Oscillations of the orbital magnetic moment due to d-band quantum well states

The effect of electron confinement on the magnetocrystalline anisotropy of ultrathin bcc Fe films is explored by combining photoemission spectroscopy, x-ray magnetic circular dichroism, and magneto-optical Kerr effect measurements. Pronounced thickness-dependent variations in the magnetocrystalline anisotropy are ascribed to periodic changes in the density of states at the Fermi level, induced by quantization of d(xz), d(yz) out-of-plane orbitals. Our results reveal a direct correlation between quantum well states, the orbital magnetic moment, and the magnetocrystalline anisotropy.

Fractionated stereotactic radiosurgery treatment results for skull base chordomas

Chordomas are uncommon neoplasms and there is still controversy regarding establishment of diagnosis and management. The aim of this study was to evaluate efficacy and toxicity of fractionated stereotactic radiosurgery (FSRS) in skull base chordomas. There were 4 female (36%) and 7 male (64%) patients. FSRS was delivered with CyberKnife (Accuray Inc., Sunnyvale, CA). The median tumor volume was 14.7 cc (range, 3.9-40.5 cc). The median marginal tumor dose was 30 Gy (range, 20-36 Gy) in a median 5 fractions (range, 3-5 fractions). The median follow-up time was 42 months (range, 17-63 months). At the time of analysis, 10 (91%) patients were alive and 1 (9%) had died due to tumor progression. Of 10 patients, 8 (73%) had stable disease and the remaining 2 (18%) had progressive disease. The actuarial overall survival (OS) after FSRS was 91% at two-years. Two patients developed radiation-induced brain necrosis as a complication in the 8th and 28th months of follow-up, respectively. Our results with robotic FSRS in skull base chordomas are promising for selected patients. However, due to the slow growth pattern of skull base chordomas, a longer follow-up is required to determine exact treatment results and late morbidity.

Robotic Stereotactic Radiosurgery in Patients with Unresectable Glomus Jugulare Tumors

We evaluated the treatment results of robotic stereotactic radiosurgery (SRS) in our patients with unresectable glomus jugulare tumors (GJTs). The medical charts of fourteen patients with GJT, who were treated with robotic SRS, were retrospectively evaluated. The gross tumor volume was described as the clinical target volume. The median dose to the tumor was 25 Gy in median 5 fractions. The dose was normalized to 80% isodose line. All patients were evaluated for tumor growth and clinical outcome every 6 months in the first 2 years and then annually. Median follow-up was 39 months (range, 7–60 months). Lesions were stable in 8 patients, and tumor regression was observed in 6 patients. We did not observe any treatment related toxicity in our patients. In conclusion, according to our early experience, robotic SRS seems to be successful treatment option in the management of unresectable GJTs.

SU-E-T-208: The Secondary Malignancy Risk Estimation Due to the Neutron Contamination in 3D-CRT and IMRT Treatment Techniques by Using Bubble Detectors

PURPOSE

In this study, the neutron measurements were performed in free in air and RW3 solid water phantom to estimate the secondary malignancy risk for three dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) techniques in prostate cancer treatment.

METHODS

Neutron dose were measured in 18 MV Elekta Synergy Platform and Varian Clinac linear accelerators by using bubble detector for personal neutron dosimetry (BD-PND). To determine the neutron equivalent dose in different depths and different distance from the edge of treatment field RW3 solid water phantom was used and organs location was defined in Alderson Rando phantom with respect to target (prostate) position in the treatment field. By using these data, we determined the neutron equivalent dose and effective dose for the standard prostate cancer patient treated with 3D-CRT and IMRT with 18 MV photon energy. The total dose was 70 Gy in 3D-CRT and 76 Gy in IMRT treatment in the current study. For both of these treatment techniques, we estimated the risk of secondary malignancies due to the neutron contamination by using the International Commission on Radiological Protection (ICRP) report 103.

RESULTS

The equivalent dose and effective dose due the neutron contamination were considerably high in 18 MV IMRT technique. The secondary malignancy risk estimation for 3D-CRT and IMRT were found to be 0.44% and 1.15% for Elekta Synergy Platform linear accelerator, 0.92% and 2.38% for the Varian Clinac DHX High Performance linear accelerator, respectively.

CONCLUSIONS

Therefore, one should take care of the secondary malignancy risk in case of using 18 MV in IMRT applications.

The impact of smoking on clinical features of Behçet's disease patients with glutathione S-transferase polymorphisms

OBJECTIVES

Various cancer studies have suggested that polymorphism of GSTM1 may influence the ability to detoxify chemicals in cigarette smoke. In the present study the effect of smoking on clinical features of Behçet's disease were investigated in patients having GST-M1 and/or -T1 null polymorphisms.

METHODS

Ninety-seven patients meeting International Study Group Criteria for Behçet's disease (63 male, 34 female) and 172 healthy controls (94 male, 78 female) were included into the study. GST-M1 and -T1 polymorphisms were investigated using polymerase chain reaction-restriction fragment length polymorphism technique.

RESULTS

Frequency of GSTM1- and/or GSTT1-null polymorphisms were comparable between the Behçet and the control groups. Smoking patients with GSTM1 null-polymorphism have decreased risk of developing papulopustuler lesions (OR=0.227 [0.063-0.818], χ2=5.463, p=0.019). Non-smoking patients with GSTM1 null-polymorphism has increased risk for having chronic arthritis (OR=5.988 [0.845-43.478]) but smoking patients with GSTM1 null-polymorphism have decreased risk (OR=0.741 [0.593-0.926]). GSTT1 null-polymorphism is associated with the presence of venous insufficiency (χ2=6.273, p=0.012, OR=2.740 [1.224-6.135]); smoking further increases the risk (χ2=7.840, OR=3.333 [1.412-7.874], p=0.005). GSTM1 null-polymorphism seemed to effect development of large vessel vasculitis (OR=1.158 [0.981-1.367], χ2=4.760, p=0.029). Male smoker Behçet patients even have more risk (OR=1.250 [0.971-1.610]).

CONCLUSIONS

Several manifestations of Behçet's disease may be influenced by smoking, and this effect can be augmented in patients carrying GST gene polymorphism, which code enzymes crucial for the detoxification of chemicals.

The Effects of Inhaled Steroid and Theophylline on Systemic Inflammation in Copd

Chronic obstructive pulmonary disease (COPD) is a systemic disease characterized by chronic, progressive airflow limitation and airway inflammation. In this study, our aim is to compare the effects of inhaled corticosteroids and theophylline on systemic inflammatory markers in COPD. Twenty-nine moderate to severe COPD patients were randomly separated into two groups. In Group 1, inhaled corticosteroids (fluticasone propionate, 1000 meg/day) were added to regular bronchodilator therapy for 8 weeks, and theophylline (400mg/day) was added in Group 2. Pulmonary function tests were performed and serum CRP, TNF-α, and IL-6 levels were measured before and after treatment. There was a statistically significant decrease in serum CRP levels in both groups following treatment (ICS group 1.06±1.2 vs 0.49±0.22 mg/dl p< 0.05; THEO group 1.66±2.23 vs 0.59±0.35 mg/dl p< 0.05). There was a significant reduction in serum TNF-α levels in the THEO group (3.82±3.44 vs 1.89±1.33 pg/ml p< 0.05). There was no significant change in IL-6 level following treatment in either group. There was a significant increase in FEV1 in the ICS group while a non-significant increase was noted in the THEO group following treatment. It has been suggested that both ICS and THEO could be used as an anti-inflammatory agent in the treatment of COPD. Furthermore, the measurement of serum inflammatory markers is an easy and non-invasive method for the determination and follow-up of systemic inflammation in COPD. Further studies including larger patient population are needed.