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A new holographic observation technique for 180 [degree] domains is demonstrate with a cerium-doped strontium barium niobate sample containing two antiparallel ferroelectric domains. The method relies on the fact that the phase shift of holographically written refractive-index gratings is +[Pi]/2 or -[Pi]/2 with respect to the initial light interference pattern depending on the orientation of the domains. As a consequence, readout of these gratings creates at the exit face of the sample new interference patterns shifted by 0 or [Pi] with respect to the initial one. These patterns, providing an image of the domain structure, are observed by microscope.

Introduction: Salvage ablative therapy (SAT) has been developed as a form of localized treatment for localized recurrence of prostate cancers following radiation therapy. To better address the utility of SAT, prospective clinical trials must address the aspects of accepted standards in the initial evaluation, treatment, follow-up, and outcomes in the oncology community. We undertook this study to achieve consensus on uniform standardized trial design for SAT trials., Methods: A literature search was performed and an international multidisciplinary group of experts was identified. A questionnaire was constructed and sent out to 71 participants in 3 consecutive rounds according to the Delphi method. The project was concluded with a face-to-face meeting in which the results were reviewed and conclusions were formulated., Results: Patients with recurrent disease after radiation therapy were considered candidates for a SAT trial using any ablation scenario performed with cryotherapy or high-intensity focused ultrasound. It is feasible to compare different sources of energy or to compare with historical data on salvage radical prostatectomy outcomes. The primary objective should be to assess the efficacy of the treatment for negative biopsy rate at 12 months. Secondary objectives should include safety parameters and quality-of-life assessment. Exclusion criteria should include evidence of local or distant metastases. The optimal biopsy strategy is image-guided targeted biopsies. Follow-up includes multiparametric magnetic resonance imaging, prostate-specific antigen level, and quality of life for at least 5 years., Conclusions: A multidisciplinary board from international experts reached consensus on trial design for SAT in prostate cancer and provides a standard for designing a feasible SAT trial., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: The concept of magnetic fluid hyperthermia is clinically evaluated after development of the whole body magnetic field applicator MFH 300F and the magnetofluid MFL 082AS. This new system for localized thermotherapy is suitable either for hyperthermia or thermoablation. The magnetic fluid, composed of iron oxide nanoparticles dispersed in water, must be distributed in the tumour and is subsequently heated by exposing to an alternating magnetic field in the applicator. We performed a feasibility study with 22 patients suffering from heavily pretreated recurrences of different tumour entities, where hyperthermia in conjunction with irradiation and/or chemotherapy was an option. The potential to estimate (by post-implantation analyses) and to achieve (by improving the technique) a satisfactory temperature distribution was evaluated in dependency on the implantation technique., Material and Methods: Three implantation methods were established: Infiltration under CT fluoroscopy (group A), TRUS (transrectal ultrasound)--guided implantation with X-fluoroscopy (group B) and intra-operative infiltration under visual control (group C). In group A and B the distribution of the nanoparticles can be planned prior to implantation on the basis of three-dimensional image datasets. The specific absorption rates (SAR in W/kg) can be derived from the particle distribution imaged via CT together with the actual H-field strength (in kA/m). The temperature distribution in the tumour region is calculated using the bioheat-transfer equation assessing a mean perfusion value, which is determined by matching calculated temperatures to direct (invasive or endoluminal) temperature measurements in reference points in or near the target region., Results: Instillation of the magnetic fluid and the thermotherapy treatments were tolerated without or with only moderate side effects, respectively. Using tolerable H-field-strengths of 3.0-6.0 kA/m in the pelvis, up to 7.5 kA/m in the thoracic and neck region and >10.0 kA/m for the head, we achieved SAR of 60-380 W/kg in the target leading to a 40 degrees C heat-coverage of 86%. However, the coverage with > or =42 degrees C is unsatisfactory at present (30% of the target volume in group A and only 0.2% in group B)., Conclusion: Further improvement of the temperature distribution is required by refining the implantation techniques or simply by increasing the amount of nanofluid or elevation of the magnetic field strength. From the actual nanoparticle distribution and derived temperatures we can extrapolate, that already a moderate increase of the H-field by only 2 kA/m would significantly improve the 42 degrees C coverage towards 100% (98%). This illustrates the great potential of the nanofluid-based heating technology.

Background and Purpose: To assess acute as well as long-term toxicity after permanent prostate seed implantation. To find predictive clinical or dosimetric factors for side effects in order to work out strategies for improvement., Patients and Methods: A group of 174 patients with localised prostate cancer was treated with permanent seed implantation between 1999 and 2001, either alone (140 patients) or in combination with external radiotherapy (34 patients). For the majority (114/174, i.e. 66%) a CT was performed four weeks after implantation and analysed in the planning system VariSeed. In the postimplant analysis, dosimetric descriptors (doses, volumes) were determined for the prostate and rectum and compared with the intraoperative values. In addition, a questionnaire was sent to all patients to assess and quantify acute and chronic toxicity (urinary, rectal, sexual) and the impact on subjective acceptance and quality of life (return rate of questionnaires 83%). The derived score changes were correlated with clinical and dosimetric factors., Results: In the mono-brachytherapy group 14% (16/140) required a bladder catheter, of them 8% (9/140) with a manifest urinary obstruction. Long-term rectal toxicity (<5%) and impairment of potency (<30%) are moderate and obviously below other treatment options. Urinary toxicity is dominant with an overall long-term dysuria up to 30% (at a mean observation interval of ten months), and a significant trend to decline with follow-up time. Conversely, the erectile function tends to deteriorate with follow-up time. Nevertheless, quality of life is not significantly reduced and acceptance is high. Our analysis suggests that the main factor for urinary toxicity and impaired erectile function is the dose load to larger portions of the prostate (D(50)>240 Gy), which appears to be attributed to unnecessarily high numbers of seeds (for a fixed activity per seed) and needles. The rectal toxicity is correlated with the high dose regions in the rectum (>/=145 Gy). Urinary toxicity is lower for combined-brachytherapy, while rectal toxicity and impairment of potency are slightly higher., Conclusions: Toxicity spectrum and quality of life after permanent seed implantation for early prostate cancer are acceptable for nearly all patients (98%). To further improve tolerance we should attempt to achieve a better dose homogeneity, i.e. by reducing D(50). Therefore, special attention should be given to D(50) during the real-time planning process. The necessity of more homogeneous dose distributions might imply a reduction of the activity per seed, e.g. from 0.7 mCi down to 0.6 mCi.

Background: Interstitial brachytherapy with I-125 seeds can be used for successful treatment of early stage prostate cancer. There is presented the technique of permanent transperineal implantation of I-125 seeds with intraoperative treatment planning which is suited for the treatment of prostate cancer up to the clinical stage of T2a., Material and Methods: Some weeks before the implantation of the seeds the prostate volume is determined using transrectal ultrasound (TRUS) so as to estimate the required number of I-125 seeds. At the outset of the treatment the prostate is stabilized by two perineally inserted needles. Subsequently there is carried out an ultrasound guided treatment planning that allows to optimize the distribution of the seeds within the prostate. In interstitial brachytherapy we use RAPID STRANDS((R)), i. e. the I-125 seeds are embedded in vicryl suture at distances of 1 cm. During implantation of the I-125 seeds the transversal placement of the applicator needles is controlled by TRUS and the cranio-caudal placement of the applicator needles is controlled using the fluoroscopic unit as well as TRUS. About 4 weeks after the implantation of the seeds there is carried out a postoperative computation of the dose distribution of the implant using CT imaging., Results: The procedure possesses the advantage that ultrasound imaging, treatment planning and seed implantation are carried out with the prostate remaining in an unaltered position. During implantation the combined imaging of TRUS and fluoroscopy allows a safe placement of the seeds with in the prostate., Conclusion: The methods for the calculation of the actually attained dose distribution must still be optimized, because the postoperative examination of the individual results has so far been possible only with difficulties resulting from methodological inconveniences.

Prostate cancer is together with the carcinoma of the lung the most common cancer in the western world. Better screening methods especially the introduction of PSA (prostate specific antigen) in the beginning of the 90's has increased the early detection rate. In the United States only 30% of prostate tumors were in their early stages before the introduction of PSA-screening as compared to 60% nowadays. The early detection also increased the rate of younger men amongst these patients. Patient demands have increased with respect to incontinence and impotence especially amongst those young patients. Radical prostatectomy still is the gold standard for therapy of localized prostate cancer. Better operating techniques have decreased the side effect rate of this operations but many patients still do not undergo this operation because they fear these side effects. Originating from the USA the low dose rate brachytherapy (LDR) using permanent seeds had a renaissance in recent years. In 1999 alone more than 40,000 patients were successfully operated using this technique. 10 year data published in 1998 showed similar results as compared to a multitude of radical prostatectomy studies and superior results to most of the published external beam studies with significantly less side effects. In Germany and western Europe more and more centers start with LDR-brachytherapy. In contrary to the U.S. where brachytherapy is mostly performed as an outpatient procedure, nearly all European centers do only inpatient brachytherapy. Only very few centers perform outpatient procedures; the first results are very encouraging showing few complications and a very high standard of quality of the treatment.

Upto April 1999 interstitial seed implants were being performed throughout Europe only as an in-patient treatment. Consequently, we questioned whether this same method could be performed as an out-patient treatment without forfeiting the required quality and safety normally observed with in-patients. Since April 1999 we have treated 73 patients with iodine 125 seed implants (RAPID strand). The average patient age was 65 yrs, the average PSA was 11.5 ng/ml, tumor stage was either T1 or T2. All treatments were carried out in general anesthesia under ultrasound and flouroscopy monitoring. Pre- and post implant dosimetry was planned using the Variplan 6.7 computer program (former MMS). All patients tolerated the out-patient treatment very well. The average duration for anesthesia was 76 minutes, total time per patient spent in the center on implant day was 250 minutes. 54 patients were treated with a monotherapy 145 Gy, while 19 patients received external beam radiotherapy (45 Gy) plus the iodine seed boost (100 Gy). Almost 75% of the patients experienced some form of voiding discomfort during the 4-10th post implant week. In the CT post plan dosimetry performed 4 weeks after the implant, 95% of the patients obtained a good coverage of the prostate with the planned prescription dose. Iodine seed implants can be considered a safe out-patient form of treatment with a low complication and morbidity rate and a high standard of quality. The technical improvements in computer dosimetry software, modified application methods, constantly updated equipment and critical quality assessment has lead to improved overall long term results.

Little is known about the mechanisms and determining factors of shock wave-induced kidney trauma. After classification of the renal lesion in a canine model, we attempted to establish an ex vivo model using the isolated kidney of the pig perfused by Tyrode's solution under physiologic conditions. After shock wave application on the Modulith SL 20, vessel lesions were evaluated by microangiography to determine the size and frequency of dye extravasation in the different areas of the organ. Variation of the focus localization caused different patterns of lesions that characterized the pathway of the shock wave. In particular, constant petechial extravasation in the cortex was observed. The generator voltage correlated with the diameter and the frequency of the lesion area. The number of shock waves primarily affected the incidence of vessel rupture in the regions adjacent to the focal zone. Light microscopy revealed dose-dependent necrosis of tubular cells up to gap-like parenchymal defects. Even after application of the minimal shock wave doses, electron microscopy demonstrated vacuolization of tubular cells in the shock wave focus. Traumatic junctions between capillaries and the tubulur system can explain clinically observed macrohematuria without renal hematomas. With this model, it was possible to evaluate localization and dose dependence of shock wave-induced kidney trauma with high sensitivity and reproducibility. Further advantages of the model were easy availability and the fact that studies on living animals were not necessary. Therefore, standardization and comparison of different lithotripters becomes possible.