Abstract. Pulmonary cryptococcosis is most commonly reported in immunocompromised patients, whereas immunocompetent hosts are rarely affected and may be asymptomatic, resulting in reduced diagnostic performance of computed tomography (CT) imaging. Thus, the aim of the present study was to review the plain and contrast-enhanced chest CT scan findings of primary pulmonary cryptococcosis in immunocompetent patients, with the aim of improving the diagnosis of this type of pulmonary disease. In the present study, a total of 27 immunocompetent patients of clinically confirmed pulmonary cryptococcosis were analyzed retrospectively. Of the 27 patients, 14 patients underwent plain and contrast-enhanced chest CT scans, while 13 patients only underwent plain chest CT scanning. The clinical and imaging characteristics, including the location, shape, size, number, edge and attenuation or intensity of each lesion, in unenhanced and contrast-enhanced CT scans were reviewed. The results indicated that the most common CT finding was pulmonary nodules (40.74%), with multiple nodules (25.93%) being more common compared with solitary nodules (14.81%). The majority of the nodules were poorly defined and inhomogeneous with observed air-bubble sign. Other findings included consolidation (25.93%), ground-glass opacities (GGO; 22.22%) and a mass (11.11%). The halo, air bronchogram and cavity signs were observed more frequently (22.22, 18.52 and 14.81%, respectively). The pulmonary lesions presented a predominant distribution in the lower lung lobes and peripheral area in 55.55 and 74.07% of the cases, respectively. On the contrast-enhanced CT images, the majority of nodules presented ring enhancement with the mean maximal enhancement value of 20.92±5.67 Hu, and masses demonstrated inhomogeneous enhancement with a mean maximal enhancement value of 35.61±8.32 Hu. In conclusion, familiarity with the CT findings and occupational environment exposure history will assist in earlier and easier diagnosis of pulmonary cryptococcosis in immunocompetent patients.

We used serial (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) to evaluate tumors' maximum standardized uptake value (SUV(max)) before, during, and after radiotherapy to explore the biological behavior of and response to radiation therapy in various subtypes of nasopharyngeal carcinoma (NPC). Sixty-one patients with pathologically diagnosed NPC were prospectively enrolled into the study. WHO type II(B) disease had a higher initial SUV(max) and more significant biological response at the primary site as compared with type II(A) subtype. The two subtypes of WHO type II NPC may significantly differ in their biological behavior and response to radiotherapy.

Current tumor imaging agents are often limited by their liability to dissipate from tumor tissues. As cell sugar sorting enables exogenous sugars to be delivered into predetermined subcellular locations, we synthesized sialic acid (Sia) derivatives with rhodamine-X conjugated at C-9 ( ROX Sia), which hitchhikes cell sialic acid sorting to target tumor cell lysosomes, exhibiting pH-independent long-term probe retention in lysosomes. ROX Sia gives selective, bright, and endured fluorescence signals in subcutaneous tumors and orthotopic tumors in mice models. These results indicate the potential of ROX Sia as a lysosome-targeted optical agent for fluorescence-guided tumor resection.

Background: As involved in tumor angiogenesis, Neuropilin Receptor type-1 (NRP-1) serves as an attractive target for cancer molecular imaging and therapy. Widespread expression of NRP-1 in normal tissues may affect anti-NRP-1 antibody tumor uptake. Objective: To assess a novel anti-NRP-1 monoclonal antibody A6-11-26 biodistribution in NRP-1 positive tumor xenograft models to understand the relationships between dose, normal tissue uptake and tumor uptake. Methods: The A6-11-26 was radiolabeled with 131I and the mice bearing U87MG xenografts were then administered with 131I-labelled A6-11-26 along with 0, 2.5, 5, and 10mg·kg-1 unlabelled antibody A6-11-26. Biodistribution and SPECT/CT imaging were evaluated. Results: 131I-A6-11-26 was synthesized successfully by hybridoma within 60min. It showed that most of 131IA6- 11-26 were in the plasma and serum (98.5 ± 0.16 and 88.9 ± 5.84, respectively), whereas, less in blood cells. For in vivo biodistribution studies, after only injection of 131I-A6-11-26, high levels of radioactivity were observed in the liver, moderate level in lungs. However, liver and lungs radioactivity uptakes could be competitively blocked by an increasing amount of unlabeled antibody A6-11-26, which can increase tumor radioactivity levels, but not in a dose-dependent manner. A dose between 10 and 20mg·kg-1 of unlabeled antibody A6-11-26 may be the optimal dose that maximized tumor exposure. Conclusion: Widespread expression of NRP-1 in normal tissue may affect the distribution of A6-11-26 to tumor tissue. An appropriate antibody A6-11-26 dose would be required to saturate normal tissue antigenic sinks to achieve acceptable tumor exposure.

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