Utility of intravaginal ultrasound gel for local staging of cervical carcinoma on MRI

Viscous Aqueous Gel Illustrating Natural Anatomy: The VAGINA method in gynaecological MRI simulation

Accurately defining gross tumour volume (GTV) and organs at risk (OAR) is key to successful radiation therapy (RT) treatment outcomes for patients with gynaecological cancers. With improved access to magnetic resonance imaging (MRI) for RT simulation and planning, the optimisation and tailoring of proven diagnostic MRI techniques towards RT specific planning goals is fast evolving. Modifying MRI techniques for radiation oncology (RO) with the priority of anatomy visualisation and spatial location over diagnosis and disease characterisation relies heavily on successful collaboration between radiology and radiation oncology staff. This 'How I Do It' paper describes a qualitative analysis of the adaptation of a diagnostic MRI vaginal opacification technique into an RT specific MRI simulation procedure using aqueous ultrasound gel for improving natural anatomical visualisation of the vaginal canal. This technique is explained and could be introduced in other RO departments for dedicated RT planning scans in MR-Sim sessions with minimal difficulty. We found 10-15 cc of aqueous gel delivered vaginally produced optimal MRI planning images for most patients. With this small amount of gel and careful application technique, the full extent of the vaginal vault and cervix can be well visualised on T2 Weighted (T2W) imaging, while tending not to unfold the natural fornices of the collapsed vagina, representing a significant improvement in image quality from the outdated tampon procedure.

MR Imaging in Cervical Cancer

Cervical cancer remains a significant contributor to morbidity and mortality for women globally despite medical advances in preventative medicine and treatment. The 2018 Internal Federation of Gynecology and Obstetrics committee modified their original 2009 staging scheme to incorporate advanced imaging modalities, where available, to increase the accuracy of staging and to guide evolving treatments. Having a robust understanding of the newest staging iteration, its consequences on treatment pathways, and common imaging pitfalls will aid the radiologist in generating valuable and practical reports to optimize treatment strategies.

Patient acceptability and quality of self-administered intravaginal gel for pelvic MRI

Background:

MRI of the pelvis can be limited for infiltrating lesions or those of same signal intensity as surrounding structures. Vaginal distension using aqueous gel counters this by defining the fornices, cervix and anterior rectal wall. This increases the accuracy of diagnosis and staging of various pelvic pathology, however, there is currently neither a universally accepted protocol for using gel nor focus on patient self-administration.

Aims:

To improve patient expectations regarding pelvic MRI with intravaginal gel, as well as the service we provide should they prefer self-administration and this produces vaginal distension of radiological quality equivalent to doctor-administration.

Methods:

Illustrated information explaining the benefits of gel and the technique of self-administration was sent to patients scheduled for pelvic MRI between March 2020 and April 2021 at our study centre. This included a questionnaire to assess understanding and preference for self-administration. Vaginal distension achieved on imaging was analysed using TeraRecon and compared between self and doctor-administered cases.

Results:

38 of 45 patients opted for self-administration of gel. Those who identified as White British were more likely to self-administer. There was comparable quality of vaginal distension between self and doctor administered cases, with no significant difference between orthogonal measurements and retained gel volume.

Conclusion:

Self-administration of intravaginal gel for pelvic MRI is acceptable to patients and frees a doctor of this duty. It is a well tolerated technique which produces high quality vaginal distention on imaging. We recommend wider use of intravaginal and even rectal gel in the investigation of complex endometriosis and pelvic tumours.

[Uterine Cervical Cancer: Emphasis on Revised FIGO Staging 2018 and MRI]

Uterine cervical cancer is a common gynecological cancer prevalent in Korea. Early detection, precise diagnosis, and appropriate treatment can affect its prognosis. Imaging approaches play an important role in staging, treatment planning, and follow-up. MRI specifically provides the advantage of assessing tumor size and disease severity with high soft tissue contrast. The revised version of the International Federation of Gynecology and Obstetrics (FIGO) staging system has been introduced in 2018, which incorporates subdivided primary tumor size and lymph node metastasis. In this review, the staging of uterine cervical cancer based on previous studies, the recently revised FIGO staging, and various post-treatment images are primarily described using MRI.

Multimodality Imaging of Uterine Cervical Malignancies

OBJECTIVE. In this article, we provide an updated review on the role of imaging in initial staging, treatment monitoring, and follow-up of cervical cancer with a focus on the role of MRI and FDG PET/CT. In addition, the 2018 International Federation of Gynecology and Obstetrics staging system and its implication on management of cervical cancer are explored. CONCLUSION. Imaging plays a major role in treatment planning and as a prognostic indicator in patients with cervical cancer. MRI and PET/CT have complementary roles: MRI is essential for the local staging of the primary tumor, and PET/CT is the most useful modality for detecting regional nodal and distant metastases.

Assessment of the Effectiveness of the Vaginal Contrast Media in Magnetic Resonance Imaging for Detection of Pelvic Pathologies: A Meta-analysis

OBJECTIVE

Magnetic resonance imaging (MRI) is an excellent modality for pelvic imaging. The anatomy of uterine cavity and vagina is optimally evaluated when the walls, which may spontaneously be collapsed, are distended. Distension of these cavities during pelvic MRI for evaluation of gynecologic diseases has been conducted with vagina, filled with ultrasound gel or saline solution. In this meta-analysis, we aim to assess the effectiveness of vaginal contrast media in MRI for improving the detection of pelvic pathologies.

METHODS

The PubMed, MEDLINE, EMBASE, Web of Science, Google Scholar, Science Citation Index, and Cochrane Library databases were systematically searched through March 2019 for studies of the accuracy of MRI using vaginal contrast media in the diagnosis and staging of pelvic pathologies. Four eligible studies of a total of 120 patients were included in the meta-analysis. The sensitivity rates and relative risk for MRI, before and after vaginal contrast medium administration, were pooled, and their 95% confidence intervals (CIs) were determined.

RESULTS

The pooled sensitivity rate for MRI before administering intravaginal contrast medium in detecting pelvic pathologies was 63% (95% CI, 54%-72%), and that after was 89% (95% CI, 83%-93%). The interstudy heterogeneity rate (assessed using the I statistic) was relatively low: 13% (P = 0.33) and 0% (P = 0.45) before and after vaginal contrast medium use, respectively. The average relative risk was 1.54 (SD, 0.22; 95% CI, 1.18-1.89; median, 1.50; range, 1.34-1.80). This demonstrated that, on average, the sensitivity rate for MRI in detecting pelvic disorders increased by 54% after the use of a vaginal contrast medium.

CONCLUSIONS

Use of vaginal contrast media improved the diagnostic ability of MRI in identifying pelvic pathologies.

MRI of cervical cancer with a surgical perspective: staging, prognostic implications and pitfalls

LEARNING OBJECTIVES

Magnetic resonance imaging (MRI) of the pelvis is the most reliable imaging modality for staging, treatment planning, and follow-up of cervical cancer; and its findings may now be incorporated into the International Federation of Gynecology and Obstetrics Federation (FIGO) 2018 clinical staging of cervical cancer. It is imperative that radiologists are familiar with the imaging appearance of the different stages of cervical cancer as well as the post-treatment changes and imaging pitfalls given the respective clinical manifestations, treatment regimens, and prognosis of an accurate diagnosis. In addition to the different stages of cervical cancer, we address the imaging techniques for diagnosis, staging and treatment implications as well as the changes of the new FIGO staging system.

BACKGROUND

The use of MRI to diagnose and stage cervical cancer is steadily increasing and the new FIGO stagi ng system, previously based on clinical examination, now allows the staging or change of staging based on the imaging findings. MRI can evaluate the extent of disease because of its excellent contrast resolution for pelvic tissues and organs, high accuracy and detailed elaboration of the cervical/uterovaginal anatomy.

CONTENT

Relevant anatomy, including normal MRI appearance of the cervix, parametria and pelvic ligaments; different stages of cervical cancer on MRI with prognostic and therapeutic implications; MRI sequences, other imaging modalities used in the staging and follow-up, treatment of different stages and the appearance of the cervix and cervical cancer post-treatment. Since clinical implications and therapeutic strategies for cervical cancer treatment vary tremendously according to degree of tumor extension, familiarity with relevant MRI techniques and findings is essential for radiologists. It is important that radiologists interpreting pelvic MRI are aware with the different stages of cervical cancer to provide useful information regarding treatment and prognosis. Pitfalls regarding the interpretation of tumor extension can interfere with an accurate diagnosis and have significant therapeutic implications.