Search

Background: To retrospectively investigate scatter radiation (SCR) exposure among staff in the endourology operating theatre. Methods: During surgeries under fluoroscopic guidance, five professional groups (urological surgeon [US], surgical nurse [SN], assistant surgical nurse [ASN], anaesthetist [A], and anaesthesia care [AC]) wore real-time dosimeters (Philips DoseAware System) on their head and chest over lead aprons between July 2023 and February 2024. The SCR data were analysed and correlated with procedural and patient factors. Results: In total, 249 procedures were performed, including 86 retrograde intrarenal surgeries and 10 percutaneous nephrolithotomies. Median SCR exposure was 38.81, 17.20, 7.71, 11.58, 0.63, 0.23, 0.12, and 0.15 Microsievert (µSv) for US chest (USC), US head (USH), SN chest (SNC), SN head (SNH), A chest (AC), AC chest (ACC), ASN chest (ASNC), and ASN head (ASNH), respectively. There was a significant correlation between DAP and SCR doses detected by USC, USH, SNC, SNH, AC, and ACC dosimeters (p < 0.05). The median chest-to-eye conversion factor (CECF) was 2.11 for the US and 0.71 for the SN. Conclusions: This study, using real-time dosimetry, is among the first to assess staff occupational SCR exposure in endourology. It highlights a substantial SCR exposure, indicating an occupational health hazard that warrants further investigation. [ABSTRACT FROM AUTHOR]

Purpose: The goal of this work was to evaluate toxicity and local control following hypofractionated stereotactic radiation treatment with special focus on changes in tumor volume and hearing capacity.Patients and Methods: In all, 29 patients with unilateral acoustic neuroma were treated between 2001 and 2007 within a prospective radiation protocol (7 × 4 Gy ICRU dose). Median tumor volume was 0.9 ml. Follow-up started at 6 months and was repeated annually with MRI volumetry and audiometry. Hearing preservation was defined as preservation of Class A/B hearing according to the guidelines of the American Academy of Otolaryngology (1995).Results: No patient had any intervention after a median imaging follow-up of 89.5 months, one patient showed radiological progression. Transient increase of tumor volume developed in 17/29 patients, whereas 22/29 patients (75.9%) presented with a volume reduction at last follow-up. A total of 21 patients were eligible for hearing evaluation. Mean pure tone average (PTA) deteriorated from 39.3 to 65.9 dB and mean speech discrimination score (SDS) dropped from 74.3 to 38.1%. The 5-year actuarial Class A/B hearing preservation rate was 50.0 ± 14.4%.Conclusion: Radiation increases only minimally, if at all, the hearing deterioration which emerges by observation alone. Presbyacusis is not responsible for this deterioration. Transient tumor enlargement is common. Today radiation of small- and medium-sized acoustic neuroma can be performed with different highly conformal techniques as fractionated treatment or single low-dose radiosurgery with equal results regarding tumor control, hearing preservation, and side effects. Hypofractionation is more comfortable for the patient than conventional regimens and represents a serious alternative to frameless radiosurgery. [ABSTRACT FROM AUTHOR]

Copyright of Strahlentherapie und Onkologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: In this study we investigate the accuracy of industrial six axes robots employed for patient positioning at the Heidelberg Ion Beam Therapy Center. Methods: In total 1018 patient setups were monitored with a laser tracker and subsequently analyzed. The measurements were performed in the two rooms with a fixed horizontal beam line. Both, the 3d translational errors and the rotational errors around the three table axes were determined. Results: For the first room the 3d error was smaller than 0.72 mm in 95 percent of all setups. The standard deviation of the rotational errors was at most 0.026° for all axes. For the second room Siemens implemented an improved approach strategy to the final couch positions. The 95 percent quantile of the 3d error could in this room be reduced to 0.53 mm; the standard deviation of the rotational errors was also at most 0.026°. Conclusions: Robots are very flexible tools for patient positioning in six degrees of freedom. This study proved that the robots are able to achieve clinically acceptable accuracy in real patient setups, too. [ABSTRACT FROM AUTHOR]

Copyright of Strahlentherapie und Onkologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Strahlentherapie und Onkologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The standard treatment for early breast cancer comprises wide local excision, sentinel lymph node biopsy or axillary lymph node dissection, adjuvant medical treatment and radiotherapy to the whole breast. Many studies suggest that local control plays a crucial role in overall survival. The local recurrence rate is estimated to be 1% per year and varies between 4 and 7% after 5 years and up to 10 to 20% in the long-term follow up. On the basis of low local recurrence rates the concept of whole breast irradiation comes up for discussion, and partial breast irradiation (PBI) is increasingly under consideration. Intraoperative radiotherapy (IORT) is referred to as the delivery of a single high dose of irradiation directly to the tumor bed (confined target) during surgery. PBI (limited field radiation therapy, accelerated partial breast irradiation APBI) is the irradiation exclusively confined to a breast volume, the tumor surrounding tissue (tumor bed) either during surgery or after surgery without whole breast irradiation. Various methods and techniques for IORT or PBI are under investigation. The advantage of a very short radiation time or the integration of the complete radiation treatment into the surgical procedure convinces at a first glance. The promising short-term results of those studies must not fail to mention that local recurrence rates could probably increase and furthermore give rise to distant metastases and a reduction in overall survival. The combination of IORT in boost modality and whole breast irradiation has the ability to reduce local recurrence rates. The EBCTCG overview approves that differences in local treatment that substantially affect local recurrence rates would avoid about one breast cancer death over the next 15 years for every four local recurrences avoided, and should reduce 15-year overall mortality. [ABSTRACT FROM AUTHOR]

Aim of this study is to show that ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery can be reduced by proper surgery and modern radiotherapy techniques. Three hundred and seventy eight women with stage I or II breast cancer had breast conserving surgery and received 51-56.1 Gy of postoperative radiation to the whole breast in 1.7 Gy fractions, but patients received different boost strategies. Group 1 ( n = 188) received electron boost radiation of 12 Gy subsequent to the irradiation to the whole breast, group 2 ( n = 190) received intraoperative electron boost radiation of 9 Gy directly to the tumor bed, followed by whole breast irradiation. After a median follow up period of 81.0 months in group 1 and a median follow up period of 51.1 months in group 2, 12 IBTRs (6.4%) could be observed in group 1 and no IBTR could be observed in group 2 (0.0%). The 5-year actuarial rates of IBTR were 4.3% (95% CI, 1.9-8.3%) and 0.0% (95% CI, 0.0-1.9%), respectively ( p = 0.0018). The 5-year actuarial rates of distant recurrence were 8.6% (95% CI, 4.9-13.5%) and 4.2% (95% CI, 1.8-8.2%), respectively ( p = 0.08). The 5 year disease-free survival rates were 90.9% (95% CI, 85.8-94.7%) in group 1 and 95.8% (95% CI, 91.8-98.2%) in group 2 ( p = 0.064). Immediate IORT-boost and whole breast irradiation yields excellent local control at 5 years, and was associated with a statistically significant decreased rate of IBTR compared with a similar cohort of patients treated with whole breast irradiation and conventional electron boost. © 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Wave-particle duality is frequently the first topic students encounter in elementary quantum physics. Although this phenomenon has been demonstrated with photons, electrons, neutrons, and atoms, the dual quantum character of the famous double-slit experiment can be best explained with the largest and most classical objects, which are currently the fullerene molecules. The soccer-ball-shaped carbon cages C[sub 60] are large, massive, and appealing objects for which it is clear that they must behave like particles under ordinary circumstances. We present the results of a multislit diffraction experiment with such objects to demonstrate their wave nature. The experiment serves as the basis for a discussion of several quantum concepts such as coherence, randomness, complementarity, and wave-particle duality. In particular, the effect of longitudinal (spectral) coherence can be demonstrated by a direct comparison of interferograms obtained with a thermal beam and a velocity selected beam in close analogy to the usual two-slit experiments using light. [ABSTRACT FROM AUTHOR]

We discuss the experimental challenges in coherent matter wave optics with fullerenes. In particular, the properties of our matter wave source and the features of our efficient, molecule-selective detector with high spatial resolution are presented. Their development was crucial for the successful recording of the molecular quantum interference patterns of individual molecules. [ABSTRACT FROM AUTHOR]

The article examines the relationship between primary tumor size and radiation dose in non-operated patients with non-small cell lung cancer (NSCLC). Methodology-wise, majority of patients has been employed with the conformal target splitting technique. Based on the results, the researchers concluded that twice daily applied radiotherapy using the technique of target splitting seems to be highly efficient in regard of locoregional tumor control and survival.

Deals with experiments showing that molecules of the fullerene C60 have wave as well as particle properties. Observation of a de Broglie wave interference of C60 fullerenes; Utilization of a Kirchhoff diffraction theory.

Background: In this study we investigate the accuracy of industrial six axes robots employed for patient positioning at the Heidelberg Ion Beam Therapy Center.Methods: In total 1018 patient setups were monitored with a laser tracker and subsequently analyzed. The measurements were performed in the two rooms with a fixed horizontal beam line. Both, the 3d translational errors and the rotational errors around the three table axes were determined.Results: For the first room the 3d error was smaller than 0.72 mm in 95 percent of all setups. The standard deviation of the rotational errors was at most 0.026° for all axes. For the second room Siemens implemented an improved approach strategy to the final couch positions. The 95 percent quantile of the 3d error could in this room be reduced to 0.53 mm; the standard deviation of the rotational errors was also at most 0.026°.Conclusions: Robots are very flexible tools for patient positioning in six degrees of freedom. This study proved that the robots are able to achieve clinically acceptable accuracy in real patient setups, too. [ABSTRACT FROM AUTHOR]