An unusual origin of a papillary muscle of the right ventricle.

Knowledge of anatomical variations of the heart are important to cardiac surgeons, cardiologists, and radiologist. During routine dissection of a 77-year-old male cadaver, we observed an unusual origin of a papillary muscle of the right ventricle arising from the atrioventricular aspect of the moderator band. This papillary muscle was 6.7mm long and 2.6mm wide. It gave rise to two chordae tendineae: one to the inferior (posterior) papillary muscle of the right ventricle and one directly to the inferior (posterior) leaflet of the tricuspid valve. Variants of the internal anatomy of the heart as exemplified in the present case report should be born in mind during image interpretation and invasive procedures of the right ventricle of the heart.

Comparison of EPR response of alanine and Gd2O3-alanine dosimeters exposed to TRIGA Mainz reactor.

In this work we report some preliminary results regarding the analysis of electron paramagnetic resonance (EPR) response of alanine pellets and alanine pellets added with gadolinium used for dosimetry at the TRIGA research reactor in Mainz, Germany. Two set-ups were evaluated: irradiation inside PMMA phantom and irradiation inside boric acid phantom. We observed that the presence of Gd2O3 inside alanine pellets increases the EPR signal by a factor of 3.45 and 1.24 in case of PMMA and boric acid phantoms, respectively. We can conclude that in the case of neutron beam with a predominant thermal neutron component the addition of gadolinium oxide can significantly improve neutron sensitivity of alanine pellets. Monte Carlo (MC) simulations of both response of alanine and Gd-added alanine pellets with FLUKA code were performed and a good agreement was achieved for pure alanine dosimeters. For Gd2O3-alanine deviations between MC simulations and experimental data were observed and discussed.

The alanine detector in BNCT dosimetry: dose response in thermal and epithermal neutron fields.

PURPOSE: The response of alanine solid state dosimeters to ionizing radiation strongly depends on particle type and energy. Due to nuclear interactions, neutron fields usually also consist of secondary particles such as photons and protons of diverse energies. Various experiments have been carried out in three different neutron beams to explore the alanine dose response behavior and to validate model predictions. Additionally, application in medical neutron fields for boron neutron capture therapy is discussed. METHODS: Alanine detectors have been irradiated in the thermal neutron field of the research reactor TRIGA Mainz, Germany, in five experimental conditions, generating different secondary particle spectra. Further irradiations have been made in the epithermal neutron beams at the research reactors FiR 1 in Helsinki, Finland, and Tsing Hua open pool reactor in HsinChu, Taiwan ROC. Readout has been performed with electron spin resonance spectrometry with reference to an absorbed dose standard in a (60)Co gamma ray beam. Absorbed doses and dose components have been calculated using the Monte Carlo codes fluka and mcnp. The relative effectiveness (RE), linking absorbed dose and detector response, has been calculated using the Hansen & Olsen alanine response model. RESULTS: The measured dose response of the alanine detector in the different experiments has been evaluated and compared to model predictions. Therefore, a relative effectiveness has been calculated for each dose component, accounting for its dependence on particle type and energy. Agreement within 5% between model and measurement has been achieved for most irradiated detectors. Significant differences have been observed in response behavior between thermal and epithermal neutron fields, especially regarding dose composition and depth dose curves. The calculated dose components could be verified with the experimental results in the different primary and secondary particle fields. CONCLUSIONS: The alanine detector can be used without difficulty in neutron fields. The response has been understood with the model used which includes the relative effectiveness. Results and the corresponding discussion lead to the conclusion that application in neutron fields for medical purpose is limited by its sensitivity but that it is a useful tool as supplement to other detectors and verification of neutron source descriptions.

Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples.

Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis.

Dosimetric feasibility study for an extracorporeal BNCT application on liver metastases at the TRIGA Mainz.

This study investigates the dosimetric feasibility of Boron Neutron Capture Therapy (BNCT) of explanted livers in the thermal column of the research reactor in Mainz. The Monte Carlo code MCNP5 is used to calculate the biologically weighted dose for different ratios of the (10)B-concentration in tumour to normal liver tissue. The simulation results show that dosimetric goals are only partially met. To guarantee effective BNCT treatment the organ has to be better shielded from all gamma radiation.

Fast determination of impurities in metallurgical grade silicon for photovoltaics by instrumental neutron activation analysis.

Standard wafer solar cells are made of near-semiconductor quality silicon. This high quality material makes up a significant part of the total costs of a solar module. Therefore, new concepts with less expensive so called solar grade silicon directly based on physiochemically upgraded metallurgical grade silicon are investigated. Metallurgical grade silicon contains large amounts of impurities, mainly transition metals like Fe, Cr, Mn, and Co, which degrade the minority carrier lifetime and thus the solar cell efficiency. A major reduction of the transition metal content occurs during the unidirectional crystallization due to the low segregation coefficient between the solid and liquid phase. A further reduction of the impurity level has to be done by gettering procedures applied to the silicon wafers. The efficiency of such cleaning procedures of metallurgical grade silicon is studied by instrumental neutron activation analysis (INAA). Small sized silicon wafers of approximately 200mg with and without gettering step were analyzed. To accelerate the detection of transition metals in a crystallized silicon ingot, experiments of scanning whole vertical silicon columns with a diameter of approximately 1cm by gamma spectroscopy were carried out. It was demonstrated that impurity profiles can be obtained in a comparably short time. Relatively constant transition metal ratios were found throughout an entire silicon ingot. This led to the conclusion that the determination of several metal profiles might be possible by the detection of only one "leading element". As the determination of Mn in silicon can be done quite fast compared to elements like Fe, Cr, and Co, it could be used as a rough marker for the overall metal concentration level. Thus, a fast way to determine impurities in photovoltaic silicon material is demonstrated.

Boron determination in liver tissue by combining quantitative neutron capture radiography (QNCR) and histological analysis for BNCT treatment planning at the TRIGA Mainz.

The typical primary malignancies of the liver are hepatocellular carcinoma and cholangiocarcinoma, whereas colorectal liver metastases are the most frequently occurring secondary tumors. In many cases, only palliative treatment is possible. Boron neutron capture therapy (BNCT) represents a technique that potentially destroys tumor tissue selectively by use of externally induced, locally confined secondary particle irradiation. In 2001 and 2003, BNCT was applied to two patients with colorectal liver metastases in Pavia, Italy. To scrutinize the rationale of BNCT, a clinical pilot study on patients with colorectal liver metastases was carried out at the University of Mainz. The distribution of the (10)B carrier (p-borono-phenylalanine) in the liver and its uptake in cancerous and tumor-free tissue were determined, focusing on a potential correlation between the uptake of p-borono-phenylalanine and the biological characteristics of cancerous tissue. Samples were analyzed using quantitative neutron capture radiography of cryosections combined with histological analysis. Methodological aspects of the combination of these techniques and results from four patients enrolled in the study are presented that indicate that the uptake of p-borono-phenylalanine strongly depends on the metabolic activity of cells.

Determination of boron concentration in blood and tissue samples from patients with liver metastases of colorectal carcinoma using Prompt Gamma Ray Activation Analysis (PGAA).

As part of the studies on Boron Neutron Capture Therapy at the University of Mainz, Germany, a clinical trial has been started in which, four patients suffering from liver metastases of colorectal carcinoma have been enrolled. Specimens of blood and healthy tissue samples taken from the patients were measured at the PGAA facilities at the HFR in Petten, The Netherlands, and at the FRM II in Munich, Germany. From the measured boron concentrations, pharmacokinetic curves and blood-to-tissue concentration ratios were produced.

Irradiation facility at the TRIGA Mainz for treatment of liver metastases.

The TRIGA Mark II reactor at the University of Mainz provides ideal conditions for duplicating BNCT treatment as performed in Pavia, Italy, in 2001 and 2003 [Pinelli, T., Zonta, A., Altieri, S., Barni, S., Braghieri, A., Pedroni, P., Bruschi, P., Chiari, P., Ferrari, C., Fossati, F., Nano, R., Ngnitejeu Tata, S., Prati, U., Ricevuti, G., Roveda, L., Zonta, C., 2002. TAOrMINA: from the first idea to the application to the human liver. In: Sauerwein et al. (Eds.), Research and Development in Neutron Capture Therapy. Proceedings of the 10th International Congress on Neutron Capture Therapy, Monduzzi editore, Bologna, pp. 1065-1072]. In order to determine the optimal parameters for the planned therapy and therefore for the design of the thermal column, calculations were conducted using the MCNP-code and the transport code ATTILA. The results of the parameter study as well as a possible configuration for the irradiation of the liver are presented.

Determination of the irradiation field at the research reactor TRIGA Mainz for BNCT.

For the application of the BNCT for the excorporal treatment of organs at the TRIGA Mainz, the basic characteristics of the radiation field in the thermal column as beam geometry, neutron and gamma ray energies, angular distributions, neutron flux, as well as absorbed gamma and neutron doses must be determined in a reproducible way. To determine the mixed irradiation field thermoluminescence detectors (TLD) made of CaF(2):Tm with a newly developed energy-compensation filter system and LiF:Mg,Ti materials with different (6)Li concentrations and different thicknesses as well as thin gold foils were used.

Direct experimental verification of neutron acceleration by the material optical potential of solid 2H2.

We have measured the acceleration of neutrons by the material optical potential of solid 2H2. Using a gravitational spectrometer, we find a minimal kinetic energy Ec = (99+/-7) neV of neutrons from a superthermal ultracold neutron (UCN) source with solid 2H2 as an UCN converter. The result is in excellent agreement with theoretical predictions, Ec = 106 neV.

Application of different TL detectors for the photon dosimetry in mixed radiation fields used for BNCT.

Different approaches for the measurement of a relatively small gamma dose in strong fields of thermal and epithermal neutrons as used for Boron Neutron Capture Therapy (BNCT) have been studied with various thermoluminescence detectors (TLDs). CaF(2):Tm detectors are insensitive to thermal neutrons but not tissue-equivalent. A disadvantage of applying tissue-equivalent (7)LiF detectors is a strong neutron signal resulting from the unavoidable presence of (6)Li traces. To overcome this problem it is usual to apply pairs of LiF detectors with different (6)Li content. The experimental determination of the thermal neutron response ratio of such a pair at the Geesthacht Neutron Facility (GeNF) operated by PTB enables measurement of the photon dose. In the experimental mixed field of thermal neutrons and photons of the TRIGA reactor at Mainz the photon dose measured with different types of (7)LiF/(nat)LiF TLD pairs agree within a standard uncertainty of 6% whereas the CaF(2):Tm detectors exhibit a photon dose by more than a factor of 2 higher. It is proposed to determine suitable photon energy correction factors for CaF(2):Tm detectors with the help of the (7)LiF/(nat)LiF TLD pairs in the radiation field of interest.

Cathepsins B, H, L and cysteine protease inhibitors in malignant prostate cell lines, primary cultured prostatic cells and prostatic tissue.

Elevated activities of cysteine proteinases, the cathepsins B, H, L (CB, CH, CL) and diminished cysteine protease inhibitors (CPI) have been demonstrated in a variety of tumours and have been suggested to contribute to invasion and metastasis. The situation for prostate cancer is still unknown. In this study, using fluorimetric assays, the catalytic activities of CB, CH, CL were measured in prostatic tissue samples after radical prostatectomy, adenomectomy, transurethral resection of the prostate, in cell cultures grown from cancerous and non-cancerous parts of human prostate after prostatectomy and in the cell lines LNCaP, DU 145 and PC 3. CPIs were determined using heat activation before testing their inhibitory activity against purified CB. Comparing matched pairs of normal and cancerous tissue samples from the prostate, significantly decreased levels of CB, CL in malignant parts of the prostate were found. In contrast, primary cell cultures from cancerous samples showed elevated levels of CB, CH, CL and increased ratios of cathepsins to CPI compared with cell cultures from normal prostate. Established cell lines showed a similar distribution pattern of each cathepsin, DU 145 containing the highest levels, followed by LNCaP and PC 3. Our results suggest that elevated cathepsin levels and consequently increased ratios of cathepsins to CPI in primary cell cultures from cancerous versus non-cancerous parts of the prostate may be indicative of a cellular proteolytic imbalance in prostatic cancer cells. In this respect, primary cell culture experiments should be preferred to determinations in tissue samples.

The use of prostate-specific antigen (PSA) for the monitoring of radiation therapy in prostate cancer.

BACKGROUND: The classic methods for surveilling the efficacy of radiotherapy in prostate cancer are not accurate enough. The objective of this analysis was to determine whether prostate-specific antigen could perform this task. MATERIALS AND METHODS: From 1/95 to 10/95, 16 patients were treated at our clinic. 7 of these underwent primary irradiation, 4 treatment for local recurrence, and 5 had adjuvant radiotherapy. Radiotherapy was carried out with a total dose of 60 Gy in 30 fractions, 10 fractions per week, to the prostate bed plus 2 cm safety margin. RESULTS: PSA levels usually start to decline between the 3rd and the 4th week of radiotherapy with a half-life of 2.5 months. Five patients had equal or rising PSA levels, including all three patients with recurrent tumor. DISCUSSION: In most cases, PSA declined continuously from the 3rd week of therapy. Our median half-life was similar to other reported results. Persisting or rising PSA levels are an indicator for local or distant recurrence; all our patients who developed a recurrence showed a corresponding PSA increase.

Antioxidant enzymes in malignant prostate cell lines and in primary cultured prostatic cells.

The antioxidant enzymes catalase, glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were determined in the androgen-response LNCaP and androgen-nonresponsive PC-3 and DU 145 cells as well as in prostatic epithelial cell cultures of benign and malignant human prostatic tissue. There were no differences between the enzyme activities of the human primary cell cultures from cancerous tissue and their normal counterparts. The enzyme activities of the three permanent cell lines were either higher (SOD, catalase, GR) or lower (GST, GPx) than in the primary cell cultures. In LNCaP cells catalase and GR were significantly higher, GST, in contrast, was significantly lower than in PC-3 and DU 145 cells. GST in PC-3 and DU 145 cells, and SOD in all the three cell lines showed no significant differences. Catalase, GPx and GR values were significantly different in the three permanent cell lines. The different enzymatic equipment of the prostate cancer cell lines provides the basis for experimental testing of new concepts of cancer treatment with the help of systematic modulations of the antioxidant defence systems in prostate cancer.

[High-dose multimodal radiotherapy of confluent destructively growing aggregated keratoacanthoma. 2 case reports]. / Hochdosierte multimodale Radiotherapie konfluierend-destruierend wachsender, aggregierter Keratoakanthome, Zwei Falldarstellungen.

BACKGROUND: Keratoacanthoma is a fairly common, benign, usually self-resolving skin lesion that arises from the hair follicle. This nodular lesion shows a predilection for areas exposed to light, mainly for the face. We report on the intensive radiation therapy of 2 cases of a rare subset of keratoacanthoma which showed a locally aggressive, seriously destructive growth. PATIENTS AND METHODS: Two female patients with previously treated, confluent-destructive growing keratoacanthoma were treated by multimodal, high-dose radiotherapy. Patient 1 showed a rapid progress of midfacial tumor with destructive infiltration of the left cheek, nasal cartilage, the cribriform plate of ethmoid and congestion of the conjunctiva close to the lacrimal caruncle. This could be shown in clinical and histopathological investigations and CT-scans. The coexistence of cutaneous and conjunctival lesions in locally rapidly enlarging keratoacanthoma of the face is unusual and unreported to our knowledge. One case of simultaneous conjunctival and multiple, eruptive keratoacanthoma of the body has been reported. Patient 2 had received soft X-ray pretreatment because of a large, relapsing keratoacanthoma of the left cheek. RESULTS: Patient 1 underwent a parallel, intensive treatment of the conjunctiva with 90Sr-contact therapy, percutaneous high-dose 60Co-gamma- and megavoltage electron treatment (10 and 18 MeV) of the midfacial lesions. Conjunctiva and caruncle showed a complete remission of keratoacanthoma. In the other facial areas no long-term regression could be reached, despite giving a fully cancericidal, total dose of more than 100 Gy in some regions. Patient 2: Further high dose radiotherapy using megavoltage electron treatment with a total dose of 50 Gy showed a complete remission of the lesion for 5 months. Another relapse of this keratoacanthoma could be operated successfully. There was no more relapse established in follow-up checks. CONCLUSIONS: The 2 case reports show that in treatment of locally destructive growing subsets of keratoacanthoma a sufficient therapy should be initiated in time. Keratoacanthoma and subsets of this lesion that do not respond well to initial treatment, recur early or show seriously aggressive growth should be treated early by combined therapy that takes previous experiences into consideration.