Dear Editor: We read with interest the paper by Lu and colleagues on RADIONUCLIDE CISTERNOGRAPHY (RNC) entitled "The Value of Changing Position in the Detection of CSF Leakage in Spontaneous Intracranial Hypotension Using Tc-99m DTPA Scintigraphy: Two Case Reports", claiming an additive value of scanning the patients in the upright position for the detection of cerebrospinal fluid (CSF) leakage. In two cases of spontaneous intracranial hypotension (SIH), the authors observed the appearance of multiple images of increased radioactivity on both sides of the spinal canal after changing the patient position, which were interpreted as direct signs of CSF leaks.

The following article aims to provide contemporary information on therapeutic nuclear medicine. Neuroblastoma is the most common malignancies among pediatric malignancies. Pediatric extra cranial solid cancer characterized by meta-iodobenzylguanidine (MIBG) avidity in=>90% of patients. There exists approximately a 30-year experience with I-131-MIBG treatment. Neuroendocrine tumors (NETs) are very rare neoplasms in the paediatric population accounting for<1% of all pediatric malignancies. These neoplasms are characterized by the presence of neuroamine uptake mechanisms and/or peptide receptors at the cell membrane. These features constitute the basis of the clinical use of peptide receptor In RADIONUCLIDE therapy (PRRNT) using radiolabeled somatostatin analogues. Patients with chemoresistant CNS acute lymphoblastic leukemia (ALL) require carniospinal radiotherapy which is assossiated with major toxicities including growth and learning disorders in young children. Radioimmunotherapy with I131-labeled anti-CD10 and anti-CD19 mAbs administered intrathechally is associated with clearing of the cerebrospinal fluid lymphoblasts. Osteosarcoma is the most common primary bone tumor in children usually treated with chemotherapy and surgery. In palliative situations bone seeking RADIONUCLIDE therapies (strontium-89 [Sr-89], rhenium-186 hydroxyethylene diphosphonate [Rh-186 HEDP] and Samarium-153-ethylene diamine tetramethylene phosphonic acid [Sm-153-EDTMP]) may be offered to patients with painful metastatic osteosarcoma or in case of recurrent bone sites inaccessible to local therapies (surgery, external irradiation). Thyroid cancer is a rare childhood malignancy but is the most frequent tumor of endocrine glands in children and adolescents. Management includes radioiodine therapy, but there are some distinct differences in comparison to adult thyroid cancer management.

Background: Magnetic resonance (MR) CISTERNOGRAPHY has the crucial role for diagnosis of cerebrospinal fluid (CSF) leakage in patients with rhinorrhea and otorrhea. Trauma is the major cause of rhinorrhea. Cephalocele is diagnosed in some rhinorrhea patients. Objectives: To evaluate the CSF leakage in patients with rhinorrhea and assess the frequency of cephalocele in the etiology of rhinorrhea. Patients and Methods: Intrathecal gadolinium enhanced MR CISTERNOGRAPHY and nonenhanced CT of paranasal sinus images of patients with suspected CSF rhinorrhea between October 2012 and September 2018 were evaluated retrospectively. Twenty-one patients with the diagnosis of contrast leakage causing rhinorrhea were included in the study. All patients had intrathecal gadolinium enhanced MR CISTERNOGRAPHY. Three dimensional (3D)-T1 weighted and 3D-fluid attenuated inversion recovery (FLAIR) head MRI was obtained after administration of 1 ml intrathecal gadoterate meglumine after half, 3, and 8 hours. Locations of contrast leakage and etiologies were analyzed. Results: Patient group consisted of 21 patients with persistent or intermittent rhinorrhea. CT imaging showed bone defect in all patients. Intrathecal gadolinium enhanced MR CISTERNOGRAPHY revealed CSF leakage (10 ethmoid, 10 sphenoid, and 1 frontal). Cephalocele was detected in 10 of 21 patients. Conclusion: MR CISTERNOGRAPHY with intrathecal gadolinium enhancement is an effective and safe imaging modality compared to other techniques used for diagnosis of CSF leakage. Accurate localization of CSF fistula and demonstration of herniating content from cranial bone defect is feasible with this technique.

RADIONUCLIDE shuntography is a safe and simple method to determine shunt patency and analyze changes in CSF (Cerebro-Spinal-Fluid) flow. We present a case of complicated CSF shunt, in which radioisotopic scan correctly identified disconnection of the shunt tubing system localizing the site of extravasation accurately. The findings were confirmed by surgery performed for correction of the shunt system