The Added Value of SPECT/CT in Sentinel Lymph Nodes Mapping for Endometrial Carcinoma.

OBJECTIVES: This study was designed to evaluate the detection rate (DR) and sensitivity of sentinel lymph node (SLN) mapping in patients with endometrial cancer using TC99m colloid and blue dye and to evaluate the contribution of preoperative planar lymphoscintigraphy (PLSG) and SPECT/CT. METHODS: A retrospective analysis of patients who underwent SLN mapping as part of their primary surgery for endometrial cancer. Patients underwent preoperative PLSG and later with additional SPECT/CT. Intraoperative detection was performed using TC99m colloid and blue dye by cervical injections. SLNs were sent separately for pathologic evaluation with ultrastaging. RESULTS: Fifty-three patients were included in this study. Successful preoperative mapping was achieved in 31 of 37 patients (84 %) who underwent SPECT/CT compared with only 30 of 45 patients (67 %) who underwent PLSG. SPECT/CT localizations of SLNs were anatomically accurate in 91 % of cases. Intraoperative DR of at least one SLN was 77 %, whilst the bilateral DR was 49 %. DR was significantly better using combined blue dye and TC99m colloid injections compared with blue dye alone: 81 versus 57 % for unilateral and 54 versus 28 % for bilateral mapping (P = 0.01, 0.009, respectively). Six cases of nodal metastasis were diagnosed: four by positive SLNs, and two cases were diagnosed using side-specific full dissection according to the SLN algorithm when SLN detection failed. There were no cases of false-negative results. CONCLUSIONS: SLN detection using cervical injections of TC99m colloid and blue dye is feasible and sensitive for patients with endometrial cancer. SPECT/CT aids to accurate locating of the SLN.

99mTc-MIBI scintigraphy in musculoskeletal tumors.

UNLABELLED: The aim of this study was to assess the value of 99mTc-hexakis2-methoxyisobutylisonitrile (MIBI) scintigraphy in patients with clinical and radiologic features of primary or metastatic musculoskeletal tumors. METHODS: The scintigraphic findings for 84 patients were compared with the surgical and histologic findings. Each patient underwent three-phase bone scanning with 99mTc-methylene diphosphonate (MDP) and dynamic and static MIBI scintigraphy. The MIBI scans were evaluated by visual and quantitative analysis. The count ratio of the lesion to the adjacent or contralateral normal area (L/N) was calculated from the region of interest drawn on the MIBI scan. The Mann-Whitney test was used to determine the differences between the uptake ratios of malignant and benign lesions. RESULTS: Although increased MDP uptake was not specific for bone malignancy, a significant difference was found between benign tumors (L/N = 1.22 +/- 0.43) and malignant tumors (L/N = 2.25 +/- 1.03) on MIBI scans. Sensitivity and specificity were 81% and 87%, respectively. Forty-six of 53 proven benign lesions did not show significant MIBI uptake. The negative predictive value was 88%. In all seven sites of pathologic fracture, significant uptake was seen. However, three malignant lesions were not detected by MIBI scintigraphy, whereas seven benign lesions showed false-positive results. CONCLUSION: The major diagnostic worth of MIBI scintigraphy is its high negative predictive value. Although not capable of replacing tissue biopsy as a definitive diagnostic modality for musculoskeletal neoplasms, MIBI scintigraphy does appear to have a role in better preoperative assessment and in distinguishing between pathologic and simple fractures.

Clinical experience with radiolabelled monoclonal antibodies in the detection of colorectal and ovarian carcinoma recurrence and review of the literature.

A retrospective study was carried out to determine the diagnostic value of OncoScint CR/OV immunoscintigraphy in assessing patients with suspected recurrence of carcinoma of the colon and ovary. The scintigraphic results of 31 patients were compared with surgical and histopathological findings, conventional radiological examinations and clinical disease outcome over an average 3-year follow-up. Detected lesions were divided by location into hepatic or extrahepatic and the latter group was classified as local recurrence at the resection site, pelvic or abdominal regional lymph node involvement and distant metastatic disease. The combined sensitivity and accuracy of immunoscintigraphy in the detection of extra-hepatic disease was significantly higher than that of cross-sectional radiological imaging (87% and 83% vs 44% and 53% respectively) with equal specificity of 74%. Scintigraphy identified 14 (36%) of 39 extra-hepatic malignant lesions not diagnosed by conventional radiological techniques and influenced therapeutic planning in 8 (26%) of 31 patients studied. In the liver, conventional imaging had a significantly higher detection rate than immunoscintigraphy (sensitivity 93% vs 28%). In conclusion, these results show that OncoScint scintigraphy is a sensitive method for the detection of local recurrence and extra-hepatic metastases in colorectal and ovarian carcinoma and has an important role in the therapeutic decision-making process.

[Technetium 99-m sestamibi bone scan in musculo-skeletal neoplasms].

It is often difficult to assess accurately the nature of a skeletal lesion. Problems include differentiating a malignant from a benign bone tumor, as well as determining the cause of a pathologic fracture. Such fractures may occur through osteoporotic bone as well as through neoplasm-affected bone. Thus, development of an imaging modality capable of distinguishing between such lesions is of importance. During 1996, we ran a prospective study in which results of Tc-99m-methyl-diphosphate (MDP) bone scans were compared with those of sestamibi (MIBI) bone scans and with subsequent biopsy and clinical course. The results of the bone scans were assessed by 2 independent "blinded" observers, and the ratios of counts in lesions to those in normal tissue (L/N ratios) were calculated. In cases of malignant (7) and benign (8) tumors, intensity of uptake in MDP scans were not predictive of degree of aggressiveness. On the other hand, MIBI bone scans demonstrated significant difference in intensity of uptake between benign and malignant bone tumors (L/N ratios 2.05 vs 2.75). In 5 of 8 benign lesions the L/N ratio was 1. In the others, increased uptake was minimal. In 2 patients changes in uptake in MIBI bone scan following chemotherapy appeared to be related to the degree of tumor necrosis achieved. While the MIBI bone scan cannot replace tissue biopsy as a definitive diagnostic modality in bone neoplasms, it does appear to allow better preoperative assessment and prognosis.

Physiological basis of differential strontium accumulation in two barley genotypes.

Studies of rates of Sr transport from nutrient solutions containing 8 concentrations of Sr indicate a definite trend towards higher rates of Sr transport by roots of intact 12-day-old Regal barley (Hordeum vulgare, L.) seedlings as compared with Tregal. Differences in rates of Sr transport between the 2 varieties were also indicated by higher concentrations of Sr in fluids exuding from decapitated Regal roots as compared to fluids exuding from decapitated Tregal roots.No differences between Regal and Tregal were found in the physical factors of distance from epidermis to endodermis, number of cortical cell layers, or transpiration rate. Furthermore, no relationship was observed between transpiration rate and rate of Sr accumulation.Dependence of Sr transport on metabolic processes was indicated by marked effects of temperature, cyanide, and dinitrophenol on rates of Sr transport. Q(10) values for Sr transport by Regal and Tregal approached 2, thereby indicating that metabolic reactions were associated with this process. Strontium transport by both Regal and Tregal was markedly depressed in the presence of either cyanide or dinitrophenol. These results led to the conclusion that the Sr transport process is dependent on metabolic energy derived from respiration.