the magnetic resonance imaging (MRI) features of a case of uterovaginal diffuse large B-cell lymphoma in a 50-year-old postmenopausal woman emphasizing Diffusion-Weighted Imaging (DWI) as a diagnostic and follow up tool. We reviewed the literature regarding the diagnostic methods for female genital lymphoma. Forty-five cases including our patient were reviewed with age range from 22 to 85 years. Vaginal bleeding was the most common presentation. The diagnosis was established by Papanicolaou smear, cervical biopsy (25/45), endometrial biopsy (6/45), vaginal biopsy (2/45), pelvic mass biopsy (2/45), iliac LN biopsy (1/45) and surgical diagnosis (8/45). Diffuse large B-cell lymphomas (DLBCL) constitute the vast majority of the cases (82%). The uterine cervix was involved at diagnosis in the majority of these cases (68%) while uterine body (42%) and vagina (28%) were less involved. Pelvic lymphadenopathy was found in 15 cases while extra genital lymphomatous infiltration in 13 cases. Sonographic findings were nonspecific while CT provided excellent data about extra-genital involvement. Thirteen cases underwent pelvic MRI that displayed superior detection of disease extension and parametric involvement. Diffusion restriction was reported only in one case without quantitative analysis of ADC map.

CONCLUSION

MRI shows unique features that help to differentiate uterovaginal lymphoma from the much more common carcinomas and discriminate post-operative changes from tumor recurrence. It exhibits a marked restricted diffusion pattern with lower ADC values than carcinomas and post-operative changes.

Diagnostic value of diffusion-weighted magnetic resonance imaging in discriminating between metastatic and non-metastatic pelvic lymph nodes in endometrial cancer

BACKGROUND

Researchers have recently focused on assessing the accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) in predicting pelvic lymph node metastases in gynecological malignancies.

PURPOSE

To evaluate the diagnostic value of DW-MRI in discriminating between metastatic and non-metastatic pelvic lymph nodes in endometrial cancer patients.

MATERIAL AND METHODS

This retrospective database study was conducted with 33 women aged 30-84 years with pathologically proven endometrial cancer that had been assessed by DW-MRI before their first treatment initiation at our referral hospital from March 2016 to April 2019. The diffusion technique (b = 50, 400, and 1000 mm²/s) was used in the imaging, and continuous apparent diffusion coefficient (ADC) metrics (ADC_min, ADC_max, ADC_mean, ADC_SD, and rADC) were compared between the metastatic and non-metastatic lymph nodes.

RESULTS

In total, 48 lymph nodes from 33 patients were assessed. All metastatic lymph nodes were restricted, while among the non-metastatic lymph nodes, only 19.3% were restricted. Considering pathological reports of metastatic and non-metastatic lymph nodes as the gold standard, DWI-related restricted and non-restricted features had a sensitivity of 80.6%, a specificity of 100%, and an accuracy of 87.5% to discriminate between a metastatic and non-metastatic pattern. ADC metrics of ADC_min, ADC_max, ADC_mean, ADC_SD, and rADC showed high values enabling differentiation between metastatic and non-metastatic lymph nodes. The best cut-off values were 0.7 × 10^-3, 1.2 × 10^-3, 1.01 × 10^-3, 123, and 0.78, respectively.

CONCLUSION

DW-MRI is a useful quantitative tool for differentiating between metastatic and benign lymph nodes in endometrial cancer patients.

Endometrial Cancer, the Current International Federation of Gynecology and Obstetrics Staging System, and the Role of Imaging

Imaging plays a crucial role in the diagnosis, staging, and follow-up of endometrial cancer. Endometrial cancer is staged surgically using the International Federation of Gynecology and Obstetrics (FIGO) staging system. Preoperative imaging can complement surgical staging but is not yet considered a required component in the current FIGO staging system. Preoperative imaging can help identify some tumor characteristics and tumor spread, both locally and distally. More accurate assessment of endometrial cancers optimizes management and treatment plan, including degree of surgical intervention. In this article, we review the epidemiology, FIGO staging system, and the importance of imaging in the staging of endometrial cancer.

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).

Is the level of diffusion restriction in celiac and cervico-thoracic sympathetic ganglia helpful in their proper recognition on PSMA ligand PET/MR?

AIM

 To check if diffusion weighted imaging (DWI) might be helpful in proper recognition of celiac (CG) and cervicothoracic (CTG) sympathetic ganglia on the whole-body multimodal PSMA-ligand PET/MR imaging, in the view of their common misleading avidity on PET potentially suggestive of malignant lesions, including metastatic lymph nodes.

METHODS

 The thickness and the level of diffusion restriction was assessed qualitatively and quantitatively in 406 sympathetic ganglia (189 CTG in 101 males and 217 CG in 116 males) on DWI maps (b-value 0 and 800 s/mm2) and apparent diffusion coefficient (ADC) maps (mean ADC) of the whole-body PET/MR 68Ga-PSMA-11 PET/MR. To form a reference group of a matching ganglia size, the smallest lymph node was chosen from each patient with metastases and underwent the same procedure.

RESULTS

 Very low and low level of diffusion restriction was noted in the majority of sympathetic ganglia (81.0 % CTG, 67.3 % CG, and 73.6 % of all). In the majority (91.7 %) of metastatic lymph nodes the level of diffusion restriction was moderate to high.The mean ADC values in sympathetic ganglia were statistically significantly higher in CTG, CG and all ganglia than in metastatic lymph nodes (p < 0.001; the effect size was large).

CONCLUSIONS

 Sympathetic celiac and cervicothoracic ganglia present very low and low level of diffusion restriction in visual DWI assessment, and significantly higher than metastatic lymph nodes mean ADC values in the majority of cases, which may serve as additional factors aiding differential diagnosis on multimodal PSMA-ligand PET/MR imaging.Therefore, PSMA-ligand PET/MR appears potentially superior to PSMA-ligand PET/CT in proper identification of sympathetic ganglia.

Assessment of Tamoxifen-Related Endometrial Changes in Premenopausal Female Patients With Diffusion-Weighted Magnetic Resonance Imaging

PURPOSE

To evaluate tamoxifen-related endometrial changes in premenopausal female patients with diffusion-weighted magnetic resonance imaging (DWI).

METHODS

This prospective study was performed on 71 premenopausal female patients (mean age, 41 years) who were receiving tamoxifen therapy. All patients underwent magnetic resonance imaging with DWI of the pelvis and hysteroscopic-guided endometrial biopsy. The apparent diffusion coefficient (ADC) values of the endometrial plate were calculated and correlated with pathological results.

RESULTS

The mean ADCs of tamoxifen-related benign endometrial lesions (1.35 ± 0.19 and 1.32 ± 0.13 × 10 mm/s) were significantly higher (P = 0.001) than those of normal endometrial plate (0.95 ± 0.11 and 0.93 ± 0.11 × 10 mm/s) by both reviewers, respectively. The cutoff ADC values used to differentiate tamoxifen-related benign endometrial lesions from normal endometrium were 1.07 and 1.02 × 10 mm/s with areas under the curve of 0.94 and 0.93 and accuracy of 94.4 and 95.8 by both reviewers, respectively. The mean ADC values of endometrial polyp (EP) (1.44 ± 0.19 and 1.42 ± 0.22 × 10 mm/s) were significantly higher (P = 0.001) than those of endometrial hyperplasia (EH) (1.25 ± 0.19 and 1.23 ± 0.19 × 10 mm/s) by both reviewers, respectively. The cutoff ADC values used to differentiate EP from EH were 1.38 × 10 and 1.36 × 10 mm/s with areas under the curve of 0.81 and 0.77 and accuracy of 80% and 70% by both reviewers, respectively. There was an insignificant difference in ADC value between typical and atypical EH. The ADC values of endometrial cancer (0.80 and 0.78 × 10 mm/s) were lower than those of tamoxifen-related benign endometrial lesions. The final diagnosis was normal endometrium (n = 36), benign endometrial lesions either EH (n = 17), or EP (n = 16), and endometrial cancer in only 2 patients.

CONCLUSIONS

We concluded that DWI helps in detection and characterization of different tamoxifen-related endometrial changes in the premenopausal female patients.

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.

Integration of MRI and MRS approaches to monitor molecular imaging and metabolomic effects of trabectedin on a preclinical ovarian cancer model

Although several drugs are available to treat recurrences of human epithelial ovarian cancer (EOC), clinical responses often remain short lived and lead to only marginal improvements in patients' survival. One of the new drugs proposed for recurrent platinum-resistant EOC patients is trabectedin (Trab), a marine-derived antitumor agent initially isolated from the tunicate Ecteinascidia turbinata and currently produced synthetically. Predictive biomarkers of therapy response to this drug and the potential use of non-invasive functional MRI and MRS approaches for an early assessment of Trab efficacy have not yet been evaluated, although they might be relevant for improving the clinical management of EOC patients. In the present work we combined functional and spectroscopic magnetic resonance technologies, such as in vivo diffusion-weighted MRI and ¹ H MRS, with ex vivo high resolution MRS (HR-MRS) metabolomic analyses, with the aim of identifying new pharmacodynamic markers of Trab effectiveness on well characterized, highly aggressive human SKOV3.ip (a HER2-enriched cell variant derived from SKOV3 cells) EOC xenografts. In vivo treatment with Trab (three consecutive weekly 0.2 mg/kg i.v. injections) resulted in the following: (1) a significant reduction of in vivo tumor growth, along with the formation in cancer lesions of diffuse hyper-intense areas detected by T₂ -weighted MRI and attributed to necrosis, in agreement with histopathology findings; (2) significant increases in the apparent diffusion coefficient mean and median values versus saline-treated control tumors; and (3) a significant reduction in the choline-containing metabolites' signal detected by quantitative in vivo MRS. Multivariate and quantitative HR-MRS analyses on ex vivo tissue samples revealed Trab-induced alterations in phospholipid and glucose metabolism identified as a decrease in phosphocholine and an increase in lactate. Collectively, these data identify Trab-induced functional MRI and MRS alterations in EOC models as a possible basis for further developments of these non-invasive imaging methods to improve the clinical management of EOC patients.

Extended abdominopelvic MRI versus CT at the time of adnexal mass characterization for assessing radiologic peritoneal cancer index (PCI) prior to cytoreductive surgery

PURPOSE

To evaluate whether extending the MRI scan to include the abdomen at the time of adnexal mass characterization could replace additional CT for peritoneal cancer index (PCI) assessment.

METHODS

After institutional review board approval for this prospective study, 36 consecutive females with ovarian and FT malignancies were included. All patients signed an informed consent. Patients underwent preoperative CT (32 patients) and MRI (36 patients). Images were interpreted by 2 independent observers. Surgical data were available in 27 patients. Region-by-region analysis was performed for detection rates of peritoneal carcinomatosis (PC). Inter-observer agreement for each region was evaluated by kappa statistics. Radiologic PCI was calculated by CT and MRI independently and inter-observer agreement for CT and MRI as well as agreement between radiologic and surgical PCI were evaluated by weighted-kappa statistics.

RESULTS

On region-by-region analysis, the highest detection rates of PC were noted at the central abdomen and pelvis. Detection rates were higher by MRI than CT, mainly in bowel serosal surface, pelvis, and right upper abdomen regions. Inter-observer agreement of MRI was higher than CT in most regions. The median PCI by CT was 5 and 4 for the first and second observers (range 0-21 for both observers), respectively. The median PCI by MRI was 6 (range 0-23 for both observers). The inter-observer agreement of PCI was excellent by both CT and MRI (k = 0.876 and k = 0.912, respectively). The agreement between CT and surgical PCI was 0.660 and 0.590 for the first and second observers, respectively. The agreement between MRI and surgical PCI was 0.797 and 0.798 for the first and second observers, respectively.

CONCLUSIONS

Extending MRI scan to include the abdomen at the time of adnexal mass characterization allows accurate estimation of PC, with better results than CT, obviating the need for dedicated CT scan of abdomen and pelvis for imaging of PC.

Role of MRI in staging and follow-up of endometrial and cervical cancer: pitfalls and mimickers

MRI plays important roles in endometrial and cervical cancer assessment, from detection to recurrent disease evaluation. Endometrial cancer (EC) is the most common malignant tumor of the female genital tract in Western countries. EC patients are divided into risk categories based on histopathological tumor type, grade, and myometrial invasion depth. EC is surgically staged using the International Federation of Gynecology and Obstetrics (FIGO) system. Since FIGO (2009) stage correlates with prognosis, preoperative staging is essential for tailored treatment. MRI reveals myometrial invasion depth, which correlates with tumor grade and lymph node metastases, and thus correlates with prognosis. Cervical cancer (CC) is the second most common cancer, and the third leading cause of cancer-related death among females in developing countries. The FIGO Gynecologic Oncology Committee recently revised its CC staging guidelines, allowing staging based on imaging and pathological findings when available. The revised FIGO (2018) staging includes node involvement and thus enables both therapy selection and evaluation, prognosis estimation, and calculation of end results. MRI can accurately assess prognostic indicators, e.g., tumor size, parametrial invasion, pelvic sidewall, and lymph node invasion. Despite these important roles of MRI, radiologists still face challenges due to the technical and interpretation pitfalls of MRI during all phases of endometrial and cervical cancer evaluation. Awareness of mimics that can simulate both cancers is critical. With careful application, functional MRI with DWI and DCE sequences can help establish a correct diagnosis, although it is sometimes necessary to perform biopsy and histopathological analysis.

Comparison of Various Parameters of DWI in Distinguishing Solitary Pulmonary Nodules

In order to prospectively assess various parameters of diffusion weighted imaging (DWI) in differential diagnosis of benign and malignant solitary pulmonary nodules (SPNs), 58 patients (40 men and 18 women, and mean age of 48.1±10.4 years old) with SPNs undergoing conventional MR, DWI using b=500 s/mm² on a 1.5T MR scanner, were studied. Various DWI parameters [apparent diffusion coefficient (ADC), lesion-tospinal cord signal intensity ratio (LSR), signal intensity (SI) score] were calculated and compared between malignant and benign SPNs groups. A receiver operating characteristic (ROC) curve analysis was employed to compare the diagnostic capabilities of all the parameters for discrimination between benign and malignant SPNs. The results showed that there were 42 malignant and 16 benign SPNs. The ADC was significantly lower in malignant SPNs (1.40±0.44)×10^-3 mm²/s than in benign SPNs (1.81±0.58)×10^-3 mm²/s. The LSR and SI scores were significantly increased in malignant SPNs (0.90±0.37 and 2.8±1.2) as compared with those in benign SPNs (0.68±0.39 and 2.2±1.2). The area under the ROC curves (AUC) of all parameters was not significantly different between malignant SPNs and benign SPNs. It was suggested that as three reported parameters for DWI, ADC, LSR and SI scores are all feasible for discrimination of malignant and benign SPNs. The three parameters have equal diagnostic performance.

Endophytic-Type Endometrial Cancer with Adenomyosis Successfully Diagnosed with Hysteroscopic Endometrial Biopsy Using an 8.3-mm Operative Resectoscope: A Case Report

In order to diagnose endometrial cancer preoperatively, outpatient endometrial biopsy with a curette is frequently performed owing to its convenience. However, in some cases, gynecologists fail to diagnose endometrial cancer via outpatient endometrial biopsy because of the cancer's distribution in the uterus and its consistency. A 57-year-old Japanese woman (gravida 4 para 4) presented with a 6-month history of light but intermittent postmenopausal vaginal bleeding. A malignant uterine tumor was strongly suspected after imaging using ultrasound examination and magnetic resonance imaging; however, a precise pathological diagnosis was not achieved despite multiple outpatient endometrial biopsies with the aid of office hysteroscopy. Based on an endometrial biopsy obtained using a cutting loop electrode on an 8.3-mm operative resectoscope, we reached a diagnosis of endophytic-type endometrial cancer, which is in accordance with the final pathological diagnosis after abdominal hysterectomy. Three months after her first visit to our hospital, total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic/para-aortic lymph node dissection were performed. Macroscopically, the endometrium was atrophic, and there was no obvious mass in the uterine cavity; however, microscopically, the cancer cells mainly existed in the deep myometrium and the final diagnosis was International Federation of Gynecology and Obstetrics (FIGO) stage IB endometrial cancer. Operative biopsy of the uterine endometrium and deep myometrium using hysteroscopy confirmed an accurate preoperative diagnosis of uterine endometrial cancer specifically of the endophytic type.