Hironori Takekawa

Retention index of thallium-201 single photon emission computerised tomography (SPECT) as an indicator of metastasis in adenocarcinoma of the lung

We examined the relationship between the retention of thallium-201 (201Tl) on a delayed scan and the metastatic potential of adenocarcinomas of the lung. We studied 43 patients with adenocarcinoma of the lung and divided them into two groups according to the presence or absence of lymph node metastasis. 201Tl single photon emission computerised tomography (SPECT) was conducted twice: 15 min (early scan) and 120 min (delayed scan) after intravenous injection of 3 mCi of 201Tl chloride. We calculated the retention index in order to evaluate the degree of 201Tl retention in the primary tumour. The retention indices were significantly higher in the group that was positive for lymph node metastasis than in the negative group. In adenocarcinomas with high metastatic potential, 201Tl SPECT demonstrated slow washout or increased retention on the delayed scan. The retention index of 201Tl SPECT is a useful indicator of metastatic potential, thereby facilitating the prediction of prognosis, and provides insight into the relationship between 201Tl uptake and malignancy. This is the first report demonstrating a significant relationship between the retention of 201Tl SPECT and lymph node metastasis.

Predicting chemotherapeutic response to small-cell lung cancer of platinum compounds by thallium-201 single-photon emission computerized tomography

Thallium-201 single-photon emission computerized tomography (SPECT) was used to clarify the relationship between 201Tl uptake and the response in chemotherapy to platinum compounds in 21 patients with small-cell lung cancer. 201Tl-SPECT scans were obtained twice: at 15 min (early scan) and 120 min (delayed scan) after an intravenous injection of 111 MBq (3 mCi) of thallium-201 chloride. We obtained the uptake ratio from each scan and calculated the retention index:uptake ratio = region of interest uptake/contralateral normal lung uptake; retention index = (delayed ratio - early ratio)/early ratio. After 201Tl scintigraphy, 12 patients received chemotherapy consisting of platinum compounds and nine were treated with chemoradiation. Among patients receiving only chemotherapy, the retention index correlated with the responses to chemotherapy. In an in vitro study, ouabain, an inhibitor of the Na,K-ATPase pump, reduced sensitivity to cisplatin and inhibited intracellular thallium uptake in the small-cell lung cancer cell line. These studies suggest that 201Tl-SPECT is a useful indicator of response to chemotherapy with platinum compounds in small-cell lung cancer, and that Na,K-ATPase is commonly involved in transporting both thallium and platinum compounds into cancer cells.

Single photon emission computed tomography using201Tl chloride in pulmonary nodules: Comparison with67Ga citrate and99mTc-labeled hexamethyl-propyleneamine-oxime

A single photon emission computed tomography (SPECT) with201Tl chloride (Tl-201) was carried out prospectively in 50 patients with pulmonary nodules and its diagnostic value was compared with those of67Ga citrate (Ga-67) and99mTc-labeled hexamethyl-propyleneamineoxime (Tc-99m-HMPAO). Tl-201 SPECT provided 88% (early)–91% (delayed) sensitivity, 85% (early and delayed) specificity and 87% (early)–89% (delayed) accuracy. The sensitivity of the Tl-201 planar image was 56 (early)–62% (delayed), which was significantly lower than that of SPECT. Delayed SPECT images at 2 hour postinjection were more preferable to disclose the malignant pulmonary nodule than early SPECT images at 15 minutes postinjection. The application of SPECT with Ga-67 failed to improve the sensitivity of planar imaging for malignant pulmonary nodules. Tc-99m-HMPAO was concentrated in 62% of 13 patients with malignant pulmonary nodules, which was slightly higher than Ga-67 in 54% of 28 patients. In an analysis of the histologic types of lung cancer, the sensitivity of Tl-201 was not significantly different in all types. On the other hand, Ga-67 was positive only in 25% of 12 patients with adenocarcinoma.A combination of SPECT and Tl-201 is the best choice among routine scintigraphic techniques for depicting malignant pulmonary nodules. The Tl-201 SPECT image may play a complementary role in the characterization of pulmonary nodules which are revealed on a plain radiograph and computed tomography.

Clinical Evaluation of Serum Laminin P1 and 7S Collagen in Lung Cancer Patients.

健常者19例, 肺癌患者59例 (腺癌32例, 扁平上皮癌14例, 小細胞癌13例), 転移性肺腫瘍7例について, 血清ラミニンP1, 7Sコラーゲン濃度を測定した.小細胞癌患者のみで健常者より血清ラミニンP1, 7Sコラーゲン値ともに平均値が有意に増加し, 陽性率も高かった.腺癌, 扁平上皮癌患者では, 病期進行例で高値例を認めた.更に小細胞癌で治療によって測定値の変化を認め, 治療モニターとして有用となる可能性が考えられた.

Cytodiagnostic significance of AgNORs in body cavity fluids.

胸水・腹水などの体腔液細胞診で悪性細胞か否かの診断が困難な異型細胞に遭遇することがある.このような細胞の鑑別のため, 疑陽性と判定された異型細胞のSilver-bindingnucleolarorganizer regions (AgNORs) について検討した.同じく疑陽性と判定された異型細胞でも, 悪性体腔液中の異型細胞では核内AgNORs平均個数 (mean±SD) は3.4±0.7であり, 非悪性体腔液中にみられた異型細胞での2.0±0.6に比べて有意に高値であった (P<0.01).特に核内AgNORs平均個数が3以上のときは, その体腔液が悪性である可能性がきわめて高かった.また, 疑陽性と判定された悪性胸水では, 多くが胸水CEA・核内AgNORs平均個数とも高値であるが, 前者が正常, 後者が高値の例もあった.体腔液に疑陽性と判定された異型細胞がみられた場合, 核内AgNORsの計測は体腔液の良性・悪性の鑑別に有用であった.