Longitudinal evaluation of five nasopharyngeal carcinoma animal models on the microPET/MR platform

PURPOSE

We longitudinally evaluated the tumour growth and metabolic activity of three nasopharyngeal carcinoma (NPC) cell line models (C666-1, C17 and NPC43) and two xenograft models (Xeno76 and Xeno23) using a micropositron emission tomography and magnetic resonance (microPET/MR). With a better understanding of the interplay between tumour growth and metabolic characteristics of these NPC models, we aim to provide insights for the selection of appropriate NPC cell line/xenograft models to assist novel drug discovery and evaluation.

METHODS

Mice were imaged by ¹⁸F-deoxyglucose ([¹⁸F]FDG) microPET/MR twice a week for consecutive 3-7 weeks. [¹⁸F]FDG uptake was quantified by standardized uptake value (SUV) and presented as SUVmean tumour-to-liver ratio (SUVRmean). Longitudinal tumour growth patterns and metabolic patterns were recorded. SUVRmean and histological characteristics were compared across the five NPC models. Cisplatin was administrated to one selected optimal tumour model, C17, to evaluate our imaging platform.

RESULTS

We found variable tumour growth and metabolic patterns across different NPC tumour types. C17 has an optimal growth rate and higher tumour metabolic activity compared with C666-1. C666-1 has a fast growth rate but is low in SUVRmean at endpoint due to necrosis as confirmed by H&E. NPC43 and Xeno76 have relatively slow growth rates and are low in SUVRmean, due to severe necrosis. Xeno23 has the slowest growth rate, and a relative high SUVRmean. Cisplatin showed the expected therapeutic effect in the C17 model in marked reduction of tumour size and metabolism.

CONCLUSION

Our study establishes an imaging platform that characterizes the growth and metabolic patterns of different NPC models, and the platform is well able to demonstrate drug treatment outcome supporting its use in novel drug discovery and evaluation for NPC.

Development of a novel score to predict probability of growth without growth hormone after resection of paediatric craniopharyngiomas: relative to tumour growth pattern

OBJECTIVE

Some patients with paediatric craniopharyngiomas (PCs) showed normal growth despite growth hormone deficiency, which is known as growth without GH (GWGH); however, its mechanism remains unclear. We aimed to develop a novel clinical score to predict the probability of GWGH in PCs.

METHODS

A total of 708 PC patients were prospectively enrolled from six hospitals, among which 431 patients were finally included. Data from four of the six hospitals (n = 325) were used to develop the innovative clinical score (ICS), which was further validated using the data from the other two hospitals (n = 106). To establish and validate the ICS, sequential logistic regression was used to analyse the clinical characteristics including tumour growth pattern and tumour size and so on. Furthermore, C-statistic was employed to calibrate the discriminatory ability of the established clinical score, while a calibration plot was adopted for further assessment.

RESULTS

The overall incidence of GWGH was 16.9% (73/431). The ICS ranged from 2 to 23, with an optimism-corrected C-statistic of 0.820, Furthermore, the optimism-corrected C-statistic of external validation was 0.835, indicating good discriminatory power and robustness of the clinical score. Additionally, no apparent overestimation or underestimation was observed in the calibration plots, which showed excellent calibration power of the clinical score.

CONCLUSIONS

Based on tumour growth patterns and PC patients' clinical characteristics, individualized surgical strategies were promising to achieve long-term effective management of PC patients. The ICS is valuable for the evaluation of probability of developing postoperative GWGH.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT00949156.