A study on maximum skin dose in cerebral embolization procedures.

BACKGROUND AND PURPOSE: It is essential to measure the skin dose of radiation received by patients during interventional neuroradiologic procedures performed under fluoroscopic guidance, such as embolization of cerebral aneurysms, which is regarded as a high-dose interventional radiology procedure. In this study, we report a method for evaluating maximum skin dose (MSD), an ideal marker of radiation-induced effects, based on an innovative use of radiochromic films. MATERIALS AND METHODS: Forty-eight procedures were studied in 42 patients undergoing embolization of cerebral aneurysms. Fluoroscopic and digital dose-area product (DAP), fluoroscopy time, and total number of acquired images were recorded for all procedures. The MSD was measured using Gafchromic XR type R films. RESULTS: The MSD was measured in one group of 21 procedures. The coefficient (kappa) of the interpolation line between the skin dose and the DAP (kappa = 0.0029 cm(-2)) was determined. An approximate value of MSD from the DAP for the remaining 27 procedures was estimated by means of an interpolation line. The mean MSD was found to be 1.16 Gy (range, 0.23-3.20 Gy). CONCLUSION: The use of radiochromic XR type R films was shown to be an effective method for measuring MSD. These films have the advantage of supplying information on both the maximum dose and the distribution of the dose: this satisfies the most stringent interpretation of Food and Drug Administration, American College of Radiology, and international recommendations for recording skin dose.

Topical role and future perspectives of sonographic contrast agents in the differential diagnosis of solid thyroid lesions.

Gray scale sonography and US-guided biopsy are cost-effective and reliable procedures in the differential diagnosis of focal thyroid lesions. The frequent presence of multiple foci can make multiple biopsies intolerable to the patient. The use of a sonographic contrast agent (Levovist) composed of microbubbles was evaluated in the differential diagnosis of focal solid lesions of the thyroid. Time/intensity curves after bolus injection of contrast were studied with samplings at the level of focal lesions, extranodular parenchyma and common carotid in 29 lesions of 25 patients (16 females and 9 males) ranging in age 21 to 68 years. The evaluated parameters were: the curve morphology, the time to peak value, the mean enhancement time and the wash-in/out variate gamma curve. All focal lesions underwent biopsy. No significant differences were observed as for mean enhancement time while for time to peak values only two malignant lesions seemed to show values different from those of other solid lesions. Wash-in/out variate gamma curves seemed more interesting; they presented a dual morphology: 1) parenchymal for hyperplastic areas, pseudonodular neoformations during thyroiditis and healthy thyroid parenchyma, 2) vascular for malignant lesions and carotid lumen. Autonomous nodules showed an intermediate morphology. In spite of major limitations, the results seem to pave the way for additional possibilities of noninvasive differential diagnosis in the evaluation of focal solid thyroid lesions.

Double stenting procedure and coil embolization in a patient with carotid stenosis and incidental ipsilateral intracranial aneurysm. A case report and dosimetric evaluation.

We describe a case of incidental detection of an intracranial left ICA wide-necked aneurysm during digital subtraction angiography performed to assess a sub-occlusive and calcified stenosis in the extracranial portion of the same artery. Angioplasty and stenting of ICA stenosis, plus intracranial stent deployment across the aneurysm neck was performed during the same procedure. Aneurysm coil embolization was postponed to a further session one month later. The radiation dose and irradiated areas were also evaluated during endovascular procedures.

Percutaneous computed tomography-guided radiofrequency thermal ablation of small unresectable lung tumours.

The aim of the current study was to evaluate the safety and the efficacy of radiofrequency thermal ablation (RFTA) for the treatment of nonsmall cell lung cancer (NSCLC) and isolated pulmonary metastases (METs) from colorectal cancer (CRC). A total of 31 patients (15 with NSCLCs and 16 with CRC lung METs), with 36 lung tumour nodules (mean+/-sd diameter: 22+/-8 mm, range: 10-35 mm) underwent computed tomography (CT)-guided RFTA using expandable electrodes. Contrast-enhanced CT was performed before and after (immediately and 30+/-5 days) each RFTA session to assess immediate results and complications and repeated 3 and 6 months post-RFTA, as well as every 6 months thereafter, to evaluate long-term results. Complete radiological necrosis was defined as a nonenhancing area at the tumour site that was equal to or larger than the treated tumour; persistence of enhancement at the tumour site indicated incomplete treatment. Local recurrence was defined as an increase in tumour size and/or enhancing tissue at the tumour site. Complete radiological necrosis of the 36 tumours was achieved with 39 RFTA sessions and 42 electrode insertions. No major complications or deaths were observed. Six patients experienced mild-to-moderate pain during the procedure. There were five cases of pneumothorax, none requiring drainage and four cases of pneumonia, which were successfully treated with antibiotics. After a mean follow-up of 11.4+/-7.7 months (range of 3-36 months), the overall local recurrence rate was 13.9% (20 and 9.5% for NSCLC and CRC-METs patients, respectively). Nineteen of the 31 (61.3%) patients were alive (15 apparently disease free) and 12 (38.7%) had died (three from causes unrelated to their cancer). Radiofrequency thermal ablation seems to be a safe, effective method for producing complete ablation of small nonsmall cell lung cancers and pulmonary colorectal cancer metastases.