MRI-based Signatures for Survival Prediction in Cervical Cancer With Radiotherapy

Evaluation of a New Prognostic Tumor Score in Locally Advanced Cervical Cancer Integrating Clinical Examination and Magnetic Resonance Imaging

The integral results of clinical examination and magnetic resonance imaging (MRI) of patients with locally advanced cervical cancer may provide prognostic information that cannot readily be placed in current staging systems, such as proximal versus distal parametrial invasion, unilateral versus bilateral involvement, or organ infiltration on MRI. The aim was to develop and investigate the performance of a simple but comprehensive tumor score for reporting and prognostication. In the present study, 400 consecutive patients with locally advanced cervical cancer treated 2005 to 2018 with chemoradiation and image guided adaptive brachytherapy (IGABT) were analyzed. The diagnostic workup included clinical examination, positron emission tomography/computed tomography, and MRI. International Federation of Gynecology and Obstetrics 2009 stage distribution was IB to IIA 9%, IIB 61%, and III to IV 30%. Involvement of 8 anatomic locations (cervix, left parametrium, right parametrium, vagina, bladder, ureter, rectum, and uterine corpus) was scored according to a ranked ordinal scale with 0 to 3 points. The total sum of points constituted the tumor score (T-score). The median T-score was 6 (range, 0-20). Based on the frequency distribution of the T-score, 4 equally sized groups were formed: 0 to 4, 5 to 6, 7 to 9, and >9 points. The T-score grouping was highly significant in both univariate and multivariable analysis and outperformed International Federation of Gynecology and Obstetrics stage for both survival and local control enabling also intrastage prognostication. Used as a linear variable, the T-score was correlated with IGABT target volume (high-risk clinical target volume, CTV The T-score is a simple instrument for combining clinical findings and imaging into a powerful prognostic factor for survival and local control with capabilities surpassing traditional staging. In addition, the T-score may already at diagnosis predict essential IGABT parameters and may be used for audit and comparison of results in multicenter settings.

Implications of the revised cervical cancer FIGO staging system

The 2018 revised International Federation of Gynaecology and Obstetrics (FIGO) staging of cervical cancer has brought about a paradigm shift by offering the option of adding imaging and pathology to clinical staging. This makes it applicable to all types of resource situations across geographies with implications for all stakeholders, including gynaecologists, gynaecologic oncologists, radiologists, pathologists and radiation and medical oncologists. The new staging classification has more granularity, with three sub-stages of stage IB and a new category of stage IIIC for all cases with lymph node (LN) involvement. The major limitations of clinical staging were inaccurate assessment of tumour size and inability to assess pelvic and para-aortic LNs with the limited investigations permitted by FIGO to change the stage. This resulted in understaging of stages IB-III, and overstaging of stage IIIB, which has been largely overcome by incorporating imaging findings. Although any imaging modality can be used, magnetic resonance imaging appears to be the best imaging modality for early-stage disease owing to its better soft-tissue resolution. However, the use of contrast-enhanced computed tomography or ultrasonography are also feasible options, depending on the availability and resources. But wherever pathological evaluation is possible, it supersedes clinical and radiological findings.

Jacob Christian Lindegaard