Comparative study of dual energy CT iodine imaging and standardized concentrations before and after chemoradiotherapy for esophageal cancer

Abstract

BackgroundTo compare dual energy CT iodine imaging and standardized iodine concentration before and after chemoradiotherapy (CRT) for esophageal cancer and evaluate the efficacy of CRT for EC by examining DECT iodine maps and standard CT values.MethodsThe clinical data of 45 patients confirmed by pathology with newly diagnosed esophageal cancer who underwent concurrent CRT from February 2012 to January 2017 in our department of radiology were collected. All patients underwent dual-source dual-energy CT (DECT) before and after CRT. Normalized iodine concentration (NIC) and normalized CT (NCT) corresponding to the overall cancer lesion and its maximum cross-sectional area were observed and compared. Additionally, 30 healthy individuals were compared as control group. After treatment, the patients were divided into two groups according to RECIST1.1: treatment effective group and ineffective group.ResultsThere were 33 patients (CR 9, PR 24) in the effective group and 12 patients (SD 12, PD 0) in the ineffective group. There was no significant difference in the NIC-A, NIC-V, NCT-A and NCT-A indexes between the effective group (B group) and the ineffective group (C group) before treatment (P > 0.05). After the treatment, the above-mentioned indexes in the effective group of patients were significantly lower than before treatment, and compared with the ineffective group, the NIC-A, NIC-V, NCT-A and NCT-V values of the effective group were significantly lower than those of ineffective group (P < 0.05). After treatment, the NIC-V and NCT-V in the ineffective group were lower than before treatment, and the difference was statistically significant (P < 0.05). However, their NIC-A and NCT-A were not statistically different from those before treatment (P > 0.05).ConclusionUsing DECT iodine map, the changes of NIC and NIC before and after CRT in patients with esophageal cancer can evaluate the effect of CRT, and does not increase the radiation dose, so it is suitable for clinical use.

Gastrointestinal Applications of Iodine Quantification Using Dual-Energy CT: A Systematic Review

“…Similar to gastric and colorectal cancer, Ge et al [ 59 ] demonstrated a positive correlation among esophageal cancer patients between nIC and response following chemoradiotherapy based on response criteria in solid tumors (RECIST) criteria. Unlike the studies in the gastric and colorectal group [ 36 , 48 , 49 ], two studies [ 31 , 60 ] suggested that IC/nIC can differentiate between specific cancer subtypes such as squamous cell carcinoma and adenocarcinoma in the gastroesophageal junction, as well as discriminate between small bowel adenocarcinoma and primary small intestine lymphoma.…”

“…Four studies [ 42 , 45 , 50 , 59 ] investigated the correlation between IC measurements with pre- and post-chemo or chemoradiotherapy treatment (three studies = neoadjuvant, one study = curative). IC was correlated to pathological findings, and all studies found a positive correlation between IC measurements and pathological response or non-response, suggesting that IQ may be used in monitoring treatment response.…”

“…Additionally, several studies have suggested that IQ may be an alternative method to evaluate chemo- or chemoradiotherapy treatment response [ 50 ]. Ge et al [ 59 ] reported a significant difference in nIC ( p < 0.05) when comparing the effective treatment group with the ineffective group using RECIST as reference. A study by Uhrig et al [ 67 ] suggested that IQ using DECT may be a complementary method to RECIST, as RECIST only accounts for size reduction of the tumor due to the cytotoxic effects of chemotherapy.…”

Advanced Computed Tomography imaging in radiotherapy

“…Before the optimized plan delivery is started, commonly CBCT imaging is performed to verify the patient treatment position and to visually check anatomy changes that could cause the treatment dose to deviate from the calculated dose and negatively influence the treatment outcome. This kilovoltage CBCT can additionally be used for in vivo dosimetry, based on portal imaging in so called dose-guided radiotherapy (DGRT) [54].…”

“…A slider to change the PMI pseudo-monoenergetic energy (40-190 keV) in the TPS could potentially be used to optimize the image settings for delineation purposes and could even be an alternative for window levelling. Furthermore, DECT-based post processing techniques such as colored iodine maps superimposed on the CT dataset potentially improve the visibility and thus the segmentation of cancerous tissue [53][54][55]. DECT-based RED and Zeff maps can be used to perform better tissue identification and improve dose calculations, more specifically for treatments [56].…”