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The purpose of this study is to evaluate the clinical efficacy of liver SPECT (single photon emission computed tomography). The two examinations were performed in 76 cases with SOL (space occupying lesion) and 58 normal cases. The results of the image reading by the planar image only (PS) and that of the image reading by the combination of PS and SPECT (PS + SPECT) were analyzed by ROC (receiver operating characteristic) analysis. The ROC curves showed that SPECT appears to reduce the number of results which were equivocal by the image reading of PS only. The detectability of SPECT for SOL in the left lobe of liver was less than that of PS without statistical significance. However, the performance of SPECT for SOL in the right lobe of liver was significantly better than that of PS.

Sensitivity and precision of the 13C-breath test were assessed by examining a couple of limiting factors caused by the sensitivity of the instrument used for 13CO2 analysis, endogenous fluctuation of 13CO2 abundance, and the residual CO2 in sample storing tubes, vacutainers, etc. For 13CO2 analysis, a mass spectrometer equipped with a dual inlet, a dual collector, and an automated pressure matching system, was used. 15 ml vacutainers were used for sample storage. Endogenous fluctuation of 13CO2 abundance, however, was measured by putting the breath samples directly into the evacuated CO2 purification system, instead of using vacutainers. Endogenous fluctuation (S.D. = 0.202%) was the most significant limiting factor, compared with instrumental limitation (0.085%), or with influence of the residual CO2 (0.136%). Consequently, the sensitivity of the 13C-breath test was figured out to be 0.52%. This sensitivity is about 1,000 times lower than that of 14C-breath test. The precision was linearly dependent on 13C increase from basal 13C observed after administration of 13C enriched compounds, delta 13C, and was determined to be expressed as 1.94 delta 13C.

The purpose of this study is to evaluate the clinical efficacy of liver SPECT (single photon emission computed tomography). Eleven hospitals which are in or near Tokyo are participating in this study. Planar liver images and SPECT images of 134 cases which were retrospectively confirmed for its final diagnosis were collected. At the first study, the planar images (PS) were read by 13 nuclear medicine physicians. The second, the image reading by the combination of the planar images and the SPECT images (PS + SPECT) were performed. The confidence level of diagnosis for SOL (space occupying lesion) obtained by the image reading of PS and PS + SPECT has been analyzed by using the SOL detection model. The SOL detectability of PS + SPECT was higher than that of PS only. However, these differences were not statistically significant.

The value of preoperative bone scans in patients with primary breast and prostate cancer was evaluated prospectively. Of 414 patients with breast cancer, clinical stage I is 14, II is 219, IIIA is 59, IIIB is 39 and IV is 14. Of 88 patients with prostate cancer, clinical stage I is 14, II is 15, III is 18 and IV is 41. 11 percent of patients with breast cancer and 54 percent of patients with prostate cancer had bone metastases. Clavicle, ribs, thoracic spine, lumbar spine and pelvis metastasized most frequently. The incidences of bone metastases were 18.4% with Scirrhous carcinoma, 15.4% with Medullary tubular carcinoma and 3.8% with Papillotubular carcinoma. The methodology and results of ROC analysis were described in our other papers. Some results of data analysis were described in this paper.

In order to improve goodness-of-fit in RIA standard analysis, programs for computing log-logistic and cubic log-logit were written in BASIC using personal computer P-6060 (Olivetti). Iterative least square method of Taylor series was applied for non-linear estimation of logistic and log-logistic. Here "log-logistic" represents Y = (a--d)/(1+log(X)/c)b)+d As weights either 1, 1/var(Y) or 1/sigma 2 were used in logistic or log-logistic and either Y2(1--Y)2, Y2(1-Y)2/var(Y), or Y2(1--Y)2/sigma 2 were used in logistic or log-logistic and either Y2(1--Y)2, Y2(1--Y)2/var(Y), or Y2(1--Y)2/sigma 2 were used in quadratic or cubic log-logit. The term var(Y) represents squares of pure error and sigma 2 represents estimated variance calculated using a following equation log(sigma 2 + 1) = log(A)+J log(y). As indicators for goodness-of-fit, MSL/Se2, CMD% and WRV (see text) were used. Better regression was obtained in case of alpha-fetoprotein by log-logistic than by logistic. Cortisol standard curve was much better fitted with cubic log-logit than quadratic log-logit. Predicted precision of AFP standard curve was below 5% in log-logistic instead of 8% in logistic analysis. Predicted precision obtained using cubic log-logit was about five times lower than that with quadratic log-logit. Importance of selecting good models in RIA data processing was stressed in conjunction with intrinsic precision of radioimmunoassay system indicated by predicted precision.

Prospective study of bone scintigraphy was performed on 414 patients with breast carcinoma and 88 patients with prostate carcinoma. In 468 of them, confirmative diagnoses of bone, whether metastasis was existent or not, were made after the observations over a year. Finally, the incidences of bone metastasis were 11 percent for breast carcinoma and 54 percent for prostate carcinoma respectively. The efficacy of preoperative bone scintigraphy in breast carcinoma was comparable to that in prostate carcinoma with regard to improvement of predictive probability of bone metastasis: raising up the probability in the positive cases and bringing down in the negative cases.

The value of preoperative bone scans in patients with primaly breast and prostate cancer was evaluated prospectively. The methodology and some clinical results were described previously. The clinical efficacy of the bone scan was assessed by using ROC analysis and we obtained the following results. 1) Preoperative bone scan of carcinomas of the breast is effective for patients with clinical stage IIIA, IIIB and IV. It is not so effective for patients with clinical stage I and II, but there is no denying the importance of it, because it provides a base-line scan for comparison to subsequent scans obtained in the postoperative period. 2) Preoperative bone scan of prostate carcinomas is effective, especially for clavicle, the ribs and the cervical spine, when compared with bone X-ray. 3) Bone scan is effective means for patients who were diagnosed uncertainly to have bone metastasis.

Spiperone, a butyrophenone neuroleptic drug, has been used in binding studies of dopamine receptors. Långström et al. developed N-11C-methyl spiperone, and, in cooperate with Wagner et al., made it possible to visualize the distribution of dopamine receptors in the human brain in vivo. In this paper, we independently developed another synthetic method of N-11C-methyl spiperone using the phase transfer catalyst in an anhydrous solvent. Separation of the product is feasible only by passing the reactant solution through a Millipore filter and injecting it onto high pressure liquid chromatography (HPLC). The time required for the synthesis and purification of N-11C-methyl spiperone from 11C-methyl iodide and spiperone was 20 min. Radiochemical yield exceeded 35% against 11C-methyl iodide without correcting decay of the radioactivity.