Accuracy of magnetic resonance imaging in predicting residual disease in patients treated for stage IB2/II cervical carcinoma with chemoradiation therapy

Abstract

BACKGROUND The evaluation of residual disease (RD) after chemoradiation therapy (CRT) in stage IB2/II cervical carcinoma conventionally is based on a clinical examination and magnetic resonance imaging (MRI) performed 3 to 8 weeks after the end of treatment. Very few studies have correlated MRI and histologic findings specifically in cervix cancer. This was the objective of the current study. METHODS A retrospective review was undertaken of patients who fulfilled the following inclusion criteria: 1) stage IB2/II cervical cancer, 2) external radiotherapy (45 grays [Gy]) was given with concomitant chemotherapy followed by uterovaginal brachytherapy (15 Gy), 3) MRI studies were obtained between 3 weeks and 8 weeks after brachytherapy, and 4) completion surgery included at least a hysterectomy. Postsurgical histologic findings and MRI results were compared. RESULTS Forty‐four patients who were treated between 2003 and 2006 fulfilled all inclusion criteria. Twelve patients (27%) had achieved a radiologic complete response, 16 patients (36.5%) had unclassified lesions (RD or ‘fibrosis’), and 16 patients (36.5%) had radiologic residual tumor. According to the histologic results, 19 patients (43%) had no RD, 10 patients (23%) had inframillimeter RD, 2 patients (5%) had RD that measured <1 cm, and 13 patients (29%) had RD that measured >1 cm. The sensitivity and specificity of MRI in evaluating RD were 80% and 55%, respectively. CONCLUSIONS The current results indicated that the evaluation of RD 3 to 8 weeks after CRT with MRI is difficult, and the risk of false‐positive results is high. Another radiologic procedure or a more technologically advanced MRI technique, such as diffusion‐weighted MRI, should be evaluated. Cancer 2008. © 2008 American Cancer Society.

Evaluation of T2-W MR imaging and diffusion-weighted imaging for the early post-treatment local response assessment of patients treated conservatively for cervical cancer: a multicentre study

“…Oedema is typically seen in the first months after radiation therapy, at the time when response evaluation is performed to decide on complementary surgery in case of residual disease. Our finding is also in line with a previous study showing that T2-WI alone resulted in up to 50% false positives [16].…”

“…MR imaging has so far been unable to fulfil the need to detect residual disease after radiation because of a false positive rate of up to 45% [16,17] that is mainly attributable to difficulties in differentiating residual tumour from local oedema. The development of MR imaging with diffusion-weighted imaging (DWI) has led to investigations of its potential in differentiating high cellular matrix (as seen in tumour) from low cellular matrix (as seen in oedema).…”

Prognostic Factors and Morbidities After Completion Surgery in Patients Undergoing Initial Chemoradiation Therapy for Locally Advanced Cervical Cancer

“…This point also raises the important question of the evaluation of response (and thus, the potential presence of RD) at the end of CRT (should completion surgery be discussed). Response evaluation is based on a clinical examination and imaging (MRI) performed 6 -8 weeks after brachytherapy, but the accuracy of such management is still debated [41]. Perhaps adding diffusionweighted MRI or PET-CT imaging to predict potential RD could be helpful in this context [42,43].…”

Can MRI Predict Local Control Rate of Uterine Cervical Cancer Immediately after Radiation Therapy?

“…13 Several reports that determine valuable prognostic factors early during RT have also been published. 1,5,[13][14][15][16][17][18][19][20][21][22][23][24][25][26] Some suggest that several tumor regression rates during RT are useful to predict outcome, 1,15-17 but most include pelvic wall recurrence and peripheral recurrence in the local recurrence category. Therefore, we attempted to evaluate the relationship between the true local recurrence rate and the tumor volume or reduction rate just before completion of RT or just after.…”

“…15,26 Three patients with no residual tumor in the cervix (complete response or almost complete response) showed recurrence in the vaginal wall or parametrium (peripheral recurrence), thus indicating that microscopic foci of the residual tumor burden may persist after completion of RT but are too small to be detected by MR imaging. This is a limitation of MR imaging for predicting local control.…”