Twenty-eight patients with cervical cancer who had undergone uterine surgery between January 2006 and December 2010 were included in this study. The patients were between 35 and 76 years old. The cervical tumor types included 26 squamous cell carcinomas and two adenosquamous carcinomas. The study was based on the statement of ethical principles in the Declaration of Helsinki. Accordingly, the study was reviewed and approved by the clinical research ethics committee of the Affiliated Drum Tower Hospital of Nanjing University Medical School (Approval Number 2010028) and signed consent was obtained from each patient.
All patients were scanned using interstitial MR lymphography to examine lymphatic vessel drainage and lymph nodes prior to pelvic surgery. Surgery included radical hysterectomy and removal of pelvic lymph nodes according to their lesion grade. Pathological diagnoses were based on the analysis of the excised lymphatic tissue.
Inclusion criteria for this study were as follows:
(1) cervical cancer, stage Ia2-IIa;
(2) no prior pelvic surgery;
(3) no birth control ring;
(4) signed consent for MR lymphography.
Patients with contraindications to MR imaging and patients with contrast agent allergies were excluded. The patients were admitted eight hours prior to the exam, and received a clysma two hours before MR lymphography. Initially, Gadodiamide was injected intradermally into the bipedal toe web (four cases) to evaluate image quality before the study was continued using different injection locations. Subsequently, Gadodiamide was injected into the labium majus in two cases and into the cervical tissue in 22 cases to evaluate the sentinel lymph node (SLN) of cervical tissue and lymph node metastases. Patients were injected with 12–20 ml of Gadodiamide (body weight adjusted dose) plus 4 ml Lidocaine (2%) within 5 minutes. Gadodiamide was injected with a 0.20-0.25 ml/kg body weight (60 kg - 80 kg) adjusted dose leading to injected contrast agent volumes of 12–20 ml. The tissue close to the injection site was then massaged for about 30 seconds. After contrast injection, Mupirocin ointment (main components: Mupirocin, ointment matrix polyethylene glycol) was applied to the injection location to prevent infection.
MR imaging was performed immediately following administration of Gadodiamide. The MR exams were performed in the supine position on a Philips Intera 1.5 T MR system and a Philips Achieva 3.0 T TX MR system with a quadrature body coil. The following MRI sequences were used for MR lymphography of the pelvis:
1. T2-weighted(T2W)turbo spin-echo (TSE) in the axial (ax, TRA) plane;
2. T1W_TSE_ax, T2W_SPAIR coronal (COR);
3. T2W_ SPAIR sagittal (SAG);
4. PDW_ SPAIR TRA, DWIBS TRA.
Repetition Time (TR) and Echo Time (TE) were 5.6 ms and 1.86 ms, respectively. Each of the sequences included a slice thickness of 0.5 mm and 300 slices. Gadodiamide was injected into each patient within 5 minutes. Subsequently, a 3D MR lymphography sequence in the renal plane was begun after 3, 6, 9, 12, 15, and 20 minutes. In cases where the contrast injection was incomplete, the scan was repeated until completion. The MR lymphography sequence had a slice thickness of 0.5 mm and 300 slices with a TR
5.6 ms and TE
1.86 ms. Subsequently, the following MR sequences were used post-contrast:
1. T1W_TSE_ax TRA,
2. T1W_TSE_ax SAG,
3. T1W_TSE_ax COR.
The following diagnostic classifications were used in the analyses of the MR images: Lymphatic metastases:
1. Positive when lymphatic vessels were discontinuous in shape or were lymph nodes with filling defect;
2. Negative when lymphatic vessels and lymph nodes were regular in shape.
Patients with cervical cancer of stages Ia2, Ib or IIa were analyzed for lesion location and the extent of lymph node involvement using interstitial MR imaging and had radical abdominal hysterectomy and pelvic lymph node dissection following interstitial MR imaging. The pathological results were compared to the results of lymphatic MR imaging.