Localized In Vivo 1H MRS ( Proton Magnetic Resonance Spectroscopy ) for Histologic Type of the Cervical Cancer

Na, J H; Kim, Y M; Lee, J H; Cho, K S; Kim, J H; Kim, Y T; Nam, C H; Mok, J E

Abstract

Most of cervical cancers are squamous cell type and the majority of the remaining 10% to 15% are adenocarcinoma. The clinical features of these two histological types of cancers are known to be often quite different. The diagnosis depends on the histological examination via biopsy procedures, however it could be possible in some part by in vivo 1H MRS which presents the chemical composition and molecular dynamics by means of identification and quantification of metabolites and the metabolic status in cells and tissues. Unlike the histological examination and ex vivo MR spectroscopy whose results depend on where the biopsy specimens are excised, and therefore, which require the specimens from multisites, an in vivo MR spectroscopy can be performed covering a global lesion or a number of discrete lesions in the cervix noninvasively. Repetitive examinations at the same location over a period of treatment time, which are particularly useful for monitoring the progression of the disease after treatment such as chemotherapy and radiation therapy, can be performed by localized in vivo spectroscopy. The aim of this study was to investigate and characterize the patterns of 1H MR spectra of cervical cancers according to the histologic types. Localized in vivo 1H MR spectra of 36 patients diagnosed as invasive cervical cancer were acquired on a GE 1.5T SIGNA system equipped with shielded gradients(Milwaukee, WI, USA, version 5.4). Homebuilt endovaginal coils were used for a localized images for spectroscopy. The FIGO stages of these patients were IA to IIIB. Among 36 patients, 29 cases were squamous cell carcinoma and 6 were adenocarcinoma, 1 was adenosquaadenosquamous cell carcinoma. In MR spectra of cervical cancers, the resonance peaks at 0.9, 1.3, 2.0 and 3.0, 3.2 ppm were detected, which represents CH3 groups of triglycerides, CH2 groups of triglycerides, N-acetyl neuraminic acid and creatine and choline containing residues, respectively. The triglyceride peak at 1.3 ppm is characteristically intense and observed in 25 cases of the total 29 squamous cell carcinoma(sensitivity 86.2%; specificity 66.7%; overall accuracy 82.9%). Prominent peak at 2.0 ppm which was tentatively assigned N-acetyl neuraminic acid for human prostatic cancers was noted in 5 cases of adenocarcinoma, but no case of squamous cell carcinoma(sensitivity 83.3%; specificity 96.6%; overall accuracy 94.2%). In conclusion, this study demonstrated the feasibility of localized in vivo 1H MR spectroscopy to categorize the spectra according to the histological types.