Effect of carbogen on tumour oxygenation and 32P-colloid interstitial irradiation response.

BACKGROUND: Interstitial irradiation therapy using radionuclides is a slow and continual process in which the effect is exerted gradually, thus improvement of the hypoxic status of the tumor will also take a long time. It has been known that carbogen delivery of 5-15 min increases tumor oxygenation. However, the long-term effect of carbogen breathing on hypoxic cells has not yet been determined, and little is know about the effect of carbogen breathing for sensitization to interstitial irradiation therapy. MATERIAL/METHODS: 99mTc-HL91(99mTc 4,9-diaza-3,3,10,10-tetramethyldodecan-2,1-dione dioxime) hypoxic imaging was performed in 10 mice bearing sarcoma 180 (S180) before and after 2 h carbogen breathing. Radioactivity ratios of tumor to contralateral limbs (T/L) of the 2 images were calculated and compared. Mice bearing S180 were subjected to long-term carbogen breathing (2 h/day for 24 days), and were treated with or without 32P-colloid. Tumor growth rate was observed in the S180-bearing mice. RESULTS: T/L of 99mTc-HL91 uptake before and after carbogen breathing was 1.872+/-0.391 and 1.354+/-0.189, respectively (t=4.476, P<0.01). In mice in the 32P-treated air breathing group and 32P-treated carbogen breathing group, tumor growth rate did not differ on day 12 after 32P-colloid treatment, and on day 24 the tumor volume was 2.728+/-0.469 and 2.237+/-0.603 cm3 (t=2.128, P<0.05), respectively, with tumor mass being 2.437+/-0.447 and 1.965+/-0.538 g (t=2.134, P<0.05), respectively. CONCLUSIONS: Long-term carbogen breathing can increase tumor oxygenation and continual carbogen breathing is necessary for enhancing the therapeutic effect of 32P-colloid interstitial irradiation.

Evaluation of lung lesions using FDG gamma-camera PET equipped with a one-inch crystal.

The aim of this study was to evaluate the clinical value of 18-fluorodeoxyglucose (FDG) imaging with gamma-camera positron emission tomography (GCPET) equipped with a one-inch crystal for diagnosing lung lesions and determining the stage of non-small cell lung cancer (NSCLC) in regions with a high prevalence of inflammatory disease and tuberculosis. FDG-GCPET was used to examine 103 patients with suspected malignant lesions in the lung. The results of FDG-GCPET and conventional workup (CWU) including computed tomography (CT), ultrasonography and radionuclide bone scintigraphy were compared. The final diagnosis was based on the results of a histological analysis or follow-up of at least six months. The results showed 82 patients with malignant and 21 patients with benign lesions. If a lesion to background ratio > or = 2.0 was used as the threshold, then the diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of FDG-GCPET for NSCLC were 93.9, 57.1, 86.4, 89.5 and 70.6%, respectively. In 36 patients who underwent open-chest surgery, the diagnostic positive values of FDG-GCPET and CT for lymph-node involvement were 85% (17/20) and 65% (13/20), respectively. The diagnostic sensitivity, specificity, accuracy, PPV and NPV of FDG imaging were 85, 81.3, 83.3, 85 and 81.3%, respectively compared to the CT values of 65, 75, 69.4, 76.5 and 63.2%, respectively (NS). For the evaluation of distant metastases, 31 true-positive patients were identified during the follow-up. FDG imaging correctly identified 28 patients compared to 25 by CWU. In conclusion, FDG imaging with GCPET equipped with a one-inch crystal revealed a high lesion detection capability but a low level of clinical effectiveness for differentiating between malignant and benign lesions in the lung in regions with a high prevalence of inflammatory disease and tuberculosis. For N and M staging of NSCLC, this method may provide additional data that are not available from the CWU.

[89SrCl2 in the treatment of cancer patients with bone metastasis and pain].

OBJECTIVE: To evaluate the clinical value of (89)SrCl(2) (Ke xing Inc, Shanghai) as a palliative therapy modality for cancer patients with bone metastasis. METHODS: In 504 cancer patients with painful limitation of movement due to bony metastasis, a dose of 1.48-2.22 MBq/kg (40-60 uCi/kg) iv infusion of (89)SrCl(2) was given. RESULTS: In 97 patients (19.2%) there was no improvement in pain and life quality, 298 patients (59.1%) showed mild to moderate improvement (moderately effective), 109 patients (21.6%) became free of pain and were subsequently fully ambulatory (markedly effective). The pain relief appeared from D1-D46 after (89)SrCl(2) administration, most frequently from D5-D14. The palliative effect could last for about 56 days to 13 months. Repeated bone scans of some patients showed that the metastatic foci in the bone became smaller or even disappeared gradually after the administration of (89)SrCl(2). Approximately 55% of patients experienced grade I approximately III bone marrow depression attributable to (89)SrCl(2), which would return to the pre-treatment level within 3 approximately 9 months. CONCLUSION: (89)SrCl(2) is effective and safe for the relief of bone pain and improvement of quality of life in cancer patients with painful bony metastasis.