The accuracy of sentinel node biopsy by 99mTc-sodium phytate in patients with pancreatic cancer.

BACKGROUNDS/AIMS: Pancreaticoduodenectomy is the only potentially curative treatment for pancreatic cancer. The identification of the first nodal drainage site (sentinel node) may improve the detection of metastatic nodes and can contribute to a less invasive surgery. We aimed to determine the accuracy of sentinel node mapping in patients with pancreatic cancer using intraoperative radiotracer injection technique. METHODS: At surgical exposure, peritumoral injection of 0.4-0.5 mci/0.5 ml of 99mTc- sodium phytate was performed. After tumor resection, sentinel nodes were investigated in the most common areas using a hand-held gamma probe. Any lymph node with in vivo count twice the background was considered as sentinel node, thus, it was removed and sent for pathological assessment. Then a standard lymph node dissection was performed for all patients. RESULTS: Fourteen patients with cancer in the head of the pancreas were included in this study. Overall, 180 lymph nodes were harvested with a mean of 11.6±4.7 lymph nodes per patient. In eight patients, at least one sentinel node could be identified (detection rate about 64%). False negative rate of the study was 3/5 (60%). CONCLUSIONS: Our study revealed insufficient diagnostic accuracy and high false negative rate for sentinel lymph node mapping with 99mTc- sodium phytate in pancreatic cancer.

The role of "after washing imaging" in evaluation of tear drainage system by dacryoscintigraphy.

BACKGROUND: The aim of this study was to evaluate the efficacy of "after washing" imaging in interpretation of dacryoscintigraphy as a functional imaging technique used in evaluation of tearing problems. MATERIALS AND METHODS: 300 nasolacrimal systems were studied. 100 µCi of technetium-99m sodium pertechnetate as drops of activity (10 µL) were placed into the inferior fornix of each eye. Dynamic images were obtained for 15 minutes in the sitting position. "After washing" phase was done by placing a drop (10 µL) of normal saline in each eye and external ocular massage for an additional 10 minutes. The imaging patterns for each eye in the first dynamic phase and after washing phase were recorded, separately. RESULTS: First dynamic phase demonstrated a sensitivity of 97.4% and specificity of 22.6%. After washing phase showed a sensitivity of 91.2% and specificity 75.5%. After washing test, the obstruction pattern changed to "patent nasolacrimal duct" or "further progression" of the radiotracer to the nasolacrimal duct in the 25.1% and 24.4% of the nasolacrimal systems, respectively. CONCLUSIONS: After washing imaging is a useful method in dacryoscintigraphy which can improve the specificity of scan for diagnosis of lacrimal duct obstruction. It can also improve the localization of obstruction level in the lacrimal systems.

Radiotracer Injection Into the Catheter Balloon: A Subtle Pitfall Which Can Be Overlooked in Direct Radionuclide Cystography.

We reported a 4-year-old girl with history of bilateral vesicoureteral reflux who underwent direct radionuclide cystography in our department. Radiotracer was mistakenly injected in the catheter balloon. The filling phase showed no change in the bladder volume, and the catheter balloon was apparent as an intense activity in the base of the bladder. The procedure was repeated with correct injection of the tracer into the catheter. Wrong injection of the radiotracer into the catheter balloon should always be borne in mind in similar cases.

Gastric Visualization in Dacryoscintigraphy: An Unequivocal Sign of Patent Nasolacrimal Duct.

We reported a 6-year-old girl with a history of left-eye epiphora since 2 years ago who was referred to our nuclear medicine center for dacryoscintigraphy imaging. The scan showed obstruction in the proximal portion of the nasolacrimal duct in the left eye. Imaging also showed patent nasolacrimal duct of the right eye. Tc pertechnetate activity was seen in the esophagus and stomach owing to swallowing of the excreted tracer in the nasal cavity. This was an unequivocal sign of patent lacrimal apparatus.

Torsion of the undescended testis detected by 99mTc testicular scintigraphy: a case report.

We reported a case of torsion of the undescended testis in a 9-month-old boy which was diagnosed with 99mTc testicular scin-tigraphy. The scan showed diffuse increased activity in the location of the undescended testis and no photopenic area was visible. At surgery, torsion of the undescended testis was detected and fixed.