Air kerma rate constants for gamma emitters used most often in practice.

It is often required to estimate the dose rate at a distance from radionuclides that are sources of X rays and gamma rays. Such calculations may be required for planning radiation protection measures in the vicinity of radioactive sources or patients containing radionuclides, calibrations of radiation instruments or for estimating the absorbed dose rate to patients receiving brachytherapy. The factor relating activity and air kerma rate is called air kerma rate constant--gamma(delta). In this paper, the results of recalculation of this quantity for unfiltered point sources of radionuclides in practice used most often are given. The calculations included corrections for internal conversion of X rays and gamma rays and detailed accounting of the generation of the K and L series X rays from internal conversion and electron capture. Particular air kerma rate constants were calculated for each discrete line in the photon spectrum of radionuclide with a yield per decay event >0.01% and the energy >20 keV. Since the energy structure of the photon spectra and accessible discrete numerical values of the mass energy-transfer coefficient for air are not the same, the cubic spline interpolation was used to obtained the coefficient, where the photon spectrum data are available. In the calculation, the latest gamma ray spectral data for all radionuclides and latest data for the mass energy-transfer coefficient for air are used. Air kerma rate constants for the following 35 radionuclides are calculated: 11C, 13N, 15O, 18F, 24Na, 42K, 43K, 51Cr, 52Fe, 59Fe, 57Co, 58Co, 60Co, 67Ga, 68Ga, 75Se, 99Mo, 99mTc, 111In, 113mIn, 123I, 125I, 131I, 127Xe, 133Xe, 137Cs, 152Eu, 154Eu, 170Tm, 182Ta, 192Ir, 197Hg, 198Au, 201Tl and 241Am.

Measurements of environmental background radiation at location of coal-fired power plants.

Environmental radiation monitoring in the vicinity of coal-fired power plants which are used primarily to determine the variability in measured background exposures are presented in this article; this is in order to estimate the contribution due to the plants' operation. Measurements have been done using a multi-element, high sensitive dosemeter system composed of three solid, properly filtered, sintered CaSO4:Dy thermoluminescent detectors, and one low-atomic number, MgB4O7:Dy,Na thermoluminiscencent detector produced at the Vinca Institute. The dosemeters were deployed quarterly 1 m above ground level at locations within 20 km of the power plants. Twenty urban and suburban measured stations were established. Measurements were carried out over one year period, from the beginning of the summer of 1995 to the end of the spring of 1996. The registered annual absorbed dose in air, from all of the 20 stations, vary from 0.91 to 1.46 mGy a(-1). One of the highest values of the annual absorbed dose was measured at the station near to the plant, i.e. at the place the most exposed to the lighter fly ash from the plant stack, as it was expected. The annual absorbed dose registered at the measuring stations that were selected as a control because they were situated practically away from possible influence of the plants were from 0.91 to 0.98 mGy a(-1). The above values of absorbed doses become very important, by concurrence of the circumstances, because they represent the zero background radiation level before the incidence of depleted uranium over former Yougoslav territory in the Kosovo region in the spring of 1999. These measured absorbed dose exposures have to be compared with corresponding absorbed dose rates from the natural sources, such as soil having an exposure of 18-93 nGy h(-1) (average 35 nGy h(-1)) according to the UNSCEAR 2000 Report. This investigation has been primarily done in order to check the impact of coal-fired power plants on the background radiation level in its vicinity. According to the experimental results, influence was confirmed both qualitatively and quantitatively.

Limb salvage after fulminant septicemia using a free latissimus dorsi cross-leg flap.

A 15-year-old boy survived fulminant meningococcal septicemia, with extensive tissue necrosis involving the face and the right arm, complicated by peripheral gangrene of the fingers on both hands and the distal parts of the feet. Although still often fatal, the mortality of fulminant septicemia has dropped substantially in the past decades, leading to more survivors, and requiring concurrent reconstruction of all extremities. This report discusses the advantages of using a single, free, latissimus dorsi (LD) myocutaneous cross-leg flap to salvage both feet, and the use of pedicled groin flaps bilaterally for coverage of fingers and hands, as illustrated by this case.

Internal mammary vessels as a model for power Doppler imaging of recipient vessels in microsurgery.

The aim of this interdisciplinary study was to evaluate power Doppler imaging as a method of collecting reliable preoperative data concerning the diameters and topography of exemplary internal mammary vessels as recipient vessels in reconstructive microsurgery. Thirteen female patients (range, 37 to 58 years; mean, 45.6 years) were examined preoperatively with power Doppler imaging from the first to the fifth intercostal space parasternally and bilaterally. These data are compared with measurements obtained intraoperatively in each individual. Mean velocity in the artery in the second intercostal space on the right side is 47.11 cm/sec (range, 15 to 90 cm/sec) and on the left side is 42.25 cm/sec (range, 18 to 95 cm/sec). Mean velocity in the vein in the second intercostal space on the right side is 17.80 cm/sec (range, 10 to 30 cm/sec) and on the left side is 13.06 cm/sec (range, 5.3 to 32 cm/sec). The topographic results are in close agreement with intraoperative measurements and previous anatomical studies. Sonographic preoperative data of arteries (mean, 1.88 mm) show slightly smaller diameters than intraoperative measurements (mean, 2.08 mm), whereas veins show slightly larger diameters in sonography (mean, 2.33 mm) than intraoperatively (mean, 2.12 mm). Mean sonographic diameter of artery ranges from 2.14 mm (second intercostal space) to 1.46 mm (fifth intercostal space), of the vein from 2.76 (second intercostal space) to 1.25 mm (fifth intercostal space). In one case, a vein was not detectable. This noninvasive method leads to confirmation of the preoperative choice of the optimal recipient vessels for free tissue transfer and does not harm the patient.

Water phantom backscatter factors for x-rays in the 60 kV to 300 kV region.

Experimentally determined values of x-ray backscatter factors are presented in this paper. Measurements were made for x-rays generated at voltages between 60 kV and 300 kV and three water phantoms different in shape and size. To study the influence of the irradiation geometry on the backscatter factors, the measurements were performed for different photon beam field diameters at the phantom front face, at a fixed source-to-phantom distance of 1 m. An ionization chamber of volume 1 cm3 was used for dose measurement. Measured results are analysed and discussed in comparison with measured and calculated values given in the cited references.

Transpositional replantation of digits. Case reports.

Heterotopic or transpositional replantation of digits is technically feasible with results similar to those of conventional replantation procedures. Occasionally in multiple digital amputations not all the digits may be replanted in their correct place as a result of complex injuries proximal to the amputation zone or severe damage to important fingers. In these circumstances the amputated digits that are in the best condition as regards undamaged tissue are used for replantation. The primary priority is an optimal functional outcome and the secondary priority the cosmetic outcome. Amputated long digits will always be used to substitute for a non-replantable thumb rather than to replace a long finger. We present 13 cases of successful transpositional digit or joint replantations in traumatic amputations of more than one digit.

Comparison of the MCNP calculated and measured radiation field quantities near the RB reactor.

The RB experimental reactor has operated at Vinca Institute of Nuclear Sciences since the end of April 1958. In this paper, neutron and gamma-ray spectra and corresponding dose quantities near the reactor, calculated by using the MCNP code, are compared to the measured values during the Third International Intercomparison Experiment on Nuclear Accident Dosimetry carried out at the RB reactor in 1973. Discrepancies in the correlation declared power of the reactor-dose rates are found. Good agreements are obtained between measured and calculated neutron and gamma-ray spectra, and corresponding absorbed doses in air, but only after the reactor declared power is multiplied by a correction factor, determined in this study.

[Complex hand injuries. Importance of primary repair with free flaps]. / Komplexe Handverletzungen. Stellenwert der Primärversorgung mit freien Lappen.

BACKGROUND: The treatment of large and complex hand injuries is particularly challenching concerning the functional and cosmetic outcome. In this kind of injuries the primary defect cover is of paramount importance and so the initial situation for secondary reconstructive options may be evidently improved. MATERIAL & METHODS: Between October 1986 and Mai 1996 43 patients with large complex and combined hand injuries were primarily treated with 49 free flaps. The mean follow-up was 39 (6 to 92) months, the mean hospital stay was 19 (8 to 40) days. Depending on the time of the reconstruction and based on a classification established in our clinic, the patients were distributed among three groups: primarily (within 24 hours), delayed (between 2 and 7 days), and late (after 7 days till 3 weeks posttraumatically) reconstruction. RESULTS: Within the group of primary reconstruction the best results could be achieved, since radical debridement and primary defect cover by healthy tissue (free flap) led to physiological wound healing. That caused reduced hospital stay thus decreased costs, since flap failure, infection and multiple secondary surgical interventions could be diminished. Also earlier rehabilitation and reintegration into social life and profession was achievable. CONCLUSION: Due to the obtained results a primary treatment of large and complex hand injuries through radical debridement and reconstruction with free flaps seems to be effective and should already be considered in the emergency room.

Free flap reconstruction of the foot.

Free flap reconstruction of the foot has been widely performed in the last 20 years, but choice of a free transferred substitute for the soft tissue of the particular defect remains controversial. The authors present a series of 77 free flaps to the foot performed in 68 patients during October 1976 and September 1997. Long-term follow-up ranged from 12 months to 18 years (median, 44.4 months). Seventy-three flaps were transferred successfully (95%). The indications for a specific flap depended on the localization and extension of the foot defect. In weight-bearing areas the authors favored the use of a muscle flap covered with a split-thickness skin graft; the latissimus dorsi muscle was used primarily. This study shows a lower ulceration rate in muscle flaps covered with split-thickness skin grafts than in fasciocutaneous flaps in weight-bearing areas (27% vs. 60%). In nonweight-bearing areas, fasciocutaneous flaps were the best choice. In this series, the lateral arm flap was applied most often. The authors recommend free fascial flaps (serratus fascial flap or radial forearm fascial flap) covered by split- or full-thickness skin grafts for coverage of the malleolar region as well as coverage of exposed tendons of nonweight-bearing regions. Proper tailoring of the flap and postoperative care are very important to maintain a result without ulceration, as is avoiding having the suture line cross a weight-bearing area. Tactile sensation does not seem to be essential.

Reconstruction of large soft tissue defects in the inguinal and suprapubic region using a variety of flaps.

OBJECTIVES: To review a variety of optional reconstructive procedures for the surgical management of extensive soft tissue defects after radically curative or palliative resection of tumors, scars or damaged tissue in the inguinal and suprapubic region. METHODS: Clinical experience with 24 pedicled or free flaps applied in 20 patients to cover extensive defects with exposed underlying structures are presented. The proper selection of flap was based on the individual requirements of each patient taking into consideration age, cause, size, shape and deepness of the defect, donor site morbidity, the patient's general condition and the situation of vascular supply of the adjacent regions. RESULTS: A high success rate with a moderate rate of only minor complications leads to a reasonably short hospital stay with a definitive defect cover. In the cases of palliation a distinct improvement in quality of survival could be achieved. CONCLUSIONS: After extensive or radical resection almost every defect may be sufficiently covered in a single stage. The inferior epigastric flap serves as the most versatile flap, but nevertheless appropriate selection of the reconstructive technique must be adapted considering the complexity of the illness and defect in each individual case.

Clinical experience and indications of the free serratus fascia flap: a report of 21 cases.

The free "serratus fascia" flap as a free flap was first described by Wintsch and named a free fascia flap of gliding tissue; however, it has not yet been given a distinct name. The particular advantages of this flap consist of an easy access and a low donor-site morbidity without functional deficit. Additionally, it may be designed very variably and molded even three-dimensionally as a tendon wraparound flap or folded to fill up cavities. In our clinic, we used this flap in 21 patients for distinct indications and in 7 patients as a vascular graft in fingers or great toe with a minimal adjacent layer of gliding tissue around the vessels for the treatment of cold intolerance after finger replantation or severe finger or toe trauma. In the other cases, this versatile flap served for the coverage of traumatically exposed tendons or bones at the extremities, covered with a skin graft. Eighteen flaps survived completely, whereas 3 flaps developed partial or superficial necrosis. Only once did a major complication by unintentional sacrification of the long thoracic nerve during flap harvesting occur, resulting in a wing scapula. We recommend this flap for defect cover at sites where a thin vascularized gliding layer for defect cover is needed, especially in distal extremities with exposed tendons or nerves, and present the current indications in discussing our experiences.

Internal mammary vessels as a recipient site.

In breast reconstruction with a free flap, the selection of suitable recipient vessels remains one of the most critical decisions for the surgeon. Most surgeons use one of the branches of the axillary vascular system, the thoracodorsal vessels. Because of a number of difficulties using this recipient site, the authors investigated the anatomy and availability of the internal mammary vessels for free flap breast reconstruction. This article describes the anatomic considerations, surgical technique, clinical experience, advantages, and limitations of using these vessels. In recent years, free autogenous tissue transfer for breast reconstruction has become increasingly common. The free transverse rectus abdominis myocutaneous (TRAM) flap and the more recently described deep inferior epigastric artery (DIEA) perforator flap are currently the methods of choice for postmastectomy breast reconstruction. For patients who cannot have a TRAM flap, free flaps from other donor sites (superior gluteal flap, inferior gluteal flap, Rubens flap, lateral transverse thigh flap) also have become important options.

[Replantation in childhood and adolescence. Long-term outcome]. / Replantationen im Kindes- und Jugendalter. Langzeitergebnisse.

In 31 (out of 48) patients with 43 (out of 63) replanted or revascularized digits or parts of the extremities a study of long-term results was performed. Their ages were below 16 years at the time of injury. The results concerning function, sensitivity, cold intolerance, growth disturbance, patient acceptance and occupational changes were evaluated. Early complications consisted of venous stasis in 10.6% (n = 4), skin necrosis of the wound margin in 5.3% (n = 2) and in finger-tip necrosis in 5.3% (n = 2). One lower arm and one finger replanted (5.3%, n = 2) were lost after several revisions due to venous problems. In no case did arterial problems occur. Tendon adhesions were the most common complication in 28.9% (n = 11), followed by deviation of the axis in a frontal plane of more than 20 degrees in 13.3% (n = 5) and by joint instability in 5.3% (n = 2). Only twice (5.3%) did ankylosis or in another case osteomyelitis of the proximal phalanx result. At amputation level II (between the DIP joint and the nail root), 37.5% (n = 3) developed a reduction of range of active movement (RAM) with a mean of 31.7 degrees, and once an arthrodesis was necessary, whereas 50% (n = 4) of the patients have full range of active motion. At amputation level III (between the MP and DIP joint) 52.7% (n = 10) developed a reduction of RAM at the PIP joint with a mean of 29.5 degrees, and twice an arthrodesis was necessary, whereas 26.4% (n = 5) of the patients have full range of active motion. Of the patients 78.9% (n = 15) developed a reduction of RAM at the DIP joint with a mean of 35.7 degrees, and twice an arthrodesis was necessary. Only twice was ankylosis present, but 10.5% (n = 2) of the patients have full range of active motion. Excellent sensory recovery was observed with a mean dynamic two-point discrimination of 4.8 mm. In addition, only 29% (n = 9) of the patients report a surprisingly low incidence of cold intolerance, which is in contrast to adults with up to 100% cold intolerance in replanted digits. In 67.7% a radiologically measured difference of length with a mean of 3.8 mm and clinically measured a difference in the length of the digits with a mean of 4.9 mm was observed without complaints by the patients, instead, there was moderate discontent with the aesthetically disturbing fingertip atrophy, which was up to 30% in 48.4% of the patients. Of the patients who are now adult, 16.7% (n = 4) changed their choice of profession due to the trauma or because of the dissatisfactory result. These results and the success rate of 94.7% suggest the conclusion that one should not hesitate to perform a replantation or revascularization in children with even multiple amputations as the results are excellent.

Loss of lifetime due to radiation exposure-averaging problems.

A new method is presented for assessing a years of life lost (YLL) due to stochastic effects caused by the exposure to ionizing radiation. The widely accepted method from the literature uses a ratio of means of two quantities, defining in fact the loss of life as a derived quantity. We start from the real stochastic nature of the quantity (YLL), which enables us to obtain its mean values in a consistent way, using the standard averaging procedures, based on the corresponding joint probability density functions needed in this problem. Our method is mathematically different and produces lower values of average YLL. In this paper we also found certain similarities with the concept of loss of life expectancy among exposure induced deaths (LLE-EID), which is accepted in the recently published UNSCEAR report, where the same quantity is defined as years of life lost per radiation induced case (YLC). Using the same data base, the YLL and the LLE-EID are calculated and compared for the simplest exposure case-the discrete exposure at age a. It is found that LLE-EID overestimates the YLL, and that the magnitude of this overestimation reaches more than 15%, which depends on the effect under consideration.

Internal mammary veins: classification and surgical use in free-tissue transfer.

The internal mammary artery has been well-investigated due to its frequent use in cardiac surgery. However, in reconstructive microsurgery in the thoracic region, the internal mammary vessels have been used rarely as recipient vessels, due to difficulties and lack of knowledge about the internal mammary veins. This study was designed to investigate the anatomy and topography of the veins. Its goal was to gain sufficient information about their availability in free-tissue transfer. Dissection of the vessels was performed in 86 cadavers bilaterally to the sternum. At the level of the fourth rib, which is the most desired access for microvascular anastomosis in reconstructive breast surgery with free flaps, the veins were found to be adequately large (range 0.64 to 4.45 mm). Results were in close agreement with 100 bilateral measurements obtained by color Doppler sonography in 16 patients preoperatively, and additionally in 34 healthy volunteers. Preoperative detection of vessels with the aid of sonography facilitated planning of surgical procedures. According to these findings, the internal mammary veins may be used as suitable recipient veins for free microvascular tissue transfer, especially for established autologous breast reconstruction with the free transverse rectus abdominis myocutaneous flap, or for reconstruction of complex thoracic-wall defects.