Clinical evaluation of tumor scanning with 57Co-bleomycin

Tumour uptake of 57-cobalt-bleomycin in patients with breast cancer

17 patients with breast carcinoma were studied with 57-cobalt-bleomycin scintigraphy. Scans showed increased tumour uptake in all patients. Results expressed as percentage of the injected dose (ID) normalised by the size of the tumour region (% ID/pixel) showed higher tumour uptake in patients with T3-T4 breast carcinomas (n = 5) than in patients with T1-T2 breast cancer (n = 12) (8.4 +/- 0.55 x 10(-3) vs. 5.25 +/- 1.71 x 10(-3)% ID/pixel, respectively, P < 0.05). An inverse correlation between tumour uptake of 57-cobalt-bleomycin and progesterone receptor concentration was also found in all tumours tested (r = -0.60, P < 0.05, n = 10) and was confirmed in the group of patients with T2 breast carcinomas (r = -0.89, P < 0.05, n = 6). We conclude that a quantitative analysis of 57-cobalt-bleomycin uptake can give additional information suitable for the presurgical characterisation of a tumour.

A practical SPECT technique for quantitation of drug delivery to human tumors and organ absorbed radiation dose

A practical quantitative single photon emission computed tomographic (SPECT) technique based on an empirical threshold analysis permits accurate measurements in humans of drug delivery and absorbed radiation dose. The limits of the method have been explored using a wide range of phantom volumes, concentrations, and target-to-nontarget ratios. A threshold of 43% was found to give the best results using volumes of 30 to 3,800 cc. An excellent correlation (r = .99 with a standard error of estimate [SEE] of 41 cc) was found between SPECT measured volumes and actual phantom volumes. A similarly high correlation (r = .98, SEE = 260 counts/voxel) was found in 77 measurements of concentrations between 0.01 and 3.6 microCi/cc. There was a direct relationship between the target-to-nontarget ratio of phantoms and the accuracy of volume measurements. The technique has been validated by an excellent in vivo/in vitro correlation of uptake in human tumors. The tumor cumulative concentration and tumor-to-blood ratio were used for assessment of drug delivery. In vivo quantitative measurements of the pharmacokinetics of technetium-99m (99mTc) glucoheptonate, cobalt-57 (57Co) bleomycin and platinum-195m (195mPt) cisplatin in human tumors in vivo indicates that, in contrast with tumor models in animals, there is a marked variability in drug delivery even in tumors with the same histology. Future development of labeled drugs should make it possible to use quantitative SPECT for predicting tumor response to therapy and for tailoring chemotherapy for the individual patient under treatment. SPECT quantitation of organ concentration was used for Medical Internal Radiation Dose committee (MIRD) calculations of organ absorbed radiation dose from 99mTc-labeled RBCs. Excellent in vivo/in vitro correlations were obtained between SPECT measured concentrations of blood radioactivity in the heart and in vitro measurements of blood samples. The possibilities and limitations of this technique are discussed and its use for in vivo measurement in humans of absorbed radiation dose from radiopharmaceuticals is suggested.

Monitoring of 57Co-bleomycin delivery to brain metastases and their tumors of origin

The concentration of cobalt-57 (57Co)-labeled bleomycin delivered to three brain metastases and to their tumors of origin in the lungs was measured using a single-photon emission computerized tomography technique. In two brain metastases the 57Co-bleomycin concentration measured at different times after the intravenous injection was significantly lower than that in the originating lung tumors (p less than 0.01 and p less than 0.001). In these two patients, the tumor cumulative concentration (TCC) of drug in the brain neoplasm compared to the lung carcinoma was 12.92 versus 15.12 and 10.30 versus 19.74 micrograms/cc/min. In the third patient there was no significant difference in drug concentration between the tumor in the brain and in the lung (TCC 16.02 vs. 15.09 micrograms/cc/min). There was a significant difference in the drug TCC between the three brain metastases: the difference between the lowest and highest concentrations was more than 50% (10.3 vs. 16.02 micrograms/cc/min). When the concentration in the tumor over time (CT(t)) of the 57Co-bleomycin was compared in the brain and lung tumors, a good correlation was found in each of the three cases (r = 0.93, 0.99, and 0.97). This suggests that the difference in drug uptake between brain metastases and their originating lung tumor is a quantitative rather than a qualitative phenomenon. The results show that the amount of drug to which brain metastases are exposed varies and may be very low in some tumors; therefore, effectiveness of drug delivery may play a role in the nonresponsiveness of brain metastases to treatment.

51Cr-Bleomycin in the Diagnosis of Tumours of the Chest

51Cr-bleomycin was used for the scintigraphic diagnosis of primary and secondary tumours of the thorax. The study was based on observations in 104 patients. The scintigraphy was performed using a gamma camera coupled to an on-line computer. Active lesions were scored using a semiquantitative scale of scores 0 to 5. Images were subdivided into 222 regions considered. In 72 of these, the presence of disease was diagnosed (64 malignant, 8 non-malignant) and 150 regions were classified as free from disease. At the decision threshold of score 2, over-all sensitivity and specificity of the scintigraphic detection of malignant tumours amounted to 97 and 79%, respectively. Inflammatory changes displayed some detectable accumulation of 51Cr-bleomycin but scores attributed to these lesions did not exceed the value of 2.

Scintigraphy with 57Co-bleomycin in the detection of lung cancer. A review of 268 well-documented patients

Over a 5-year period 57Co-bleomycin scintigraphy for tumor detection was performed with a large-field-of-view gamma camera. The scintigrams of 268 patients with lung cancer, with a benign lesion, or with no abnormality in the chest, were reviewed. A sensitivity of 96% was found. In a group of 193 patients in whom a preoperative pathologic diagnosis could not be obtained sensitivity was 95%, specificity was 87%. Correlation between tumor size and tumor-to-non-tumor ratio was established for squamous cell carcinoma, adenocarcinoma, and small cell anaplastic carcinoma. Adenocarcinomas were smaller and showed lower tumor-to-non-tumor ratios than other histologic types. In squamous cell carcinoma a possible correlation between tumor-to-non-tumor ratio and histologic differentiation was investigated, but could not be established. It is concluded that 57Co-bleomycin scintigraphy is helpful in the evaluation of patients with possible lung cancer in whom a preoperative pathologic diagnosis cannot be obtained.

Cobalt-57 bleomycin for imaging head and neck tumors

Cobalt-57 bleomycin imaging was performed in 11 patients with a history of head and neck cancer. Clinical and scan findings concurred on the presence and extent of tumor in 9 patients (82%); tumor was present in 7 and absent in 2 of the 9. In 2 patients (18%) the scan demonstrated tumor in the neck but failed to show metastatic sites. Cobalt-57 bleomycin images were of good technical quality, with remarkably low background activity at 24 hours after administration. Cobalt-57 bleomycin imaging appears to be a promising technique for evaluating patients with head and neck tumors.

Scintigraphic methods in the diagnosis of M. Hodgkin

The authors examined 40 patients with Hodgkin's lymphoma suspected from the localization of the process in mediastinum. They used X-ray investigation, radioisotope lung perfusion, radiogold-colloid lymphography and 67Ga-citrate scintigraphy. They found that, when the disease was diagnosed, X-ray examinations including tomography and lung perfusion gave reliable information in only half the cases whereas the other two nuclear medical methods showed positive results in 88% and 82%, respectively. In the diagnosis of relapse, the yield of these former methods was substantially higher, between 82--90%.

57-cobalt-bleomycin as a tumor scanning agent in primary hepatocellular cancer

57Co-bleomycin and 99mTc-sulfur colloid scans were performed in 13 southern African black patients with primary hepatocellular cancer (PHC) and 3 patients with other space-occupying hepatic lesions. Selective concentration of 57Co-bleomycin in the defect or defects seen on the 99mTc-sulfur colloid scan occurred in only 4 of the 13 (31%) patients with PHC. In the remaining PHC patients, as well as in the 2 patients with metastatic liver disease and the 1 patient with an amebic liver abscess, the 57 Co-bleomycin and 99mTc-sulfur colloid scans were identical. 57Co-bleomycin appears to have only a limited place as a tumor-seeking agent in the diagnosis of PHC in southern African blacks.

[Formation of giant cells in oral squamous cell carcinoma during bleomycin treatment: enzymehistochemical, electronmicroscopic and ultrahistochemical investigations (author's transl)]

During treatment of keratinizing squamous cell carcinomas with bleomycin tumor cells are devitalized by keratinization, while simple necrosis plays a minor role. Connected with this process is a marked resorptive granulomatous inflammation with numerous macrophages which is followed by a fibrous organization. In the border region of the keratinized tumor areas many multinucleated giant cells appear. The nature of these giant cells was the subject of controversy. Enzyme histochemical, electronmicroscopic, and ultrahistochemical investigations in three cases of advanced squamous cell carcinoma of the oral cavity prove that the giant cells which are formed during bleomycin treatment are not multinucleated tumor cells, but multinucleated macrophages. The enzymatic pattern is similar to macrophages with a high content of acid phosphatase and aminopeptidase. The ultrastructure of the giant cells is characterized by lysosomes with acid phosphatase activity, pinocytotic vesicles, and cytoplasmic projections on the cell surface with signs of macroendocytosis. The tumor cells show an epithelial differentiation with desmosomes, tonofibrils, and keratohyaline granula. The giant cells are formed by fusion of mononucleated (monocytogenic) macrophages. The fusions seem to be related to the functional status of the cells. It is possible, that the macrophages and the giant cells have an additional immunologic function. This is suggested by the frequent association of giant cells with lymphocytes. The importance of these facts for the evaluation of the action of bleomycin and the consequences for its therapeutic use are discussed. A combination with methods causing a dedifferentiation of the tumor or suppression of the immunologic defense seems to be problematic.