Early prediction of tumor response after radiotherapy in combination with cetuximab in nasopharyngeal carcinoma using 99m Tc-duramycin imaging

Autor: Cheng Liu, Yi Li, Xiaojia Qin, Ziyi Yang, Jianmin Luo, Jianping Zhang, Brian Gray, Koon Y. Pak, Xiaoping Xu, Jingyi Cheng, Yingjian Zhang
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Biomedicine & Pharmacotherapy, Vol 125, Iss , Pp 109947- (2020)
Druh dokumentu: article
ISSN: 0753-3322
DOI: 10.1016/j.biopha.2020.109947
Popis: Purpose: 99mTc-duramycin imaging enables specific visualization of cell death qualitatively and quantitatively. This study aimed to investigate the potential of 99mTc-duramycin imaging in the early prediction of the curative effect of radiotherapy in combination with or without cetuximab in a nasopharyngeal carcinoma (NPC) model. Methods: Male BALB/c mice bearing NPC xenografts were randomized into four groups (six mice each group). Group 1 received radiotherapy (RT, 15 Gy/mouse) in combination with cetuximab (CTX, 2 mg/mouse), group 2 received RT (15 Gy/mouse), group 3 was treated using CTX (2 mg/mouse), and group 4, the control group, was treated using a vehicle. 99mTc-duramycin imaging was performed before treatment and 24 h after treatment to evaluate tumor response. Tumor uptake of 99mTc-duramycin was validated ex vivo using γ-counting. Treatment response was further validated by cleaved caspase-3 (CC3) and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling (TUNEL). Another four groups were treated parallelly under the same conditions to observe treatment response by tumor volume changes. Results: After 24 h treatment, 99mTc-duramycin uptake in the NPC tumor models were significantly higher in group 1 than in group 2 (P < 0.05), group 3 (P < 0.05), or group 4 (P < 0.05); the uptake also increased notably in comparison with baseline values (P < 0.05). Compared with group 4, group 2 and group 3 both showed significant 99mTc-duramycin uptake in the tumors (P < 0.05). Although the 99mTc-duramycin uptake of group 2 was moderately higher than group 3, there were no significant differences between these two groups (P >0.05). There was a strong positive correlation between tumor 99mTc-duramycin uptake and CC3 (r = 0.893, p < 0.0001) and TUNEL (r = 0.918, P < 0.0001). Tumor volume decreased remarkably in the RT in combination with CTX group on day 5, in the RT alone group on day 7, and was inhibited on day 8 in the CTX alone group, whereas the tumors grew continuously in the control group. Conclusions: We demonstrated that RT in combination with CTX treatment significantly improved disease control in a NPC xenograft model compared with monotherapy with either. 99mTc-duramycin imaging might be able to reliably identify response to RT in combination with CTX as early as 24 h after therapy initiation in NPC xenograft models. This might help to isolate non-responding patients in a timely manner and avoid unnecessary side effects in the clinic in the future.
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