Isothermal dehydration of thin films of water and sugar solutions.

The process of quasi-isothermal dehydration of thin films of pure water and aqueous sugar solutions is investigated with a dual experimental and theoretical approach. A nanoporous paper disk with a homogeneous internal structure was used as a substrate. This experimental set-up makes it possible to gather thermodynamic data under well-defined conditions, develop a numerical model, and extract needed information about the dehydration process, in particular the water activity. It is found that the temperature evolution of the pure water film is not strictly isothermal during the drying process, possibly due to the influence of water diffusion through the cellulose web of the substrate. The role of sugar is clearly detectable and its influence on the dehydration process can be identified. At the end of the drying process, trehalose molecules slow down the diffusion of water molecules through the substrate in a more pronounced way than do the glucose molecules.

Gamma knife radiosurgery of recurrent atypical neurocytoma. Case report and review of the literature.

BACKGROUND AND PURPOSE: The goal of this work was to demonstrate the efficacy of stereotactic gamma knife radiosurgery (GKRS) for the treatment of neurocytoma by means of a case report and a comprehensive literature review. CASE REPORT: A locally recurrent atypical neurocytoma in the area of the left third ventricle thalamic wall occurring 7 years after primary microsurgical resection in a 59-year old woman was treated by GKRS. A marginal dose of 17 Gy was delivered to the surrounding 50% isodose. At the last follow-up, 82 months after radiosurgery, the tumor was locally controlled. For the literature review, computerized bibliographic searches of Pubmed were supplemented with hand searches of reference lists and abstracts of ASCO/ASTRO/ESTRO meetings. DISCUSSION: The present case confirms the results of the literature analysis. From 1997-2011, a total of 14 series were published providing results of GKRS in 86 patients (89 lesions). The marginal doses, which have been applied, ranged from 9.6-20.0 Gy. With median follow-up intervals between 6 and 185 months, local control was 97.2% and local tumor progression of neurocytoma after GKRS was restricted to only 4 cases. In accordance with our own experience, GKRS was not associated with a relevant early or late toxicity. CONCLUSION: GKRS can be assumed to be a safe and effective treatment modality of recurrent or residual neurocytoma.

Reconstruction and navigation system for intraoperative brachytherapy using the flab technique for colorectal tumor bed irradiation.

PURPOSE: To present the development of a new navigation and reconstruction system based on an electromagnetic free-hand tracker and on CT imaging for treatment planning of intraoperative high-dose-rate brachytherapy (IORT-HDRB) in the sacral region. Our aim is to improve accuracy and to enable individualized treatment planning and dose documentation to be performed for IORT-HDRB using a flab technique. METHODS AND MATERIALS: The material consists of an electromagnetic 3D tracker system, a PC workstation with Microsoft Windows NT 4.0 operating system, and a recognition program for continuous speech. In addition, we designed an external reference system constructed of titanium and Perspex, which is positioned in the pelvis, and a special digitizer pen for reconstruction of the flab geometry. The flab design incorporates a series of silicon 10-mm-diameter spherical pellets. Measurements were made with a pelvic phantom in order to study the accuracy of the system. The reconstruction results are stored and can be exported via network or floppy to our different treatment planning systems. RESULTS: Our results for the reconstruction of a flab with six catheters and a total of 100 spherical pellets give mean errors in the range (2.5 +/- 0.6) mm to (3.5 +/- 0.8) mm depending on the positions of the pelvic phantom and transmitter relative to the operation table. These errors are calculated by comparing the reconstruction results of our system with those using a CT-based reconstruction of the flab geometry. For the accuracy of the navigation system for the pelvic phantom, we obtained mean errors in the range (2.2 +/- 0.7) mm to (3. 1 +/- 1.0) mm. CONCLUSIONS: The new system we have developed enables navigation and reconstruction within the surgical environment with a clinically acceptable level of accuracy. It offers the possibility of individualized treatment planning and effective documentation of the 3D dose distribution in IORT-HDRB using a flab technique.

192IR endovascular brachytherapy for avoidance of intimal hyperplasia after percutaneous transluminal angioplasty and stent implantation in peripheral vessels: 6 years of experience.

PURPOSE: Percutaneous transluminal angioplasty (PTA) with or without stent implantation is the accepted standard in the therapy of occlusive arterial disease. Despite improvements in the technique and medical equipment, there is still a restenosis rate of up to 40%. A high-dose-rate afterloading technique to avoid vascular stenosis or occlusion after PTA and subsequent stent implantation caused by intimal hyperplasia is presented with long-term results. METHODS AND MATERIALS: Intravascular brachytherapy with a 10-Ci 192Ir source was performed in cases of recurrent vascular occlusion or stenosis which appeared within 6 months after a previous PTA. After recanalization by PTA and stent implantation, a 9-Fr ReKa catheter was positioned within the stent to center the applicator with its tip 2 cm below the stent. This catheter served as a guide for a 5-Fr flexible applicator. After this procedure the isodose was calculated and a 12-Gy to 3-mm source distance was applied. The procedure was followed by 72 h of heparinization. RESULTS: From May 1990 to June 1996, 28 patients (21 male and seven female) were treated with endovascular brachytherapy. All patients had a clinically relevant restenosis or reocclusion of the arteria femoralis. Follow-up time ranged from 1 to 71 months. Twenty-eight patients had a sufficient follow-up time; 25 of these patients were examined. Twenty-one patients had treated vessel segments; four patients had no flow in the treated area. Two patients moved away with unknown addresses, and one patient died without any follow-up examination. Radiation-associated side effects were not notable. CONCLUSION: Intraluminal brachytherapy with 192Ir is a safe and useful procedure to avoid endovascular hyperplasia after transluminal percutaneous angioplasty.

Navigation system for interstitial brachytherapy.

PURPOSE: To develop a computed tomography (CT) based electromagnetic navigation system for interstitial brachytherapy. This is especially designed for situations when needles have to be positioned adjacent to or within critical anatomical structures. In such instances interactive 3D visualisation of the needle positions is essential. METHODS AND MATERIALS: The material consisted of a Polhemus electromagnetic 3D digitizer, a Pentium 200 MHz laptop and a voice recognition for continuous speech. In addition, we developed an external reference system constructed of Perspex which could be positioned above the tumour region and attached to the patient using a non-invasive fixation method. A specially designed needle holder and patient bed were also developed. Measurements were made on a series of phantoms in order to study the efficacy and accuracy of the navigation system. RESULTS: The mean navigation accuracy of positioning the 20.0 cm length metallic needles within the phantoms was in the range 2.0-4.1 mm with a maximum of 5.4 mm. This is an improvement on the accuracy of a CT-guided technique which was in the range 6.1-11.3 mm with a maximum of 19.4 mm. The mean reconstruction accuracy of the implant geometry was 3.2 mm within a non-ferromagnetic environment. We found that although the needles were metallic this did not have a significant influence. We also found for our experimental setups that the CT table and operation table non-ferromagnetic parts had no significant influence on the navigation accuracy. CONCLUSIONS: This navigation system will be a very useful clinical tool for interstitial brachytherapy applications, particularly when critical structures have to be avoided. It also should provide a significant improvement on our existing technique.

New interstitial HDR brachytherapy technique for prostate cancer: CT based 3D planning after transrectal implantation.

We have developed a new interstitial HDR brachytherapy technique for the treatment of prostate cancer using CT based 3D planning after transrectal implantation of four non-parallel needles. CT based needle reconstruction, target definition, evaluation and documentation, including DVHs and 3D imaging, is a feasible, safe and well tolerated treatment concept.

MR knee imaging: axial 3DFT GRASS pulse sequence versus spin-echo imaging for detecting meniscal tears.

The knees of 17 patients (34 menisci) referred for magnetic resonance (MR) imaging to evaluate knee pain were examined using thin axial three-dimensional Fourier transform (3DFT) gradient-refocused acquisition in a steady state (GRASS) images through the menisci, to determine if this method is sensitive and specific for detecting meniscal tears. Results were compared with spin-echo images with long TR and double-echo TE in both coronal and sagittal planes. Arthroscopy results, available in each case, were used as the "gold standard." Twelve meniscal tears were identified at arthroscopy. Axial 3DFT GRASS technique detected 10 of the 12 meniscal tears compared to 9 or 12 using spin-echo technique. With axial 3DFT GRASS technique one false-positive meniscal tear was reported, compared with two false-positive tears on spin-echo images. Axial 3DFT GRASS images were very useful in detecting peripheral tears, showing displaced meniscal fragments, and evaluating complex tears. In this small study, thin axial 3DFT GRASS images were comparable to spin-echo images for detecting meniscal tears, and were helpful in complicated cases in which they provided complementary information to that obtained from spin-echo images.

Can prophylactic application of immunoglobulin decrease radiotherapy-induced oral mucositis?

Therapeutic application of immunoglobulin is reported to be successful in radiation-induced oral and oropharyngeal mucositis. In this study the efficacy of prophylactic application of immunoglobulin was investigated. In 42 patients with head and neck cancer, postoperative radiation treatment or radiation combined with chemotherapy was performed. In 20 consecutive patients, prophylactic mucositis treatment consisted of panthenol (4 x 10 ml/day) and nystatin (4 x 1 ml/day). The 22 following patients received, supplementary to panthenol and nystatin, 800 mg (5 ml) human immunoglobulin intramuscularly once weekly. During the treatment time, the degree of mucositis was examined 3 times a week. The distribution of maximal mucositis degree revealed slightly more severe mucous membrane reaction in the control group compared with the immunoglobulin group (n.s.). The analysis of mean mucositis degrees in both groups demonstrated statistically significant differences (t test, p = 0.031) related to the entire group (n = 42) and to those 16 patients receiving radiation combined with chemotherapy. There was no significant immunoglobulin-induced effect on mucositis in patients treated by radiation alone. The time from the beginning of therapy to the first interruption could be prolonged 5 days in the immunoglobulin group (n.s.). In conclusion, it is demonstrated that the prophylactic application of immunoglobulin seems to lower the degree of radiation-induced mucositis. In comparison to the published data about therapeutically given immunoglobulin, the clinical efficacy of the prophylactic application of immunoglobulin as it is performed in this study is less evident.

Radiation therapy for the prevention of heterotopic ossification at the elbow.

We present nine patients (five men and four women) who underwent surgical excision of clinically significant heterotopic ossification at the elbow. They also received perioperative radiation therapy using total doses between 600 and 1000 cGy. Five received fractionated radiotherapy, with two fractions of 500 cGy applied on the first two postoperative days, and the remaining four were irradiated with single doses of 600 and 700 cGy. After a mean period of observation of 7.7 months (6 to 13) none had radiological recurrence of heterotopic ossification and eight showed clinical improvement. Assessment of the functional outcome showed a mean improvement in the Morrey score from 33.3 to 84.5 points indicating a high therapeutic efficacy of prophylactic irradiation.

First Report of Beech Bark Disease in Michigan.

Beech bark disease of American beech (Fagus grandifolia) is caused by the interaction of an introduced scale insect (Cryptococcus fagisuga) and the native fungus Nectria galligena, or N. coccinea var. faginata, which is thought to be introduced. Infestations of the insect precede development of the disease, and N. galligena is often found before N. coccinea var. faginata. Previously published records indicate that the beech scale extends as far west as eastern Ohio (2) and southern Ontario (Sajan, personal communication). The scale is now well established in several locations in both the Upper Peninsula (UP) and Lower Peninsula (LP) of Michigan. The scale insect has been found in beech stands throughout three counties (Oceana, Mason, and Muskegon) along the Lake Michigan shore in the LP, extending for at least 100 km from north to south, and occurring up to about 80 km inland. In the eastern UP, beech scale has been found in four counties (Alger, Chippewa, Luce, and Schoolcraft). The heaviest beech scale infestations are distributed around Ludington State Park in the west central LP and the Bass Lake Forest Campground in the eastern UP. The extent of the insect infestation suggests that it has been present in Michigan for many years, with anecdotal accounts placing the first observations of beech scale at Ludington State Park around 1990. These infection centers are distant from previously known beech scale infestations and are located in heavily used recreation areas, suggesting that the insect may have been transported by human activity. Perithecia of N. coccinea var. faginata were found in Ludington State Park in the LP at N 44° 1.951', W 86° 29.956' and perithecia of N. galligena were found at the Bass Lake site in the UP, at N 46° 27.748', W 85° 42.478'. The identity of the fungi collected from each location was confirmed by measurements of perithecium and ascospore morphology (1). Perithecia at both sites were scarce and difficult to find. Surveys planned for the summer and fall of 2001 will further delimit the occurrence and distribution of the pathogens involved in the disease in Michigan. To our knowledge, this is the first report of the beech scale and beech bark disease in Michigan, with N. galligena and N. coccinea var. faginata identified as the pathogens. References: (1) H. V. T. Cotter and R. O. Blanchard. Plant Dis. 65:332-334, 1981. (2) M. E. Mielke et al. Plant Dis. 69:905, 1985.

[Radiotherapy in Langerhans-cell histiocytosis. 2 case reports and review of the literature]. / Strahlentherapie bei der Langerhanszell-Histiozytose. Zwei Einzelfallberichte--Literaturübersicht.

The use of radiotherapy in the treatment of Langerhans' cell histiocytosis was first reported in the literature in 1930 and has been proven as effective in numerous studies. We present the results of two female adults with eosinophilic granuloma of bone who underwent conventionally fractionated radiation therapy with total doses of 7 x 1.8 Gy and 7 x 2.0 Gy in four different sites. After observation periods raging from three months to six years local control of the disease was achieved in all treated locations. A review of 18 previously published studies include a total of 310 sites of eosinophilic granuloma of bone in 216 patients. It was demonstrated in 13 studies that the patients had complete relief of symptoms. An average of 94.3% had local control of the symptoms. Furthermore, in 12 studies for a total of 344 cases with involvement of other organs local control was reported in an average of 64.8% (range: 14.3-100%). Based on our own observations and on the literature review we conclude that low dose radiation therapy plays an important role in the management of localised Langerhans' cell histiocytosis. In order to minimise the risk of radiation induced neoplasms an accurate and precise radiation technique is required.

Hypofractionated radiotherapy for Graves' orbitopathy.

BACKGROUND: Radiotherapy (RT) has been proven effective in the management of Graves' orbitopathy in numerous studies. Most commonly is the use of conventional fractionated RT and the value of hypofractionated irradiation has not been investigated. MATERIALS AND METHODS: The results in 33 euthyroid cases who underwent RT with a total dose of 21.0 Gy given in three weekly fractions of 3.0 Gy are retrospectively analyzed. The duration of symptoms ranged from 1-84 months and all of the cases had treatment failure after previous administration of corticosteroids. After a mean follow-up period of 33.6 months the overall results were assessed according to the criteria by Donaldson et al. and for evaluation of the clinical outcome a classification with the main criteria being eye-lid changes, exophthalmos, myopathy and eye nerve involvement was used. RESULTS: At follow-up, the overall response to RT was 84.8% (28/33 cases). The analysis with the clinical classification demonstrated that in 19/33 (57.6%) cases occurred a decrease of eye lid changes and exophthalmos and 12/33 (36.4%) had a relief of myopathy. 2/33 cases (6.0%) developed an eye nerve compression causing the necessity of surgical decompression. 3/33 cases (9.0%) had a progression of at least of one of the single criteria of the score and therefore they were classified as non-responders. CONCLUSIONS: Hypofractionated RT has been proven effective for treatment of severe cases of Graves' orbitopathy in cases with a prolongated duration of symptoms. The comparison with literature data demonstrate that the results after hypofractionated RT are comparable to those obtained after conventional fractionated RT.

[Postoperative, conventional fractionated radiotherapy for prevention of heterotopic ossification after total endoprosthesis of the hip joint]. / Die postoperative, konventionell fraktionierte Strahlentherapie zur Prävention heterotoper Ossifikationen nach TEP des Hüftgelenkes.

Radiotherapy is the only local means of treatment in the prevention of heterotopic bone formation. It is possible to reduce the incidence of HO following total hip arthroplasty from an average of 50% without further treatment to an average of 8% using different doses and fractionation schemes. In this retrospective clinical study 22 hips of 20 patients were treated with a conventional fractionated radiotherapy. Total doses of 12.0-20.0 Gy in daily fractionation of 200 cGy single doses were applied 18 hips were postoperatively irradiated as secondary prophylaxis against recurrence of HO. 4 hips were high-risk cases with contralateral HO after previous hip surgery. After 6-30 months observation periods the roentgenogramms were analyzed with a modified Brooker-Score. Patients with a score > II were classified as nonresponders. 95.5% of the treated hips showed satisfactory results, only one hip (4.5%) achieved a score IIIA. In this case radiotherapy was interrupted after 3 x 200 cGy. The high therapeutic efficiency of local irradiation in the prevention of heterotopic bone formation following total hip replacement could be proved. No considerable side effects were observed. Further prospective clinical investigations are necessary to optimize the doses and fractionation schemes.

[Radiotherapy in vertebral hemangioma]. / Strahlentherapie bei Wirbelkörperhämangiomen.

Vertebral hemangiomas are the most common benign spinal tumors with an incidence range of 10-12%. Approximately 1-2% of the cases develop clinically significant symptoms causing the necessity for treatment. Based on our own results and a review of the literature we discuss the role of radiotherapy in the management of symptomatic vertebral hemangiomas. A total dose of 30.0 Gy given in five weekly fractions of 2.0 Gy has been proven as effective for the primary treatment and postsurgical irradiation for the prevention of a recurrence. In the literature review the results are summarized of 59 reports in the period of 1929-2000 for a total of 327 cases. The analysis of 55 studies reporting results in 210 cases which underwent primary radiotherapy or combinations with other methods of treatment demonstrated that in 54% occurred a complete relief of symptoms (CR), in 32% a partial relief (PR), and 11% were non-responders (NR). The analysis of 21 reports of 63 cases which were treated with radiotherapy as the sole measure of treatment demonstrated that 57% had a complete remission of symptoms (CR), 32% a partial remission (PR), and 11% did not respond to radiotherapy (NR). We conclude that radiation therapy is very effective in the management of symptomatic vertebral hemangiomas. With regard on the delayed effects of the irradiation, cases with an acute compression of the spinal cord should be treated primarily with a surgical procedure and a postsurgical irradiation is recommended to prevent a relapse of symptoms. In order to minimise acute or late toxicity and the risk of radiation-induced neoplasms the total dose should not exceed 30 Gy.

[The role of external beam radiation therapy in the adjuvant treatment of pigmented villonodular synovitis]. / Stellenwert der externen Radiotherapie bei der adjuvanten Behandlung der pigmentierten villonodulären Synovitis.

AIM: Pigmented villonodular synovitis (PVNS) is a rare proliferative disorder arising from synovial cells of the tendon sheets and joint capsules. The potential value of external beam radiation therapy in the interdisciplinary management of PVNS is demonstrated by a comprehensive literature review on the clinical use of radiotherapy and the results of national patterns of care study (PCS) which was conducted by the German Cooperative Group on Radiotherapy in Benign Diseases (GCG-BD) in 2008-2009. MATERIAL AND METHOD: A structured questionnaire was mailed to all 227 RT institutions in Germany to assess all previous treatments, the RT indication and techniques, the rate of local control, the functional outcome and the possible adverse effects related to the use of external beam radiation therapy (RT). For comparison of the clinical outcome data, a systematic literature research in several international electronic databases and a conventional library search were performed to identify publications addressing the use of RT for PVNS. RESULTS: Based on an overall response rate of 83.2%, the PCS was nationally representative. Ten percent of institutions presented clinical experience with the use of RT for PVNS; from this database a total of 41 treated sites from 14 institutions were evaluable for long-term analysis. The primary therapeutic approach was cytoreductive surgery in all cases. In cases of residual tissue or complete resection of extensive local recurrences, RT was applied in 39 cases (95.1%). An excellent or good functional outcome was noted in 34 cases (82.9%). The use of RT was not associated with early or late toxicity larger than RTOG grade II. The literature review identified 19 published studies (1940-2009) which represented a total of 140 cases or patients, respectively. After follow-up periods ranging from 1-250 months and administration of total doses in the range of 16-50 Gy the overall rate of local control was 84.5%. CONCLUSION: Both the results of the national PCS and the literature review demonstrate that RT is a very safe and effective treatment option for the prevention of disease progression or recurrence in PVNS after primary surgical interventions. The planned treatment volume should include the whole synovial space and eventually all invasive components of the disease. Currently, total doses in the range of 30-36 Gy are recommended.