Role of serial quantitative gallium-67 tumor uptake in assessing response rates for chemotherapy in lymphoma patients.

PURPOSE: To evaluate in serial gallium-67 scans (GS) the role of semiquantitative tumor-to-background (Tm/Bg) and tumor-to-liver ratios in assessing response rates to chemotherapy, in Hodgkin's disease and non-Hodgkin's lymphoma. MATERIALS AND METHODS: Twenty-seven consecutive patients (15 Hodgkin's disease and 12 non-Hodgkin's lymphoma patients) with an average age of 30 (range, 5-60) years underwent GS at prechemotherapy, early chemotherapy (after first cycle), and postchemotherapy. Average tumor, background, and liver region of interest counts obtained and Tm/Bg, tumor-to-liver, and liver region to background ratios were derived for each patient on serial GS. All patients were assessed by visual and quantitative GS and followed up clinically for more than 7 years. RESULTS: At early visual GS, 70% (19 of 27) of the patients showed rapid response, 15% (four of 27) showed delayed response (negative at post-GS), and 15% showed no response. Mean early-GS Tm/Bg ratio of disease-free patients (1+/-0.04) was significantly different from relapsed (1.4+/-0.2) (P<0.025) and progressive disease (1.8+/-0.7) patients. A significant difference was noted (P<0.01) in serial paired comparisons of Tm/Bg ratios between pretherapy and early-therapy scans in relapsed patients, whereas progressive disease patients showed no significant change during the same time. At early-GS, 15 patients showed quantitative rapid response (Tm/Bg ratio 1.04), nine patients showed quantitative delayed response (Tm/Bg ratio >1.04 with significant serial change between pretherapy and early-therapy GS), and three patients showed quantitative no response (Tm/Bg ratio >1.04 with nonsignificant serial change between pretherapy and posttherapy GS). CONCLUSION: Quantitative GS is an effective tool in the detection of early response to chemotherapy. Quantitative response rates after the first cycle can more reliably identify patients who are most likely to be disease-free or relapse after first-line therapy or those that will show no response to therapy as compared with visual analysis alone.

The value of quantitative uptake of (99m)Tc-MDP and (99m)Tc-HMPAO white blood cells in detecting osteomyelitis in violated peripheral bones.

UNLABELLED: Our objective in this study was to evaluate whether measurement of quantitative uptake of (99m)Tc-methylene diphosphate (MDP) and (99m)Tc-hexamethylpropyleneamine oxime (HMPAO) white blood cells (WBCs) is useful in detecting osteomyelitis in peripheral bony lesions. METHODS: Twenty-four patients (12 men and 12 women; age range, 25-72 y) were referred for imaging because of clinically suspected osteomyelitis. They had a traumatic fracture (n = 10), knee prosthesis (n = 5), hip prosthesis (n = 2), diabetic foot (n = 4), or chronic osteomyelitis (n = 3). Three-phase bone scanning and (99m)Tc-HMPAO WBC studies were performed on all patients within the same week. Regions of interest were drawn over the abnormal bony sites and the contralateral normal sites, and the abnormal-to-normal uptake ratios (A/N ratios) were obtained for both studies. RESULTS: All patients had abnormal findings on 3-phase bone scanning, whereas 17 (71%) had abnormal findings on (99m)Tc-HMPAO WBC studies, of which 15 were confirmed to be true-positive. In those 15 patients, the mean A/N ratios for (99m)Tc-MDP and (99m)Tc-HMPAO WBC were 3.0 +/- 1.6 (range, 1.3-6.2) and 1.8 +/- 0.3 (range, 1.4-2.2), respectively. In the other 9 patients, whose scan results were clinically confirmed to be true-negative, the mean A/N ratios for (99m)Tc-MDP and (99m)Tc-HMPAO WBC were 2.1 +/- 1.2 and 1.2 +/- 0.2, respectively. In the group with a (99m)Tc-MDP A/N ratio greater than 2 (n = 15), 87% (13/15) had a high (99m)Tc-HMPAO WBC A/N ratio (>1.5), including 2 that were false-positive. In the remaining 2 patients, one with chronic osteomyelitis and the other with a recent hip prosthesis, (99m)Tc-HMPAO WBC ratios were normal. In the group with a bone A/N ratio of less than 2 (n = 9), only 4 patients (44%) were true-positive for acute osteomyelitis. CONCLUSION: (99m)Tc-MDP bone scanning alone, with an A/N ratio of more than 2, is useful in detecting osteomyelitis in violated bone except in the case of a recent hip prosthesis or chronic osteomyelitis.