MRI in intracavitary brachytherapy planning for cervical cancer malignancy, the pitfalls and complications

Learning objectives

• Discuss the role and benefits of MRI in planning for brachytherapy treatment in cervical cancer.

• Discuss the key mechanisms of the applicator and the technical aspects of planning brachytherapy.

• Discuss the role of MRI imaging in recognising the features of appropriate applicator placement and common complications.

• Review key MRI features of radiation-related alterations in the pelvis post treatment and tumour response assessment.

Contents

• Anatomy of the female pelvic organs on MRI

• Key MRI imaging features of cervical cancer on MRI

• Review the staging of cervical cancer amenable to brachytherapy (FIGO)

• Advantages of brachytherapy versus external beam radiotherapy in treating cervical cancer.

• Technical aspects of applicator selection and positioning in brachytherapy.

• MRI features in assessment of appropriate placement of brachytherapy device, recognition of “organs at risk”.

• Benefits of MRI versus more traditional imaging techniques CT and Radiographs, in brachytherapy planning.

• “Red flag” features of brachytherapy device misplacement in MRI.

• Features of tumour response and target organ assessment.

• Complications of brachytherapy including post radiation fibrosis.

Conclusion

• Analysis of MRI findings at the time of brachytherapy with the applicator is essential in the assessment of gross tumour volume, clinical target volumes and patho-anatomical structures.

• T2-weighted MR images minimise potential misinterpretation due to partial volume effects, which improves depiction of tumour in parametria, vaginal fornices, and cervix.