Gastric xenon trapping mimicking COPD: Recognition using an effervescent agent

Trapping of xenon 133 in the stomach due to gas swallowing can mimic xenon 133 retention in the left lower lobe due to obstructive lung disease on pulmonary ventilation/perfusion studies. In such cases, ingestion of sodium citrate-bicarbonate-simethicone crystals, which from CO 2 gas on contact with water, can distend the xenoncontaining stomach and allow clear delineation of its gastric location. This approach is useful in selected cases and may help avoid false-positive diagnoses of obstructive airways disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46824/1/259_2004_Article_BF00276710.pd

Use of Integrated SPECT/CT Imaging for Tumor Dosimetry in I-131 Radioimmunotherapy: A Pilot Patient Study

Abstract Integrated systems combining functional (single-photon emission computed tomography; SPECT) imaging with anatomic (computed tomography; CT) imaging have the potential to greatly improve the accuracy of dose estimation in radionuclide therapy. In this article, we present the methodology for highly patient-specific tumor dosimetry by utilizing such a system and apply it to a pilot study of 4 follicular lymphoma patients treated with I-131 tositumomab. SPECT quantification included three-dimensional ordered-subset expectation-maximization reconstruction and CT-defined tumor outlines at each time point. SPECT/CT images from multiple time points were coupled to a Monte Carlo algorithm to calculate a mean tumor dose that incorporated measured changes in tumor volume. The tumor shrinkage, defined as the difference between volumes drawn on the first and last CT scan (a typical time period of 15 days) was in the range 5%-49%. The therapy-delivered mean tumor-absorbed dose was in the range 146-334cGy. For comparison, the therapy dose was also calculated by assuming a static volume from the initial CT and was found to underestimate this dose by up to 47%. The agreement between tracer-predicted and therapy-delivered tumor-absorbed dose was in the range 7%-21%. In summary, malignant lymphomas can have dramatic tumor regression within days of treatment, and advanced imaging methods allow for a highly patient-specific tumor-dosimetry calculation that accounts for this regression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78152/1/cbr.2008.0568.pd

Опыт применения золадекса у больных эндометриозом и рецидивирующими гиперпластическими процессами эндометрия

ЭНДОМЕТРИОЗ /ЛЕК ТЕРЭНДОМЕТРИЯ ГИПЕРПЛАЗИЯ /ЛЕК ТЕРЗОЛАДЕК

Fractionated 131I anti-CEA radioimmunotherapy: effects on xenograft tumour growth and haematological toxicity in mice

Dose fractionation has been proposed as a method to improve the therapeutic ratio of radioimmunotherapy (RIT). This study compared a single administration of 7.4 MBq 131I-anti-CEA antibody given on day 1 with the same total activity given as fractionated treatment: 3.7 MBq (days 1 and 3), 2.4 MBq (days 1, 3, and 5) or 1.8 MBq (days 1, 3, 5, and 8). Studies in nude mice, bearing the human colorectal xenograft LS174T, showed that increasing the fractionation significantly reduced the efficacy of therapy. Fractionation was associated with a decrease in systemic toxicity as assessed by weight, but did not lead to any significant decrease in acute haematological toxicity. Similarly, no significant decrease in marrow toxicity, as assessed by colony-forming unit assays for granulocytes and macrophages (CFUgm), was seen. However, there was a significant depression of CFUgm counts when all treated animals were compared with untreated controls, suggesting that treatment did suppress marrow function. In conclusion, in this tumour model system, fractionated RIT causes less systemic toxicity, but is also less effective at treating tumours

Therapeutic Radionuclides: Making the Right Choice

Recently, there has been a resurgence of interest in nuclear medicine therapeutic procedures. Using unsealed sources for therapy is not a new concept; it has been around since the beginnings of nuclear medicine. Treatment of thyroid disorders with radioiodine is a classic example. The availability of radionuclides with suitable therapeutic properties for specific applications, as well as methods for their selective targeting to diseased tissue have, however, remained the main obstacles for therapy to assume a more widespread role in nuclear medicine. Nonetheless, a number of new techniques that have recently emerged, (e.g., tumor therapy with radiolabeled monoclonal antibodies, treatment of metastatic bone pain, etc.) appear to have provided a substantial impetus to research on production of new therapeutic radionuclides. Although there are a number of new therapeutic approaches requiring specific radionuclides, only selected broad areas will be used as examples in this article

Identification and manipulation of tumor associated macrophages in human cancers

Evading immune destruction and tumor promoting inflammation are important hallmarks in the development of cancer. Macrophages are present in most human tumors and are often associated with bad prognosis. Tumor associated macrophages come in many functional flavors ranging from what is known as classically activated macrophages (M1) associated with acute inflammation and T-cell immunity to immune suppressive macrophages (M2) associated with the promotion of tumor growth. The role of these functionally different myeloid cells is extensively studied in mice tumor models but dissimilarities in markers and receptors make the direct translation to human cancer difficult. This review focuses on recent reports discriminating the type of infiltrating macrophages in human tumors and the environmental cues present that steer their differentiation. Finally, immunotherapeutic approaches to interfere in this process are discussed