鼻咽癌原发灶乏氧和动态的变化及临床意义

目的分析初治鼻咽癌治疗前原发灶乏氧和治疗中、治疗末的动态变化及其与肿瘤消退的关系。方法62例患者分别于治疗前、中、末行头部^99Tc^m-4,9-二氮3,3,10,10-四甲基十二烷-2,22-二酮二肟（^99Tc^m-HL91）乏氧显像及CT模拟扫描。（1）采用目测法和半定量法的放射性计数比（T^＋／N）分析三个时段原发灶的乏氧状况及动态变化;（2）分析治疗前乏氧程度及治疗过程的动态变化与肿瘤消退的关系。结果目测法显示治疗前56例乏氧阳性,治疗中、末分别有8例和19例转为阴性;半定量法显示同-病例治疗前、中、末T^＋／N值逐渐降低（F=109．073,P=0．000）。治疗前重度乏氧（T^＋／N≥1．52）者治疗中、末肿瘤消退率均明显低于轻度乏氧（T^＋／N〈1．52）者（P=0．019和0．000）和乏氧阴性者（P=0．038和0．000）,其治疗中、末T^＋／N值的变化与相应时段肿瘤消退率呈正相关趋势（r=0．587,P=0．003和r=0．655,P=0．001）。结论初治鼻咽癌原发灶乏氧随治疗的进程逐渐减轻或消失。治疗前乏氧程度及其在治疗中的变化与肿瘤的消退速度相关。

Changes of hypoxia in primary lesion of nasopharyngeal carcinoma during the treatment course and the clinical value thereof

OBJECTIVE: To investigate the hypoxia status in the primary lesion of nasopharyngeal carcinoma (NPC) during the treatment and the clinical value thereof. METHODS: Sixty-two patients with untreated NPC were examined by 99m Tc-4, 9-diaza-3, 3, 10, 10-tetramethy ldodecan-2, 11-dione dioxime (99 Tcm-HL91) SPECT imaging and CT-simulation (CT-Sim) scan before the treatment, in the mid-treatment (after receiving about 40 Gy) and at the end of treatment respectively. (1) All hypoxia images obtained at the 3 time pints were analyzed by visual analysis and semi-quantitative analysis, the radioactivity ratio of the high density region in the nasopharyngeal lesion to the normal nasopharyngeal tissue (T+/N) was calculated with the technique of region of interesting (ROI). Then the changes of hypoxia status during the treatment were evaluated according to the changes of the visual results and the ratios of T+/N. (2) The tumor volumes in different time points were measured by relevant CT-Sim images in the CT-Sim working station (Exomio 2.0, Medintec), and the percentage of tumor shrinkage in the mid-treatment and at the end of treatment were calculated to evaluate the tumor's response to treatment. The relationships between the hypoxia status before treatment, hypoxic changes during the treatment, and the tumor's response to treatment were analyzed finally. RESULTS: Fifty-six of the 62 NPC cases were hypoxia-positive before the treatment, the hypoxic location in the same patient remained in the same site in different time points, and no new hypoxic area was found during the treatment. Eight cases changed to negative in the mid- treatment and 19 changed to negative at the end of treatment. The ratio of T+/N decreased gradually in the same case (F = 109.073, P = 0.000). The tumor shrinkage rates in the mid-treatment and at the end of treatment of those with high-grade hypoxia (T+/N >or= 1.52) were all both significantly lower than those of the cases with low-grade hypoxia (T+/N < 1.52) (P = 0.019 and 0.000) and those of the hypoxia-negative group (P = 0.038 and 0.000). The ratios of T+/N variation in the mid-treatment and at the end of treatment were both positively correlated with the percentages of tumor shrinkage in the mid-treatment and at the end of treatment (r = 0.587, P = 0.003 and r = 0.655, P = 0.001). CONCLUSION: The hypoxia of the primary lesion of NPC alleviates gradually or disappears along with the treatment course. Hypoxia has some negative effects on the tumor response to treatment.