竹田 芳弘

We evaluated the respiratory functions of patients with pulmonary emphysema who underwent lung volume reduction surgery (LVRS) by the mean transit time (MTT) with Xe-133 lung ventilation scintigraphy, forced expiration volume in 1 sec (FEV1.0), residual volume (RV), distance walked in 6 min (6-min walk), and the Hugh-Jones classification (H-J classification) before and after LVRS. In 69 patients with pulmonary emphysema (62 men, 7 women; age range, 47-75 years; mean age, 65.4 years +/- 6.1, preoperative H-J classification, III (two were II)-V) who underwent LVRS, all preoperative and postoperative parameters (MTT 3 weeks after LVRS and the others 3 months after LVRS) were judged statistically by the Wilcoxon signed-ranks test and Odds ratio. Every postoperative parameter was improved with a significant difference (P < 0.05) compared to preoperative parameters. MTT at 3 weeks after LVRS was not associated with %FEV1.0 and the H-J classification at 3 months after LVRS, but was associated with RV and a 6-min walk at 3 months after LVRS. MTT was useful for the clinical evalution of aerobic capability after LVRS.

We studied the differentiation of thyroid nodules using fine-needle aspiration biopsy (FNA) and Tl-201 scintigraphy quantitative analysis. One-hundred and thirty-one thyroid nodules were examined: 83 follicular lesions (58 benign and 25 malignant lesions) and 48 non-follicular lesions (8 benign and 40 malignant lesions). During Tl-201 scintigraphy examinations, an early and a delayed image were acquired 10 and 120 min after an intravenous injection, respectively. The T/N ratio (counts of nodular lesion/counts of contralateral normal thyroid tissue) of each image was calculated quantitatively. We assessed the ability of the Tl-201 scintigraphy and of the FNA analysis to differentiate benign and malignant lesions and determined the cut-off levels for the assays. For the follicular lesions, the area under the ROC (Receiver Operating Characteristic) curve (Az) for the Tl-201 scintigraphy data was greater than that for the FNA data. For the non-follicular lesions, the Az for the FNA data was greater than that for the Tl-201 scintigraphy data. We set cut-off levels at 1.370 for follicular lesions, and 1.070 for non-follicular lesions. The sensitivity and specificity were 76% and 82.7% for follicular lesions, and 90% and 87.5% for non-follicular lesions, respectively. The overall accuracy of the analysis was 84.0%.

To investigate the correlation between nuclear medicine parameters determined by technetium-99m-DTPA-galactosyl-human serum albumin (Tc-99m-GSA) and liver function tests, canonical correlation analysis was performed. Tc-99m-GSA studies were performed on 47 patients with hepatocellular carcinoma (HCC) who had undergone transcatheter arterial embolization (TAE). The nuclear medicine parameters LU15, HH15 and LHL15, which are results of nuclear imaging tests, were chosen in combination with the following liver function tests: the serum bilirubin level (T.Bil), the serum albumin level (Alb), serum cholinesterase activity (Ch-E), the clearance rate of indocyanine green (KICG), the hepaplastin test (HPT) and the prothrombin time (PT). The canonical correlation coefficient was 0.7345 and the upper tail probability was 0.00167. A significant correlation was observed between the two sets of variables. The high structural coefficients of Ch-E, KICG and HPT indicated a close relationship with the nuclear medicine parameters, supporting the notion that these nuclear medicine parameters are useful for the estimation of liver damage. The structural coefficients of the nuclear medicine parameters were also high, with LU15 being a parameter as useful as both HH15 and LHL15. T.Bil may evaluate a liver function that is not measured by nuclear imaging techniques, so we should take T.Bil results into account before considering TAE.

We performed a long-term follow-up of 4 patients with penile cancer who underwent hyperthermotherapy from August 1985 until August 1992. Hyperthermia was applied using a frequency of 350 MHz with a waveguide applicator twice a week for 60 min each for an average of 9.5 times (varying from 6 to 13 times). The total heating time that the temperature of urethra could be kept above 42 degrees C, was 166 min on the average (ranging from 0 to 463 min). Two patients classified as stage I according to the Jackson classification and 1 patient classified as stage IV underwent combined radiotherapy and received an average radiation dose of 53 Gy (range, 40-70 Gy). Among these patients 2 underwent combined chemotherapy with bleomycin or peplomycin. Malignant cells disappeared posttherapeutically and in August 1992, after an average of 5 years and 9 months (varying from 4 years 6 months to 6 years 10 months), the patients were free of recurrences. The one patient on stage IV had extensive invasion of the abdominal wall, but still recovered completely. One patient on stage III underwent combined chemotherapy and hyperthermotherapy, but heating had obviously been insufficient. There was a residue of malignant cells after the treatment and we performed a penectomy. Regarding functional preservation of the penis a multidisciplinary therapy incorporating hyperthermotherapy can be expected to increase the curativity. This indicates that it could induce in an advanced case, where an operation would be difficult, complete remission.

A total of 124 lesions from 1 to 6cm in diameter, including 31 cavernous hemangiomas, 32 metastases and 61 hepatocellular carcinomas (HCC) were analyzed to study the usefulness of magnetic resonance imaging (MRI) at 0.5 Tesla to differentiate focal hepatic lesions on the basis of qualitative criteria. Each focal hepatic lesion was assessed for shape, internal architecture and signal intensity relative to normal liver parenchyma. While all cavernous hemangiomas and metastases except one lesion could be detected, detection rate of HCC was significantly inferior to that of the other two diseases. A tumor capsule and a hyperintense focus on T1-weighted images were demonstrated in only HCC lesions in strong contrast with the other two diseases; however, metastases with slow-growing characteristics or subacute hematoma may appear as similar images. Cavernous hemangiomas appeared markedly hyperintense on T2-weighted images in 23 of 31 lesions, but one metastasis and one HCC had similar images. A multivariate analysis of several MRI resulted in the following mean discriminant scores: cavernous hemangioma, -1.2652; metastasis, 0.1830; and HCC, 0.7138. It appeared to be possible to differentiate the three diseases with 84.4 percent accuracy.

Between November 1984 and August 1992 we used hyperthermotherapy in six cases of local recurrence of rectal cancer. Hyperthermotherapy was performed on the average 8.7 times (range: 3-18) for each patient for 60 min each. All patients underwent combined radiotherapy and received a mean radiation dose of 42.5 Gy (range: 9-60 Gy). Five patients underwent heating within 1 h after irradiation and one patient simultaneously with the irradiation. Four patients underwent combined chemotherapy and two patients immunotherapy. Before the treatment all patients had painful lesions, but pain decreased posttherapeutically in five patients. Performance status improved in two patients. High carcinoembryonic antigen levels prior to the therapy in four patients decreased in all cases after treatment. Posttherapeutical computed tomograms revealed only minor response or no changes. After the treatment, four patients died of exacerbations of recurrent tumors and one patient of distant metastases. The patient who underwent simultaneous radiohyperthermotherapy is presently alive, in August 1992, 38 months after initiation of the treatment. The 50% survival time after initiation of the treatment was 25 months (range: 10-38 months). Hyperthermotherapy combined with radiotherapy, chemotherapy and/or immunotherapy was useful for the alleviation of pain in patients who developed local recurrence after surgery, and improved survival after recurrences can be expected.

A non-invasive method for measuring portal blood flow by magnetic resonance (MR) phase contrast was evaluated in a flow phantom and 20 healthy volunteers. In a flow phantom study, the flow volumes and mean flow velocities measured by MR phase contrast showed close correlations with those measured by electromagnetic flowmetry. In 20 healthy volunteers, the cross-sectional areas, flow volumes and mean flow velocities measured by MR phase contrast correlated well with those measured by the Doppler ultrasound method. Portal blood flow averaged during the imaging time could be measured under natural breathing conditions by using a large number of acquisitions without the limitations imposed on the Doppler ultrasound method. MR phase contrast is considered to be useful for the non-invasive measurement of portal blood flow.