Combined Early and Late [68Ga]PSMA-HBED-CC PET Scans Improve Lesion Detectability in Biochemical Recurrence of Prostate Cancer with Low PSA Levels.

PURPOSE: Our aim was to evaluate the benefit of early (1 h post-injection (p.i.)) and late (3 h p.i.) [68Ga]PSMA-HBED-CC positron emission tomography (PET)/x-ray computed tomography (CT) imaging for detection of biochemical recurrence (BCR) of prostate cancer (PCa). PROCEDURES: Seventy patients with BCR of the PCa and prostate-specific antigen (PSA) levels of less than 2.0 µg/l were subjected to [68Ga]PSMA-HBED-CC PET (mean injected activity 180 MBq). While early imaging contained whole body scans, late imaging was confined to the pelvis and the lower abdomen. Uptake in suspicious lesions was analyzed by peak and maximum standardized uptake values (SUVpeak/max). Tumor-to-background ratios were calculated for all lesions in which the liver served as reference organ. The Wilcoxon matched-pair signed-rank test was used to compare the uptake in suspicious lesions between early and late imaging. Follow-up data were used to validate the existence of the additionally detected lesions. RESULTS: Forty-four of the 70 patients thus examined were interpreted as PSMA-positive in early and/or late scans while 26 remained without suspicion of PSMA tracer uptake. A total of 70 suspicious lesions were analyzed. Ten tumor-suspicious lesions from seven different patients were better or exclusively visible in the late measurements while three tumor-suspicious lesions from three different patients were better or exclusively visible in the early images. A validation by follow-up data was possible for 11 of these 13 additionally detected lesions. In direct comparison between early and late imaging, the mean SUVmax in PSMA-positive lesions was 74 % higher (p < 0.001) and the mean SUVpeak was 36 % higher (p = 0.001) in the late scans. The SUVmean in the reference regions was decreasing in the late measurements, whereas the mean TBR increased by a factor of 3 (p < 0.001). Taking confirmed lesions only into account, we estimated a 10 % gain in additionally detected PSMA-positive lesions (7/70) within the patient cohort. CONCLUSIONS: The time period between injection and data acquisition influences the detection rate of [68Ga]PSMA-HBED-CC PET/CT. In biochemical recurrence with low PSA levels, late [68Ga]PSMA-HBED-CC PET/CT imaging offers frequent advantages with regard to lesion contrast.

Formas atípicas de enfermedad por arañazo de gato, Valdivia / Atypical presentation of Cat Scratch Disease in Valdivia

La enfermedad por arañazo de gato (EAG), es considerada la causa más frecuente de linfoadenopatía benigna crónica en niños y adolescentes. En los casos existe el antecedente de contacto con gatos (90 por ciento) y de rasguño y/o mordedura (60 por ciento). La infección con Bartonella spp se manifiesta como desde una linfoadenopatía (EAG) a una enfermedad sistémica. El 10 po ciento tiene manifestaciones atípicas y 2 por ciento presenta complicaciones graves. Debe sospecharse EAG por exclusión de otras etiologías habituales y por el antecedente epidemiológico de contacto y/o rasguño de gato, con o sin lesión de inoculación primaria. Se presentan 4 casos de EAG atípicas en niños del S.S. Valdivia, donde se confirmó el agente por IFI IgG contra Bartonella henselae, con títulos > 1: 256.

Photolocalized varicella in a middle-aged adult.

We report a case of photolocalized varicella occurring in a middle-aged woman. Photolocalized or actinic varicella is rarely described, and most reported cases have occurred in children. This is the first case in a middle-aged adult.