Introduction

Dynamic contrast enhanced MRI (DCE-MRI) is very useful in the follow-up of patients with cervical cancer as it helps in differentiation of radiation fibrosis from tumor recurrence and it has been shown to predict tumor response to chemo-radiotherapy. Diffusion weighted imaging (DWI) is also very useful in detection of recurrent tumor in patients with gynecologic malignancies and can predict treatment response in patients with cervical and ovarian cancer.

Endometrial Cancer:

Most patients are cured following primary treatment and only approximately 15% of patients ultimately develop recurrent disease. Recognizing those patients with an increased risk of recurrence and the likely time scale might potentially direct a suitable approach for follow-up imaging. MRI plays a crucial role in the evaluation of surgical resectability, if pelvis is the sole site of recurrence. The vaginal vault is the sole site of recurrence in 30-50% of patients with endometrial carcinoma, depicted on T2W images as a mass with signal intensity similar to that of the primary tumour that obliterates the linear, low signal intensity of the vaginal vault.

Cervical Cancer:

There is no consensus regarding routine imaging follow-up after radical hysterectomy. Imaging is only undertaken if indicated by clinical symptoms or signs or in cases treated with fertility preserving radical trachelectomy. In patients treated with primary chemoradiation, MRI is routinely used to monitor response during and at the completion of treatment. If a small area of residual tumor is detected at the completion of treatment, there is a window of opportunity to offer exenterative surgery. If, after chemoradiation, the patient is found to have a complete response, no further routine imaging is required. Change in tumor size on sequential MRI is the standard method for evaluating response to chemoradiotherapy in patients with advanced cervical carcinoma. Decrease in tumor volume can be seen as early as 2 months after treatment and predicts a good prognosis. The reconstitution of the normal low signal intensity cervical stroma is the most reliable indicator of a tumor-free post-radiation cervix with a negative predictive value of 97%. DW-MRI and DCE-MRI show signs of promise as complementary to standard morphological response assessment based on tumor size. Pre-treatment DCE-MRI parameters can be used to predict response to chemoradiotherapy in patients with advanced cervical cancer. MRI parameters reflecting heterogeneous tumor perfusion and subtle tumor volume change early during chemoradiotherapy are independent and better predictors of tumor recurrence and death than clinical prognostic factors. The combination of clinical prognostic factors and MRI parameters further improves early prediction of treatment failure and may therefore enable a window of opportunity to alter treatment strategy. DW-MRI has also been studied as a potential response biomarker in cervical cancer. The ADC value of the tumor at two weeks following the start of radiotherapy as well as the change in ADC from pre-treatment to that time are associated with the eventual response on MRI at the end of treatment. This technique has the potential to allow early monitoring of response to chemoradiotherapy.

Ovarian Cancer:

CT is routinely used for monitoring treatment response and in the detection of recurrent disease, with MRI serving a problem solving role, particularly when surgery is contemplated for solitary pelvic recurrences. Recurrent tumor invading the pelvic side wall represents non-resectable disease. Side-wall involvement is confirmed when there is pelvic muscle or bone invasion, but this should also be suspected when tumor lies within 3 mm of the pelvic side wall, ureteric obstruction is present or when the iliac vessels are surrounded or distorted by tumor. Dynamic multiphase contrast-enhanced MRI is comparable (sensitivity 90% and specificity 88%) to laparotomy (sensitivity 88% and specificity 100%) and superior to serum CA-125 (sensitivity 65% and specificity 88%) for detecting recurrent peritoneal and serosal ovarian cancer implants. DW-MRI is very useful in detection of localized tumor recurrence within the pelvis as well as detection of disseminated peritoneal recurrence.

Acknowledgements

No acknowledgement found.