PET/CT and SPECT/CT imaging of 90Y hepatic radioembolization at therapeutic and diagnostic activity levels: Anthropomorphic phantom study.

PURPOSE: Prior to 90Y radioembolization procedure, a pretherapy simulation using 99mTc-MAA is performed. Alternatively, a small dosage of 90Y microspheres could be used. We aimed to assess the accuracy of lung shunt fraction (LSF) estimation in both high activity 90Y posttreatment and pretreatment scans with isotope activity of ~100 MBq, using different imaging techniques. Additionally, we assessed the feasibility of visualising hot and cold hepatic tumours in PET/CT and Bremsstrahlung SPECT/CT images. MATERIALS AND METHODS: Anthropomorphic phantom including liver (with two spherical tumours) and lung inserts was filled with 90Y chloride to simulate an LSF of 9.8%. The total initial activity in the liver was 1451 MBq, including 19.4 MBq in the hot sphere. Nine measurement sessions including PET/CT, SPECT/CT, and planar images were acquired at activities in the whole phantom ranging from 1618 MBq down to 43 MBq. The visibility of the tumours was appraised based on independent observers' scores. Quantitatively, contrast-to-noise ratio (CNR) was calculated for both spheres in all images. RESULTS: LSF estimation. For high activity in the phantom, PET reconstructions slightly underestimated the LSF; absolute difference was <1.5pp (percent point). For activity <100 MBq, the LSF was overestimated. Both SPECT and planar scintigraphy overestimated the LSF for all activities. Lesion visibility. For SPECT/CT, the cold tumour proved too small to be discernible (CNR <0.5) regardless of the 90Y activity in the liver, while hot sphere was visible for activity >200 MBq (CNR>4). For PET/CT, the cold tumour was only visible with the highest 90Y activity (CNR>4), whereas the hot one was seen for activity >100 MBq (CNR>5). CONCLUSIONS: PET/CT may accurately estimate the LSF in a 90Y posttreatment procedure. However, at low activities of about 100 MBq it seems to provide unreliable estimations. PET imaging provided better visualisation of both hot and cold tumours.

Challenging the gold standard: methods of sampling for microbial culture in patients with chronic rhinosinusitis.

PURPOSE: Chronic rhinosinusitis (CRS) is a highly prevalent multifactorial disorder. Culture-directed antibiotics are frequently prescribed to patients with CRS and the middle nasal meatus (MM) is traditionally believed to be a representative sampling site of the sinuses as a whole. The purpose of our study was to reevaluate the reliability of the MM as a sampling site in patients with CRS who suffer from impaired drainage from the sinuses to the MM. METHODS: Swabs and tissue biopsies were collected from the MM, maxillary sinus and frontal sinus from 50 patients with CRS. The results of bacterial culture were compared between sampling methods and sites in relation to the patency of the sinus ostia. RESULTS: 782 bacterial isolates were cultured from the samples. Concordant results between the MM and the sinus cavity were noted in 80% of patients for the maxillary sinus, but only 66% for the frontal sinus and 76% for the sinuses a whole. The differences were similarly prevalent in patients with open and occluded sinus ostia. Notably, swabs from all three sites provided representative information in 92% of patients and tissue biopsies did not provide additional information compared to multiple swabs. CONCLUSION: The traditional method of sampling from the middle meatus provides inadequate information in 24% of patients with CRS, which may result in inadequate antibiotic therapy and contribute to increasing antibiotic resistance. Additional sampling from the sinuses should be recommended whenever possible, while invasive sampling is not necessary.

Evaluation of qualitative and quantitative data of Y-90 imaging in SPECT/CT and PET/CT phantom studies.

INTRODUCTION: We aimed to assess the feasibility of SPECT and PET Y-90 imaging, and to compare these modalities by visualizing hot and cold foci in phantoms for varying isotope concentrations. MATERIALS AND METHODS: The data was acquired from the Jaszczak and NEMA phantoms. In the Jaszczak phantom Y-90 concentrations of 0.1 MBq/ml and 0.2 MBq/ml were used, while higher concentrations, up to 1.0 MBq/ml, were simulated by acquisition time extension with respect to the standard clinical protocol of 30 sec/projection for SPECT and 30 min/bed position for PET imaging. For NEMA phantom, the hot foci had concentrations of about 4 MB/ml and the background 0.1 or 0.0 MBq/ml. All of the acquired data was analysed both qualitatively and quantitatively. Qualitative assessment was conducted by six observers asked to identify the number of visible cold or hot foci. Inter-observer agreement was assessed. Quantitative analysis included calculations of contrast and contrast-to-noise ratio (CNR), and comparisons with the qualitative results. RESULTS: For SPECT data up to two cold foci were discernible, while for PET four foci were visible. We have shown that CNR (with Rose criterion) is a good measure of foci visibility for both modalities. We also found good concordance of qualitative results for the Jaszczak phantom studies between the observers (corresponding Krippendorf's alpha coefficients of 0.76 to 0.84). In the NEMA phantom without background activity all foci were visible in SPECT/CT images. With isotope in the background, 5 of 6 spheres were discernible (CNR of 3.0 for the smallest foci). For PET studies all hot spheres were visible, regardless of the background activity. CONCLUSIONS: PET Y-90 imaging provided better results than Bremsstrahlung based SPECT imaging. This indicates that PET/CT might become the method of choice in Y-90 post radioembolization imaging for visualisation of both necrotic and hot lesions in the liver.

(90)Y microspheres prepared by sol-gel method, promising medical material for radioembolization of liver malignancies.

A new technology for the production of radiopharmaceutical (90)Y microspheres in the form of spherical yttrium oxide grains obtained by sol-gel method has been described. The authors present and discuss the results of investigations performed in the development of new production technology of yttrium microspheres and determination of their physic-chemical properties. The final product has the structure of spherical yttrium oxide grains with a diameter 25-100µm, is stable and free from contaminants. Irradiation of 20mg samples of grains with diameter of 20-50µm in the thermal neutron flux of 1.7×10(14)cm(-2)s(-1) at the core of MARIA research nuclear reactor allowed to obtain microspheres labelled with the (90)Y isotope on the way of the nuclear reaction (89)Y(n, ɤ)(90)Y. Specific activity of irradiated microspheres has been determined by application of absolute triple to double coincidence ratio method (TDCR) and has been evaluated at 190MBq/mg Y. (90)Y microspheres prepared by the proposed technique can be regarded as a promising medical material for radioembolization of liver malignancies.

Synthesis and structural investigations of gel metal oxide composites WO3-ZrO2, WO3-TiO2, WO3-ZrO2-SiO2, and their evaluation as materials for the preparation of ¹88W/¹88Re generator.

The gel composites of WO3-ZrO2, WO3-TiO2, WO3-ZrO2-SiO2 at different molar ratios of oxides were synthesized. The elution profiles of the generator columns packed with gel samples activated at the Polish nuclear research reactor MARIA were studied. The best results of elution were found for WO3-ZrO2 and WO3-TiO2 both at 1:2M ratio annealed at 500°C and 650°C, respectively. Their structure determined with X-ray and neutron diffraction is completely amorphous with spherical grains of ∼23nm diameter. The efficiency of (188)W/(188)Re generators with WO3-ZrO2 gel of natural isotope composition as well as enriched in (186)W were investigated.

[How can an otolaryngologist benefit from artificial neural networks?]. / Co moze uzyskac otolaryngolog, stosujac sztuczne sieci neuronowe?

Artificial neural networks are informatic systems that have unique computational capabilities. The principle of their functioning is based on the rules of data processing in the brain. This article discusses the most important features of the artificial neural networks with reference to their applications in otolaryngology. The cited studies concern the fields of rhinology, audiology, phoniatrics, vestibulology, oncology, sleep apnea and salivary gland diseases. The authors also refer to their own experience with predictive neural models designed in the Department of Otolaryngology of the Jagiellonian University Medical College in Krakow. The applications of artificial neural networks in clinical diagnosis, automated signal interpretation and outcome prediction are presented. Moreover, the article explains how the artificial neural networks work and how the otolaryngologists can use them in their clinical practice and research.

[Orbital complications of sinusitis treated endoscopically]. / Endoskopowe leczenie chorych z powiklaniami oczodolowymi zapalen zatok przynosowych.

BACKGROUND: Subperiosteal inflammatory disease, subperiosteal abscess and orbital cellulitis are the most common sequelae of both acute and chronic sinusitis. Early, appropriate evaluation and management observing signs and symptoms of orbital inflammation are required to prevent blindness. Computerised tomography (CT) is the investigation of choice in diagnosing the discussed pathological conditions. Cellulitis does not require drainage of the orbit on a routine basis. Conventionally, the orbital abscess is drained via an external incision and sinus surgery is performed at the same time to remove the focus of infection. More recently, successful treatment both of the sinuses and decompression of the orbit has been accomplished endoscopically via an intranasal approach. AIM: The aim of the paper was to analyse the results of intranasal endoscopic procedures performed in individuals with orbital complications of sinusitis in search for optimal treatment of this group of patients. MATERIAL AND METHODS: Records of 7 patients aged from 14 to 68 (mean 33) years treated in our department for orbital complications of sinusitis between February 2005 and August 2006 were analysed retrospectively. One retrobulbar abscess was diagnosed. In the remaining 6 patients the diagnosis of cellulitis, in one case complicated with cavernous sinus thrombosis, was established. 7 endoscopic frontosphenoethmoidectomies, one with endonasal decompression of the orbital abscess, were performed. RESULTS: All preoperative symptoms subsided in all operated individuals. No complications were observed. CONCLUSIONS: Surgical treatment of the focus of infection in the sinuses and drainage of orbital abscess can be accomplished endoscopically via an intranasal approach with little morbidity, easy identification of anatomical structures, physiological drainage of the sinuses and superior cosmetic result. Our experience suggests that the optimal method of treatment consists in surgical endoscopic removal of the focus of infection located in the sinuses with simultaneous drainage of the abscess in the orbit.

[Endoscopic management of osteomas of the paranasal sinuses--own experience]. / Endoskopowe leczenie chorych z kostniakami zatok przynosowych--doswiadczenie wlasne.

Osteomas are relatively common, benign, slow-growing, often asymptomatic neoplasms of the paranasal sinuses, occurring mainly in frontal and ethmoid sinuses. Surgical removal is done if they extend beyond the boundaries of the sinus, keep enlarging, are localised in the region adjacent to the nasofrontal duct, or if signs of chronic sinusitis are present and, irrespective of their size, in symptomatic tumours. Progressive headaches and chronic inflammation of the adjacent mucous membrane are most common symptoms. Endoscopic surgery plays an important role in management of ethmoid, sphenoid and frontal osteomas. Aim. The aim of the paper was to report own experience in endoscopic treatment of patients with osteomas of the paranasal sinuses. Material and methods. 6 patients with osteomas of paranasal sinuses were included in the group, mean age 36 years (range 15-52). Most common involvement was ethmoid cells (3). There were also patients with frontal, maxillary and sphenoid osteoma. All tumours were removed under endoscopic giudance. Frontoethmoidectomy was performed to remove ethmoid and frontal osteomas. Antrotomy was used in case of maxillary involvement and sphenoethmoidectomy in the patient with sphenoid sinus osteoma. Sphenoid sinus was approached through its anterior wall with a Stammberger punch. All the tumours were removed using fine forceps. Results. No post-operative complications were observed. No recurrences were noted. All patients remain asymptomatic. Conclusions. Resection of small and medium size osteomas of the paranasal sinuses can be safely and radically performed using endoscopic techniques. It allows their radical resection and very good cosmetic effects.

[Endoscopic surgical treatment of patients with isolated sphenoid sinus disease]. / Endoskopowe leczenie chorych z izolowanymi stanami patologicznymi zatoki klinowej.

INTRODUCTION: Cases of isolated lesions of the sphenoid sinus are rare. For descriptive purposes, clinicians divide them into inflammatory and non-inflammatory with prevalence of the former. Symptoms of the sphenoid sinus disease are difficult to characterise, the most common of them being vague headache and visual disturbances. Thorough preoperative evaluation of the lesion is essential - nasal endoscopy must be performed and computerised tomography or magnetic resonance imaging results analysed. The purpose of the study is to present the assessment of endoscopic surgery outcome in the own group of patients with isolated sphenoid disease. MATERIAL AND METHODS: Clinical data of 22 subjects were analysed retrospectively. There were 5 patients with bacterial sinusitis, 6 with fungal sinusitis, 4 with allergic thickening of the mucous membrane with no evidence of bacterial or fungal infection, 2 with mucocele, 1 with sphenoid osteoma, 1 with inverted papilloma, 1 with a foreign body and 2 with cerebral fluid fistula. Each patient had preoperative nasal endoscopy and CT/MRI imaging performed. Then they underwent endoscopic transnasal sphenoethmoidectomy with removal of the lesion or closure of the fistula. The sphenoid sinus was approached through its front wall. RESULTS: The patients' postoperative course was uneventful. They noted improvement in all preoperative symptoms, except for bilateral oculomotor nerve paralysis in one individual, and were asymptomatic to ophthalmological examination. CONCLUSIONS: Isolated lesions of the sphenoid sinus, even very rare tumours like those presented here, can be in most cases safely approached and removed endoscopically. All risks of the method must be considered prior to the operation. High frequency of fungal sinusitis should be noted.

[Endoscopic treatment of cerebral rhinorrhea]. / Endoskopowe leczenie plynotoku nosowego.

INTRODUCTION: The frequency of different factors causing cerebrospinal fluid rhinorrhea (CFR) has lately changed. The incidence of iatrogenic CFR has reached 10% of all cases of CFR, due to an increasing number of endoscopic operations of the sinuses and skull base, while idiopathic CFR is nowadays very rare. The current treatment method for CFR is surgical repair of the fistula. Endoscopic surgery of the anterior skull base has become the standard procedure for the repair of cerebrospinal fluid (CSF) leaks of various origins. The aim of this study was to analyse results of endoscopic surgical technique used in our department for the treatment of CFR. MATERIAL AND METHODS: Records of 5 patients aged from 46 to 69 (mean 58.2) years treated in the department between April 2004 and March 2006 were analysed retrospectively. 4 individuals had underwent endoscopic sinus surgery for sinus problems which resulted in iatrogenic CSF leak. One patient had idiopathic CFR. 3 fistulas localised in the neighbourhood of the cribriform plate were closed using an "underlay" technique with synthetic dura, and covered with free mucosal grafts from the nasal septum, kept in place by fibrin glue. The fistula in the neighbourhood of the sphenoid sinus posterior wall was closed using an ,,overlay" technique with surgical, covered with synthetic dura. RESULTS: In the 3 patients with cribriform plate fistulas the closure was successful and CFR did not recur during 6 to 9 month's follow-up. In the patient with sphenoid sinus fistula CFR recurred on exertion after 4 months. In one patient with cribriform plate fistula, CFR resolved spontaneously during preparation to surgery. CONCLUSIONS: Endoscopic closure of the skull base fistula represents a minimally invasive and highly successful procedure. Our experience suggests thet the optimal surgical technique in the region of cribriform plate consists in performing an "underlay" procedure with synthetic dura and covering the graft with free mucosal grafts from the nasal septum.

[Analysis of patients under 45 years of age with cancer of the larynx]. / Analiza chorych na raka krtani w wieku ponizej 45 roku zycia.

INTRODUCTION: In last years we observe more frequently squamous cell carcinoma in patients below 45 years of age. Especially we examined patients with cancer of the larynx. MATERIAL AND METHODS: Estimation of surgical treatment of patients with cancer of the larynx under 45 years age after prior analysis of the following factors: localization of laryngeal carcinoma, local and regional advancement, the incidence of "occult metastases", the presence of metastases in the pre-laryngeal node, the regions of the neck affected by metastases. An analysis of a group of 140 patients who underwent surgery for laryngeal carcinoma in the period 1950-1998 was carried out. In all of the cases partial or total laryngectomy with unilateral or bilateral neck dissection was performed. RESULTS: In patients under 45 years of age, metastases to the lymph nodes were more frequently observed. The incidence of "occult metastases" and metastases to the pre-laryngeal node were more frequently. CONCLUSIONS: The cancer of the larynx in "young adults" is more aggressive and worse prognosis than in older patients population.