Implications of the new FIGO staging and the role of imaging in cervical cancer

Abstract

International Federation of Gynecology and Obstetrics (FIGO) staging, which is the fundamentally important cancer staging system for cervical cancer, has changed in 2018. New FIGO staging includes considerable progress in the incorporation of imaging findings for tumour size measurement and evaluating lymph node (LN) metastasis in addition to tumour extent evaluation. MRI with high spatial resolution is expected for tumour size measurements and the high accuracy of positron emmision tomography/CT for LN evaluation. The purpose of this review is firstly review the diagnostic ability of each imaging modality with the clinical background of those two factors newly added and the current state for LN evaluation. Secondly, we overview the fundamental imaging findings with characteristics of modalities and sequences in MRI for accurate diagnosis depending on the focus to be evaluated and for early detection of recurrent tumour. In addition, the role of images in treatment response and prognosis prediction is given with the development of recent technique of image analysis including radiomics and deep learning.

Figure 1.

45 y.o. female, Cervical cancer Stage Ib3. (a) A quite large tumour larger than 4 cm involving the whole cervical stroma and extending beyond the internal os. The tumour also extends exophytically by expanding the vaginal fornix. (b) Oblique axial image shows the tumour is located within the vagina. Then the stage was inferred as Stage IB3 on MRI. Left ovarian cyst is observed.

Figure 2.

Cervical cancer stage Ib1. (a) Cervical tumour observed at the surface of anterior to posterior lip of the cervix as slightly increased signal intensity on T₂WI. (b) DWI clearly shows the tumour margin of less than 2 cm maximum diameter. The distance between the tumour to internal os was greater 1 cm. Trachelectomy was considered. (c) Patient received laparoscopic radical trachelectomy. Patients had two deliveries and have been disease-free more than ten years since surgery. DWI, diffusion-weighted imaging.

Figure 3.

Cervical cancer Stage IB2. (a) The tumour grows exophytically to vaginal cavity. Vaginal fornix was expanded by the tumour, but the tumour is confined within the cervix as observed by oblique axial image perpendicular to cervical long axis (b). The maximum tumour size was 33 mm. The tumour stage was inferred as IB2 under the new FIGO staging.

Figure 4.

43 y.o. female. The tumour crawls on the surface of the anterior lip of the cervix to anterior fornix of vagina. (b) Sagittal and (c) axial DWI clearly show tumour extension to the anterior vaginal fornix. Vaginal wall invasion was suspected at anterior fornix by irregularity. This case was diagnosed as Stage IIA in 2017 under the previous FIGO stage system. (d) Round lymph node about 8 mm diameter was observed at the left obturator node (arrow). (e) FDG-PET/CT showed mild uptake, with suspected lymph node metastasis. At operation, lymph node metastasis was confirmed. Therefore, this case is Stage IIIC1 at the present FIGO stage. DWI, diffusion-weighted imaging; PET, positron emission tomography.

Figure 5.

53 y.o. female with abnormal genital bleeding. (a) Sagittal T₂WI shows diffuse infiltration of the tumour from the uterine cervix to the uterine body. (b) On axial T₂WI, parametrial invasion is observed in all directions and diagnosed as Stage IIB. Low signal tumour extension along the uterosacral ligament in both directions (arrows).

Figure 6.

47 y.o. female with abnormal genital bleeding and lower abdominal pain. (a) On CT, left hydronephrosis is observed. (b) Sagittal T₂WI showed a large irregular shaped tumour involve cervix and extend along the vaginal wall and uterine body. The tumour also extends anteriorly to the bladder. No intact fat tissue was observed between the tumour and bladder wall. (c) Axial T₂WI showed parametrial invasion to anterior and left side-of the cervix. The tumour involved the left ureter (arrow). Disruption of the low-signal intensity bladder wall (arrowhead) by the tumour was suspected. Mucosal oedema is also observed. (d) Oblique axial T₂WI showed no disruption of the bladder wall (arrowhead), but only oedema. Cystoscopy revealed mucosal oedema as prominent, and the left ureteral orifice was not observed. Tumour invasion to the mucosa of bladder wall was not recognised. The case was designated as Stage IIIB.

Figure 7.

The same patients as those for Figure 4 after 6 months of total hysterectomy, salpingo-opholectomy and pelvic lymph node resection. (a) PET/CT clarified the dissemination at upper left abdomen (arrow) and multiple lymph node metastases (arrowheads) at paraaortic and pelvic region. (b) Dissemination was located anterior of the spleen. Liver metastasis was also found on CT, but not on PET. PET, positron emmision tomography.

Figure 8.

68 y.o. female with abnormal genital bleeding. (a) A large tumour involving the entire cervix and extend along vaginal wall. The tumour margin was irregular at the posterior vaginal wall, with suspected parametrial invasion. (b) Axial contrast-enhanced T₁WI shows irregularly enhanced lesion at the right pubic bone, diagnosed as bone metastasis and Stage IVB. (c) After the patient received chemotherapy, the tumour decreased dramatically (d) Slightly high signal intensity was found at right posterior lip both on axial T₂WI (d) and DWI (e). FDG-PET/CT showed no uptake at local lesion. It was diagnosed as no residual tumour. High signal intensity area on MRI was oedema after chemotherapy.