Novel rectangular spiral antennas

Thesis (Master)--Izmir Institute of Technology, Electronics and Communication Engineering, Izmir, 2008Includes bibliographical references (leaves: 36-37)Text in English; Abstract: Turkish and Englishviii, 37 leavesRound spiral antennas are generally designed by using Archimedean spiral geometries which have linear growth rates. To obtain smaller antennas with nearly the same performance, square spiral Archimedean geometries are also widely used instead. In this study, novel square antennas are proposed, designed and examined. At first two similar but different approaches are employed to design new antennas by considering the design procedure used to obtain log-periodic antennas. Then, the performance of these antennas is improved by considering another property of log-periodic antennas. Simulations are performed by using two different numerical methods which are Finite Difference Time Domain Method (FDTD) and Method of Moments (MoM). The results obtained from the simulations are compared with those of the Archimedean spiral antennas in terms of the frequency dependency of fundamental antenna parameters such as antenna gain and radiation pattern. The simulation results are compared with the ones obtained from the experimental study

Synthesis and characterisation of novel azamacrocyclic chelators for biomedical applications : biological activity and radiolabelling

Azamacrocyclic derivatives that contain nitrogen donors have been used for decades in analytical, industrial and medical applications. They are good hosts for metal ions, anions, neutral molecules and organic cation guests. Azamacrocyclic complexes that are biologically active have been used in the identification of diseased tissues. Transition metal macrocyclic complexes have also received significant attention due to their pharmacological properties such as toxicity against bacterial and fungal growth. Many macrocyclic complexes have been reported to have anti-inflammatory properties.A number of azamacrocyclic ligands have been used in the design of bifunctional chelators (BFCs) that have been utilised in molecular imaging. Incorporation of a positron emitting metal radioisotope such as 68Ga requires a BFC to form a stable complex in vivo and for covalent bond formation (conjugation) with a targeting moiety. Macrocyclic complexes are essential to a number of biological systems and have shown affinity for the CXCR4 chemokine receptor. Studies confirmed that CXCR4 is an important factor in the migration, invasiveness, proliferation and metastasis of tumours and overexpression of CXCR4 has been shown in twenty three different human tumours including non-small cell lung cancer, ovarian cancer, prostate cancer, colorectal cancer and breast cancer.In this work three different classes of azamacrocycles have been synthesised. The first group is a series of configurationally restricted copper(II), zinc(II) and nickel(II) mono-ring macrocycles bearing benzimidazole derivatised pendant arms. The antifungal activity has been determined for both ligands and their transition metal complexes. Most of the compounds tested showed a recognisable activity. The zinc(II) complexes of the ligands (side-bridged cyclen benzimidazole and side-bridged cyclen 4-nitrobenzyl benzimidazole) showed the highest antifungal activity of the compounds tested.The second class of azamacrocyclic derivatives synthesised comprises five novel bifunctional chelators based on benzimidazole TACN and NO2A derivatives. Four 68Ga complexes of the following ligands: NO2A benzimidazole, TACN tris 4-nitrobenzyl benzimidazole, NO2A 4-nitrobenzyl benzimidazole and NO2A 4-aminobenzyl benzimidazole, have been synthesised in radiochemical yields of 73%, 55%, 25% and 37% respectively at RT with a 5 minute reaction time.The third type of azamacrocyclic ligands are C-functionalised bis-tetraazamacrocyclic derivatives to be used as CXCR4 antagonists. Four new C-functionalised bis-azamacrocycles that have an amino group to allow for subsequent conjugation were synthesised: 4-aminobenzyl-C-functionalised side-bridged bis-cyclam, 4-aminobenzyl-C-functionalised side-bridged bis-cyclam cyclen, 4-aminobenzyl-C-functionalised bis-cyclam and 4-aminobenzyl-C-functionalised bis-cyclam cyclen. Zinc(II), nickel(II) and copper(II) complexes of the 4-nitrobenzyl-C-functionalised side-bridged bis-cyclam were synthesised and characterised as CXCR4 antagonists. A selection of the synthesised compounds was biologically evaluated in a number of assays (displacement assays, anti-HIV assays, cytotoxicity assays and calcium(II) signalling assays) with the free ligands showing activity and the metal complexes also acxtive and significantly more potent

Solitary Fibrous Tumors of Chest: Another Look with the Oncologic Perspective

Solitary fibrous tumors are mesenchymal lesions that arise at a variety of sites, most commonly the pleura. Most patients are asymptomatic at diagnosis, with lesions being detected incidentally. Nevertheless, some patients present due to symptoms from local tumor compression (eg. of the airways and pulmonary parenchyma). Furthermore, radiological methods are not always conclusive in making a diagnosis, and thus, pathological analysis is often required. In the past three decades, immunohistochemical techniques have provided a gold standard in solitary fibrous tumor diagnosis. The signature marker of solitary fibrous tumor is the presence of the NAB2-STAT6 fusion that can be reliably detected with a STAT6 antibody. While solitary fibrous tumors are most often benign, they can be malignant in 10-20% of the cases. Unfortunately, histological parameters are not always predictive of benign vs malignant solitary fibrous tumors. As solitary fibrous tumors are generally regarded as relatively chemoresistant tumors; treatment is often limited to localized treatment modalities. The optimal treatment of solitary fibrous tumors appears to be complete surgical resection for both primary and local recurrent disease. However, in cases of suboptimal resection, large disease burden, or advanced recurrence, a multidisciplinary approach may be preferable. Specifically, radiotherapy for inoperable local disease can provide palliation/shrinkage. Given their sometimes -unpredictable and often- protracted clinical course, long-term follow-up post-resection is recommended

Postmastectomy irradiation in breast in breast cancer patients with T1-2 and 1-3 positive axillary lymph nodes: Is there a role for radiation therapy?

<p>Abstract</p> <p>Background</p> <p>We aimed to evaluate retrospectively the correlation of loco-regional relapse (LRR) rate, distant metastasis (DM) rate, disease free survival (DFS) and overall survival (OS) in a group of breast cancer (BC) patients who are at intermediate risk for LRR (T1-2 tumor and 1-3 positive axillary nodes) treated with or without postmastectomy radiotherapy (PMRT) following modified radical mastectomy (MRM).</p> <p>Methods</p> <p>Ninety patients, with T1-T2 tumor, and 1-3 positive nodes who had undergone MRM received adjuvant systemic therapy with (n = 66) or without (n = 24) PMRT. Patient-related characteristics (age, menopausal status, pathological stage/tumor size, tumor location, histology, estrogen/progesterone receptor status, histological grade, nuclear grade, extracapsular extension, lymphatic, vascular and perineural invasion and ratio of involved nodes/dissected nodes) and treatment-related factors (PMRT, chemotherapy and hormonal therapy) were evaluated in terms of LRR and DM rate. The 5-year Kaplan-Meier DFS and OS rates were analysed.</p> <p>Results</p> <p>Differences between RT and no-RT groups were statistically significant for all comparisons in favor of RT group except OS: LRR rate (3%vs 17%, p = 0.038), DM rate (12% vs 42%, p = 0.004), 5 year DFS (82.4% vs 52.4%, p = 0.034), 5 year OS (90,2% vs 61,9%, p = 0.087). In multivariate analysis DM and lymphatic invasion were independent poor prognostic factors for OS.</p> <p>Conclusion</p> <p>PMRT for T1-2, N1-3 positive BC patients has to be reconsidered according to the prognostic factors and the decision has to be made individually with the consideration of long-term morbidity and with the patient approval.</p

Non–Small Cell Lung Cancer: Prognostic Importance of Positive FDG PET Findings in the Mediastinum for Patients with N0–N1 Disease at Pathologic Analysis

In non-small cell lung cancer, preoperative evaluation of the mediastinum with PET may complement the surgical and histologic findings

A novel square-spiral strip antenna

2nd International ITG Conference on Antennas, INICA 2007; Munich; Germany; 28 March 2007 through 30 March 2007A square-spiral strip antenna is designed considering the procedure used to obtain log-periodic antennas. Simulation results of the new design are compared with those of the well known and widely used Archimedean spiral antenna in terms of the frequency dependency. The effect of dielectric substrate used to support the antennas is also investigated

Metástases nas leptomeninges da espinal medula num doente com carcinoma de céculas escamosas do pulmão Spinal leptomeningeal metastasis in a patient with squamous cell lung cancer

As metástases nas leptomeninges da espinal medula ocorrem raramente nos tumores sólidos e o prognóstico é bastante reservado. Os adenocarcinomas e os carcinomas de pequenas células são os grupos histológicos mais envolvidos no que se refere aos tumores pulmonares. Um homem de 58 anos com história de carcinoma de células escamosas do pulmão com inversão mediastínica e metástases cerebrais apresenta lombalgias e fraqueza em ambos os membros inferiores. A RMN da coluna vertebral revelou espessamento na espinal medula e múltiplos nódulos do grupo das fibras da cauda equina. Tanto quanto sabemos, trata-se do segundo caso relatado de carcinoma pulmonar de células escamosas que apresenta metástases nas leptomeninges da espinal medula.Spinal leptomeningeal metastasis occurs rarely in solid tumors, and the prognosis is extremely poor. Adenocarcinomas and small-cell carcinomas are the most common histological type detected among lung tumors. A 58-year-old man with a history of squamous-cell lung carcinoma with mediastinal invasion and brain metastasis was examined because of his low back pain and weakness in both lower limbs. Spinal MRI revealed subpial enhancement in the spinal cord; and innumerable nodules with thickening of the cauda equina fibres. To our knowledge, this is the second reported case of squamous cell lung cancer with spinal leptomeningeal metastasis

Dosımetric comparıson of sıngle and multıple arc treatment plans ın sterotactic ablative treatment of early stage non-small cell lung cancer

Tıbbi sebeplerle inoperabl, erken evre (T1-2 N0) KHDAK’inin güncel tedavisi stereotaktik ablatif radyoterapidir (SABR). SABR, toraks, batın, pelvis, spinal ve paraspinal bölge yerleşimli primer ve oligometastik lezyonların tedavisinde yüksek tümör kontrol oranları sağlayan etkili bir radyoterapi (RT) tekniğidir. SABR’yi konvansiyonel RT tekniklerinden ayıran en önemli özellik yüksek fraksiyon dozlarının (>5Gy), az sayıda fraksiyon ile (1-12) küçük bir tümör hacmine odaklanarak (genellikle <5 cm) verilmesidir. SABR’de normal doku toksisitesini en aza indirebilmek için, hedefin hemen dışında keskin doz düşüşünün gerçekleşmesi gerekmektedir. Bu çalışmanın amacı, erken evre küçük hücreli dışı akciğer kanseri (KHDAK) tanılı hastalarda dört farklı SABR tekniğinin (coplanar tek ışın tek-ark, tek ışın iki-ark, iki ışın ikiark ve non-coplanar iki ışın iki-ark) doz/hacim parametrelerini karşılaştırmaktır. Bu amaçla erken evre KHDAK’i tanısı ile tedavi edilmiş 20 hastanın BT-sim görüntüleri retrospektif olarak kullanıldı. Her hasta için yeniden hedef hacim ve risk altındaki organ (RAO) konturlamaları yapıldı ve dört ayrı teknik için Monoco Planlama Sistemi (TPS) kullanılarak tedavi planları (60Gy/8fr) oluşturuldu. Hedef hacmin %98-99’unun 60Gy tam dozu alması için her dört uygulamada da benzer şekilde normalizasyon yapıldı. Seri yapıdaki RAO’ların doz hacim kriterlerine uymak için tüm planlar optimize edildi. Doz-hacim histogramlarından (DVH) faydalanılarak, her planda Dmaks, D95, Dmin değerleri bulunarak gruplar arasında istatistiksel olarak karşılaştırıldı. Ayrıca kalp için Dmaks ve Dort, proksimal bronşiyal ağaç, ösofagus, medulla spinalis, göğüs duvarı ve büyük damarlar için Dmaks, toplam akciğer için V5, V10, V20, Dort, aynı taraf akciğer için Dort, karşı taraf akciğer için ise Dort ve V5 değerleri 60 karşılaştırıldı. Aynı zamanda, monitor unit değerleri ve tedavi süreleri kaydedildi; heterojenite indeksi, konformite indeksi ve gradient indeks değerleri hesaplanarak, bu değerlerin gruplar arasındaki karşılaştırmaları yapıldı. Hedef hacim için değerlendirilen, Dmaks, D95 ve Dmin dozları planlar arasında karşılaştırılabilir bulunmuştur. Yalnızca, PTV’nin Dmaks dozu, tek ışın tek ark grubunda tek ışın iki ark grubuna göre istatiksel olarak anlamlı düzeyde büyüktür (p=0,033). Santral yerleşimli risk altındaki organlar için bakılmış olan, proksimal bronşiyal ağaç, ösofagus ve medulla spinalis maksimum doz değerleri non-coplanar iki ışın iki ark uygulamasında coplanar uygulamalara göre anlamlı düzeyde düşüktür. Toplam akciğerin V5 ve V10 değerleri ve karşı taraf akciğerin V5 değerleri, non-coplanar iki ışın iki ark uygulamasında diğer uygulamalara göre istatiksel anlamlılık düzeyinde düşük bulunmuştur. Toplam akciğer V20, Dort; aynı taraf akciğer Dort ve karşı akciğer Dort değerleri açısından, planlar arasında anlamlı fark bulunmamıştır. Sonuç olarak, Monaco TPS kullanılarak oluşturulan tek ışın tek ark SABR planları iki ark uygulamalara kıyasla daha düşük monitör unit değerleri ve tedavi sürelerine sahiptir. Aslında, tüm planlamalarda genel olarak uygun hedef ve RAO doz-hacim değerleri elde edilmiştir. Non-coplanar SABR planları, daha düşük gradient indeks, RAO maksimum doz ve doz-hacim değerleri elde etmek gerektiğinde kullanılabilir. Özellikle seri dizilimli RAO’lara yakın yerleşimli lezyonların SABR uygulamalarında, non-coplanar teknik bu yapıların maksimum dozlarını düşürmede fayda sağlayabilir. Ancak tek ark SABR planları, erken evre KHDAK'li hastaların tedavisinde genellikle uygun konformite ve gradient indeks değerleri ve hedef hacim ve RAO dozları sağlayabilmekte ve nispeten kısa tedavi süresi ve düşük set-up hatası riski ile uygulanabilmektedir.The current treatment of medically inoperable early stage NSCLC is stereotactic ablative radiotherapy (SABR). SABR is an effective radiotherapy (RT) technique that provides high tumor control rates in the treatment of primary or oligo-metastatic lesions located in the thorax, abdomen, pelvis, spinal and paraspinal regions. The most important feature that distinguishes SABR from conventional RT techniques is that high fraction doses (> 5Gy) are given with a small number of fractions (1-12 fx), focusing on a small tumor volume (usually <5 cm). In SABR applications, in order to minimize the risk of normal tissue toxicity, a sharp dose reduction is required just beyond the target. The aim of this study is to compare the dose /volume parameters of four different SABR techniques (coplanar single-beam single-arc, single-beam two-arc, two-beam two-arc ve non-coplanar two-beam two-arc) in patients with early stage non-small cell lung cancer (NSCLC). For this purpose, CT-simulation images of 20 patients with early stage NSCLC were used retrospectively. Target volumes and organs at risk (OAR) were delineated for each patient and then treatment plans (60Gy/8fr) generated by Monoca Treatment Planning System (TPS) were created separately for each different planning techniques. Similar 62 normalization process was performed for all four applications to ensure that 98-99% of the target volume received the full 60Gy dose. At the same time, monitor unit values and treatment times were recorded; heterogeneity index, conformity index and gradient index values were calculated and statistical comparisons of these values were made between the groups. All plans were optimized to comply with the dose volume criteria of the serial OARs. Using dose-volume histograms (DVH), Dmax, D95 and Dmin values were found in each plan and these were compared statistically between the groups. Besides, Dmax and Dort doses for the heart; Dmax values for proximal bronchial tree, esophagus, medulla spinalis, chest wall and great vessels; V5, V10, V20, Dort for the total lung; Dort for the ipsilateral lung, Dort and V5 values for the contra-lateral lung were calculated in all groups and compared each other statistically. The Dmax, D95 and Dmin doses evaluated for target volume were comparable between the plans. Only, the Dmax dose was statistically significantly higher in the single-beam singlearc group than in the single-beam two-arc group (p = 0.033). The proximal bronchial tree, esophagus and medulla spinalis maximum dose values (as centrally located serial organs at risk) were significantly lower in non-coplanar two-beam two-arc application compared to other (coplanar) plans. There was no significant difference between the groups in terms of Dmax values of the chest wall and great vessels. V5 and V10 values of the total lung and V5 values of the contralateral lung were found to be significantly lower in non-coplanar twobeam two-arc applications compared to other applications. V20 and Dort of the total lung, Dort of the ipsilateral lung and Dort of the contralateral lung did not show a significant difference between the plans. In conclusion, single-beam single-arc SABR plans created by Monaco TPS had lower monitor unit values and treatment times compared to all two-arc techniques. In fact, with all SABR planning techniques evaluated in our study, generally appropriate target and OAR dose-volume values were obtained. Non-coplanar SABR plans can be used when it is necessary to obtain a lower gradient index, maximum dose and dose-volume values of the OAR’s. Especially in SABR applications of lesions located close to serial OARs, noncoplanar technique can be beneficial in reducing the maximum doses of these structures. However, single-arc SABR plans can generally provide appropriate conformity and gradient index values and target volume and OAR doses in the treatment of patients with early stage 63 NSCLC and can be applied with a relatively short treatment time and low risk of set-up errors

Metástases nas leptomeninges da espinal medula num doente com carcinoma de céculas escamosas do pulmão

Resumo: As metástases nas leptomeninges da espinal medula ocorrem raramente nos tumores sólidos e o prognóstico é bastante reservado. Os adenocarcinomas e os carcinomas de pequenas células são os grupos histológicos mais envolvidos no que se refere aos tumores pulmonares. Um homem de 58 anos com história de carcinoma de células escamosas do pulmão com inversão mediastínica e metástases cerebrais apresenta lombalgias e fraqueza em ambos os membros inferiores. A RMN da coluna vertebral revelou espessamento na espinal medula e múltiplos nódulos do grupo das fibras da cauda equina. Tanto quanto sabemos, trata-se do segundo caso relatado de carcinoma pulmonar de células escamosas que apresenta metástases nas leptomeninges da espinal medula.Rev Port Pneumol 2008; XIV (6): 875-879 Abstract: Spinal leptomeningeal metastasis occurs rarely in solid tumors, and the prognosis is extremely poor. Adenocarcinomas and small-cell carcinomas are the most common histological type detected among lung tumors. A 58-year-old man with a history of squamous-cell lung carcinoma with mediastinal invasion and brain metastasis was examined because of his low back pain and weakness in both lower limbs. Spinal MRI revealed subpial enhancement in the spinal cord; and innumerable nodules with thickening of the cauda equina fibres. To our knowledge, this is the second reported case of squamous cell lung cancer with spinal leptomeningeal metastasis.Rev Port Pneumol 2008; XIV (6): 875-879 Palavras-chave: Espinal medula, leptomeninges, metástases, ressonância magnética nuclear, Key-words: Spinal, leptomeningeal, metastasis, lung cancer, magnetic resonance imagin