Prognostic value of the primary lesion apparent diffusion coefficient (ADC) in nasopharyngeal carcinoma: a retrospective study of 541 cases

Abstract

The prognostic value of the primary lesion pretreatment apparent diffusion coefficient (ADC), which is obtained by diffusion-weighted magnetic resonance imaging (MR-DWI), remains unknown in nasopharyngeal carcinoma (NPC). Thus, to investigate whether the pretreatment ADC value as measured from the primary site on MR-DWI is an independent prognostic factor in NPC, we retrospectively reviewed a cohort of 541 patients with histologically-proven stage I-IVB NPC. All patients underwent MRI using a 3-Tesla system (Trio Tim; Siemens, Erlangen Germany). To calculate ADC, the primary lesion was designated on the ADC map at the level of the largest tumor diameter to cover most of the lesion, avoiding cystic or necrotic components. Median and mean (±SD) pretreatment ADC were 0.713 and 0.716 ± 0.079 × 10−3 mm2/s, respectively. Univariate and multivariate analysis confirmed high pretreatment ADC was a good prognostic factor for poor local relapse-free survival and disease-free survival. Furthermore, the area under the ROC curve for prediction of local failure significantly increased when pretreatment ADC was combined with T classification (P = 0.004). Thus, pretreatment ADC might provide useful information for predicting outcome and selecting high-risk patients appropriate for more aggressive therapy. Further studies are warranted to investigate the biological basis of this observation.

Diffusion-Weighted Imaging of Nasopharyngeal Carcinoma: Can Pretreatment DWI Predict Local Failure Based on Long-Term Outcome?

“…Our study broadly supports the findings of Zhang et al, 15 with high primary tumor ADC values being associated with poor local response. However, we were unable to show this correlation by using the ADC mean and could only show such a correlation by using the ADC skewness.…”

“…[12][13][14] These 3 studies showed mixed results with both low [12][13] and high 14 pretreatment ADCs reported in tumors with poor outcomes, with the results being significant in only 1 of the studies. 12 However, a recent NPC study by Zhang et al 15 with long-term follow-up and a large sample size of 541 patients showed a significant association between a high mean ADC in primary tumors pretreatment and poor survival at 3 years. That study measured the pretreatment mean ADC at the level of the largest primary tumor diameter and used ROC curve analysis to identify an optimal cutoff ADC for LF of Ն0.747 ϫ 10 Ϫ3 mm 2 /s (area under the ROC curve ϭ 0.68, P ϭ .004), which was shown to correlate with both local relapse-free survival and disease-free survival.…”

“…Currently, there are only a few NPC DWI studies that have correlated diffusion parameters with tumor characteristics at diagnosis, such as T-stage, 23,24 early intratreatment response, 25 and posttreatment response. [12][13][14][15]26 Regarding using pretreatment tumor ADC to predict posttreatment response, 12-15 3 of these studies were based on short-term outcome at the end or 3 months after the end of treatment. [12][13][14] These 3 studies showed mixed results with both low [12][13] and high 14 pretreatment ADCs reported in tumors with poor outcomes, with the results being significant in only 1 of the studies.…”

“…11 Currently, most predictive treatment-response NPC studies are based on a relatively short-term outcome ranging up to 3 months posttreatment, [12][13][14] and only 1 study has reported results based on longer term outcome correlating pretreatment DWI with local relapse-free or disease-free survival at 3 years. 15 Therefore, the aim of this study was to determine the diagnostic performance of pretreatment DWI of the primary tumor site for the prediction of local failure (LF) based on long-term follow-up at a minimum of 5 years for patients diagnosed with local control (LC) in NPC.…”

The Research Progress of Long Noncoding RNAs in Nasopharyngeal Carcinoma

“…Because of nasopharyngeal carcinoma is mainly located at the top and lateral wall of nasopharynx, relatively hidden, when the early onset of symptoms is not obvious, or lack of specificity, and is easy to be ignored by the patients. And the vast majority of poorly differentiated nasopharyngeal carcinoma, malignant degree is high, easy early cervical lymph node and distant metastases, most patients were advanced nasopharyngeal car-cinoma on symptoms or when they see a doctor [2]. Nasopharyngeal carcinoma is generally sensitive to radiotherapy.…”