In-house-Prepared Semisolid Bolus for Esophageal Transit Scintigraphy in Normal Volunteers and its Comparison with Liquid Bolus.

BACKGROUND/AIMS: Esophageal transit scintigraphy (ETS) is a useful tool for evaluating esophageal motility disorders, although conflicting results are seen due to lack of ideal bolus. Semisolid/solid boluses have shown superiority over liquid boluses, and the present study aims to establish the utility of in-house-prepared bolus in normal volunteers and its comparison with liquid bolus. MATERIALS AND METHODS: Thirty-three healthy volunteers were selected for ETS with in-house-prepared semisolid bolus jelly containing 99mTc-sulfur colloid. Dynamic studies were acquired in anterior projection with single swallow for both supine and sitting positions. T90% esophageal emptying time (EET) was calculated for whole and three equally divided segments of esophagus and also done with liquid bolus on different day. RESULTS: The median value of EET for semisolid bolus for whole esophagus in sitting and supine positions was 11.7 s (interquartile range [IQR]: 8.0-16.7) and 17.7 s (IQR: 12.0-33.0). EET of liquid bolus for whole esophagus in sitting and supine positions was 9.3 s (IQR: 8.0-13.3) and 13.0 s (IQR: 9.7-25.0), respectively. Significantly different EET for whole esophagus and lower one-third esophagus between sitting and supine positions was seen for semisolid (whole esophagus;P = 0.003, lower one-third esophagus; P = 0.025) and liquid boluses (whole esophagus; P = 0.032, lower one-third esophagus; P = 0.016). Comparing EET using semisolid and liquid boluses, only lower one-third esophagus in supine position showed significant difference (P = 0.033). CONCLUSIONS: In-house-prepared semisolid radiolabeled jelly is inexpensive, easy to prepare with good radiolabeling. Condensed dynamic images from semisolid bolus were better, sharper, and reproducible in comparison to liquid bolus without fragmentation. This study standardized semisolid bolus and verified its suitability for clinical use.

Oncogenic osteomalacia: role of Ga-68 DOTANOC PET/CT scan in identifying the culprit lesion and its management.

OBJECTIVE: The aim of this study was to evaluate the role of 68Ga-DOTANOC positron emission tomography (PET)/CT scan in localization of culprit lesion for biopsy and required intervention [surgical excision/radiofrequency ablation (RFA)] in patients with long-standing oncogenic osteomalacia (OOM)/tumour-induced osteomalacia. METHODS: 17 patients (8 males and 9 females) underwent 68Ga-DOTANOC PET/CT scan. The patients referred with clinical and biochemical evidence of hypophosphatemia and raised fibroblast growth factor-23. Qualitative and semi-quantitative parameters were used to identify culprit lesions. RESULTS: 68Ga-DOTANOC PET/CT scan revealed 52 lesions in 17 patients, and 37/52 of these lesions were tracer avid. 26/37 lesions were non-specific focal tracer-avid skeletal lesions (fractures or degenerative changes). 11/37 tracer-avid skeletal lesions present in 9 patients (3 lesions in 1 patient and 1 each in rest of the 8 patients) were highly suspicious for culprit lesions in view of high maximum standardized uptake value (SUVmax) (range 1.5-15.4; mean 7.0 ± 4.6), lesion size (0.9-5.0 cm; mean 3.3 ± 1.5) and associated soft-tissue component. During subsequent imaging with CT/MRI, 7/9 patients showed concordant lesions which were excised or biopsied and histopathologically verified as phosphaturic mesenchymal tumours. Surgical excision was resorted to in most of the detected lesions, and RFA was performed in one patient. CONCLUSION: There is some overlap in SUVmax between fracture-/bone-associated lesions and culprit lesions with a tendency of most non-culprit lesions to have lower SUVmax and no associated soft-tissue component. In such scenario, intensely tracer-avid, larger non-fracture lesions with soft-tissue component may lead to identification of culprit lesion among multiple lesions. Following detection of culprit lesion, surgical removal is the best treatment. RFA is alternative to surgery in cases where surgery is not possible owing to osteopenia/poor bone health. Advances in knowledge: The main challenge in patients of long-standing OOM is the presence of multiple skeletal lesions (both tumour- or tracer-avid fractures), and it is confusing to identify culprit lesion. This was noted in our study with 68Ga-DOTANOC and has not been mentioned in studies performed with 68Ga-DOTATATE/TOC PET/CT. In such scenario, 68Ga-DOTANOC PET/CT needs to be reviewed and read thoroughly to localize the culprit lesion out of the multiple tracer-avid lesions.

Polylactide-co-glycolide nanoparticles of antitubercular drugs: formulation, characterization and biodistribution studies.

BACKGROUND: The present study was designed to prepare and characterize poly lactide-co-glycolide nanoparticles of antitubercular drugs (ATDs) for delivery through oral route to alveolar macrophages. METHODS: Nanoparticles were prepared by double emulsification solvent evaporation method. Ex vivo and in vivo drug accumulation studies were performed in alveolar macrophages, harvested by broncheoalveolar lavaging. Internalization of nanoparticles was studied by confocal laser scanning microscopy. γ-scintigraphy imaging using technetium-99m was done to study the biodistribution pattern of nanoparticles. RESULTS: High intracellular concentrations of ATDs were observed in macrophages within 30 min of administration of nanoparticles. Intense radioactivity recorded in liver, spleen and lungs revealed uptake of nanoparticles in macrophages, abundantly present in mononuclear phagocyte system present in these organs. CONCLUSION: Targeted delivery of ATDs will help reduce dose and associated side effects including hepatotoxicity of ATDs. Further studies are required to assess the potential therapeutic advantages for treatment of TB.