Bom H S, Kim Y C, Song H C, Min J J, Kim J Y, Park K O
Department of Nuclear Medicine, Chonnam University Hospital, Kwangju, Korea.
J Nucl Med. 1998 Jan;39(1):91-4.
Patients with small cell lung cancer (SCLC) often fail to respond to chemotherapy due to multidrug resistance (MDR). Technetium-99m-MIBI was reported to be a suitable transport substrate of P-glycoprotein, which is a cytoplasmic membrane protein encoded by the MDR gene. The purpose of this study was to evaluate whether or not the degree of MIBI uptake in SCLC or its retention on delayed imaging correlated with response to chemotherapy.
Twenty-five patients (19 men, 6 women; mean age 59 +/- 10 yr) with biopsy-proven SCLC had MIBI SPECT 3-7 days before starting chemotherapy. Imaging was acquired 1 and 4 hr after injection of 740 MBq MIBI using a single-head rotating gamma camera. Tumor-to-normal lung uptake ratio (T/NL) was measured. Percent retention (%R) was measured as: %R = 100 x (T/NL at 4 hr)/(T/NL at 1 hr). All patients received VAP chemotherapy (VP-16 100 mg/m2, adriamycin 40 mg/m2, cisplatin 25 mg/m2) every 4 wk for at least three times. Response to chemotherapy was grouped as complete remission, partial remission and no remission according to the change of tumor size on chest radiograph and CT images. Differences in T/NL and %R among the three groups were analyzed using ANOVA.
T/NL of patients with complete remission (n = 7) and partial remission (n = 10) were significantly higher than that of no remission (n = 8) in 1 hr and 4 hr. T/NL at 1 hr in three groups were 2.75 +/- 0.78, 2.35 +/- 0.31 and 1.65 +/- 0.36, respectively. T/NL at 4 hr in three groups was 2.61 +/- 0.94, 2.48 +/- 0.50 and 1.66 +/- 0.42, respectively. However, %R was not different among three groups. Percent retention in three groups was 109.40 +/- 22.10, 96.71 +/- 14.25 and 103.59 +/- 28.43, respectively.
SCLC with a higher MIBI uptake was more likely to respond to chemotherapy than that with a lower uptake. However, there was a considerable overlap of MIBI uptake among subjects. No significant correlation between the MIBI retention between 1 hr and 4 hr, and the response to chemotherapy was noted.
小细胞肺癌（SCLC）患者常因多药耐药（MDR）而对化疗无反应。据报道，锝-99m-甲氧基异丁基异腈（MIBI）是P-糖蛋白的合适转运底物，P-糖蛋白是一种由MDR基因编码的细胞质膜蛋白。本研究的目的是评估SCLC中MIBI摄取程度或其延迟显像时的滞留情况是否与化疗反应相关。
25例经活检证实为SCLC的患者（19例男性，6例女性；平均年龄59±10岁）在开始化疗前3 - 7天进行MIBI单光子发射计算机断层显像（SPECT）。注射740 MBq MIBI后1小时和4小时，使用单头旋转γ相机进行显像。测量肿瘤与正常肺组织摄取比值（T/NL）。滞留百分比（%R）的测量方法为：%R = 100×（4小时时的T/NL）/（1小时时的T/NL）。所有患者每4周接受一次VAP化疗（依托泊苷100 mg/m²、阿霉素40 mg/m²、顺铂25 mg/m²），至少进行三次。根据胸部X线片和CT图像上肿瘤大小的变化，将化疗反应分为完全缓解、部分缓解和无缓解。使用方差分析（ANOVA）分析三组之间T/NL和%R的差异。
完全缓解组（n = 7）和部分缓解组（n = 10）患者在1小时和4小时时的T/NL显著高于无缓解组（n = 8）。三组在1小时时的T/NL分别为2.75±0.78、2.35±0.31和1.
