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Sample records for tomography-guided stereotactic implantation

  1. Application and machine accuracy of a new frameless computed tomography-guided stereotactic brain biopsy system in dogs.

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    Taylor, Amanda R; Cohen, Noah D; Fletcher, Stephen; Griffin, John F; Levine, Jonathan M

    2013-01-01

    The purpose of this study was to describe application and machine accuracy for a new computed tomography (CT) guided, frameless, stereotactic brain biopsy system in dogs. Heads from ten canine cadavers were secured to a bite-plate with six attached fiducial markers and imaged using CT. Fiducialized CT images were imported into stereotactic software and spherical phantom lesions between 3.9 and 5.5 mm in diameter were created in six locations. Infrared cameras and reflective markers were used to register fiducials to the reconstructed image set. Coordinates in the X, Y, and Z planes were identified for each lesion center. Iohexol (1.5 μl of 240 mgI/ml) was injected into the center of each lesion and CT scans were repeated. Pre- and postinjection CT images for each cadaver were fused using the system software. Application accuracy was calculated using the center of each phantom lesion and the center of each injected contrast material location. Machine accuracy was calculated using a phantom with known distances between four fixed points in the X, Y, and Z planes. Mean application accuracy in the first 5 cadavers was 4.3 mm (95% confidence interval [CI] 2.9-4.3 mm) and in the second 5 cadavers was 2.9 mm (95% CI 2-3.9 mm). The more superficial lesions were targeted significantly less accurately than the deeper lesions (P = 0.0183). Median machine accuracy was 0.1 mm and the range was 0.1-0.2 mm. Findings supported use of the new biopsy system for canine brain lesions >3.9 mm in diameter. © 2013 Veterinary Radiology & Ultrasound.

  2. Clinical efficacy of computed tomography-guided iodine-125 seed implantation therapy in patients with advanced spinal metastatic tumors

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    Zhang LY

    2015-12-01

    invasive method for the treatment of patients with spinal metastatic tumors. It is a possible alternative therapy for the treatment of spinal metastases. Keywords: spinal metastatic tumor, iodine isotopes, computed tomography guided, interventional treatment

  3. Computed tomography-guided iodine-125 interstitial implantation as an alternative treatment option for lung cancer.

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    Jiang, G; Li, Z; Ding, A; Zhou, F; Jiao, W; Tang, D; Qiu, W; Yue, L; Xu, W

    2015-02-01

    The aim was to evaluate the safety, feasibility and efficacy of computed tomography (CT)-guided percutaneous interstitial brachytherapy using radioactive iodine-125 ( 125 I) seeds for the treatment of lung cancer. Included in this study were 45 male and 35 female patients aged 52-85 years (mean 72-year) who were diagnosed with lung cancer. Of the 80 cases of lung cancer, 38 were pathologically confirmed as squamous cell carcinoma, 29 as adenocarcinoma, 2 as small cell lung cancer, and 11 as metastatic lung cancer. Percutaneous interstitial implantation of radioactive 125 I seeds was performed under CT guidance. The treatment planning system was used to reconstruct three-dimensional images of the tumor to determine the quantity and distribution of 125 I seeds to be implanted. Under CT guidance, 125 I seeds were embedded into the tumor, with the matched peripheral dose set at 100-130 Gy. Follow-up CT scan was done in 2-month to explore the treatment efficacy. The procedure was successful in all patients. No major procedure-associated death occurred. The duration of follow-up was 6-month. Complete response (CR) was seen in 38 cases (47.5%), partial response (PR) in 27 cases (33.75%), stable disease (SD) in 10 cases (12.5%), and progressive disease in 5 cases (6.25%), with a local control rate (CR + PR + SD) of 93.75%. The 2-, 4- and 6-month overall response rate (CR + PR) was 78%, 83% and 81%, respectively. Implantation of CT-guided 125 I seeds is a safe and effective alternative option for the treatment of lung cancer.

  4. An analysis of brachytherapy with computed tomography-guided permanent implantation of Iodine-125 seeds for recurrent nonkeratin nasopharyngeal carcinoma

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    Shen X

    2015-05-01

    Full Text Available Xinying Shen,1,2 Yong Li,2 Yanfang Zhang,2 Jian Kong,2 Yanhao Li1 1Department of Interventional Radiology, Nanfang Hospital, Southern Medical University, Guangzhou, 2Department of Interventional Radiology, Shenzhen People’s Hospital, The Second Clinical Medical College of Jinan University, Shenzhen, People’s Republic of China Background: 125I seed implantation is a new method in treatment of nasopharyngeal carcinoma (NPC, and it is worthwhile to evaluate its feasibility. In this study, we performed brachytherapy with computed tomography (CT-guided permanent implantation of 125I seeds in the treatment of patients with the recurrence of NPC.Methods: A total 30 patients (20 male and ten female at the median age of 55 (range 25–80 years were diagnosed with recurrent nonkeratin NPC, with a total 38 lesions and a short disease-free interval (median ~11 months after primary radiotherapy alone or combined with chemotherapy. Patients received CT scan, starting from 2 months after the treatment. Follow-up was conducted for ~2–38 months to observe the local control rate and overall survival rate. We also analyzed the possible correlation between survival periods and the status of recurrent tumors.Results: The local control rates at 6, 12, 24, 30, and 36 months after the procedure of 125I seed implantation were 86.8%, 73.7%, 26.3%, 15.8%, and 5.3%, respectively. The overall 1-, 2-, and 3-year survival rates were 80.0% (24/30, 30.0% (9/30, and 6.7% (2/30, respectively, with a median survival period of 18 months (17.6±8.6 months. Interestingly, the survival periods of the patients who had primary radiotherapy with or without chemotherapy were 15.8±7.9 and 24.3±7.9 months, respectively. Kaplan–Meier survival analysis demonstrated that χ2 (log rank was 7.555, with very significant difference (P<0.01. The survival periods of patients in tumor stages I, II, III, and IV were 25.4±8.7, 19.8±9.4, 16.1±4.5, and 12.8±7.8 months, respectively, with

  5. Stereotactic technique of RF antenna implantation for brain hyperthermia

    International Nuclear Information System (INIS)

    Takahashi, H.; Uzuka, T.; Grinev, I.; Tanaka, R.

    2005-01-01

    Full text: We have tried 13.56 MHz RF interstitial hyperthermia for the patients with malignant brain tumor. The purpose of this report is to assess the complication risk rate and the achievement yield of stereotactic procedure for RF antenna implantation into the deep-seated brain tumor. One hundred and twenty-five patients underwent 144 stereotactic RF antenna implantation procedures for interstitial hyperthermia for malignant brain tumors at Niigata University, Japan. One hundred and eight patients had malignant gliomas (54 primary, 54 recurrent), 24 had metastatic tumors, 5 had malignant lymphomas, 5 had meningiomas and 2 had miscellaneous tumors. Indication of this trial was the tumor with inoperative deep-seated tumor or elderly patients. RF antennas and catheters for thermistor probes were set into the tumor with stereotactic apparatus under local anesthesia. Postoperative CT scan underwent in order to assess the accuracy of antenna setting and to check the complications. The hyperthermic treatment underwent with a single antenna in 85 patients, 2 antennas in 43 patients, 3 in 2, 4 in 12, 5 in 1 and 6 antennas in 1 patient. Appropriate RF antenna positioning was obtained in 138 of 144 procedures (95.8 %). Six patients incurred complications (4.2 %). Three patients suffered intratumoral hemorrhage. RF antennas were set into the inappropriate position in 2 cases, hyperthermia was not achieved. One patient occurred with liquorrhea. However, six patients (4.2 %) incurred complications, stereotactic RF antenna setting was a safe and reliable technique of the hyperthermic treatment for the patients with malignant brain tumors. (author)

  6. Stability of percutaneously implanted markers for lung stereotactic radiotherapy

    DEFF Research Database (Denmark)

    Persson, Gitte Bjørnsen Fredberg; Josipovic, Mirjana; Von Der Recke, Peter

    2013-01-01

    The purpose of this study was to evaluate the stability of complex markers implanted into lung tumors throughout a course of stereotactic body radiotherapy (SBRT). Fifteen patients referred for lung SBRT were prospectively included. Radio-opaque markers were implanted percutaneously, guided...... by computed tomography (CT). Deep inspiration breath-hold CT scans (BHCT) were acquired at planning and on three treatment days. The treatment days' BHCTs were registered to the planning BHCT. Intraobserver uncertainty in both tumor and marker registration was determined. Deviations in the difference between...... tumor and marker-based image registrations of the BHCT scans during treatment quantified the marker stability. Marker position deviation relative to tumor position of less than 2 mm in all three dimensions was considered acceptable for treatment delivery precision. Intra observer uncertainties for image...

  7. Treatment by stereotactic radiotherapy of tumoral injuries after implant placement: preliminary study

    International Nuclear Information System (INIS)

    Meingan, P.; Rio, E.; Labbe-Devilliers, C.; Geffroy, D.; Ricaud-Couprie, M.; Doutriaux-Dumoulin, I.

    2009-01-01

    Objective: to evaluate the interest and the place of stereotactic radiotherapy in the treatment of primitive or secondary tumoral injuries of the liver. To describe the technique of implants placement. Conclusion: the liver stereotactic radiotherapy, after implant placement, seems to be an alternative or complementary therapy to the radiofrequency for patients refused for surgery, with moderated side effects and a noticeable survival. Complementary studies, especially associated to radiofrequency must be considered. (N.C.)

  8. Refractory nasopharyngeal carcinoma: positron emission tomography combined with computed tomography-guided 125I seed implantation therapy after repeated traditional radiochemotherapy.

    Science.gov (United States)

    Zhang, Fujun; Wu, Ketong; Gao, Fei; Zhang, Weidong; Shi, Feng; Li, Chuanxing

    2013-09-01

    To evaluate the feasibility of positron emission tomography combined with computed tomography (PET-CT)-guided (125)I seed implantation in the treatment of patients with refractory nasopharyngeal carcinoma after repeated traditional radiochemotherapy. Case series with chart review. University medical center. A total of 26 patients (18 men, 8 women; mean age, 51.3 ± 10.8 years; totaling 53 lesions with an average diameter of 2.86 ± 1.61 cm) were treated by PET-CT-guided (125)I seed implantation. All of the patients received a PET-CT scan 2 months after the treatment. Follow-up was conducted for ~2 to 43 months (median, 28.2 months) to observe the local control rate, overall survival rate, and clinical complications. The local control rates of refractory nasopharyngeal carcinoma after repeated traditional radiochemotherapy after 3, 6, 12, 24, and 36 months were 90.6% (48/53), 79.3% (42/53), 71.7% (38/53), 62.3% (33/53), and 56.6% (30/53), respectively. The overall 1-, 2-, and 3-year survival rates were 87.2%, 71.3%, and 56.5%, respectively, with a median survival time of 28.2 months. Of all patients, 19.2% (5/26) died of local recurrence and 15.4% (4/26) died of metastases. One patient died of hypertensive cerebral hemorrhage, and another patient died from cachexia and infection. The long-term complications included hyperpigmentation at operative sites (n = 5), insensible feeling on the lateral cheek (n = 2), dryness of the oral cavity (n = 1), and headache (n = 1). PET-CT-guided (125)I seed implantation is an acceptable and feasible method for treating refractory nasopharyngeal carcinoma with minimal damage and few complications.

  9. Cardiac embolization of an implanted fiducial marker for hepatic stereotactic body radiotherapy: a case report

    Directory of Open Access Journals (Sweden)

    Hennessey Hooman

    2009-11-01

    Full Text Available Abstract Introduction In liver stereotactic body radiotherapy, reduction of normal tissue irradiation requires daily image guidance. This is typically accomplished by imaging a surrogate to the tumor. The surrogate is often an implanted metal fiducial marker. There are few reports addressing the specific risks of hepatic fiducial marker implantation. These risks are assumed to be similar to percutaneous liver biopsies which are associated with a 1-4% complication rate - almost always pain or bleeding. To the best of our knowledge, we present the first case of such a fiducial marker migrating to the heart. Case presentation An 81-year-old Caucasian man (5 years post-gastrectomy for a gastric adenocarcinoma was referred post-second line palliative chemotherapy for radiotherapy of an isolated liver metastasis. It was decided to proceed with treatment and platinum fiducials were chosen for radiation targeting. Under local anesthesia, three Nester embolization coils (Cook Medical Inc., Bloomington, IN, USA were implanted under computed tomography guidance. Before the placement of each coil, the location of the tip of the delivery needle was confirmed by computed tomography imaging. During the procedure, the third coil unexpectedly migrated through the hepatic vein to the inferior vena cava and lodged at the junction of the vena cava and the right atrium. The patient remained asymptomatic. He was immediately referred to angiography for extraction of the coil. Using fluoroscopic guidance, an EN Snare Retrieval System (Hatch Medical L.L.C., Snellville, GA, USA was introduced through a jugular catheter; it successfully grasped the coil and the coil was removed. The patient was kept overnight for observation and no immediate or delayed complications were encountered due to the migration or retrieval of the coil. He subsequently went on to be treated using the remaining fiducials. Conclusion Implanted fiducial markers are increasingly used for stereotactic

  10. The dosimetric impact of implants on the spinal cord dose during stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Yazici, Gozde; Sari, Sezin Yuce; Yedekci, Fazli Yagiz; Yucekul, Altug; Birgi, Sumerya Duru; Demirkiran, Gokhan; Gultekin, Melis; Hurmuz, Pervin; Yazici, Muharrem; Ozyigit, Gokhan; Cengiz, Mustafa

    2016-01-01

    The effects of spinal implants on dose distribution have been studied for conformal treatment plans. However, the dosimetric impact of spinal implants in stereotactic body radiotherapy (SBRT) treatments has not been studied in spatial orientation. In this study we evaluated the effect of spinal implants placed in sawbone vertebra models implanted as in vivo instrumentations. Four different spinal implant reconstruction techniques were performed using the standard sawbone lumbar vertebrae model; 1. L2-L4 posterior instrumentation without anterior column reconstruction (PI); 2. L2-L4 anterior instrumentation, L3 corpectomy, and anterior column reconstruction with a titanium cage (AIAC); 3. L2-L4 posterior instrumentation, L3 corpectomy, and anterior column reconstruction with a titanium cage (PIAC); 4. L2-L4 anterior instrumentation, L3 corpectomy, and anterior column reconstruction with chest tubes filled with bone cement (AIABc). The target was defined as the spinous process and lamina of the lumbar (L) 3 vertebra. A thermoluminescent dosimeter (TLD, LiF:Mg,Ti) was located on the measurement point anterior to the spinal cord. The prescription dose was 8 Gy and the treatment was administered in a single fraction using a CyberKnife® (Accuray Inc., Sunnyvale, CA, USA). We performed two different treatment plans. In Plan A beam interaction with the rod was not limited. In plan B the rod was considered a structure of avoidance, and interaction between the rod and beam was prevented. TLD measurements were compared with the point dose calculated by the treatment planning system (TPS). In plan A, the difference between TLD measurement and the dose calculated by the TPS was 1.7 %, 2.8 %, and 2.7 % for the sawbone with no implant, PI, and PIAC models, respectively. For the AIAC model the TLD dose was 13.8 % higher than the TPS dose; the difference was 18.6 % for the AIABc model. In plan B for the AIAC and AIABc models, TLD measurement was 2.5 % and 0.9 % higher than the

  11. A technique for accurate planning of stereotactic brain implants prior to head ring fixation

    International Nuclear Information System (INIS)

    Ulin, Kenneth; Bornstein, Linda E.; Ling, Marilyn N.; Saris, Stephen; Wu, Julian K.; Curran, Bruce H.; Wazer, David E.

    1997-01-01

    Purpose: A two-step procedure is described for accurate planning of stereotactic brain implants prior to head-ring fixation. Methods and Materials: Approximately 2 weeks prior to implant a CT scan without the head ring is performed for treatment-planning purposes. An entry point and a reference point, both marked with barium and later tattooed, facilitate planning and permit correlation of the images with a later CT scan. A plan is generated using a conventional treatment-planning system to determine the number and activity of I-125 seeds required and the position of each catheter. I-125 seed anisotropy is taken into account by means of a modification to the treatment planning program. On the day of the implant a second CT scan is performed with the head ring affixed to the skull and with the same points marked as in the previous scan. The planned catheter coordinates are then mapped into the coordinate system of the second CT scan by means of a manual translational correction and a computer-calculated rotational correction derived from the reference point coordinates in the two scans. Results: The rotational correction algorithm was verified experimentally in a Rando phantom before it was used clinically. For analysis of the results with individual patients a third CT scan is performed 1 day following the implant and is used for calculating the final dosimetry. Conclusion: The technique that is described has two important advantages: 1) the number and activity of seeds required can be accurately determined in advance; and 2) sufficient time is allowed to derive the best possible plan

  12. Analysis of activity and motor coordination in rats undergoing stereotactic surgery and implantation of a cannula into the dorsal hippocampus.

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    Hernández-López, F; Rodríguez-Landa, J F; Puga-Olguín, A; Germán-Ponciano, L J; Rivadeneyra-Domínguez, E; Bernal-Morales, B

    Stereotactic surgery is used to place electrodes or cannulas in the brain in order to study the function of several brain structures in preclinical research. The hippocampus has been extensively studied with this methodology due to its involvement in a wide range of neurological, cognitive, emotional, and affective disorders. However, the effects of stereotactic surgery on coordination and motor activity should be evaluated in order to determine whether this surgical procedure causes any neurological alterations that may bias the results of studies incorporating this technique. We evaluated the effects of stereotactic surgery and implantation of a cannula into the hippocampus of female Wistar rats on the motor activity, forced swim, and rotarod tests. The stage of the oestrous cycle was included in the statistical analysis. Stereotactic surgery had no impact on any of the motor activity variables assessed in the open field (squares crossed, time spent in grooming, and rearing), forced swim (turning behaviour, lateral swimming, latency to first immobility, and time spent immobile), and rotarod (latency to fall) tests, compared with intact rats. Regardless of surgical manipulation, rats in the metestrus and diestrus stages crossed a greater number of squares and displayed longer immobility times than those in the proestrus and estrus stages. Stereotactic surgery for cannula placement in the dorsal hippocampus does not affect coordination and motor activity in rats. We can therefore conclude that this procedure has no neurological complications that may interfere in the interpretation of results of studies applying this technique. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Interventional management of intractable sympathetically mediated pain by computed tomography-guided catheter implantation for block and neuroablation of the thoracic sympathetic chain: technical approach and review of 322 procedures.

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    Agarwal-Kozlowski, K; Lorke, D E; Habermann, C R; Schulte am Esch, J; Beck, H

    2011-08-01

    We retrospectively evaluated the safety and efficacy of computed tomography-guided placement of percutaneous catheters in close proximity to the thoracic sympathetic chain by rating pain intensity and systematically reviewing charts and computed tomography scans. Interventions were performed 322 times in 293 patients of mean (SD) age 59.4 (17.0) years, and male to female ratio 105:188, with postherpetic neuralgia (n = 103, 35.1%), various neuralgias (n = 88, 30.0%), complex regional pain syndrome (n = 69, 23.6%), facial pain (n = 17, 5.8%), ischaemic limb pain (n = 7, 2.4%), phantom limb pain (n = 4, 1.4%), pain following cerebrovascular accident (n = 2, 0.7%), syringomyelia (n = 2, 0.7%) and palmar hyperhidrosis (n = 1, 0.3%). The interventions were associated with a total of 23 adverse events (7.1% of all procedures): catheter dislocation (n = 9, 2.8%); increase in pain intensity (n = 8, 2.5%); pneumothorax (n = 3, 0.9%); local infection (n = 2, 0.6%); and puncture of the spinal cord (n = 1, 0.3%). Continuous infusion of 10 ml.h(-1) ropivacaine 0.2% through the catheters decreased median (IQR [range]) pain scores from 8 (6-9 [2-10]) to 2 (1-3 [0-10]) (p < 0.0001). Chemical neuroablation was necessary in 137 patients (46.8%). We conclude that this procedure leads to a significant reduction of pain intensity in otherwise obstinate burning or stabbing pain and is associated with few hazards. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

  14. Potentials and Limitations of Guiding Liver Stereotactic Body Radiation Therapy Set-Up on Liver-Implanted Fiducial Markers

    International Nuclear Information System (INIS)

    Wunderink, Wouter; Mendez Romero, Alejandra; Seppenwoolde, Yvette; Boer, Hans de; Levendag, Peter; Heijmen, Ben

    2010-01-01

    Purpose: We investigated the potentials and limitations of guiding liver stereotactic body radiation therapy (SBRT) set-up on liver-implanted fiducial markers. Methods and Materials: Twelve patients undergoing compression-supported SBRT in a stereotactic body frame received fluoroscopy at treatment preparation and before each treatment fraction. In fluoroscopic videos we localized the markers and diaphragm tip at expiration and the spine (measurements on free-breathing and abdominal compression). Day-to-day displacements, rotations (markers only), and deformations were determined. Marker guidance was compared to conventional set-up strategies in treatment set-up simulations. Results: For compression, day-to-day motion of markers with respect to their centers of mass (COM) was σ = 0.9 mm (random error SD), Σ = 0.4 mm (systematic error SD), and o and 7.2 o were observed. For markers not surrounding the tumor, e.g., 5 cm between respective COMs, these changes could effect residual tumor set-up errors up to 8.4 mm, 1.1 mm median (deformations), and 3.1 mm to 6.3 mm (rotations). Compression did not systematically contribute to deformations and rotations, since similar results were observed for free-breathing. Conclusions: If markers can be implanted near and around the tumor, residual set-up errors by marker guidance are small compared to those of conventional set-up methods, allowing high-precision tumor radiation set-up. However, substantial errors may result if markers are not implanted precisely, requiring further research to obtain adequate safety margins.

  15. Kilovoltage Imaging of Implanted Fiducials to Monitor Intrafraction Motion With Abdominal Compression During Stereotactic Body Radiation Therapy for Gastrointestinal Tumors

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    Yorke, Ellen, E-mail: yorke@mskcc.org [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Xiong, Ying [Department of Radiation Oncology, China-Japan Friendship Hospital, Beijing (China); Han, Qian [Department of Radiotherapy, Henan Provincial People' s Hospital, Zhengzhou (China); Zhang, Pengpeng; Mageras, Gikas; Lovelock, Michael; Pham, Hai; Xiong, Jian-Ping [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Goodman, Karyn A. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

    2016-07-01

    Purpose: To assess intrafraction respiratory motion using a commercial kilovoltage imaging system for abdominal tumor patients with implanted fiducials and breathing constrained by pneumatic compression during stereotactic body radiation therapy (SBRT). Methods and Materials: A pneumatic compression belt limited respiratory motion in 19 patients with radiopaque fiducials in or near their tumor during SBRT for abdominal tumors. Kilovoltage images were acquired at 5- to 6-second intervals during treatment using a commercial system. Intrafractional fiducial displacements were measured using in-house software. The dosimetric effect of the observed displacements was calculated for 3 sessions for each patient. Results: Intrafraction displacement patterns varied between patients and between individual treatment sessions. Averaged over 19 patients, 73 sessions, 7.6% of craniocaudal displacements exceeded 0.5 cm, and 1.2% exceeded 0.75 cm. The calculated single-session dose to 95% of gross tumor volume differed from planned by an average of −1.2% (range, −11.1% to 4.8%) but only for 4 patients was the total 3-session calculated dose to 95% of gross tumor volume more than 3% different from planned. Conclusions: Our pneumatic compression limited intrafractional abdominal target motion, maintained target position established at setup, and was moderately effective in preserving coverage. Commercially available intrafractional imaging is useful for surveillance but can be made more effective and reliable.

  16. CT-guided stereotactic neurosurgery

    International Nuclear Information System (INIS)

    Takizawa, Takaaki; Sato, Shoju; Matsumoto, Akira; Sano, Akira; Takahashi, Kazunori; Murakami, Yuji; Ohta, Kosuke

    1985-01-01

    Brown-Roberts-Wells stereotactic instruments were used for CT guided stereotactic surgery in 54 cases (65 operations). Stereotactic biopsy was done in 9 cases and successive regional chemotherapy was done in 3 cases. Stereotactic drainage was done in 2 cases of bacterial abcess, 3 cases of cystic neoplasm and 33 cases (43 operations) of intracerebral hematoma. CT guided stereotactic procedure was valuable for the correct cannulation to the center of the cavity. We tried to utilize CT image for the selection of targets for stereotactic functional neurosurgical procedures in 6 cases. In the cases of thalamotomy, the information derived from CT made the operation safer than that by contrast ventriculography alone. In all cases of electrode implantation for deep brain stimulation, accurate and precise electrode placement was achieved from CT images alone. This rapid and easy surgical technique was useful also for poor risk patients. (author)

  17. An interactive program system for the stereotactic interstitial implantation of radionuclids in brain tumors

    International Nuclear Information System (INIS)

    Birg, W.; Schneider, J.; Bauer, S.; Mundinger, F.

    1979-01-01

    The dose-volume calculation in interstitial long time irradiation (Ir-192 and I-125) poses special problems in the case of cerebral tumors, due to the functional importance of neighboring structures. The knowledge of the isodose distribution is of vital importance. To overcome these problems the authors have developed an interactive program system using the data from CT-scans to localize the radioactive implants and to calculate the therapeutic activities. The CT-picture is projected by means of an epidiascope onto the working board of a digitizer. Then the tumor contours are fed in the computer under program control and the computer calculates the ''activity'' center of the tumor contour previously stored together with its mean radius. The corresponding isodose curves are plotted onto the graphic screen together with the tumor contours, and these can then be plotted onto a transparent X-ray film. (Auth.)

  18. High Retention and Safety of Percutaneously Implanted Endovascular Embolization Coils as Fiducial Markers for Image-Guided Stereotactic Ablative Radiotherapy of Pulmonary Tumors

    International Nuclear Information System (INIS)

    Hong, Julian C.; Yu Yao; Rao, Aarti K.; Dieterich, Sonja; Maxim, Peter G.; Le, Quynh-Thu; Diehn, Maximilian; Sze, Daniel Y.; Kothary, Nishita; Loo, Billy W.

    2011-01-01

    Purpose: To compare the retention rates of two types of implanted fiducial markers for stereotactic ablative radiotherapy (SABR) of pulmonary tumors, smooth cylindrical gold 'seed' markers ('seeds') and platinum endovascular embolization coils ('coils'), and to compare the complication rates associated with the respective implantation procedures. Methods and Materials: We retrospectively analyzed the retention of percutaneously implanted markers in 54 consecutive patients between January 2004 and June 2009. A total of 270 markers (129 seeds, 141 coils) were implanted in or around 60 pulmonary tumors over 59 procedures. Markers were implanted using a percutaneous approach under computed tomography (CT) guidance. Postimplantation and follow-up imaging studies were analyzed to score marker retention relative to the number of markers implanted. Markers remaining near the tumor were scored as retained. Markers in a distant location (e.g., pleural space) were scored as lost. CT imaging artifacts near markers were quantified on radiation therapy planning scans. Results: Immediately after implantation, 140 of 141 coils (99.3%) were retained, compared to 110 of 129 seeds (85.3%); the difference was highly significant (p < 0.0001). Of the total number of lost markers, 45% were reported lost during implantation, but 55% were lost immediately afterwards. No additional markers were lost on longer-term follow-up. Implanted lesions were peripherally located for both seeds (mean distance, 0.33 cm from pleural surface) and coils (0.34 cm) (p = 0.96). Incidences of all pneumothorax (including asymptomatic) and pneumothorax requiring chest tube placement were lower in implantation of coils (23% and 3%, respectively) vs. seeds (54% and 29%, respectively; p = 0.02 and 0.01). The degree of CT artifact was similar between marker types. Conclusions: Retention of CT-guided percutaneously implanted coils is significantly better than that of seed markers. Furthermore, implanting coils is at

  19. Computerized method for estimation of the location of a lung tumor on EPID cine images without implanted markers in stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Arimura, H; Toyofuku, F; Higashida, Y; Onizuka, Y; Terashima, H; Egashira, Y; Shioyama, Y; Nomoto, S; Honda, H; Nakamura, K; Yoshidome, S; Anai, S

    2009-01-01

    The purpose of this study was to develop a computerized method for estimation of the location of a lung tumor in cine images on an electronic portal imaging device (EPID) without implanted markers during stereotactic body radiotherapy (SBRT). Each tumor region was segmented in the first EPID cine image, i.e., reference portal image, based on a multiple-gray level thresholding technique and a region growing technique, and then the image including the tumor region was cropped as a 'tumor template' image. The tumor location was determined as the position in which the tumor template image took the maximum cross-correlation value within each consecutive portal image, which was acquired in cine mode on the EPID in treatment. EPID images with 512 x 384 pixels (pixel size: 0.56 mm) were acquired at a sampling rate of 0.5 frame s -1 by using energies of 4, 6 or 10 MV on linear accelerators. We applied our proposed method to EPID cine images (226 frames) of 12 clinical cases (ages: 51-83, mean: 72) with a non-small cell lung cancer. As a result, the average location error between tumor points obtained by our method and the manual method was 1.47 ± 0.60 mm. This preliminary study suggests that our method based on the tumor template matching technique might be feasible for tracking the location of a lung tumor without implanted markers in SBRT.

  20. Computerized tomography-guided neurolytic splanchnic nerve block

    International Nuclear Information System (INIS)

    Henriquet, Franco; De Martini, Giuseppe; Roy, Maria Teresa; Pretrolesi, Fabio; Martinoli, Carlo; Cariati, Maurizio; Fiorentini, Franco.

    1997-01-01

    Computerized tomography-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. Computerized tomography yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholism. 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and diet 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as a second line treatment when large lesions change celia anatomy and complicate the percutaneous block of the celiac plexus. Endosulfan, Malathion and Methyl parathion, on the metabolic rate of the estuarine clam, Villorita cyprinoides var. cochinensis, have been investigated. The animals exposed to the lower sublethal concentrations of Endosulfan, Malthion and Methyl parathion consumed oxygen at the rate of 1.60, 1.98 and 2.09 ml. 0 2 g - 1 h -1 respectively, while at the higher concentrations of the pesticides, consumption of oxygen by the animal dropped to nearly half the control value. When compared to Malathion and Methyl parathion. Endosulfan induced animals recorded a greater reduction in her percentage deviation (from control) of oxygen consumption, possibly due to hypoxia induced by the pollutants

  1. Computed tomography-guided percutaneous biopsy of pancreatic masses using pneumodissection

    Directory of Open Access Journals (Sweden)

    Chiang Jeng Tyng

    2013-06-01

    Full Text Available Objective To describe the technique of computed tomography-guided percutaneous biopsy of pancreatic tumors with pneumodissection. Materials and Methods In the period from June 2011 to May 2012, seven computed tomography-guided percutaneous biopsies of pancreatic tumors utilizing pneumodissection were performed in the authors' institution. All the procedures were performed with an automatic biopsy gun and coaxial system with Tru-core needles. The biopsy specimens were histologically assessed. Results In all the cases the pancreatic mass could not be directly approached by computed tomography without passing through major organs and structures. The injection of air allowed the displacement of adjacent structures and creation of a safe coaxial needle pathway toward the lesion. Biopsy was successfully performed in all the cases, yielding appropriate specimens for pathological analysis. Conclusion Pneumodissection is a safe, inexpensive and technically easy approach to perform percutaneous biopsy in selected cases where direct access to the pancreatic tumor is not feasible.

  2. Computed tomography-guided percutaneous biopsy of pancreatic masses using pneumodissection

    International Nuclear Information System (INIS)

    Tyng, Chiang Jeng; Bitencourt, Almir Galvao Vieira; Almeida, Maria Fernanda Arruda; Barbosa, Paula Nicole Vieira; Martins, Eduardo Bruno Lobato; Junior, Joao Paulo Kawaoka Matushita; Chojniak, Rubens; Coimbra, Felipe Jose Fernandez

    2013-01-01

    Objective: to describe the technique of computed tomography-guided percutaneous biopsy of pancreatic tumors with pneumodissection. Materials and methods: in the period from June 2011 to May 2012, seven computed tomography guided percutaneous biopsies of pancreatic tumors utilizing pneumodissection were performed in the authors' institution. All the procedures were performed with an automatic biopsy gun and coaxial system with Tru-core needles. The biopsy specimens were histologically assessed. Results: in all the cases the pancreatic mass could not be directly approached by computed tomography without passing through major organs and structures. The injection of air allowed the displacement of adjacent structures and creation of a safe coaxial needle pathway toward the lesion. Biopsy was successfully performed in all the cases, yielding appropriate specimens for pathological analysis. Conclusion: Pneumodissection is a safe, inexpensive and technically easy approach to perform percutaneous biopsy in selected cases where direct access to the pancreatic tumor is not feasible. (author)

  3. Computed tomography-guided percutaneous gastrostomy: initial experience at a cancer center

    Energy Technology Data Exchange (ETDEWEB)

    Tyng, Chiang Jeng; Santos, Erich Frank Vater; Guerra, Luiz Felipe Alves; Bitencourt, Almir Galvao Vieira; Barbosa, Paula Nicole Vieira Pinto; Chojniak, Rubens [A. C. Camargo Cancer Center, Sao Paulo, SP (Brazil); Universidade Federal do Espirito Santo (HUCAM/UFES), Vitoria, ES (Brazil). Hospital Universitario Cassiano Antonio de Morais. Radiologia e Diagnostico por Imagem

    2017-03-15

    Gastrostomy is indicated for patients with conditions that do not allow adequate oral nutrition. To reduce the morbidity and costs associated with the procedure, there is a trend toward the use of percutaneous gastrostomy, guided by endoscopy, fluoroscopy, or, most recently, computed tomography. The purpose of this paper was to review the computed tomography-guided gastrostomy procedure, as well as the indications for its use and the potential complications. (author)

  4. ICES (Intraoperative Stereotactic Computed Tomography-Guided Endoscopic Surgery) for Brain Hemorrhage: A Multicenter Randomized Controlled Trial.

    Science.gov (United States)

    Vespa, Paul; Hanley, Daniel; Betz, Joshua; Hoffer, Alan; Engh, Johnathan; Carter, Robert; Nakaji, Peter; Ogilvy, Chris; Jallo, Jack; Selman, Warren; Bistran-Hall, Amanda; Lane, Karen; McBee, Nichol; Saver, Jeffery; Thompson, Richard E; Martin, Neil

    2016-11-01

    Intracerebral hemorrhage (ICH) is a devastating disease without a proven therapy to improve long-term outcome. Considerable controversy about the role of surgery remains. Minimally invasive endoscopic surgery for ICH offers the potential of improved neurological outcome. We tested the hypothesis that intraoperative computerized tomographic image-guided endoscopic surgery is safe and effectively removes the majority of the hematoma rapidly. A prospective randomized controlled study was performed on 20 subjects (14 surgical and 4 medical) with primary ICH of >20 mL volume within 48 hours of ICH onset. We prospectively used a contemporaneous medical control cohort (n=36) from the MISTIE trial (Minimally Invasive Surgery and r-tPA for ICH Evacuation). We evaluated surgical safety and neurological outcomes at 6 months and 1 year. The intraoperative computerized tomographic image-guided endoscopic surgery procedure resulted in immediate reduction of hemorrhagic volume by 68±21.6% (interquartile range 59-84.5) within 29 hours of hemorrhage onset. Surgery was successfully completed in all cases, with a mean operative time of 1.9 hours (interquartile range 1.5-2.2 hours). One surgically related bleed occurred peri-operatively, but no patient met surgical safety stopping threshold end points for intraoperative hemorrhage, infection, or death. The surgical intervention group had a greater percentage of patients with good neurological outcome (modified Rankin scale score 0-3) at 180 and 365 days as compared with medical control subjects (42.9% versus 23.7%; P=0.19). Early computerized tomographic image-guided endoscopic surgery is a safe and effective method to remove acute intracerebral hematomas, with a potential to enhance neurological recovery. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00224770. © 2016 American Heart Association, Inc.

  5. Uncommon primary tumors of the orbit diagnosed by computed tomography-guided core needle biopsy: report of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Tyng, Chiang Jeng; Matushita Junior, Joao Paulo Kawaoka; Bitencourt, Almir Galvao Vieira; Amoedo, Mauricio Kauark; Barbosa, Paula Nicole Vieira; Chojniak, Rubens, E-mail: almirgvb@yahoo.com.br [A.C.Camargo Cancer Center, Sao Paulo, SP (Brazil). Dept. de Imagem; Neves, Flavia Branco Cerqueira Serra [Hospital do Servidor Publico Estadual, Sao Paulo, SP (Brazil). Div. de Oftalmologia

    2014-11-15

    Computed tomography-guided percutaneous biopsy is a safe and effective alternative method for evaluating selected intra-orbital lesions where the preoperative diagnosis is important for the therapeutic planning. The authors describe two cases of patients with uncommon primary orbital tumors whose diagnosis was obtained by means of computed tomography-guided core needle biopsy, with emphasis on the technical aspects of the procedure. (author)

  6. Corneal perforation by an astigmatic keratotomy performed with an optical coherence tomography-guided femtosecond laser.

    Science.gov (United States)

    Cherfan, Daniel G; Melki, Samir A

    2014-07-01

    We present a case of corneal perforation secondary to an intrastromal astigmatic keratotomy performed with an optical coherence tomography-guided femtosecond laser. The keratotomy was concomitant with cataract surgery and resulted in a flat anterior chamber prior to the start of lens extraction. Interrupted nylon sutures were placed to seal the keratotomy prior to phacoemulsification. Escape of cavitation bubbles into the anterior chamber or the liquid interface can alert the surgeon to the possibility of unintended perforation of the endothelium or the epithelium, respectively. Neither author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Multiple Large Splenic Abscesses Managed with Computed Tomography-guided Percutaneous Catheter Drainage in Children

    Directory of Open Access Journals (Sweden)

    Jung Sook Yeom

    2013-12-01

    Full Text Available Splenic abscess is a rare finding in children. Splenectomy combined with broad-spectrum antibiotics has been the treatment of choice for multiple splenic abscesses. Herein, we report the case of a 14-year-old girl with multiple large splenic abscesses that were successfully managed after two image-guided percutaneous drainage procedures and administration of intravenous antibiotics. Initially, an abscess located at the periphery in the lower pole of the spleen was aspirated under ultrasound guidance. Finally, another abscess located near the hilum of the spleen was drained under computed tomography guidance. To the best of our knowledge, this is the first report of multiple large splenic abscesses treated with computed tomography-guided percutaneous drainage.

  8. Percutaneous computed tomography-guided ethanol injection in aldosterone-producing adrenocortical adenoma

    International Nuclear Information System (INIS)

    Rossi, R.; Savastano, S.; Tommaselli, A.P.

    1995-01-01

    The feasibility, safety and effectiveness of percutaneous computed tomography-guided ethanol injection (PEI-CT) was investigated in a patient affected by aldosterone-producing adenoma (APA). A 42-year-old male patient with typical features of hyperaldosteronism presented a solitary left adrenal adenoma measuring 2 cm, with a normal contralateral gland, evidenced by both CT scan and adrenal [ 75 Se-19]-nor-cholesterol scintigraphy. After normalization of potassium plasma levels, 4 ml of sterile 95% ethanol with 0.5 ml of 80% iothalamate sodium was injected. The procedure was completed in about 30 min. No severe pain or local complication was noted. Five hour after PEI, a fourfold and a twofold increase in aldosterone and cortisol plasma levels were observed, respectively. After 11 days on a normal sodium and potassium diet, normal potassium plasma levels and reduced aldosterone plasma levels were present, with reappearance of an aldosterone postural response. Plasma renin activity and aldosterone plasma levels normalized 1 month later, with reappearance also of a plasma renin activity postural response and maintenance of normal potassium plasma levels on a high sodium and normal potassium diet. The patient has remained hypertensive, although lower antihypertensive drug dosages have been employed. After 17 months, normal biochemical, hormonal and morphological findings were present. The authors suggested PEI-CT as a further alternative approach to surgery in the management of carefully selected patients with APA. 15 refs., 2 figs., 1 tab

  9. Stereotactic imaging in functional neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Hirabayashi, Hidehiro

    2012-07-01

    MRI were compared regarding the volume of the visible RF lesions. The volume was analysed with regard to coagulation parameters, and the location and size of the lesions were further evaluated concerning the clinical outcome. Results:Minor deviations were seen between MRI and CT coordinates of brain targets. The rostro-caudal direction of these deviations were such that they would be easily accounted for during surgery, why MRI can obviate the need for CT in these procedures. MRI using a proton density sequence provided detailed images of the pallidal structures, which demonstrated considerable inter-individual variations in relation to the landmarks of the 3{sup rd} ventricle. By using a direct visualization of the target, each patient will act as his or her own atlas, avoiding the uncertainties of atlas-based targeting. The STN could be visualized on various brands of MRI machines in 8 centers in 6 countries with good discrimination and with a short acquisition time, allowing direct visual targeting. The same scanning technique could be used for postoperative localization of the implanted electrodes. In cases where the lateral and inferior borders of the STN cannot be easily distinguished on MRI the Sukeroku sign and the dent internal-capsule-sign signs might be useful. The volume of a stereotactic RF lesion could be as accurately assessed by CT as by MRI. The lesion's size was most strongly influenced by the temperature used for coagulation. The lesions' volumes were however rather scattered and difficult to predict in the individual patient based solely on the coagulation parameters. For thalamotomy, the results on tremor was not related to the lesion's volume. For pallidotomy, larger and more posterior-ventral lesions had better effect on akinesia while effects on tremor and dyskinesias were not related to size or location of the lesions. Conclusions: The minor deviations of MRI from CT coordinates can be accounted for during surgery, why MRI can

  10. Stereotactic imaging in functional neurosurgery

    International Nuclear Information System (INIS)

    Hirabayashi, Hidehiro

    2012-01-01

    were compared regarding the volume of the visible RF lesions. The volume was analysed with regard to coagulation parameters, and the location and size of the lesions were further evaluated concerning the clinical outcome. Results:Minor deviations were seen between MRI and CT coordinates of brain targets. The rostro-caudal direction of these deviations were such that they would be easily accounted for during surgery, why MRI can obviate the need for CT in these procedures. MRI using a proton density sequence provided detailed images of the pallidal structures, which demonstrated considerable inter-individual variations in relation to the landmarks of the 3 rd ventricle. By using a direct visualization of the target, each patient will act as his or her own atlas, avoiding the uncertainties of atlas-based targeting. The STN could be visualized on various brands of MRI machines in 8 centers in 6 countries with good discrimination and with a short acquisition time, allowing direct visual targeting. The same scanning technique could be used for postoperative localization of the implanted electrodes. In cases where the lateral and inferior borders of the STN cannot be easily distinguished on MRI the Sukeroku sign and the dent internal-capsule-sign signs might be useful. The volume of a stereotactic RF lesion could be as accurately assessed by CT as by MRI. The lesion's size was most strongly influenced by the temperature used for coagulation. The lesions' volumes were however rather scattered and difficult to predict in the individual patient based solely on the coagulation parameters. For thalamotomy, the results on tremor was not related to the lesion's volume. For pallidotomy, larger and more posterior-ventral lesions had better effect on akinesia while effects on tremor and dyskinesias were not related to size or location of the lesions. Conclusions: The minor deviations of MRI from CT coordinates can be accounted for during surgery, why MRI can obviate the need of CT in

  11. Merging DBS with viral vector or stem cell implantation: “hybrid” stereotactic surgery as an evolution in the surgical treatment of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Nathan C Rowland

    2016-01-01

    Full Text Available Parkinson's disease (PD is a complex neurodegenerative disorder that is currently managed using a broad array of symptom-based strategies. However, targeting its molecular origins represents the potential to discover disease-modifying therapies. Deep brain stimulation (DBS, a highly successful treatment modality for PD symptoms, addresses errant electrophysiological signaling pathways in the basal ganglia. In contrast, ongoing clinical trials testing gene and cell replacement therapies propose to protect or restore neuronal-based physiologic dopamine transmission in the striatum. Given promising new platforms to enhance target localization'such as interventional MRI-guided stereotaxy'the opportunity now exists to create hybrid therapies that combine DBS with gene therapy and/or cell implantation. In this mini-review, we discuss approaches used for central nervous system biologic delivery in PD patients in previous trials and propose a new set of strategies based on novel molecular targets. A multifaceted approach, if successful, may not only contribute to our understanding of PD pathology but could introduce a new era of disease modification.

  12. Stereotactic neurosurgery for tremor

    NARCIS (Netherlands)

    Speelman, Johannes D.; Schuurman, Richard; de Bie, Rob M. A.; Esselink, Rianne A. J.; Bosch, D. Andries

    2002-01-01

    The role of the motor thalamus as surgical target in stereotactic neurosurgery for different kinds of tremor is discussed. For tremor in Parkinson's disease. the subthalamic nucleus becomes more and more often the surgical target, because this target also gives relief of other and more

  13. Sensitivity of Computed Tomography-guided Transthoracic Biopsies in a Nigerian Tertiary Institution.

    Science.gov (United States)

    Edaigbini, Sunday Adoga; Aminu, Muhammad Balarabe; Delia, Ibrahim Zira; Anumenechi, Ndubuisi; Alioke, Ikechukwuka Ifeanyichukwu; Fomete, Benjamine; Samaila, Modupeola Omotara A

    2017-01-01

    The indications for open biopsies for intrathoracic lesions have become almost negligible. This development was made possible by less invasive maneuvers such as computed tomography-guided (CT-guided) biopsy, thoracoscopy or video-assisted thoracoscopy, and bronchoscopy. CT-guided percutaneous lung biopsy was first reported in 1976. The aim of the study is to report our experience with CT-guided transthoracic biopsy. Patients with clinical and radiological evidence of intrathoracic mass were counseled and consent obtained for the procedure. They were positioned in the gantry, either supine or prone. A scout scan of the entire chest was taken at 5 mm intervals. The procedure was carried out by the consultants and senior registrar. Following visualization of the lesion, its position in terms of depth and distance from the midline was measured with the machine in centimeter to determine the point of insertion of the trucut needle (14-18-G). The presumed site of the lesion was indicated with a metallic object held in place with two to three strips of plasters after cleaning the site with Povidone-iodine. After insertion, repeat scans were performed to confirm that the needle was within the mass. A minimum of 3 core cuts was taken to be certain that the samples were representative. The results were analyzed by the determination of means and percentages. Twenty-six patients underwent this procedure between 2011 and 2015. There were 15 males and 11 females (M:F = 1.4:1). The age range was between 30 and 99 years with a mean of 55 years. Histological diagnosis was obtained in 24 of the patients giving sensitivity of 92.3%. There were 3 mild complications giving a rate of 11.5%. The complications included a case of mild hemoptysis and two patients who had mild pneumothoraces which did not require tube thoracostomy. CT-guided biopsy is a reliable procedure for obtaining deep-seated intrathoracic biopsies with high sensitivity and minimal complication rate.

  14. Sensitivity of computed tomography-guided transthoracic biopsies in a Nigerian tertiary institution

    Directory of Open Access Journals (Sweden)

    Sunday Adoga Edaigbini

    2017-01-01

    Full Text Available Introduction: The indications for open biopsies for intrathoracic lesions have become almost negligible. This development was made possible by less invasive maneuvers such as computed tomography-guided (CT-guided biopsy, thoracoscopy or video-assisted thoracoscopy, and bronchoscopy. CT-guided percutaneous lung biopsy was first reported in 1976. Aim of Study: The aim of the study is to report our experience with CT-guided transthoracic biopsy. Materials and Methods: Patients with clinical and radiological evidence of intrathoracic mass were counseled and consent obtained for the procedure. They were positioned in the gantry, either supine or prone. A scout scan of the entire chest was taken at 5 mm intervals. The procedure was carried out by the consultants and senior registrar. Following visualization of the lesion, its position in terms of depth and distance from the midline was measured with the machine in centimeter to determine the point of insertion of the trucut needle (14–18-G. The presumed site of the lesion was indicated with a metallic object held in place with two to three strips of plasters after cleaning the site with Povidone-iodine. After insertion, repeat scans were performed to confirm that the needle was within the mass. A minimum of 3 core cuts was taken to be certain that the samples were representative. The results were analyzed by the determination of means and percentages. Results: Twenty-six patients underwent this procedure between 2011 and 2015. There were 15 males and 11 females (M:F = 1.4:1. The age range was between 30 and 99 years with a mean of 55 years. Histological diagnosis was obtained in 24 of the patients giving sensitivity of 92.3%. There were 3 mild complications giving a rate of 11.5%. The complications included a case of mild hemoptysis and two patients who had mild pneumothoraces which did not require tube thoracostomy. Conclusion: CT-guided biopsy is a reliable procedure for obtaining deep

  15. Percutaneous transthoracic computed tomography-guided AICD insertion in a patient with extracardiac Fontan conduit.

    LENUS (Irish Health Repository)

    Murphy, Darra T

    2011-02-01

    Percutaneous pulmonary venous atrial puncture was performed under computed tomography guidance to successfully place an automated implantable cardiac defibrillator into a 26-year-old patient with extracardiac Fontan conduit who had presented with two out-of-hospital cardiac arrests. The procedure avoided the need for lead placement at thoracotomy.

  16. Stereotactic surgery for eating disorders.

    Science.gov (United States)

    Sun, Bomin; Liu, Wei

    2013-01-01

    EATING DISORDERS (EDS) ARE A GROUP OF SEVERELY IMPAIRED EATING BEHAVIORS, WHICH INCLUDE THREE SUBGROUPS: anorexia nervosa (AN), bulimia nervosa (BN), and ED not otherwise specified (EDNOS). The precise mechanism of EDs is still unclear and the disorders cause remarkable agony for the patients and their families. Although there are many available treatment methods for EDs today, such as family therapy, cognitive behavioral therapy, medication, psychotherapy, and so on, almost half of the patients are refractory to all current medical treatment and never fully recover. For treatment-refractory EDs, stereotactic surgery may be an alternative therapy. This review discusses the history of stereotactic surgery, the modern procedures, and the mostly used targets of stereotactic surgery in EDs. In spite of the limited application of stereotactic surgery in ED nowadays, stereotactic lesion and deep brain stimulation (DBS) are promising treatments with the development of modern functional imaging techniques and the increasing understanding of its mechanism in the future.

  17. Stereotactic radiotherapy in pediatric indications

    International Nuclear Information System (INIS)

    Bernier-Chastagner, V.; Supiot, S.; Carrie, C.; Helfre, S.

    2012-01-01

    Stereotactic radiotherapy is a very high precision procedure, which has been limited to radiosurgery for a long time. Technological improvements allowed the development of radiotherapy in stereotactic conditions, leading to a lot of innovations. Previously indicated for cerebral pathologies, this procedure is now developed for extra-cerebral locations. In paediatrics, stereotactic radiotherapy is still limited, delivered precociously, due to the possibility of long-term late effects that needs to be addressed. This review reports the different useful conditions, technical evolutions, and the current validated paediatric indications, with differences from adults, and future directions. (authors)

  18. Stereotactic Radiosurgery (SRS) / Stereotactic body radiotherapy (SBRT): Benefit to Irish patients and Irish Healthcare Economy

    LENUS (Irish Health Repository)

    Cagney, DN

    2017-01-01

    Cancer incidence across Europe is projected to rise rapidly over the next decade. This rising cancer incidence is mirrored by increasing use of and indications for stereotactic radiation. This paper seeks to summarize the exponential increase in indications for stereotactic radiotherapy as well as the evolving economic advantages of stereotactic radiosurgery and stereotactic body radiotherapy

  19. Apparatus for stereotactic surgery

    International Nuclear Information System (INIS)

    Koslow, M.A.M.

    1982-01-01

    Apparatus for stereotactic surgery consisting of a probe and a computerized tomographic scanning system is described. The scanning system comprises a display and means for reconstructing cross-sectional images on the display using data from partial circumferential scans of source and detectors. It operates on the data with an algorithm that provides the difference between the local values of the linear attenuation coefficient and average of these values within a circle centered at each reconstruction point. The scanning system includes a means of maintaining the frames of reference of the probe and scanning system rigid with respect to one another. The position of the probe, which may be a cryogenic probe, with respect to the actual anatomical structure of the body, particularly a human head, may thus be viewed by the surgeon. (author)

  20. Stereotactic treatment. Definitions and literature overview

    International Nuclear Information System (INIS)

    Fontenla, D.P.

    2008-01-01

    The topics discussed include, among others, the following: Radiosurgery definitions; Stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT); Available uncertainties in SRS; Gamma knife; Linac-based SRS; Components of a radiosurgery system; Stereotactic hardware (brain lab); m3 linac attachment; Radiosurgery - clinical procedure; Cancer management; Rationale for SRT; Role of radiosurgery in the management of intracranial tumors; Indications for stereotactic SRS/SRT; Physical components required for SRS/SRT; Stereotactic patient set-up; Stereotactic CT scan for SRS; Physical components required for SRT: Relocatable head frame (GTC); Patient immobilization; Treatment planning system; Basic requirements for SRS dosimetry (Linac based); Stereotactic set-up QA (Linac); Stereotactic frames and QA; Beam dose measurements; Dose evaluation tools; Phantoms. (P.A.)

  1. Computed tomography-guided percutaneous biopsy of pancreatic masses using pneumodissection; Biopsia percutanea de massas pancreaticas guiada por tomografia computadorizada com pneumodisseccao

    Energy Technology Data Exchange (ETDEWEB)

    Tyng, Chiang Jeng; Bitencourt, Almir Galvao Vieira; Almeida, Maria Fernanda Arruda; Barbosa, Paula Nicole Vieira; Martins, Eduardo Bruno Lobato; Junior, Joao Paulo Kawaoka Matushita; Chojniak, Rubens, E-mail: chiangjengtyng@gmail.com [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Imagem; Coimbra, Felipe Jose Fernandez [Hospital A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Cirurgia Abdominal

    2013-05-15

    Objective: to describe the technique of computed tomography-guided percutaneous biopsy of pancreatic tumors with pneumodissection. Materials and methods: in the period from June 2011 to May 2012, seven computed tomography guided percutaneous biopsies of pancreatic tumors utilizing pneumodissection were performed in the authors' institution. All the procedures were performed with an automatic biopsy gun and coaxial system with Tru-core needles. The biopsy specimens were histologically assessed. Results: in all the cases the pancreatic mass could not be directly approached by computed tomography without passing through major organs and structures. The injection of air allowed the displacement of adjacent structures and creation of a safe coaxial needle pathway toward the lesion. Biopsy was successfully performed in all the cases, yielding appropriate specimens for pathological analysis. Conclusion: Pneumodissection is a safe, inexpensive and technically easy approach to perform percutaneous biopsy in selected cases where direct access to the pancreatic tumor is not feasible. (author)

  2. Resection of deep-seated gliomas using neuroimaging for stereotactic placement of guidance catheters

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Kengo; Higashi, Hisato; Tomita, Susumu; Furuta, Tomohisa; Ohmoto, Takashi [Okayama Univ. (Japan). School of Medicine

    1995-03-01

    A simple computed tomography- (CT) or magnetic resonance (MR) imaging-guided stereotactic method for guided microsurgical resection of either deep-seated gliomas or tumors adjacent to an eloquent area is described. The technique employs the Brown-Roberts-Wells stereotactic system and twist drills, 2.7 mm in diameter, for the stereotactic placement of 2.4 mm diameter scaled guidance catheters through the calvaria. In a patient with a deep-seated small glioma, less than 2 cm diameter, one catheter was implanted into the center of the enhanced mass through the cerebral cortex. In the other 14 patients, three to six catheters were used which made the tumor border clearer. After implantation of the guidance catheters, the stereotactic frame was removed and a standard open craniotomy performed. Target localization is not affected by brain movement, which is inevitable during open surgery. The tumor involved the frontal lobe in eight patients, the parietal lobe in two, and the thalamus in five. In all cases the lesion was quickly localized and radical removal was acheived. Neurological complications occurred in only one patient who suffered transient hemiparesis after the resection of a lesion in the pyramidal tract. The results demonstrate that microsurgery combined with CT- or MR imaging-guided stereotactic placement of guidance catheters is a new option for surgery of deep-seated gliomas or tumors adjacent to an eloquent area. (author).

  3. Systematic study of target localization for bioluminescence tomography guided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jingjing [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 and School of Physics and Information Technology, Shaanxi Normal University, Shaanxi 710119 (China); Zhang, Bin; Reyes, Juvenal; Wong, John W.; Wang, Ken Kang-Hsin, E-mail: kwang27@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 (United States); Iordachita, Iulian I. [Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Lu, Zhihao [Department of Oncology and Department of Surgery, Johns Hopkins University, Baltimore, Maryland 21231 and Key laboratory of Carcinogenesis and Translational Research, Department of GI Oncology, Peking University, Beijing Cancer Hospital and Institute, Beijing 100142 (China); Brock, Malcolm V. [Department of Oncology and Department of Surgery, Johns Hopkins University, Baltimore, Maryland 21231 (United States); Patterson, Michael S. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4L8 (Canada)

    2016-05-15

    Purpose: To overcome the limitation of CT/cone-beam CT (CBCT) in guiding radiation for soft tissue targets, the authors developed a spectrally resolved bioluminescence tomography (BLT) system for the small animal radiation research platform. The authors systematically assessed the performance of the BLT system in terms of target localization and the ability to resolve two neighboring sources in simulations, tissue-mimicking phantom, and in vivo environments. Methods: Multispectral measurements acquired in a single projection were used for the BLT reconstruction. The incomplete variables truncated conjugate gradient algorithm with an iterative permissible region shrinking strategy was employed as the optimization scheme to reconstruct source distributions. Simulation studies were conducted for single spherical sources with sizes from 0.5 to 3 mm radius at depth of 3–12 mm. The same configuration was also applied for the double source simulation with source separations varying from 3 to 9 mm. Experiments were performed in a standalone BLT/CBCT system. Two self-illuminated sources with 3 and 4.7 mm separations placed inside a tissue-mimicking phantom were chosen as the test cases. Live mice implanted with single-source at 6 and 9 mm depth, two sources at 3 and 5 mm separation at depth of 5 mm, or three sources in the abdomen were also used to illustrate the localization capability of the BLT system for multiple targets in vivo. Results: For simulation study, approximate 1 mm accuracy can be achieved at localizing center of mass (CoM) for single-source and grouped CoM for double source cases. For the case of 1.5 mm radius source, a common tumor size used in preclinical study, their simulation shows that for all the source separations considered, except for the 3 mm separation at 9 and 12 mm depth, the two neighboring sources can be resolved at depths from 3 to 12 mm. Phantom experiments illustrated that 2D bioluminescence imaging failed to distinguish two sources

  4. Stereotactic radiotherapy for vestibular schwannoma

    DEFF Research Database (Denmark)

    Muzevic, Dario; Legcevic, Jelena; Splavski, Bruno

    2014-01-01

    BACKGROUND: Vestibular schwannomas (acoustic neuromas) are common benign tumours that arise from the Schwann cells of the vestibular nerve. Management options include observation with neuroradiological follow-up, microsurgical resection and stereotactic radiotherapy. OBJECTIVES: To assess...... the effect of stereotactic radiotherapy compared to observation, microsurgical resection, any other treatment modality, or a combination of two or more of the above approaches for vestibular schwannoma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL......; Web of Science; CAB Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the search was 24 July 2014. SELECTION CRITERIA: Randomised controlled trials (RCTs) exploring the efficacy of stereotactic radiotherapy compared with observation alone, microsurgical...

  5. Stereotactic radiosurgery: incision less surgery

    International Nuclear Information System (INIS)

    Alvarez, Victor M.; Palma, Raul B.

    1997-01-01

    Stereotactic Radiosurgery (SRS) involves the application of focused high dose, high energy radiation to precisely (stereotactically) localized targets in the head without opening the skull for the purpose of destroying pathologic tissues like tumors, and also for producing discrete lesions for the relief of certain functional disorders. This procedure was pioneered by Lars Leksel in the 1950s and has progressively been refined with the development of more powerful computer technology and more precise and safer radiation delivery systems. The used of the Linear Accelerator (LINAC)- based radiosurgery system would be the most cost-effective and appropriate system for this treatment

  6. Detection of progression of glaucomatous retinal nerve fibre layer defects using optical coherence tomography-guided progression analysis.

    Science.gov (United States)

    Hwang, Young Hoon; Kim, Min Kyung; Wi, Jae Min; Chung, Jae Keun; Lee, Kwan Bok

    2018-01-01

    The aim was to investigate the agreement for detection of progression of glaucomatous retinal nerve fibre layer defects (RNFLD) between optical coherence tomography-guided progression analysis (OCT GPA) and conventional red-free fundus photography. Four hundred and fifteen glaucomatous eyes that underwent at least four serial red-free photographic and OCT examinations were included in the study. Based on the inspection of the red-free fundus photographs and GPA maps, RNFLD progression was defined as the development of a new defect, widening or deepening of a pre-existing RNFLD in red-free fundus photography (photographic progression) or 'Likely Loss' on a GPA map (GPA progression). The agreement of photographic and OCT GPA progression and the factors influencing it, including refractive error, severity of glaucoma (mean deviation of the visual field), type of RNFLD (localised versus diffuse), width of the baseline RNFLD, type of RNFLD progression (new defect, widening, deepening) and location of RNFLD progression (clock-hour sector) were assessed. Among the 415 eyes, 82 (19.8 per cent) showed photographic or GPA progression. Among the 82 eyes with progression, progression was detected only in red-free fundus photography in nine (11.0 per cent) eyes and only in GPA in 32 (39.0 per cent) eyes. In 41 eyes (50.0 per cent), progression was detected with both methods. Detection of RNFLD progression only in GPA was associated with a higher myopia, diffuse RNFLD, deepening of the RNFLD and RNFLD progression at the 6, 9 and 12 o'clock positions (p < 0.05). OCT GPA may be a useful supplement to conventional red-free fundus photography for detecting RNFLD progression. © 2017 Optometry Australia.

  7. Stereotactic radiosurgery for hemangioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Yoshimasa; Kobayashi, Tatsuya; Yamada, Yasushi; Kida, Yoshihisa; Iwakoshi, Takayasu; Yoshimoto, Masayuki [Komaki City Hospital, Aichi (Japan). Gamma Knife Center

    2001-12-01

    We evaluated the treatment results of Gamma Knife radiosurgery for intracranial hemanigioblastoma of von Hippel-Lindau syndrome or sporadic disease. Stereotactic radiosurgery was performed in 20 patients with 35 hemangioblastomas over a 9-year interval. The mean age of the patients was 48.5 years (range, 18-79 years). The volume of the tumors varied from 0.03 to 19 ml (mean, 3.0 ml), and the mean tumor margin dose was 17.8 Gy (range, 14-24 Gy). Clinical and neuroimaging follow-up was obtained 6 to 58 months (mean 26.2 months) after radiosurgery. Thirty-one (89%) of 35 tumors were controlled locally. Two tumors (6%) disappeared and 11 (31%) decreased in size during follow-up period. Eighteen (52%) remained unchanged in size. Three out of four enlarged tumors were resected surgically after radiosurgery. Another tumor was resected surgically to improve the patient's symptoms of nausea and vomiting caused by persistent perifocal edema in spite of reduced tumor volume. Only one patient, who had a tumor in the 4th ventricle arising from the brainstem, died 12 months after radiosurgery. Although the treated tumor remained stable in size, he developed aspiration pneumonia due to brainstem dysfunction caused by perifocal edema. All tumors less than 1 cm in diameter did not progress during follow-up period. For small hemangioblastomas, radiosurgery is a safe and effective option to control disease. If a large tumor is treated by radiosurgery, careful observation of the patient's neurological condition is necessary. (author)

  8. Extracranial Stereotactic Radioablation

    Energy Technology Data Exchange (ETDEWEB)

    Papie, Lech; Timmerman, Robert; Desrosiers, Colleen; Randall, Marcus [Indiana University School of Medicine, Indianapolis, IN (United States). Dept. of Radiation Oncology

    2003-12-01

    Extracranial stereotactic radioablation (ESR) involves treating well-demarcated targeted tissues (e.g. tumor with minimal margin for set-up uncertainties) with very large doses of radiation in single or a few fractions with the intent of causing profound late tissue damage within the targeted volume. In such circumstances, considerable effort must be taken to reduce non-target tissue exposure to the high dose levels in order to prevent late complications to involved organs. Consequently, the following conditions for effective delivery of the ESR techniques have to be satisfied: 1) delivery of a high dose per fraction, i.e. 10-24 Gy; 2) delivery of only a few fractions per course of treatment (e.g. 1-4); 3) shaping of the prescription isodose surface conformally to the target surface; 4) delivery of a non-uniform dose distribution within the target with the highest dose in centrally located regions of hypoxia; 5) rapid fall-off of dose from the target volume to healthy tissue in all directions. In this paper it is shown that high doses per fraction in few fractions can be delivered to a variety of locations with both efficacy and acceptable toxicity (conditions 1 and 2). Conformal shaping of the high isodose surfaces is best accomplished by employing many beams (5-10) each with carefully milled apertures precisely coincident with the target projection (condition 3). Beam intensity modulation creating parabolic beam entrance fluence profiles both concentrates the highest dose in central regions of tumor hypoxia and increases fall-off gradients outside of the target (conditions 4 and 5). It is also shown that isotropic, highly non-coplanar beam arrangements avoiding oppositional fields allow more optimal fall-off gradients to normal tissue as opposed to coplanar treatments (condition 5)

  9. Stereotactic intracranial radiotherapy: Dose prescription

    International Nuclear Information System (INIS)

    Schlienger, M.; Lartigau, E.; Nataf, F.; Mornex, F.; Latorzeff, I.; Lisbona, A.; Mahe, M.

    2012-01-01

    The aim of this article was the study of the successive steps permitting the prescription of dose in stereotactic intracranial radiotherapy, which includes radiosurgery and fractionated stereotactic radiotherapy. The successive steps studied are: the choice of stereotactic intracranial radiotherapy among the therapeutic options, based on curative or palliative treatment intent, then the selection of lesions according to size/volume, pathological type and their number permitting the choice between radiosurgery or fractionated stereotactic radiotherapy, which have the same methodological basis. Clinical experience has determined the level of dose to treat the lesions and limit the irradiation of healthy adjacent tissues and organs at risk structures. The last step is the optimization of the different parameters to obtain a safe compromise between the lesion dose and healthy adjacent structures. Study of dose-volume histograms, coverage indices and 3D imaging permit the optimization of irradiation. For lesions close to or included in a critical area, the prescribed dose is planned using the inverse planing method. Implementation of the successively described steps is mandatory to insure the prescription of an optimized dose. The whole procedure is based on the delineation of the lesion and adjacent healthy tissues. There are sometimes difficulties to assess the delineation and the volume of the target, however improvement of local control rates and reduction of secondary effects are the proof that the totality of the successive procedures are progressively improved. In practice, stereotactic intracranial radiotherapy is a continually improved treatment method, which constantly benefits from improvements in the choice of indications, imaging, techniques of irradiation, planing/optimization methodology and irradiation technique and from data collected from prolonged follow-up. (authors)

  10. Pulmonary Mucosa-associated Lymphoid Tissue Lymphoma with Spontaneous Regression after Computed Tomography-guided Needle Biopsy: A Case Report and Summary of 8 Reported Cases

    Science.gov (United States)

    Fukushima, Kazuaki; Hirosako, Susumu; Tenjin, Yuki; Mukasa, Yosuke; Kojima, Keisuke; Saeki, Sho; Okamoto, Shinichiro; Ichiyasu, Hidenori; Fujii, Kazuhiko; Kikukawa, Yoshitaka; Kawanaka, Koichi; Kohrogi, Hirotsugu

    2016-01-01

    A 72-year-old woman was admitted to our hospital with a solitary right lung nodule. She had no symptoms and no abnormal physical findings except for bladder cancer. Tumor markers were mildly elevated but no other abnormal laboratory data were found. The nodule was diagnosed to be pulmonary mucosa-associated lymphoid tissue lymphoma on computed tomography-guided needle biopsy. Thereafter, she first underwent surgery for bladder cancer. The lung nodule was found to have slightly increased at three months and then disappeared at 15 months after the biopsy. The notable clinical course of this rare disease suggests the effectiveness of a non-interventional treatment strategy. PMID:27980268

  11. Stereotactic Radiotherapy in the Treatment of Lung Metastases from Bone and Soft-tissue Sarcomas.

    Science.gov (United States)

    Frakulli, Rezarta; Salvi, Fabrizio; Balestrini, Damiano; Parisi, Alessandro; Palombarini, Marcella; Cammelli, Silvia; Rocca, Michele; Salone, Mariacristina; Longhi, Alessandra; Ferrari, Stefano; Morganti, Alessio G; Frezza, Giovanni

    2015-10-01

    The purpose of this study was to evaluate local control and toxicity in a group of patients treated with stereotactic body radiotherapy (SBRT) for lung metastases (LM) from bone and soft tissue sarcomas. From October 2010 to July 2014, patients with LM from sarcomas not suitable for surgery were treated with daily cone-beam computed tomography-guided SBRT. The dose administered ranged from 30 to 60 Gy in 3-8 fractions. Acute and late toxicity were scored according to Common Terminology Criteria for Adverse Events version 4.0. A total of 24 patients with 68 LM from sarcomas were treated with SBRT. The median follow-up after SBRT was 17 months (range=11-51 months). Two-year actuarial lesion local control and overall survival were 85.9% and 66.4%, respectively. No G3 or greater acute and late toxicities were observed. SBRT is a safe and effective treatment for LM from sarcoma and might be used as an alternative option in patients unfit for surgery. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  12. Optical Tracking Technology in Stereotactic Radiation Therapy

    International Nuclear Information System (INIS)

    Wagner, Thomas H.; Meeks, Sanford L.; Bova, Frank J.; Friedman, William A.; Willoughby, Twyla R.; Kupelian, Patrick A.; Tome, Wolfgang

    2007-01-01

    The last decade has seen the introduction of advanced technologies that have enabled much more precise application of therapeutic radiation. These relatively new technologies include multileaf collimators, 3-dimensional conformal radiotherapy planning, and intensity modulated radiotherapy in radiotherapy. Therapeutic dose distributions have become more conformal to volumes of disease, sometimes utilizing sharp dose gradients to deliver high doses to target volumes while sparing nearby radiosensitive structures. Thus, accurate patient positioning has become even more important, so that the treatment delivered to the patient matches the virtual treatment plan in the computer treatment planning system. Optical and image-guided radiation therapy systems offer the potential to improve the precision of patient treatment by providing a more robust fiducial system than is typically used in conventional radiotherapy. The ability to accurately position internal targets relative to the linac isocenter and to provide real-time patient tracking theoretically enables significant reductions in the amount of normal tissue irradiated. This report reviews the concepts, technology, and clinical applications of optical tracking systems currently in use for stereotactic radiation therapy. Applications of radiotherapy optical tracking technology to respiratory gating and the monitoring of implanted fiducial markers are also discussed

  13. Stereotactic CO2 laser therapy for hydrocephalus

    Science.gov (United States)

    Kozodoy-Pins, Rebecca L.; Harrington, James A.; Zazanis, George A.; Nosko, Michael G.; Lehman, Richard M.

    1994-05-01

    A new fiber-optic delivery system for CO2 radiation has been used to successfully treat non-communicating hydrocephalus. This system consists of a hollow sapphire waveguide employed in the lumen of a stereotactically-guided neuroendoscope. CO2 gas flows through the bore of the hollow waveguide, creating a path for the laser beam through the cerebrospinal fluid (CSF). This delivery system has the advantages of both visualization and guided CO2 laser radiation without the same 4.3 mm diameter scope. Several patients with hydrocephalus were treated with this new system. The laser was used to create a passage in the floor of the ventricle to allow the flow of CSF from the ventricles to the sub-arachnoid space. Initial postoperative results demonstrated a relief of the clinical symptoms. Long-term results will indicate if this type of therapy will be superior to the use of implanted silicone shunts. Since CO2 laser radiation at 10.6 micrometers is strongly absorbed by the water in tissue and CSF, damage to tissue surrounding the lesion with each laser pulse is limited. The accuracy and safety of this technique may prove it to be an advantageous therapy for obstructive hydrocephalus.

  14. A computational model to compare different investment scenarios for mini-stereotactic frame approach to deep brain stimulation surgery.

    Science.gov (United States)

    Lanotte, M; Cavallo, M; Franzini, A; Grifi, M; Marchese, E; Pantaleoni, M; Piacentino, M; Servello, D

    2010-09-01

    Deep brain stimulation (DBS) alleviates symptoms of many neurological disorders by applying electrical impulses to the brain by means of implanted electrodes, generally put in place using a conventional stereotactic frame. A new image guided disposable mini-stereotactic system has been designed to help shorten and simplify DBS procedures when compared to standard stereotaxy. A small number of studies have been conducted which demonstrate localization accuracies of the system similar to those achievable by the conventional frame. However no data are available to date on the economic impact of this new frame. The aim of this paper was to develop a computational model to evaluate the investment required to introduce the image guided mini-stereotactic technology for stereotactic DBS neurosurgery. A standard DBS patient care pathway was developed and related costs were analyzed. A differential analysis was conducted to capture the impact of introducing the image guided system on the procedure workflow. The analysis was carried out in five Italian neurosurgical centers. A computational model was developed to estimate upfront investments and surgery costs leading to a definition of the best financial option to introduce the new frame. Investments may vary from Euro 1.900 (purchasing of Image Guided [IG] mini-stereotactic frame only) to Euro 158.000.000. Moreover the model demonstrates how the introduction of the IG mini-stereotactic frame doesn't substantially affect the DBS procedure costs.

  15. Stereotactic lesioning for mental illness.

    Science.gov (United States)

    Kim, M-C; Lee, T-K

    2008-01-01

    The authors report stereotactically created lesioning by radiofrequency or Cyberknife radiosurgery for patients with mental illness. Since 1993, thirty-eight patients have undergone stereotactic psychosurgery for medically intractable mental illnesses. Two patients had aggressive behavior. Twenty-five patients suffered from Obsessive-Compulsive Disorder (OCD) and ten patients had depression. Another patient suffered from atypical psychosis. Bilateral amygdalotomy and subcaudate tractotomy were done for aggressive behavior. Limbic leucotomy or anterior cingulotomy was done for OCD and subcaudate tractotomy with or without cingulotomy was done for depression. In twenty-three patients, the lesions were made by a radiofrequency (RF) lesion generator. In fifteen cases, the lesions were made with CyberKnife Radiosurgery (CKRS). The Overt Aggression Scale (OAS) declined from 8 to 2 with clinical improvement during follow up period. With long-term follow up (meaning 57 months) in 25 OCDs, the mean Yale Brown Obsessive Compulsive Score (YBOCS) declined from 34 to 13 (n = 25). The Hamilton Depression scale (HAMD) for ten patients with depression declined from 38.5 to 10.5 (n = 10). There was no operative mortality and no significant morbidity except one case with transient urinary incontinence. Authors suggest that stereotactic psychosurgery by RF and CKRS could be a safe and effective means of treating some medically intractable mental illnesses.

  16. Stereotactic lesioning for mental illness

    International Nuclear Information System (INIS)

    Kim, M.-C.; Lee, T.-K.

    2008-01-01

    The authors report stereotactically created lesioning by radiofrequency or Cyberknife radiosurgery for patients with mental illness. Since 1993, thirty-eight patients have undergone stereotactic psychosurgery for medically intractable mental illnesses. Two patients had aggressive behavior. Twenty-five patients suffered from Obsessive-Compulsive Disorder (OCD) and ten patients had depression. Another patient suffered from atypical psychosis. Bilateral amygdalotomy and subcaudate tractotomy were done for aggressive behavior. Limbic leucotomy or anterior cingulotomy was done for CCD and subcaudate tractotomy with or without cingulotomy was done for depression. In twenty-three patients, the lesions were made by a radiofrequency (RF) lesion generator. In fifteen cases, the lesions were made with Cyberknife Radiosurgery (CKRS). The Overt Aggression Scale (OAS) declined from 8 to 2 with clinical improvement during follow up period. With long-term follow up (meaning 57 months) in 25 OCDs, the mean Yale Brown Obsessive Compulsive Score (YBOCS) declined from 34 to 13 (n = 25). The Hamilton Depression scale (HAMD) for ten patients with depression declined from 38.5 to 10.5 (n = 10). There was no operative mortality and no significant morbidity except one case with transient urinary incontinence. Authors suggest that stereotactic psychosurgery by RF and CKRS could be a safe and effective means of treating some medically intractable mental illnesses. (author)

  17. Percutaneous computed tomography-guided biopsy of the lung: data from a hospital; Biopsia pulmonar percutanea guiada por tomografia computadorizada: dados de um hospital

    Energy Technology Data Exchange (ETDEWEB)

    Carazzai, Emilio Humberto; Rossi, Marcelo D' Andrea [Maximagem Diagnosticos por Imagem, Sao Paulo, SP (Brazil); Andreosi, Maristela [Hospital Beneficencia Portuguesa, Sao Paulo, SP (Brazil); Gonzalez, Fabio Mota; Tornin, Olger de Souza [Hospital Heliopolis, Sao Paulo, SP (Brazil)]. E-mail: olger1@uol.com.br; Gonzalez, Sandra de Quadros Uzeda [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil)

    2006-07-15

    Objective: to present the experience of Santa Cecilia Hospital (Sao Paulo, SP, Brazil) radiology service in the handling of computed tomography-guided fine-needle aspiration biopsy and percutaneous core biopsy of pulmonary lesions, analyzing their importance and associated complications. Materials and methods: one hundred and sixty-eight computed tomography-guided biopsies were performed in 84 men and 84 women. Sixty-four patients underwent fine-needle aspiration biopsy, 68 underwent percutaneous core biopsy and 36 patients underwent both techniques. Results: pneumothorax occurred in 38 patients, and pulmonary hemorrhage in then cases. The biopsied lesions ranged in size from 0.5 to 15 cm. The diagnosis was achieved at the first attempt in 132 cases and at the second attempt, in ten cases. Conclusion: the accuracy of fine-needle aspiration and percutaneous core biopsies depends both on the size of the lesion and the patient's cooperation. These techniques are relatively safe and present a high diagnostic accuracy when performed by an experienced professional. (author)

  18. Linac based radiosurgery and stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Mackie, T.R.

    2008-01-01

    The following topics were discussed: Definition of stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT); Stereo market; Indications for SRS/SRT; History of linac-based SRS/SRT; Variety of systems; QA for SRS; Localization; and Imaging. (P.A.)

  19. Cone-Beam Computed Tomography-Guided Management of C-Shaped Type III Dens Invaginatus With Peri-invagination Periodontitis in a Maxillary Canine: A Case Report.

    Science.gov (United States)

    Mittal, Priya; Jadhav, Ganesh R; Syed, Shibli; Bhujbal, Nikita D

    2016-06-01

    Dens invaginatus (DI) is a developmental anomaly seen infrequently in maxillary canines. This article describes cone-beam computed tomography-guided nonsurgical management of type III (subtype B) DI in a permanent maxillary canine associated with a sinus tract and peri-invagination periodontitis in a 17-year-old female. After gaining access to the root canal, thorough chemo-mechanical preparation was performed and usage of intracanal medicament of calcium hydroxide was prescribed for 3 weeks, during which the sinus tract healed completely. Obturation was completed by a technique of down-packing master-cone gutta-percha, followed by backfilling with thermoplasticized gutta-percha. At 12-months follow-up, the patient was asymptomatic with complete resolution of the sinus tract and radiographic evidence of healing of periapical pathology.

  20. Assessment of Needle Guidance Devices for Their Potential to Reduce Fluoroscopy Time and Operator Hand Dose during C-Arm Cone-Beam Computed Tomography-Guided Needle Interventions

    NARCIS (Netherlands)

    Kroes, M.W.; Busser, W.M.H.; Futterer, J.J.; Arntz, M.J.; Janssen, C.M.M.; Hoogeveen, Y.L.; Lange, F. de; Schultze Kool, L.J.

    2013-01-01

    PURPOSE: To assess whether the use of needle guidance devices can reduce fluoroscopy time and operator hand dose during cone-beam computed tomography-guided needle interventions. MATERIALS AND METHODS: The freehand technique was compared with techniques employing two distinct needle holders and a

  1. Optical Coherence Tomography Guided Percutaneous Coronary Intervention With Nobori Stent Implantation in Patients With Non-ST-Segment-Elevation Myocardial Infarction (OCTACS) Trial

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Thayssen, Per; Maehara, Akiko

    2015-01-01

    (s). A final OCT was performed in case of reintervention. Six-month OCT follow-up was available in 85 patients. Twenty-three (46%) OCT-guided patients had additional postdilation or stenting. The percentage of acutely malapposed struts was substantially lower in the OCT-guided group (3.4% [interquartile range......, 0.3-7.6] versus 7.8% [interquartile range, 2.3-19.4]; Pinterquartile range, 1.2-9.8] versus 9.0% [interquartile range, 5.5-14.5], P

  2. Frameless stereotactic subcaudate tractotomy for intractable obsessive-compulsive disorder.

    Science.gov (United States)

    Woerdeman, P A; Willems, P W A; Noordmans, H J; Berkelbach van der Sprenkel, J W; van Rijen, P C

    2006-06-01

    Obsessive-compulsive disorder (OCD) is a chronic, disabling disorder. Psychosurgery may be indicated for a subset of patients for whom no conventional treatment is satisfactory. This paper focuses on the stereotactic subcaudate tractotomy (SST). Thus far, these procedures have been carried out using frame-based stereotactic techniques. However, modern - highly accurate - frameless stereotactic procedures have successfully been introduced in neurosurgical practice. We developed a novel frameless stereotactic subcaudate tractotomy procedure with promising initial results in a patient suffering from intractable OCD. This is the first report on frameless SST. Future studies should examine whether other ablative stereotactic psychosurgery procedures can be done using frameless stereotactic methods.

  3. Stereotactic body radiotherapy a practical guide

    CERN Document Server

    Gaya, Andrew

    2015-01-01

    Collecting the key information in this burgeoning field into a single volume, this handbook for clinical oncology trainees and consultants covers all of the basic aspects of stereotactic radiotherapy systems and treatment and includes plenty of case studies.

  4. The lesion in stereotactic suscaudate tractotomy.

    Science.gov (United States)

    Newcombe, R

    1975-05-01

    The anatomical distribution of 25 stereotactic tractotomy lesions is described. The posterior half of these lesions lie in a subcaudate position and the anterior half, for the most part, lies beneath the central segment of frontal white matter.

  5. Stereotactic IMRT using a MMLC

    International Nuclear Information System (INIS)

    Hoban, P.; Short, R.; Biggs, D.; Rose, A.; Smee, R.; Schneider, M.

    2001-01-01

    Full text: The leaf width of the multileaf collimator (MLC) used for intensity modulated radiotherapy (IMRT ) largely determines the resolution of the intensity maps that define the entire profile of each beam. In turn it is this resolution, and consequently the achievable degree of beam modulation, that determines the ability to conform the 3D dose distribution to complex target volumes. As such, the leaf width is of more importance than in fixed-field MLC treatments where only the beam edges are affected.A Radionics micro-multileaf collimator (MMLC) with 4 mm leaf width, attached to a Siemens Primus linear accelerator, is in use for stereotactic IMRT at PbWH. Treatment planning is performed with the XPlan system including an integrated IMRT module. Cases treated have so far been with conventional fractionation, including both malignant and benign cranial lesions. Meningiomas in particular often require a complex dose distribution because of their en-plaque nature and/or proximity to the brainstem. Stereotactic localisation and fixation is with the Gill-Thomas-Cosman head-ring or Head and Neck localiser. Cases are typically planned both for fixed-field treatment and IMRT, with IMRT being used if significant benefit is seen. IMRT treatment with the Siemens MLC is also an option. A quality assurance system has been set up, including a flowchart/checklist and phantom dosimetry using TLDs. As expected, treatment plans show IMRT with the MMLC to consistently be the best option dosimetrically. In particular, for a given target coverage there is always better sparing of nearby organs at risk (OARs) with MMLC rather than MLC-based IMRT. Adjustments such as the inclusion of a margin around the target volume or an increase in the penalty for target underdosage improve coverage for MLC plans but generally at the expense of increased OAR involvement. MMLC IMRT treatments commonly require 30-50 fields and can be delivered in approximately 10-15 minutes using an autosequence

  6. Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion

    International Nuclear Information System (INIS)

    Koutrouvelis, Panos; Lailas, Niko; Hendricks, Fred; Gil-Montero, Guillermo; Sehn, James; Katz, Stuart

    2001-01-01

    Purpose: To treat patients with prostate cancer and seminal vesicle invasion with monotherapeutic three dimensional computed tomography (3-DCT)-guided posterior pararectal brachytherapy. Methods and materials: Three hundred and sixty two patients with clinical stage T1 a,b or T2 a,b of prostate cancer were referred for 3-DCT-guided brachytherapy. Each underwent further staging with 3-D CT-guided pararectal biopsy of the seminal vesicles under local anesthesia during the pre-treatment CT-planning. Forty-three patients (12%) were upstaged to T3 cNoMo disease. In the set of 43 patients, Eight had Gleason's score≤6, 24 Gleason's score=7, and 11 patients ≥8. Initial PSA was 20 in 18 patients. Of the 43 patients, 37 patients were treated monotherapeutically with 3-D CT-guided brachytherapy. No patients received hormone therapy after the implant. The prescribed dosage to the seminal vesicles and prostate is 120 Gy with Pd-103 seeds and 144 Gy with 1-125 seeds. Results: The prescribed dosage was achieved in all 37 patient's throughout the seminal vesicles whose range of target radiation extended 5-10 mm outside the target in the adjacent fat as calculated with post-implant CT-dosimetry with Varian Brachy Vision or MMS software. Prostate Specific Antigen (PSA) outcome data were available in 34 patients treated with monotherapy and follow up ranged from 12-56 months (median, 24 months). Decreased PSA levels were stratified into six groups based on the presenting Gleason's score and initial PSA. In the first group (with Gleason's score≤6 and initial PSA 20 ng/ml), PSA decreased to less than 0.5 ng/ml in four out of eight patients (50%). All of the patients in the fourth group (with Gleason's score≥8 and initial PSA 20 ng/ml). There were no patients with Gleason's score of 1-6 and greater than 20 ng/ml initial PSA. Patients, irrespective of the Gleason's score and PSA, had an overall response of decreased PSA (less than 1 ng/ml) of 79%. Conclusion: 3-D CT

  7. Hematological Toxicity After Robotic Stereotactic Body Radiosurgery for Treatment of Metastatic Gynecologic Malignancies

    International Nuclear Information System (INIS)

    Kunos, Charles A.; Debernardo, Robert; Radivoyevitch, Tomas; Fabien, Jeffrey; Dobbins, Donald C.; Zhang Yuxia; Brindle, James

    2012-01-01

    Purpose: To evaluate hematological toxicity after robotic stereotactic body radiosurgery (SBRT) for treatment of women with metastatic abdominopelvic gynecologic malignancies. Methods and Materials: A total of 61 women with stage IV gynecologic malignancies treated with abdominopelvic SBRT were analyzed after ablative radiation (2400 cGy/3 divided consecutive daily doses) delivered by a robotic-armed Cyberknife SBRT system. Abdominopelvic bone marrow was identified using computed tomography-guided contouring. Fatigue and hematologic toxicities were graded by retrospective assignment of common toxicity criteria for adverse events (version 4.0). Bone marrow volume receiving 1000 cGy (V10) was tested for association with post-therapy (median 32 days [25%-75% quartile, 28-45 days]) white- or red-cell counts, hemoglobin levels, and platelet counts as marrow toxicity surrogates. Results: In all, 61 women undergoing abdominopelvic SBRT had a median bone marrow V10 of 2% (25%-75% quartile: 0%-8%). Fifty-seven (93%) of 61 women had received at least 1 pre-SBRT marrow-taxing chemotherapy regimen for metastatic disease. Bone marrow V10 did not associate with hematological adverse events. In all, 15 grade 2 (25%) and 2 grade 3 (3%) fatigue symptoms were self-reported among the 61 women within the first 10 days post-therapy, with fatigue resolved spontaneously in all 17 women by 30 days post-therapy. Neutropenia was not observed. Three (5%) women had a grade 1 drop in hemoglobin level to <10.0 g/dL. Single grade 1, 2, and 3 thrombocytopenias were documented in 3 women. Conclusions: Abdominopelvic SBRT provided ablative radiation dose to cancer targets without increased bone marrow toxicity. Abdominopelvic SBRT for metastatic gynecologic malignancies warrants further study.

  8. Stereotactic radiotherapy in oligometastatic cancer.

    Science.gov (United States)

    Kennedy, Thomas A C; Corkum, Mark T; Louie, Alexander V

    2017-09-01

    Oligometastatic cancer describes a disease state somewhere between localized and metastatic cancer. Proposed definitions of oligometastatic disease have typically used a cut-off of five or fewer sites of disease. Treatment of oligometastatic disease should have the goal of long-term local control, and in selected cases, disease remission. While several retrospective cohorts argue for surgical excision of limited metastases (metastasectomy) as the preferred treatment option for several clinical indications, limited randomized data exists for treating oligometastases. Alternatively, stereotactic ablative radiotherapy (SABR) is a radiotherapy technique that combines high radiation doses per fraction with precision targeting with the goal of achieving long-term local control of treated sites. Published cohort studies of SABR have demonstrated excellent local control rates of 70-90% in oligometastatic disease, with long-term survival in some series approaching 20-40%. A recent randomized phase 2 clinical trial by Gomez et al. demonstrated significantly improved progression free survival with aggressive consolidative therapy (surgery, radiotherapy ± chemotherapy or SABR) in oli-gometastatic non-small cell lung cancer (NSCLC). As additional randomized controlled trials are ongoing to determine the efficacy of SABR in oligometastatic disease, SABR is increasingly being used within routine clinical practice. This review article aims to sum-marize the history and current paradigm of the oligometastatic state, review recently pub-lished literature of SABR in oligometastatic cancer and discuss ongoing trials and future directions in this context.

  9. Breast Implants

    Science.gov (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Breast Implants Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Breast implants are medical devices that are implanted under the ...

  10. Hypofractionated stereotactic irradiation. Basic and clinical researches

    International Nuclear Information System (INIS)

    Shibamoto, Yuta; Miyakawa, Akifumi; Iwata, Hiromitsu; Otsuka, Shinya; Ogino, Hiroyuki; Ayakawa, Shiho

    2011-01-01

    Hypofractionated stereotactic radiotherapy (SRT) has a number of biological advantages over single-session radiosurgery. An apparent trend is seen in the clinic towards shift from the latter to the former; however, there is no adequate model to convert single doses to hypofractionated doses. The linear-quadratic model overestimates the effect of single-fraction radiation. This should be kept in mind in evaluating the doses of stereotactic irradiation. ''Biological effective dose'' should not be used in radiosurgery and hypofractionated SRT. Clinically, we have used 3- to 10-fraction SRT for acoustic neuroma and benign skull base tumors using cyberknife and tomotherapy. Preliminary results are encouraging. (author)

  11. Noninvasive patient fixation for extracranial stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Lohr, Frank; Debus, Juergen; Frank, Claudia; Herfarth, Klaus; Pastyr, Otto; Rhein, Bernhard; Bahner, Malte L.; Schlegel, Wolfgang; Wannenmacher, Michael

    1999-01-01

    Purpose: To evaluate the setup accuracy that can be achieved with a novel noninvasive patient fixation technique based on a body cast attached to a recently developed stereotactic body frame during fractionated extracranial stereotactic radiotherapy. Methods and Materials: Thirty-one CT studies (≥ 20 slices, thickness: 3 mm) from 5 patients who were immobilized in a body cast attached to a stereotactic body frame for treatment of para medullary tumors in the thoracic or lumbar spine were evaluated with respect to setup accuracy. The immobilization device consisted of a custom-made wrap-around body cast that extended from the neck to the thighs and a separate head mask, both made from Scotchcast. Each CT study was performed immediately before or after every second or third actual treatment fraction without repositioning the patient between CT and treatment. The stereotactic localization system was mounted and the isocenter as initially located stereo tactically was marked with fiducials for each CT study. Deviation of the treated isocenter as compared to the planned position was measured in all three dimensions. Results: The immobilization device can be easily handled, attached to and removed from the stereotactic frame and thus enables treatment of multiple patients with the same stereotactic frame each day. Mean patient movements of 1.6 mm ± 1.2 mm (laterolateral [LL]), 1.4 mm ± 1.0 mm (anterior-posterior [AP]), 2.3 mm ± 1.3 mm (transversal vectorial error [VE]) and < slice thickness = 3 mm (cranio caudal [CC]) were recorded for the targets in the thoracic spine and 1.4 mm ± 1.0 mm (LL), 1.2 mm ± 0.7 mm (AP), 1.8 mm ± 1.2 mm (VE), and < 3 mm (CC) for the lumbar spine. The worst case deviation was 3.9 mm for the first patient with the target in the thoracic spine (in the LL direction). Combining those numbers (mean transversal VE for both locations and maximum CC error of 3 mm), the mean three-dimensional vectorial patient movement and thus the mean overall

  12. Interactive computer graphics for stereotactic neurosurgery

    International Nuclear Information System (INIS)

    Goodman, J.H.; Davis, J.R.; Gahbauer, R.A.

    1986-01-01

    A microcomputer (IBM PC/AT) system has been developed to incorporate multiple image sources for stereotactic neurosurgery. Hard copy data is calibrated and captured with a video camera and frame grabber. Line contours are generated automatically on the basis of gray scale density or digitized manually. Interactive computer graphics provide a format with acceptable speed and accuracy for stereotactic neurosurgery. The ability to dimensionally integrate existing image data from multiple sources for target selection makes preoperative scans and scanner compatible head holders unnecessary. The system description and examples of use for brain tumor biopsy and brachytherapy ware presented

  13. Automated location detection of injection site for preclinical stereotactic neurosurgery procedure

    Science.gov (United States)

    Abbaszadeh, Shiva; Wu, Hemmings C. H.

    2017-03-01

    Currently, during stereotactic neurosurgery procedures, the manual task of locating the proper area for needle insertion or implantation of electrode/cannula/optic fiber can be time consuming. The requirement of the task is to quickly and accurately find the location for insertion. In this study we investigate an automated method to locate the entry point of region of interest. This method leverages a digital image capture system, pattern recognition, and motorized stages. Template matching of known anatomical identifiable regions is used to find regions of interest (e.g. Bregma) in rodents. For our initial study, we tackle the problem of automatically detecting the entry point.

  14. Glaucomatous progression in the retinal nerve fibre and retinal ganglion cell-inner plexiform layers determined using optical coherence tomography-guided progression analysis.

    Science.gov (United States)

    Hwang, Young Hoon; Kim, Yeji; Chung, Jae Keun; Lee, Kwan Bok

    2018-02-01

    To investigate the characteristics of glaucomatous progression in circumpapillary retinal nerve fibre layer (RNFL) and macular retinal ganglion cell-inner plexiform layer (GCIPL) determined using optical coherence tomography-guided progression analysis (OCT-GPA). Serial OCT images of 527 glaucomatous eyes with greater than four OCT tests were screened. Among them, 106 (20.1 per cent) eyes with progression in either RNFL or GCIPL determined using OCT-GPA were included. Based on the agreement of progression detection between RNFL and GCIPL, the eyes were classified into the 'RNFL progression earlier group', 'GCIPL progression earlier group', or 'simultaneous progression group'. The type of progression was classified as diffuse, localised or mixed. Among the 106 eyes with progression, 100 (94.3 per cent) showed RNFL progression and 83 (78.3 per cent) showed GCIPL progression. Fifty-four (50.9 per cent), 13 (12.3 per cent), and 39 (36.8 per cent) eyes were classified into the RNFL progression earlier group, GCIPL progression earlier group, and simultaneous progression group, respectively. Diffuse-type progression was found in three (three per cent) eyes with RNFL progression and 32 (38.6 per cent) eyes with GCIPL progression. The most common location of progression was the 7 o'clock sector (42.0 per cent) in the RNFL and the inferotemporal sector (39.8 per cent) in the GCIPL. The most common characteristic of RNFL and GCIPL progression determined using OCT-GPA was localised thinning in the inferotemporal area. Progression was more frequently found in the RNFL than in the GCIPL, and diffuse-type progression was more frequent in the GCIPL than in the RNFL. © 2018 Optometry Australia.

  15. Dosimetry studies with TLDs for stereotactic radiation techniques for intraocular tumours

    International Nuclear Information System (INIS)

    Ertl, A.; Schoeggl, A.; Zehetmayer, M.; Kindl, P.; Hartl, R.

    1997-01-01

    Between March 1993 and January 1997, stereotactic radiation techniques were used to irradiate 66 intraocular tumour patients with the Gamma Knife (Leksell Gamma Knife, model B unit) at the University of Vienna, Austria. This study investigates the dosimetry for stereotactic irradiation of ocular structures. For the dosimetry program KULA 4.4, Gamma Knife stereotactic irradiation of the eye represents an extreme frontal skull position. In addition, irradiation of the eye may be performed in the usual supine position in exceptional cases only. With the patient in the prone position, the dose planning program has to calculate with a significantly large number of single-beam extrapolations. In our first experiment we measured the isocentre dose for eight different γ-angle positions, both in prone and supine positions, using TLD measurements in an Alderson head phantom. We found a maximum deviation of ±1.6% using these individually calibrated TLDs. In the second experiment we examined the dose cross profiles for the two most frequently used treatment positions (supine position, γ = 65 deg., and prone position, γ = 140 deg.). For this purpose we implanted a specially designed TLD array into the orbit of a human cadaver head. We found excellent agreement of the dose values measured for the isocentre as well as the posterior part of the eye with orbit with deviations of less than -2.7%. However, for the anterior part of the eye, deviations between computer-generated calculations and the TLD measurements were found to range up to -30%. These differences were noticed both for supine and prone positions. For the Gamma Knife stereotactic irradiation of ocular tumours or pathologies, precautions should be taken to avoid significant underdosage in the anterior part of the radiation field. (author)

  16. Neuropsychological outcomes following stereotactic laser amygdalohippocampectomy.

    Science.gov (United States)

    Greenway, Melanie R F; Lucas, John A; Feyissa, Anteneh M; Grewal, Sanjeet; Wharen, Robert E; Tatum, William O

    2017-10-01

    The objective was to analyze neuropsychological testing data from 15 patients before and after stereotactic laser ablation surgery for temporal lobe epilepsy and to describe the seizure outcomes after stereotactic laser ablation surgery. A retrospective review of 15 patients who underwent stereotactic laser ablation and who also underwent neuropsychological testing before and after surgery was performed. Verbal and visual memory was assessed in all 15 patients using California Verbal Learning Test and Wechsler Memory Scale IV. Naming was assessed in 9 of 15 patients using the Boston Naming Test. Statistical analysis was performed to determine clinically significant changes using previously validated reliable change indices and proprietary Advanced Clinical Solutions software. Seizure outcome data were evaluated using Engel classification. Postsurgery neuropsychological evaluation demonstrated that all 15 patients experienced at least 1 clinically significant decline in either verbal or visual memory. Ten patients in this series, including five with dominant-hemisphere surgery, demonstrated decline in delayed memory for narrative information (Logical Memory II). By contrast, the Boston Naming Test demonstrated more favorable results after surgery. Two of nine patients demonstrated a clinically significant increase in naming ability, and only one of nine patients demonstrated a clinically significant decline in naming ability. With at least 6months of follow-up after surgery, 33% reported seizure freedom. Stereotactic laser ablation can result in clinically significant and meaningful decline in verbal and visual memory when comparing patients to their own presurgical baseline. Naming ability, conversely, is much less likely to be impacted by stereotactic laser ablation and may improve after the procedure. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Penile Implants

    Science.gov (United States)

    ... the discussion with your doctor. Types of penile implants There are two main types of penile implants: ... might help reduce the risk of infection. Comparing implant types When choosing which type of penile implant ...

  18. Preliminary experience with frameless stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Buatti, John M.; Bova, Frank J.; Friedman, William A.; Meeks, Sanford L.; Ellis, Thomas L.; Marcus, Robert B.; Zuofeng, Li; Mendenhall, William M.

    1997-01-01

    Purpose/Objective: To report our initial clinical experience using a novel high-precision frameless stereotactic radiotherapy system in 50 patients who have received 1271 treatments. Materials and Methods: Fifty patients ranging in age from 2 to 72 yr were treated with fractionated stereotactic radiotherapy. Thirty-two were treated with stereotactic radiotherapy alone, and 18 had stereotactic radiotherapy interdigitated as a boost in addition to standard irradiation. Pathologies treated included meningioma (13), low grade astrocytoma (10), germinoma (9), craniopharyngioma (4), schwannoma (2), and pituitary adenoma (2). Two additional patients had miscellaneous benign neoplasms and 8 patients had the technique used as a dose escalation strategy for malignant lesions including chordoma, primitive neuroectodermal tumor, sarcoma, and anaplastic oligoastrocytoma. Treatment reproducibility was initially gauged by comparing the bite plate position using infrared light emitting diodes (irleds) with the stereotactic radiosurgery reference system. This test of accuracy consisted of 10 bite plate repositionings for each patient and 100 readings of each of the 6 irleds on the bite plate at each new position. Each of the 1271 patient treatments was monitored for continuous digital position, and a reading was made before treating each arc of radiation. We chose 0.3 mm translation and 0.3 degrees rotation as the maximum tolerated misalignment before treating each arc. Results: With a mean follow-up of 9 mo, no patient had a marginal or distal failure. One patient with a malignant glioma had central disease progression. Acute side effects were minimal. In 3 of 9 low grade astrocytomas, a marked increase in imaging enhancement and edema occurred in the first year after treatment that resolved with steroids. The initial test of accuracy revealed bite plate reproducibility as follows. Translational errors (mm): Anterior-posterior, 0.06 ± 0.06; lateral, 0.03 ± 0.05; axial, 0.07 ± 0

  19. Implications for high-precision dose radiation therapy planning or limited surgical resection after percutaneous computed tomography-guided lung nodule biopsy using a tract sealant

    Directory of Open Access Journals (Sweden)

    Patricia M. de Groot, MD

    2018-04-01

    Full Text Available Purpose: Precision radiation therapy such as stereotactic body radiation therapy and limited resection are being used more frequently to treat intrathoracic malignancies. Effective local control requires precise radiation target delineation or complete resection. Lung biopsy tracts (LBT on computed tomography (CT scans after the use of tract sealants can mimic malignant tract seeding (MTS and it is unclear whether these LBTs should be included in the calculated tumor volume or resected. This study evaluates the incidence, appearance, evolution, and malignant seeding of LBTs. Methods and materials: A total of 406 lung biopsies were performed in oncology patients using a tract sealant over 19 months. Of these patients, 326 had follow-up CT scans and were included in the study group. Four thoracic radiologists retrospectively analyzed the imaging, and a pathologist examined 10 resected LBTs. Results: A total of 234 of 326 biopsies (72%, including primary lung cancer [n = 98]; metastases [n = 81]; benign [n = 50]; and nondiagnostic [n = 5] showed an LBT on CT. LBTs were identified on imaging 0 to 3 months after biopsy. LBTs were typically straight or serpiginous with a thickness of 2 to 5 mm. Most LBTs were unchanged (92% or decreased (6.3% over time. An increase in LBT thickness/nodularity that was suspicious for MTS occurred in 4 of 234 biopsies (1.7%. MTS only occurred after biopsy of metastases from extrathoracic malignancies, and none occurred in patients with lung cancer. Conclusions: LBTs are common on CT after lung biopsy using a tract sealant. MTS is uncommon and only occurred in patients with extrathoracic malignancies. No MTS was found in patients with primary lung cancer. Accordingly, potential alteration in planned therapy should be considered only in patients with LBTs and extrathoracic malignancies being considered for stereotactic body radiation therapy or wedge resection.

  20. ULTRASONOGRAPHY AND COMPUTED TOMOGRAPHY GUIDED FINE NEEDLE ASPIRATION CYTOLOGY IN DIAGNOSING INTRA-ABDOMINAL LESIONS- A 6-YEAR RETROSPECTIVE STUDY IN A TERTIARY CARE HOSPITAL IN MANIPUR

    Directory of Open Access Journals (Sweden)

    Ratan Konjengbam

    2017-07-01

    Full Text Available BACKGROUND Fine-Needle Aspiration Cytology (FNAC is a widely used method, which is accurate and safe in a readily palpable masses. But, in those inaccessible lesions and deeper organs are safely aspirated using fine needle radiological procedure like ultrasound or computed tomography guided. The aim of the study is to assess the utility of FNAC in the diagnosis of intra-abdominal lesions and different pattern of lesions in particular to the sites. MATERIALS AND METHODS This retrospective study was done in the Department of Pathology, Regional Institute of Medical Sciences (RIMS, Imphal, between June 2010 and June 2016. The study included 128 intra-abdominal masses. Giemsa and Papanicolaou’s stains were used. The cytological diagnosis was correlated with clinical and radiological data to arrive at a final diagnosis. RESULTS Reports on FNAC smears were retrospectively analysed, which had been done in various anatomic sites- liver (70 cases, colon (19 cases, gallbladder (17 cases, mesenteric lymph nodes (12 cases, ovary (3 cases, adrenals (2 cases and 1 case each of pancreas, peritoneal wall, pelvic, suprapubic and flank masses. The mean age was 42.16 years with M:F of 1.3:1. The diagnostic yield was 85.2% in combination for Ultrasound Guided (USG and Computed Tomography (CT guided aspiration. The smears were classified as benign neoplastic, malignant neoplastic, non-neoplastic, inconclusive and unsatisfactory for interpretation. There were 79 (61.7% malignant neoplastic lesion, 5 (3.9% benign neoplastic lesion, 25 (19.5% non-neoplastic lesion, one (0.7% inconclusive lesions and 18 (14.1% unsatisfactory smears. The liver and the colon were the most common sites. Adenocarcinomas and Hepatocellular Carcinoma (HCC were the most common malignant lesions comprising of 35 (44.3% and 25 (31.6% of the total malignant lesions diagnosed. CONCLUSION Intra-abdominal FNA is a simple, economical and a safe procedure with high sensitivity, specificity and

  1. Stereotactic radiosurgery for brain metastases

    International Nuclear Information System (INIS)

    Obedian, E.; Lotbiniere, A.C.J. de; Haffty, B.G.; Piepmeier, J.M.; Fischer, D.B.; Knisely, J.P.S.

    1997-01-01

    Purpose: This study evaluates the influence of several prognostic factors on overall survival and progression free survival in patients undergoing stereotactic radiosurgery (SRS) for brain metastases. Materials and Methods: Records of 61 coecutive patients with pathologically confirmed extra-cranial malignancies undergoing SRS at Yale University School of Medicine between 12/18/91 and 7/2/96 were reviewed. All patients underwent head frame localization and CT and/or MRI based treatment planning. Outcome was analyzed with respect to age, number of lesions, size of lesions, location of lesions, site and stage of primary tumor, status of primary tumor at time of SRS, history of whole brain radiation therapy (WBRT), surgery, and/or chemotherapy prior to or after SRS, delay in SRS from diagnosis of brain metastases, dose of radiation delivered, and brain metastasis free interval. Both overall survival and progression free survival were analyzed by the Kaplan-Meier method. Tests for statistical significance were performed using the Cox proportional hazards model. Results: Median follow-up was 29 months. 3% ((8(61))) of patients displayed evidence of progressive disease at the site of SRS, and 87% ((53(61))) of patients have died. Overall and progression free survival rates for the entire cohort of patients were 43.8% and 89.5% at 1 year and 11.1% and 71.4% at 2 years, respectively. Patients undergoing SRS for a solitary brain metastasis had a significant improvement in overall survival with 1 year survival rates of 52.6% vs. 32.7% for patients undergoing SRS for more than 1 brain metastasis (p=0.002). Patients who presented with progressive systemic disease at the time of SRS had an inferior overall survival with a 1 year survival rate of 15.4% compared to patients with presumed/known stable disease who had a 1 year survival rate of 51.5%/54.2% (p<0.001). Patients treated for cerebral metastases had a higher progression free survival compared to patients undergoing SRS

  2. Stereotactic radiosurgery with an upper partial denture

    International Nuclear Information System (INIS)

    Tayama, Shusaku; Kunieda, Etsuo; Takeda, Atsushi; Takeda, Toshiaki; Oku, Yohei

    2009-01-01

    A 54-year-old male with partial denture underwent stereotactic radiosurgery with an infrared camera-guided system for a metastatic brain tumor arising from lung cancer. Although this method utilizes a biteplate mounted on the upper jaw to detect head movement, the patient only had four teeth in his upper jaw. In order to stabilize the biteplate, the maxillary denture was fixed to the biteplate with an autopolymerizing resin. In addition, the rest-occlusal position of the lower jaw was impressed on the inferior surface of the biteplate with an autopolymerizing resin. To assess reproducibility and stability, the distance between the left and right incus and left and right markers was measured during pre-planning, as well as before and after stereotactic irradiation. Wearing the biteplate ensures the accuracy of radiotherapy planning for the implementation of radiosurgery in patients who have many maxillary teeth missing. However, a large degree of error was observed when the biteplate was removed. (author)

  3. Multimodality image integration for stereotactic surgical planning.

    Science.gov (United States)

    Henri, C J; Collins, D L; Peters, T M

    1991-01-01

    A method is presented for integrating stereotactic projection and tomographic image data to give composite 3-D images (stereo pairs) of cerebral anatomy and vasculature. The technique serves to combine complementary information from each modality and allows the imaged volume to be viewed directly. The procedure is largely automated and requires no additional apparatus or information beyond that which is ordinarily employed during stereotactic surgical planning. The two types of data are combined by superimposing the projection angiogram (DSA) onto a translucent volume rendered CT or MR image. Since the rendering algorithm employs an orthographic projection technique, the tomographic volume must first be reshaped and oriented to yield a perspective view that matches the DSA projection. During this process, the data undergo various interpolations which consequently affect the accuracy of target identification based on the resulting images. The integrity of the matching procedure was assessed using simulated data sets. Also, calculations were performed to estimate the resolution of measurements made from digitized stereoscopic images. The resulting sub-pixel accuracy of the matched images suggests that the technique has potential for stereotactic applications. Preliminary results are presented illustrating combined CT-DSA and MR-DSA data sets.

  4. Stereotactic mesencephalotomy for cancer - related facial pain.

    Science.gov (United States)

    Kim, Deok-Ryeong; Lee, Sang-Won; Son, Byung-Chul

    2014-07-01

    Cancer-related facial pain refractory to pharmacologic management or nondestructive means is a major indication for destructive pain surgery. Stereotactic mesencephalotomy can be a valuable procedure in the management of cancer pain involving the upper extremities or the face, with the assistance of magnetic resonance imaging (MRI) and electrophysiologic mapping. A 72-year-old man presented with a 3-year history of intractable left-sided facial pain. When pharmacologic and nondestructive measures failed to provide pain alleviation, he was reexamined and diagnosed with inoperable hard palate cancer with intracranial extension. During the concurrent chemoradiation treatment, his cancer-related facial pain was aggravated and became medically intractable. After careful consideration, MRI-based stereotactic mesencephalotomy was performed at a point 5 mm behind the posterior commissure, 6 mm lateral to and 5 mm below the intercommissural plane using a 2-mm electrode, with the temperature of the electrode raised to 80℃ for 60 seconds. Up until now, the pain has been relatively well-controlled by intermittent intraventricular morphine injection and oral opioids, with the pain level remaining at visual analogue scale 4 or 5. Stereotactic mesencephalotomy with the use of high-resolution MRI and electrophysiologic localization is a valuable procedure in patients with cancer-related facial pain.

  5. Stereotactic radiation therapy for large vestibular schwannomas

    International Nuclear Information System (INIS)

    Mandl, Ellen S.; Meijer, Otto W.M.; Slotman, Ben J.; Vandertop, W. Peter; Peerdeman, Saskia M.

    2010-01-01

    Background and purpose: To evaluate the morbidity and tumor-control rate in the treatment of large vestibular schwannomas (VS) after stereotactic radiation therapy in our institution. Material and methods: Twenty-five consecutive patients (17 men, 8 women) with large VS (diameter 3.0 cm or larger), treated with stereotactic radiotherapy (SRT) or stereotactic radiosurgery (SRS) between 1992 and 2007, were retrospectively studied after a mean follow-up period of three years with respect to tumor-control rate and complications. Results: Actuarial 5-year maintenance of pre-treatment hearing level probability of 30% was achieved. Five of 17 patients suffered permanent new facial nerve dysfunction. The actuarial 5-year facial nerve preservation probability was 80%. Permanent new trigeminal nerve neuropathy occurred in two of 15 patients, resulting in an actuarial 5-year trigeminal nerve preservation probability of 85%. Tumor progression occurred in four of 25 (16%) patients. The overall 5-year tumor control probability was 82%. Conclusion: Increased morbidity rates were found in patients with large VS treated with SRT or SRS compared to the published series on regular sized VS and other smaller retrospective studies on large VS.

  6. Preliminary experience with frameless stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Buatti, John M.; Bova, Francis J.; Friedman, William A.; Meeks, Sanford L.; Marcus, Robert B.; Mickle, J. Parker; Ellis, Thomas L.; Mendenhall, William M.

    1998-01-01

    Purpose: To report initial clinical experience with a novel high-precision stereotactic radiotherapy system. Methods and Materials: Sixty patients ranging in age from 2 to 82 years received a total of 1426 treatments with the University of Florida frameless stereotactic radiotherapy system. Of the total, 39 (65%) were treated with stereotactic radiotherapy (SRT) alone, and 21 (35%) received SRT as a component of radiotherapy. Pathologic diagnoses included meningiomas (15 patients), low-grade astrocytomas (11 patients), germinomas (9 patients), and craniopharyngiomas (5 patients). The technique was used as means of dose escalation in 11 patients (18%) with aggressive tumors. Treatment reproducibility was measured by comparing bite plate positioning registered by infrared light-emitting diodes (IRLEDs) with the stereotactic radiosurgery reference system, and with measurements from each treatment arc for the 1426 daily treatments (5808 positions). We chose 0.3 mm vector translation error and 0.3 deg. rotation about each axis as the maximum tolerated misalignment before treating each arc. Results: With a mean follow-up of 11 months, 3 patients had recurrence of malignant disease. Acute side effects were minimal. Of 11 patients with low grade astrocytomas, 4 (36%) had cerebral edema and increased enhancement on MR scans in the first year, and 2 required steroids. All had resolution and marked tumor involution on follow-up imaging. Bite plate reproducibility was as follows. Translational errors: anterior-posterior, 0.01 ± 0.10; lateral, 0.02 ± 0.07; axial, 0.01 ± 0.10. Rotational errors (degrees): anterior-posterior, 0.00 ± 0.03; lateral, 0.00 ± 0.06; axial, 0.01 ± 0.04. No patient treatment was delivered beyond the maximum tolerated misalignment. Daily treatment was delivered in approximately 15 min per patient. Conclusion: Our initial experience with stereotactic radiotherapy using the infrared camera guidance system was good. Patient selection and treatment

  7. A novel stereotactic device for spinal irradiation in rats designed for a linear accelerator.

    Science.gov (United States)

    Galván, Ernesto E; Lárraga-Gutiérrez, José M; Celis, Miguel Angel; Moreno-Jiménez, Sergio; Díaz-Ruiz, Araceli; Rios, Camilo

    2010-01-01

    Our purpose was to report the design and positioning accuracy testing of a stereotactic device designed for a linear accelerator to perform spinal radiosurgery in rats. To define the spatial and repositioning accuracy of the device, we measured the 3-dimensional (3D) translation of a paraspinal fiducial mark implanted by microsurgery in 5 Wistar rats during a sequence of setups and treatment simulations, thus obtaining final 3D translation vectors and maximum displacements. For spatial accuracy, the differential coordinate translations were 0.8 +/- 0.3, 0.6 +/- 0.2 and 0.5 +/- 0.1 mm in the x-, y- and z-directions, respectively. The median magnitude of the 3D vector was 1.3 mm (sigma = 0.2 mm), with a maximum error of 2.2 mm. The differential coordinate translation for the repositioning accuracy showed values of 1.4 +/- 0.3, 1.3 +/- 0.3 and 0.8 +/- 0.1 mm for the x-, y- and z-coordinates, resulting in a 3D displacement vector of 2.2 mm (sigma = 0.2 mm) and a maximum displacement error of 3.6 mm. Using a linear accelerator, our novel stereotactic device provides accurate immobilization and repositioning of paraspinal structures under experimental conditions in rats. (c) 2010 S. Karger AG, Basel.

  8. Stereotactic radiosurgery: a “targeted” therapy for cancer

    Science.gov (United States)

    Zeng, Ming; Han, Liang-Fu

    2012-01-01

    The developments of medicine always follow innovations in science and technology. In the past decade, such innovations have made cancer-related targeted therapies possible. In general, the term “targeted therapy” has been used in reference to cellular and molecular level oriented therapies. However, improvements in the delivery and planning of traditional radiation therapy have also provided cancer patients more options for “targeted” treatment, notably stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT). In this review, the progress and controversies of SRS and SBRT are discussed to show the role of stereotactic radiation therapy in the ever evolving multidisciplinary care of cancer patients. PMID:22835385

  9. Novel Technique for Hepatic Fiducial Marker Placement for Stereotactic Body Radiation Therapy

    International Nuclear Information System (INIS)

    Jarraya, Hajer; Chalayer, Chloé; Tresch, Emmanuelle; Bonodeau, Francois; Lacornerie, Thomas; Mirabel, Xavier; Boulanger, Thomas; Taieb, Sophie; Kramar, Andrew; Lartigau, Eric; Ceugnart, Luc

    2014-01-01

    Purpose: To report experience with fiducial marker insertion and describe an advantageous, novel technique for fiducial placement in the liver for stereotactic body radiation therapy with respiratory tracking. Methods and Materials: We implanted 1444 fiducials (single: 834; linked: 610) in 328 patients with 424 hepatic lesions. Two methods of implantation were compared: the standard method (631 single fiducials) performed on 153 patients from May 2007 to May 2010, and the cube method (813 fiducials: 610 linked/203 single) applied to 175 patients from April 2010 to March 2013. The standard method involved implanting a single marker at a time. The novel technique entailed implanting 2 pairs of linked markers when possible in a way to occupy the perpendicular edges of a cube containing the tumor inside. Results: Mean duration of the cube method was shorter than the standard method (46 vs 61 minutes; P<.0001). Median numbers of skin and subcapsular entries were significantly smaller with the cube method (2 vs 4, P<.0001, and 2 vs 4, P<.0001, respectively). The rate of overall complications (total, major, and minor) was significantly lower in the cube method group compared with the standard method group (5.7% vs 13.7%; P=.013). Major complications occurred while using single markers only. The success rate was 98.9% for the cube method and 99.3% for the standard method. Conclusions: We propose a new technique of hepatic fiducial implantation that makes use of linked fiducials and involves fewer skin entries and shorter time of implantation. The technique is less complication-prone and is migration-resistant

  10. Multimedia educational services in stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Bazioglou, M.; Theodorou, K.; Kappas, C.

    1999-01-01

    The computer-based learning methods in medicine have been well established as stand-alone learning systems. Recently, these systems were enriched with the use of telematics technology to provide distance learning capabilities. Stereotactic radiotherapy is more of the most representative advanced radiotherapy techniques. Due to the multidisciplinary character of the technique and the rapid evolution of technology implemented, the demands in training have increased. The potential of interactive multimedia and Internet technologies for the achievement of distance learning capabilities in this domain are investigated. The realization of a computer-based educational program in stereotactic radiotherapy in a multimedia format is a new application in the computer-aided distance learning field. The system is built according to a client and server architecture, based on the Internet infrastructure, and composed of server nodes. The impact of the system may be described in terms of: time and transportation costs saving, flexibility in training (scheduling, rate and subject selection), online communication and interaction with experts, cost effective access to material (delivery or access by a large number of users and revision of the material by avoiding and database development. (authors)

  11. Pulmonary oligometastases: Metastasectomy or stereotactic ablative radiotherapy?

    International Nuclear Information System (INIS)

    Widder, Joachim; Klinkenberg, Theo J.; Ubbels, Jan F.; Wiegman, Erwin M.; Groen, Harry J.M.; Langendijk, Johannes A.

    2013-01-01

    Background and purpose: Stereotactic ablative radiotherapy (SABR; or stereotactic body radiotherapy, SBRT) emerges as treatment option for pulmonary oligometastatic disease (OMD), but there are no studies comparing SABR with pulmonary metastasectomy (PME). We analysed consecutive patients referred via a university-hospital based multidisciplinary team. Material and methods: Patients were offered PME as first choice and SABR in case they were considered to be less suitable surgical candidates. Overall survival was the primary endpoint. Secondary endpoints were progression-free-survival, local control of treated metastases, and freedom-from-failure of a local-only treatment strategy without systemic therapy. Results: From 2007 until 2010, 110 patients were treated and analysed (PME, n = 68; SABR, n = 42). Median follow-up time was 43 months (minimally, 25). Estimated overall survival rates at one, three, and five years were 87%, 62%, and 41% for PME, and 98%, 60%, and 49% for SABR, respectively (logrank-test, p = 0.43). Local control at two years was 94% for SABR and 90% for PME. Progression-free survival was 17% at three years, but 43% of the patients still had not failed a local-only treatment strategy. Conclusions: Although SABR was second choice after PME, survival after PME was not better than after SABR. Prospective comparative studies are clearly required to define the role of both, SABR and PME in OMD

  12. Stereotactic radiosurgery: basic concepts and current status

    International Nuclear Information System (INIS)

    Gaur, Maheep Singh

    2016-01-01

    Term Stereotactic Radiosurgery was coined by Prof Lars Leksell in 1951 as concept. Leksell's experimented together with the radiobiologist Borje Larsson in Uppsala, on trying to develop 'stereotactic radiosurgery', aimed at lesioning in the central brain in functional operations such as thalamotomy and capsulotomy. Clinical experiments using a proton beam were initiated at the Gustav Werner Institute in Uppsala, and a few patients had been treated. Experiences from these led Leksell to design a multi-source 'beam knife', which became ready for use in 1967 as the first 'Gamma Knife' and installed at the private hospital Sophiahammet in Stockholm as a clinical research unit. Moving from functional neurosurgery today Gamma knife is used for a wide range on brain tumors, vascular malformations and functional disorders. Introduction of newer technology in navigation and radiation delivery has made it possible to do whole body Radiosurgery. Various technologies, basic principles, radiobiological aspects and applications will be discussed. (author)

  13. Stereotactic radiofrequency amygdalohippocampectomy: Two years of good neuropsychological outcomes

    Czech Academy of Sciences Publication Activity Database

    Malíková, H.; Krámská, L.; Vojtěch, Z.; Lukavský, Jiří; Liščák, R.

    2013-01-01

    Roč. 106, č. 3 (2013), s. 423-432 ISSN 0920-1211 Institutional support: RVO:68081740 Keywords : temporal lobe epilepsy * stereotactic surgery * neuropsychology outcome Subject RIV: AN - Psychology Impact factor: 2.190, year: 2013

  14. The development of the international stereotactic radiosurgery society.

    Science.gov (United States)

    Lunsford, L Dade

    2011-01-01

    In this report the origins of the International Stereotactic Radiosurgery Society (ISRS) are described from the viewpoint of one of the early organizers and first president. The value of the society, the subsequent leadership, and the Jacob Fabrikant Award winners are also presented. A brief and incomplete timeline for the field of stereotactic radiosurgery is shown. The goals and mission of the ISRS continue to be met via the sponsorship of biennial meetings and publications.

  15. Targeting tumour hypoxia to improve outcome of stereotactic radiotherapy

    DEFF Research Database (Denmark)

    Wittenborn, Thomas R; Horsman, Michael R

    2015-01-01

    BACKGROUND: Hypoxia is a characteristic feature of solid tumours that significantly reduces the efficacy of conventional radiation therapy. In this study we investigated the role of hypoxia in a stereotactic radiation schedule by using a variety of hypoxic modifiers in a preclinical tumour model...... OXi4503 and heat with the final 15 Gy had a significantly larger effect (TCD50 = 2 Gy). CONCLUSIONS: Clinically relevant modifiers of hypoxia effectively enhanced an equivalent stereotactic radiation treatment confirming the importance of hypoxia in such schedules....

  16. Cerebral control and survival after stereotactic radiotherapy of brain metastases

    International Nuclear Information System (INIS)

    Arnold, Elmar Till

    2014-01-01

    This retrospective study, including 275 patients who underwent stereotactic radiotherapy due to brain metastases between 2003 and 2008, investigates influencing factors regarding cerebral control and survival, symptomatic effects and a potential benefit for patients older than 70 years. We were able to identify risk factors for remote brain failure which leads to a therapeutic recommendation. Furthermore we confirm a positive symptomatic effect and a benefit of stereotactic readiotherapy for patients over 70 years.

  17. Quality assurance for MR stereotactic imaging for three Siemens scanners

    International Nuclear Information System (INIS)

    Kozubikova, P.; Novotny, J. Jr.; Kulhova, K.; Mihalova, P.; Tamasova, J.; Veselsk, T.

    2014-01-01

    Quality assurance of stereotactic imaging, especially with MRI (magnetic resonance imaging), is a complex issue. It can be divided in the basic verification and commissioning of a particular new scanner or a new scanning MRI protocol that is being implemented into a clinical practice and the routine quality assurance performed for each single radiosurgical case. The aim of this study was geometric distortion assessment in MRI with a special PTGR (Physikalisch-Technische Gesellschaft fuer Radiologie - GmbH, Tuebingen, Germany) target phantom. PTGR phantom consists of 21 three-dimensional cross-hairs filled with contrast medium. Cross hairs are positioned at known Leksell coordinates with a precision of better than 0.1 mm and covering the whole stereotactic space. The phantom can be fixed in the Leksell stereotactic frame and thus stereotactic imaging procedures can be reproduced following exactly the same steps as for a real patient, including also the stereotactic image definition in the Leksell GammaPlan. Since the geometric position (stereotactic coordinates) of each cross-hair is known based on the construction of the phantom, it can be compared with the actual measured Leksell coordinates based on the stereotactic MRI. Deviations between expected and actual coordinates provide information about the level of distortion. The measured distortions proved satisfactory accuracy precision for stereotactic localization at 1.5 T Siemens Magnetom Avanto scanner, Siemens Magnetom Symphony scanner and 3T Siemens Magnetom Skyra scanner (Na Homolce Hospital, Prague). The mean distortion for these MR scanners for standard imaging protocol (T1 weighted 3D images) were 0.8 mm, 1.1 mm and 1.1 mm and maximum distortions were 1.3 mm, 1.9 mm and 2.2 mm, respectively.There was detected dependence of the distortions on the slice orientation and the type of imaging protocol. Image distortions are also property of each particular scanner, the worst distortion were observed for 3T

  18. A neurosurgery/stereotactic radiotherapy dedicated PACS for conformal radiotherapy

    International Nuclear Information System (INIS)

    Lefkopoulos, D.; Bocquiault, P.; Levrier, M.; Merienne, L.; Schlienger, M.

    1995-01-01

    To realise conformal cerebral stereotactic irradiations we use a Neurosurgery/stereotactic dedicated PACS between two distant hospitals. It connects the stereotactic neurosurgery planification imaging system NEUROAXIS (Sopelem-Sofretec/Ste Anne Hospital) with the dosimetric TPS ARTEMIS-3D/Dosigray (Tenon Hospital). NEUROAXIS is a computer aided stereotactic biopsies and stereo-electroencephalographies, used by surgeons in operating room. The system determines the precise location data for Talairach radiological equipment (X ray source at 5 meters from film) and the geometry of scanner and MRI stereotactical referentials. It provides a full set of features for lesion localization, geometrical computations, surgical planifications, picture archiving, stereotactic angiography, CT and MRI image processing and networking. It sends images through the French public digital network ISDN (NUMERIS/France Telecom : 2x64 Kbits/s) from Ste Anne to Tenon Hospital. Stereotactic angiographic and CT images are reformatted into the DOSIGRAY image processing environment where 3-D dose distributions, displays and DVHs are computed to determine the optimal treatment. ARTEMIS-3D/Dosigray is a TPS for stereotactic radiotherapy devised by the Tenon Hospital for clinical methodology and 3D dose calculations, optimization software development and the Dosigray company for multimodality imaging, (2D(3D)) computer graphics for dose and anatomical representation and data networking. Communication within the radiation oncology department is provided by local area ETHERNET network, linking heterogeneous systems (Vaxstations-3200; Decstation (5000(240))) by means of different protocols. The works in progress are to send back via the same network the 3-D dose matrix to Neurosurgery department NEUROAXIS system. Our PACS is used since six months to treat patients. It has permitted to improve the treatment quality in comparison with our first version TPS ARTEMIS-3D

  19. BI-26HOW MUCH INSIGHT CAN A STEREOTACTIC BIOPSY DELIVER?

    OpenAIRE

    Timmer, Marco; Perrech, Moritz; Röhn, Gabriele; Rueß, Daniel; Blau, Tobias; Breuer, Nadine; Galldiks, Norbert; Goldbrunner, Roland; Ruge, Maximilian

    2014-01-01

    INTRODUCTION: Besides standard evaluation of histology, immunology and molecular markers as MGNT, IDH etc. an additional screening for biomarkers, genetic alterations and epigenetic features deriving from tissue from primary or recurrent brain tumors may harbor potential as prognostic and predictive information. With this pilot study we intended to examine in how far tissue obtained by stereotactic biopsy can be utilized for extended evaluation. METHODS: Stereotactically guided serial tissue ...

  20. Accuracy of marketing claims by providers of stereotactic radiation therapy.

    Science.gov (United States)

    Narang, Amol K; Lam, Edwin; Makary, Martin A; Deweese, Theodore L; Pawlik, Timothy M; Pronovost, Peter J; Herman, Joseph M

    2013-01-01

    Direct-to-consumer advertising by industry has been criticized for encouraging overuse of unproven therapies, but advertising by health care providers has not been as carefully scrutinized. Stereotactic radiation therapy is an emerging technology that has sparked controversy regarding the marketing campaigns of some manufacturers. Given that this technology is also being heavily advertised on the Web sites of health care providers, the accuracy of providers' marketing claims should be rigorously evaluated. We reviewed the Web sites of all U.S. hospitals and private practices that provide stereotactic radiation using two leading brands of stereotactic radiosurgery technology. Centers were identified by using data from the manufacturers. Centers without Web sites were excluded. The final study population consisted of 212 centers with online advertisements for stereotactic radiation. Web sites were evaluated for advertisements that were inconsistent with advertising guidelines provided by the American Medical Association. Most centers (76%) had individual pages dedicated to the marketing of their brand of stereotactic technology that frequently contained manufacturer-authored images (50%) or text (55%). Advertising for the treatment of tumors that have not been endorsed by professional societies was present on 66% of Web sites. Centers commonly claimed improved survival (22%), disease control (20%), quality of life (17%), and toxicity (43%) with stereotactic radiation. Although 40% of Web sites championed the center's regional expertise in delivering stereotactic treatments, only 15% of Web sites provided data to support their claims. Provider advertisements for stereotactic radiation were prominent and aggressive. Further investigation of provider advertising, its effects on quality of care, and potential oversight mechanisms is needed.

  1. Stereotactic IMRT for prostate cancer: setup accuracy of a new stereotactic body localization system.

    Science.gov (United States)

    Wang, Lu; Jacob, Rojymon; Chen, Lili; Ma, Charlie; Movsas, Benjamin; Feigenberg, Steve; Konski, Andre

    2004-01-01

    The purpose of this work is to prospectively assess the setup accuracy that can be achieved with a stereotactic body localizer (SBL) in immobilizing patients for stereotactic intensity-modulated radiotherapy (IMRT) for prostate cancer. By quantifying this important factor and target mobility in the SBL, we expect to provide a guideline for selecting planning target volume margins for stereotactic treatment planning. We analyzed data from 40 computed tomography (CT) studies (with slice thickness of 3 mm) involving 10 patients with prostate cancer. Each patient had four sets of CT scans during the course of radiotherapy. For the purpose of this study, all four sets of CT scans were obtained with the patients immobilized in a customized body pillow formed by vacuum suction. Unlike other immobilization devices, this system consists not only of a customized body pillow, but also of a fixation sheet used to suppress patient respiratory motion, a stereotactic body frame to provide stereotaxy, and a carbon fiber base board to which both the body cushion and the frame are affixed. We identified four bony landmarks and measured their coordinates in the stereotactic body frame on each set of CT scans. The displacements of the bony landmarks from their corresponding positions on the simulation scan (first CT scan) were analyzed in three dimensions in terms of overall, systematic, and random categories. The initial planned isocenter was also marked on the patients' skin with fiducials for each CT study. The distance from each bony landmark to the fiducial-based isocenter was measured and compared among the four sets of CT scans. The deviations in distances were also compared to those measured from the landmarks to the stereotactic frame center, in order to determine the effectiveness of the rigid body frame in positioning patients with prostate cancer. Target inter-fraction motion in this system was also studied for five patients by measuring the deviations in distances from

  2. Psychosurgery: stereotactic subcaudate tractomy. An indispensable treatment.

    Science.gov (United States)

    Bridges, P K; Bartlett, J R; Hale, A S; Poynton, A M; Malizia, A L; Hodgkiss, A D

    1994-11-01

    Stereotactic subcaudate tractotomy (SST) is the only type of psychosurgery performed at the Geoffrey Knight Unit, London, where nearly 1300 operations have been done since 1961. Statistically reliable data are not available to prove the effectiveness of SST. A detailed statement about contemporary psychosurgery is given. Relevant publications from the Unit and via Medline are discussed. The outcome figures are reviewed. The outcome is assessed at the Unit in global and clinical terms, associated with results of self-completed questionnaires. SST allows 40-60% of patients to live normal or near-normal lives, perhaps with continuation of medication. A reduction in suicide rate to 1% post-operatively, from 15% in cases of uncontrolled affective disorders is seen. As a treatment of last resort, no controlled trial against a comparable treatment is possible. It appears reasonable to offer SST to patients with suicidal and deluded depression or with frequently swinging moods, not responding to other treatments.

  3. [Stereotactic body radiation therapy for spinal metastases].

    Science.gov (United States)

    Pasquier, D; Martinage, G; Mirabel, X; Lacornerie, T; Makhloufi, S; Faivre, J-C; Thureau, S; Lartigau, É

    2016-10-01

    After the liver and lungs, bones are the third most common sites of cancer metastasis. Palliative radiotherapy for secondary bone tumours helps relieve pain, improve the quality of life and reduce the risk of fractures. Stereotactic body radiotherapy can deliver high radiation doses with very tight margins, which has significant advantages when treating tumours close to the spinal cord. Strict quality control is essential as dose gradient at the edge of the spinal cord is important. Optimal schedule is not defined. A range of dose-fractionation schedules have been used. Pain relief and local control are seen in over 80%. Toxicity rates are low, although vertebral fracture may occur. Ongoing prospective studies will help clarify its role in the management of oligometastatic patients. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  4. Emerging technologies in stereotactic body radiotherapy.

    Science.gov (United States)

    Ma, Lijun; Wang, Lei; Tseng, Chia-Lin; Sahgal, Arjun

    2017-09-01

    Stereotactic body radiation therapy (SBRT) stems from the initial developments of intra-cranial stereotactic radiosurgery (SRS). Despite similarity in their names and clinical goals of delivering a sufficiently high tumoricidal dose, maximal sparing of the surrounding normal tissues and a short treatment course, SBRT technologies have transformed from the early days of body frame-based treatments with X-ray verification to primarily image-guided procedures with cone-beam CT or stereoscopic X-ray systems and non-rigid body immo-bilization. As a result of the incorporation of image-guidance systems and multi-leaf col-limators into mainstream linac systems, and treatment planning systems that have also evolved to allow for routine dose calculations to permit intensity modulated radiotherapy and volumetric modulated arc therapy (VMAT), SBRT has disseminated rapidly in the community to manage many disease sites that include oligometastases, spine lesions, lung, prostate, liver, renal cell, pelvic tumors, and head and neck tumors etc. In this article, we review the physical principles and paradigms that led to the widespread adoption of SBRT practice as well as technical caveats specific to individual SBRT technologies. From the perspective of treatment delivery, we categorically described (I) C-arm linac-based SBRT technologies; (II) robotically manipulated X-band CyberKnife® technology; and (III) emerging specialized systems for SBRT that include integrated MRI-linear accelerators and the imaged-guided Gamma Knife Perfexion Icon system with expanded multi-isocenter treatments of skull-based tumors, head-and-neck and cervical-spine lesions.

  5. Dosimetric evaluation of proton stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Min, Byung Jun; Shin, Dong Ho; Yoo, Seung Hoon; Jeong, Hojin; Lee, Se Byeong

    2011-01-01

    Surgical excision, conventional external radiotherapy, and chemotherapy could prolong survival in patients with small intracranial tumors. However, surgical excision for meningiomas located in the region of the base of skull or re-resection is often difficult. Moreover, treatment is needed for patients with recurrent tumors or postoperative residual tumors. Conventional external radiotherapy is popular and has significantly increased for treating brain tumors. Stereotactic radiosurgery is an effective alternative treatment technique to microsurgical resection such as benign brain tumor or vestibular Schwannomas. In general, the dose to OAR of 3D conformal plan is lower than that of conformal arc and dynamic conformal arc plans. However, any of OARs was not reached to tolerance dose. Although mean dose of the healthy brain tissue for 3D conformal plan was slightly higher than that of arc plans, the doses of the healthy brain tissue at V10 and V20 were significantly low for dynamic conformal arc plan. The dosimetric differences were the greatest at lower doses. In contrast, 3D conformal plan was better spare at higher doses. In this study, a dosimetric evaluation of proton stereotactic radiosurgery for brain lesion tumors was using fixed and arc beams. A brass block fitted to the PTV structure was modeled for dynamic conformal collimator. Although all treatment plans offer a very good coverage of the PTV, we found that proton arc plans had significantly better conformity to the PTV than static 3D conformal plan. The V20 dose of normal brain for dynamic conformal arc therapy is dramatically reduced compare to those for other therapy techniques.

  6. Stereotactic radiosurgery for the treatment of brain metastases; results from a single institution experience.

    LENUS (Irish Health Repository)

    Burke, D

    2013-09-01

    Stereotactic radiosurgery is frequently used for the treatment of brain metastases. This study provides a retrospective evaluation of patients with secondary lesions of the brain treated with stereotactic radiosurgery (SRS) at our institution.

  7. Cochlear Implants

    Science.gov (United States)

    A cochlear implant is a small, complex electronic device that can help to provide a sense of sound. People who are ... of-hearing can get help from them. The implant consists of two parts. One part sits on ...

  8. Goserelin Implant

    Science.gov (United States)

    Goserelin implant is used in combination with radiation therapy and other medications to treat localized prostate cancer and is ... treatment of abnormal bleeding of the uterus. Goserelin implant is in a class of medications called gonadotropin- ...

  9. Dental Implant Surgery

    Science.gov (United States)

    ... here to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, surgery, ... here to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, surgery, ...

  10. Treatment accuracy of fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Kumar, Shaleen; Burke, Kevin; Nalder, Colin; Jarrett, Paula; Mubata, Cephas; A'Hern, Roger; Humphreys, Mandy; Bidmead, Margaret; Brada, Michael

    2005-01-01

    Background and purpose: To assess the geometric accuracy of the delivery of fractionated stereotactic radiotherapy (FSRT) for brain tumours using the Gill-Thomas-Cosman (GTC) relocatable frame. Accuracy of treatment delivery was measured via portal images acquired with an amorphous silicon based electronic portal imager (EPI). Results were used to assess the existing verification process and to review the current margins used for the expansion of clinical target volume (CTV) to planning target volume (PTV). Patients and methods: Patients were immobilized in a GTC frame. Target volume definition was performed on localization CT and MRI scans and a CTV to PTV margin of 5 mm (based on initial experience) was introduced in 3D. A Brown-Roberts-Wells (BRW) fiducial system was used for stereotactic coordinate definition. The existing verification process consisted of an intercomparison of the coordinates of the isocentres and anatomy between the localization and verification CT scans. Treatment was delivered with 6 MV photons using four fixed non-coplanar conformal fields using a multi-leaf collimator. Portal imaging verification consisted of the acquisition of orthogonal images centred through the treatment isocentre. Digitally reconstructed radiographs (DRRs) created from the CT localization scans were used as reference images. Semi-automated matching software was used to quantify set up deviations (displacements and rotations) between reference and portal images. Results: One hundred and twenty six anterior and 123 lateral portal images were available for analysis for set up deviations. For displacements, the total errors in the cranial/caudal direction were shown to have the largest SD's of 1.2 mm, while systematic and random errors reached SD's of 1.0 and 0.7 mm, respectively, in the cranial/caudal direction. The corresponding data for rotational errors (the largest deviation was found in the sagittal plane) was 0.7 deg. SD (total error), 0.5 deg. (systematic) and 0

  11. Radiobiological mechanisms of stereotactic body radiation therapy and stereotactic radiation surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Sook; Kim, Won Woo; Park, In Hwan; Kim, Hee Jong; Lee, Eun Jin; Jung, Jae Hoon [Research Center for Radiotherapy, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Cho, Lawrence Chin Soo; Song, Chang W. [Dept. of Radiation Oncology, University of Minnesota Medical School, Minneapolis (United States)

    2015-12-15

    Despite the increasing use of stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS) in recent years, the biological base of these high-dose hypo-fractionated radiotherapy modalities has been elusive. Given that most human tumors contain radioresistant hypoxic tumor cells, the radiobiological principles for the conventional multiple-fractionated radiotherapy cannot account for the high efficacy of SBRT and SRS. Recent emerging evidence strongly indicates that SBRT and SRS not only directly kill tumor cells, but also destroy the tumor vascular beds, thereby deteriorating intratumor microenvironment leading to indirect tumor cell death. Furthermore, indications are that the massive release of tumor antigens from the tumor cells directly and indirectly killed by SBRT and SRS stimulate anti-tumor immunity, thereby suppressing recurrence and metastatic tumor growth. The reoxygenation, repair, repopulation, and redistribution, which are important components in the response of tumors to conventional fractionated radiotherapy, play relatively little role in SBRT and SRS. The linear-quadratic model, which accounts for only direct cell death has been suggested to overestimate the cell death by high dose per fraction irradiation. However, the model may in some clinical cases incidentally do not overestimate total cell death because high-dose irradiation causes additional cell death through indirect mechanisms. For the improvement of the efficacy of SBRT and SRS, further investigation is warranted to gain detailed insights into the mechanisms underlying the SBRT and SRS.

  12. A new system for neuronavigation and stereotactic biopsy pantograph stereotactic localization and guidance system.

    Science.gov (United States)

    Abrishamkar, Saeid; Moin, Houshang; Safavi, Mohammadreza; Honarmand, Azim; Hajibabaie, Mahmood; Haghighi, Elham K; Abbasifard, Salman

    2011-07-01

    Everyday, neurosurgeons face the problem of orientation within the brain but the advent of stereotactic surgery and neuronavigation have solved this problem. Frame-based stereotactic systems (FBSS) and neuronavigation systems have their own strengths and priority and pitfalls, which were the main driving force for us to design a new system. This hybrid system comprises three main parts: main frame, monitoring system, and pantograph, which are connected to each other and to the operating table by particular attachments. For using this system, after performing CT SCAN or Magnetic Resonance Imaging (MRI) the axial view will be transferred to Liquid Cristal Display (LCD). In the operating room, the head of the patient fixes to the operating table and registration is completed by two arms of pantograph. We made a simulation operation with our system on an occipital cavernous angioma and a frontal oligodendroglioma. The software, which have been used for simulation were as follows; Poser (version-7), Catia (version 5- R18), and 3 Dimension Max (version 2008). The accuracy of this system is approximately two millimeter. The advantages of this system are: easy to use, much less expensive, and compatible with different devices, which may be needed during neurosurgical operation. For countries that do not have the opportunity to have sophisticated technology and neuronavigation system, we believe that our system is a one-stop solution.

  13. Stereotactic Radiosurgery and Fractionated Stereotactic Radiation Therapy for the Treatment of Uveal Melanoma

    International Nuclear Information System (INIS)

    Yazici, Gozde; Kiratli, Hayyam; Ozyigit, Gokhan; Sari, Sezin Yuce; Cengiz, Mustafa; Tarlan, Bercin; Mocan, Burce Ozgen; Zorlu, Faruk

    2017-01-01

    Purpose: To evaluate treatment results of stereotactic radiosurgery or fractionated stereotactic radiation therapy (SRS/FSRT) for uveal melanoma. Methods and Materials: We retrospectively evaluated 181 patients with 182 uveal melanomas receiving SRS/FSRT between 2007 and 2013. Treatment was administered with CyberKnife. Results: According to Collaborative Ocular Melanoma Study criteria, tumor size was small in 1%, medium in 49.5%, and large in 49.5% of the patients. Seventy-one tumors received <45 Gy, and 111 received ≥45 Gy. Median follow-up time was 24 months. Complete and partial response was observed in 8 and 104 eyes, respectively. The rate of 5-year overall survival was 98%, disease-free survival 57%, local recurrence-free survival 73%, distant metastasis-free survival 69%, and enucleation-free survival 73%. There was a significant correlation between tumor size and disease-free survival, SRS/FSRT dose and enucleation-free survival; and both were prognostic for local recurrence-free survival. Enucleation was performed in 41 eyes owing to progression in 26 and complications in 11. Conclusions: The radiation therapy dose is of great importance for local control and eye retention; the best treatment outcome was achieved using ≥45 Gy in 3 fractions.

  14. Stereotactic Radiosurgery and Fractionated Stereotactic Radiation Therapy for the Treatment of Uveal Melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Yazici, Gozde [Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara (Turkey); Kiratli, Hayyam [Department of Ophthalmology, Faculty of Medicine, Hacettepe University, Ankara (Turkey); Ozyigit, Gokhan; Sari, Sezin Yuce; Cengiz, Mustafa [Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara (Turkey); Tarlan, Bercin [Bascom Palmer Eye Institute, Miami, Florida (United States); Mocan, Burce Ozgen [Department of Radiology, Faculty of Medicine, Hacettepe University, Ankara (Turkey); Zorlu, Faruk, E-mail: fzorlu@hacettepe.edu.tr [Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara (Turkey)

    2017-05-01

    Purpose: To evaluate treatment results of stereotactic radiosurgery or fractionated stereotactic radiation therapy (SRS/FSRT) for uveal melanoma. Methods and Materials: We retrospectively evaluated 181 patients with 182 uveal melanomas receiving SRS/FSRT between 2007 and 2013. Treatment was administered with CyberKnife. Results: According to Collaborative Ocular Melanoma Study criteria, tumor size was small in 1%, medium in 49.5%, and large in 49.5% of the patients. Seventy-one tumors received <45 Gy, and 111 received ≥45 Gy. Median follow-up time was 24 months. Complete and partial response was observed in 8 and 104 eyes, respectively. The rate of 5-year overall survival was 98%, disease-free survival 57%, local recurrence-free survival 73%, distant metastasis-free survival 69%, and enucleation-free survival 73%. There was a significant correlation between tumor size and disease-free survival, SRS/FSRT dose and enucleation-free survival; and both were prognostic for local recurrence-free survival. Enucleation was performed in 41 eyes owing to progression in 26 and complications in 11. Conclusions: The radiation therapy dose is of great importance for local control and eye retention; the best treatment outcome was achieved using ≥45 Gy in 3 fractions.

  15. Optimisation of multiple isocentre stereotactic radiosurgery planning

    International Nuclear Information System (INIS)

    Roxby, Paul; Ungureanu, Elena; Haworth, Annette; Gavriliouk, Olena

    2011-01-01

    Full text: Finding a good treatment plan for multiple isocentre stereotactic radiosurgery (SRS) is challenging. Trial and error is too slow even for a computer when more than three isocentres are used. We present a new method which includes an optimization component and works for irregular volumes. The unequal sphere packing problem (USPP) is a well defined mathematical problem with published solutions (algorithms) for filling a convex volume with spheres of variable size. We present an algorithm for non-convex volumes, such as typical SRS targets, using mixed integer programming and linearization of constraints. Available collimator sizes are represented as spheres whose radius equals their 90% isodose. Non-overlapping spheres must lie within the target volume. One formulation maximises the fraction of the target volume covered by the spheres for a given number of isocentres (USPPmax). An alternative formulation minimises the number of isocentres required to achieve a certain packing density (USPPmin). The method was applied retrospectively to 18 recent clinical cases. Results Using USPPmin a solution was achieved in a few seconds in 14 of 18 random clinical cases. Two of the remaining four cases could be computed in under 4 min when a limit of five spheres was introduced. Low values of packing density with the maximum realistic number of isocentres indicated that a multiple isocentre approach was infeasible. Conclusions The algorithm gives the location of each isocentre and the collimator diameter to achieve an optimal multiple isocentre treatment plan. It provides a useful tool for plan design and evaluation.

  16. Quality assurance in fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Warrington, A.P.; Laing, R.W.; Brada, M.

    1994-01-01

    The recent development of fractionated stereotactic radiotherapy (SRT), which utilises the relocatable Gill-Thomas-Cosman frame (GTC 'repeat localiser'), requires comprehensive quality assurance (QA). This paper focuses on those QA procedures particularly relevant to fractionated SRT treatments, and which have been derived from the technique used at the Royal Marsden Hospital. They primarily relate to the following: (i) GTC frame fitting, initially in the mould room, and then at each imaging session and treatment fraction; (ii) checking of the linear accelerator beam geometry and alignment lasers; and (iii) setting up of the patient for each fraction of treatment. The precision of the fractionated technique therefore depends on monitoring the GTC frame relocation at each fitting, checking the accuracy of the radiation isocentre of the treatment unit, its coincidence with the patient alignment lasers and the adjustments required to set the patient up accurately. The results of our quality control checks show that setting up to a mean radiation isocentre using precisely set-up alignment lasers can be achievable to within 1 mm accuracy. When this is combined with a mean GTC frame relocatability of 1 mm on the patient, a 2-mm allowance between the prescribed isodose surface and the defined target volume is a realistic safety margin for this technique

  17. Guideline of stereotactic radiotherapy of body trunk

    International Nuclear Information System (INIS)

    Ashino, Yasuo; Ikeda, Hiroshi; Ito, Akira

    2006-01-01

    The guideline is issued for safe and effective practice of the stereotactic radiotherapy of body trunk by giving appropriate methodologies and their theoretical backgrounds to radiological stuff concerned, such as doctors, technologists, physicists, quality assurance (QA)/quality control (QC) personnel, and nurses. The issue is motivated by the recent and expected increase of facilities conducting the therapy popularized from its approval by health insurance authorities in 2004, is based on the drafts by the Study Group for improving prognosis of the accurate 3-D radiotherapy organized in the MHLW and by Jap. 3-D Conformal External Beam Radiotherapy Group and, after edition by QA committee of Jap. Soc. Ther. Radiol. Oncol., is herein published by the Society. The guideline is composed mainly from 4 chapters of Introduction, Clinical practice, Physics and technology, and QA/QC of equipments and systems. The second chapter contains, concerning the therapy, its definition, contraindication, application to health insurance (applicable diseases and requirement), target setting, radiation dose and fractionation, risk organs (serial and parallel ones) and dose limits, and progress observation post therapy. The third chapter, its definition and methods, therapeutic planning, and actual performance, and the forth, the principle, essential concept, items particularly needed (dosimetry and mechanical/geometrical accuracy of equipments, equipments for therapy planning, and QA/QC of the system). The guideline is to be revised within 2-3 years hereafter. (R.T.)

  18. Imaging of arteriovenous malformation following stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Tranchida, J.V.; Mehall, C.J.; Slovis, T.L.; Lis-Planells, M.

    1997-01-01

    Background. Stereotactic radiosurgery allows for a high dose of focused radiation to be delivered to a small lesion such as an arteriovenous malformation (AVM). The clinical change and brain response over time to this localized high-dose radiation can be quite striking. Objective. The objective of this study to describe and analyse the imaging changes following radiotherapy for AVMs. Materials and methods. The clinical presentation and the imaging changes following radiotherapy in two patients were studied over the course of 1-2 years. Results. The imaging findings include diffuse low attenuation and contrast enhancement on CT. High-signal lesions were apparent on T2-weighted MR images with prominent contrast enhancement on T1-weighted images. Ring enhancement occurred over time. While new changes appeared over 12 months, these changes diminished during the second year. Conclusion. Radiotherapy induces inflammatory changes that are generally reversible but can lead to parenchymal destruction. These imaging changes are often nonspecific and therefore must be interpreted in light of clinical symptomatology and the time course since treatment. These patients should receive routine MR imaging within 3 months after radiosurgery with follow-up imaging at 6, 12, and 18 months. (orig.). With 8 figs

  19. Stereotactic Body Radiotherapy for Oligometastatic Lung Tumors

    International Nuclear Information System (INIS)

    Norihisa, Yoshiki; Nagata, Yasushi; Takayama, Kenji; Matsuo, Yukinori; Sakamoto, Takashi; Sakamoto, Masato; Mizowaki, Takashi; Yano, Shinsuke; Hiraoka, Masahiro

    2008-01-01

    Purpose: Since 1998, we have treated primary and oligometastatic lung tumors with stereotactic body radiotherapy (SBRT). The term 'oligometastasis' is used to indicate a small number of metastases limited to an organ. We evaluated our clinical experience of SBRT for oligometastatic lung tumors. Methods and Materials: A total of 34 patients with oligometastatic lung tumors were included in this study. The primary involved organs were the lung (n = 15), colorectum (n = 9), head and neck (n = 5), kidney (n = 3), breast (n = 1), and bone (n = 1). Five to seven, noncoplanar, static 6-MV photon beams were used to deliver 48 Gy (n = 18) or 60 Gy (n = 16) at the isocenter, with 12 Gy/fraction within 4-18 days (median, 12 days). Results: The overall survival rate, local relapse-free rate, and progression-free rate at 2 years was 84.3%, 90.0%, and 34.8%, respectively. No local progression was observed in tumors irradiated with 60 Gy. SBRT-related pulmonary toxicities were observed in 4 (12%) Grade 2 cases and 1 (3%) Grade 3 case. Patients with a longer disease-free interval had a greater overall survival rate. Conclusion: The clinical result of SBRT for oligometastatic lung tumors in our institute was comparable to that after surgical metastasectomy; thus, SBRT could be an effective treatment of pulmonary oligometastases

  20. The Confluence of Stereotactic Ablative Radiotherapy and Tumor Immunology

    Directory of Open Access Journals (Sweden)

    Steven Eric Finkelstein

    2011-01-01

    Full Text Available Stereotactic radiation approaches are gaining more popularity for the treatment of intracranial as well as extracranial tumors in organs such as the liver and lung. Technology, rather than biology, is driving the rapid adoption of stereotactic body radiation therapy (SBRT, also known as stereotactic ablative radiotherapy (SABR, in the clinic due to advances in precise positioning and targeting. Dramatic improvements in tumor control have been demonstrated; however, our knowledge of normal tissue biology response mechanisms to large fraction sizes is lacking. Herein, we will discuss how SABR can induce cellular expression of MHC I, adhesion molecules, costimulatory molecules, heat shock proteins, inflammatory mediators, immunomodulatory cytokines, and death receptors to enhance antitumor immune responses.

  1. Initial clinical results of linac-based stereotactic radiosurgery and stereotactic radiotherapy for pituitary adenomas

    International Nuclear Information System (INIS)

    Mitsumori, Michihide; Shrieve, Dennis C.; Alexander, Eben; Kaiser, Ursula B.; Richardson, Gary E.; Black, Peter McL.; Loeffler, Jay S.

    1998-01-01

    Purpose: To retrospectively evaluate the initial clinical results of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) for pituitary adenomas with regard to tumor and hormonal control and adverse effects of the treatment. Subjects and Methods: Forty-eight patients with pituitary adenoma who underwent SRS or SRT between September 1989 and September 1995 were analyzed. Of these, 18 received SRS and 30 received SRT. The median tumor volumes were 1.9 cm 3 for SRS and 5.7 cm 3 for SRT. Eleven of the SRS and 18 of the SRT patients were hormonally active at the time of the initial diagnosis. Four of the SRS and none of the SRT patients had a history of prior radiation therapy. Both SRS and SRT were performed using a dedicated stereotactic 6-MV linear accelerator (LINAC). The dose and normalization used for the SRS varied from 1000 cGy at 85% of the isodose line to 1500 cGy at 65% of the isodose line. For SRT patients, a total dose of 4500 cGy at 90% or 95% of the isodose line was delivered in 25 fractions of 180 cGy daily doses. Results: Disease control--The three year tumor control rate was 91.1% (100% for SRS and 85.3% for SRT). Normalization of the hormonal abnormality was achieved in 47% of the 48 patients (33% for SRS and 54% for SRT). The average time required for normalization was 8.5 months for SRS and 18 months for SRT. Adverse effects--The 3-year rate of freedom from central nervous system adverse effects was 89.7% (72.2% for SRS and 100% for SRT). Three patients who received SRS for a tumor in the cavernous sinus developed a ring enhancement in the temporal lobe as shown by follow-up magnetic resonance imaging. Two of these cases were irreversible and were considered to be radiation necrosis. None of the 48 patients developed new neurocognitive or visual disorders attributable to the irradiation. The incidence of endocrinological adverse effects were similar in the two groups, resulting in 3-year rates of freedom from newly

  2. Stereotactic Body Radiation Therapy in Spinal Metastases

    International Nuclear Information System (INIS)

    Ahmed, Kamran A.; Stauder, Michael C.; Miller, Robert C.; Bauer, Heather J.; Rose, Peter S.; Olivier, Kenneth R.; Brown, Paul D.; Brinkmann, Debra H.; Laack, Nadia N.

    2012-01-01

    Purpose: Based on reports of safety and efficacy, stereotactic body radiotherapy (SBRT) for treatment of malignant spinal tumors was initiated at our institution. We report prospective results of this population at Mayo Clinic. Materials and Methods: Between April 2008 and December 2010, 85 lesions in 66 patients were treated with SBRT for spinal metastases. Twenty-two lesions (25.8%) were treated for recurrence after prior radiotherapy (RT). The mean age of patients was 56.8 ± 13.4 years. Patients were treated to a median dose of 24 Gy (range, 10–40 Gy) in a median of three fractions (range, 1–5). Radiation was delivered with intensity-modulated radiotherapy (IMRT) and prescribed to cover 80% of the planning target volume (PTV) with organs at risk such as the spinal cord taking priority over PTV coverage. Results: Tumor sites included 48, 22, 12, and 3 in the thoracic, lumbar, cervical, and sacral spine, respectively. The mean actuarial survival at 12 months was 52.2%. A total of 7 patients had both local and marginal failure, 1 patient experienced marginal but not local failure, and 1 patient had local failure only. Actuarial local control at 1 year was 83.3% and 91.2% in patients with and without prior RT. The median dose delivered to patients who experienced local/marginal failure was 24 Gy (range, 18–30 Gy) in a median of three fractions (range, 1–5). No cases of Grade 4 toxicity were reported. In 1 of 2 patients experiencing Grade 3 toxicity, SBRT was given after previous radiation. Conclusion: The results indicate SBRT to be an effective measure to achieve local control in spinal metastases. Toxicity of treatment was rare, including those previously irradiated. Our results appear comparable to previous reports analyzing spine SBRT. Further research is needed to determine optimum dose and fractionation to further improve local control and prevent toxicity.

  3. Stereotactic Body Radiation Therapy in Spinal Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Kamran A. [Mayo Medical School, College of Medicine, Mayo Clinic, Rochester, MN (United States); Stauder, Michael C.; Miller, Robert C.; Bauer, Heather J. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Rose, Peter S. [Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN (United States); Olivier, Kenneth R. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Brown, Paul D. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Brinkmann, Debra H. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Laack, Nadia N., E-mail: laack.nadia@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States)

    2012-04-01

    Purpose: Based on reports of safety and efficacy, stereotactic body radiotherapy (SBRT) for treatment of malignant spinal tumors was initiated at our institution. We report prospective results of this population at Mayo Clinic. Materials and Methods: Between April 2008 and December 2010, 85 lesions in 66 patients were treated with SBRT for spinal metastases. Twenty-two lesions (25.8%) were treated for recurrence after prior radiotherapy (RT). The mean age of patients was 56.8 {+-} 13.4 years. Patients were treated to a median dose of 24 Gy (range, 10-40 Gy) in a median of three fractions (range, 1-5). Radiation was delivered with intensity-modulated radiotherapy (IMRT) and prescribed to cover 80% of the planning target volume (PTV) with organs at risk such as the spinal cord taking priority over PTV coverage. Results: Tumor sites included 48, 22, 12, and 3 in the thoracic, lumbar, cervical, and sacral spine, respectively. The mean actuarial survival at 12 months was 52.2%. A total of 7 patients had both local and marginal failure, 1 patient experienced marginal but not local failure, and 1 patient had local failure only. Actuarial local control at 1 year was 83.3% and 91.2% in patients with and without prior RT. The median dose delivered to patients who experienced local/marginal failure was 24 Gy (range, 18-30 Gy) in a median of three fractions (range, 1-5). No cases of Grade 4 toxicity were reported. In 1 of 2 patients experiencing Grade 3 toxicity, SBRT was given after previous radiation. Conclusion: The results indicate SBRT to be an effective measure to achieve local control in spinal metastases. Toxicity of treatment was rare, including those previously irradiated. Our results appear comparable to previous reports analyzing spine SBRT. Further research is needed to determine optimum dose and fractionation to further improve local control and prevent toxicity.

  4. Fractionated stereotactic radiotherapy of small intracranial malignancies

    International Nuclear Information System (INIS)

    Tokuuye, Koichi; Akine, Yasuyuki; Sumi, Minako; Kagami, Yoshikazu; Murayama, Shigeyuki; Nakayama, Hidetsugu; Ikeda, Hiroshi; Tanaka, Minoru; Shibui, Soichiro; Nomura, Kazuhiro

    1998-01-01

    Purpose: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) in patients with small intracranial malignancies. Methods and Materials: From July 1991 to March 1997, 80 patients with a total of 121 brain or skull-base tumors were treated with FSRT alone, and were followed for periods ranging from 3 to 62 months (median 9.8). The majority of patients received 42 Gy in 7 fractions over 2.3 weeks, but in July 1993, protocols using smaller fraction doses were introduced for patients whose radiation-field diameters were larger than 3 cm or whose tumors were close to critical normal tissues. Results: For 64 patients with metastatic brain tumors the overall median survival was 8.3 months and 1-year actuarial survival rate was 33%. Significant prognostic factors were: the presence of extracranial tumors, pre-treatment performance status, and the lung as a primary site. Patients without extracranial tumors prior to FSRT had a median survival of 21.2 months. For seven patients with high-grade glioma, 1-year actuarial local control rate was 75%, with a median survival of 10.3 months. For patients with skull-base tumors the local control was achieved in 6 of 6 patients (100%), with a median survival of 30.7 months. No one suffered from acute complications, but three patients, two of whom had undergone FSRT as the third course of radiotherapy, developed late radiation injuries. Conclusion: Overall high local control and low morbidity rates suggest that FSRT is an effective and safe modality, even for those with a history of prior irradiation. However, patients with risk factors should be treated with smaller fraction doses

  5. Stereotactic radiosurgery for vestibular schwannoma: International Stereotactic Radiosurgery Society (ISRS) Practice Guideline.

    Science.gov (United States)

    Tsao, May N; Sahgal, Arjun; Xu, Wei; De Salles, Antonio; Hayashi, Motohiro; Levivier, Marc; Ma, Lijun; Martinez, Roberto; Régis, Jean; Ryu, Sam; Slotman, Ben J; Paddick, Ian

    2017-01-01

    The aim of this systematic review was to develop International Stereotactic Radiosurgery Society (ISRS) consensus guideline statements for vestibular schwannoma. A systematic review of the literature was performed up to April 2015. A total of 55 full-text articles were included in the analysis. All studies were retrospective, except for 2 prospective quality of life studies. Five-year tumour control rates with Gamma Knife radiosurgery (RS), single fraction linac RS, or fractionated (either hypofractionated or conventional fractionation) stereotactic radiation therapy (FSRT) were similar at 81-100%. The single fraction RS series (linac or Gamma Knife) with tumour marginal doses between 12 and 14 Gy revealed 5-year tumour control rates of 90-99%, hearing preservation rates of 41-79%, facial nerve preservation rates of 95-100% and trigeminal preservation rates of 79-99%.There were 6 non-randomized studies comparing single fraction RS versus FSRT. There was no statistically significant difference in tumour control; HR=1.66 (95% CI 0.81, 3.42), p =0.17, facial nerve function; HR = 0.67 (95% CI 0.30, 1.49), p =0.33, trigeminal nerve function; HR = 0.80 (95% CI 0.41, 1.56), p =0.51, and hearing preservation; HR = 1.10 (95% CI 0.72, 1.68), p =0.65 comparing single fraction RS with FSRT.Nine quality of life reports yielded conflicting results as to which modality (surgery, observation, or radiation) was associated with better quality of life outcomes. There are no randomized trials to help guide management of patients with vestibular schwannoma. Within the limitations of the retrospective series, a number of consensus statements were made.

  6. Fractionated stereotactic radiotherapy of vestibular schwannomas accelerates hearing loss

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric

    2012-01-01

    To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea...... and hearing preservation was also investigated....

  7. Prospective assessment of stereotactic ablative surgery for intractable major depression.

    Science.gov (United States)

    Shields, Donald C; Asaad, Wael; Eskandar, Emad N; Jain, Felipe A; Cosgrove, G Rees; Flaherty, Alice W; Cassem, Edwin H; Price, Bruce H; Rauch, Scott L; Dougherty, Darin D

    2008-09-15

    Despite therapeutic advances for major depression, a subset of patients with this disorder does not respond to conventional treatment. Stereotactic ablative procedures such as anterior cingulotomy have been performed in severely affected, treatment-resistant patients, but the long-term results of such procedures are not fully understood. Findings are reported for 33 patients with severe treatment-resistant major depression who underwent ablative stereotactic procedures (dorsal anterior cingulotomy followed if necessary by subcaudate tractotomy). Preoperative and long-term postoperative Beck Depression Inventory scores were obtained along with postoperative Clinical Global Improvement values. Both were analyzed to evaluate patients' responses to the surgical procedure(s). At mean follow-up of 30 months after one or more stereotactic ablative procedures, 11 patients (33.3%) were classified as responders, 14 (42.4%) were partial responders, and 8 (24.2%) did not respond to the surgical procedure(s). Among those (17) who underwent only one procedure, seven (41.2%) responded, whereas six (35.3%) and four (23.5%) showed partial or no response, respectively. Among patients who required multiple surgical procedures, four patients (25%) responded, whereas eight (50%) and four (25%) patients demonstrated partial or no responses, respectively, at long-term follow-up evaluations. Approximately 75% of depression patients previously resistant to antidepressant therapies received partial or substantial benefit from stereotactic ablative procedures. Those requiring only a single anterior cingulotomy tended to demonstrate more pronounced responses than patients who underwent multiple surgical procedures.

  8. A New System for Neuronavigation and Stereotactic Biopsy ...

    African Journals Online (AJOL)

    orientation within the brain. Stereotaxis as a concept in neurosurgery began by Horsley and. Clarke in 1908. The practical application of stereotaxis waited until 1947, when Spiegel and Wycis began their pioneering work. Many giant neurosurgeons find different solution for neuronavigation and stereotactic surgery.[1-5].

  9. Histological underestimation of a 9-gauge stereotactic vacuum ...

    African Journals Online (AJOL)

    Method: In this cross-sectional study, 9-gauge stereotactic biopsy histology results and breast imaging and reporting data system (BI-RADS) findings of 158 lesions (from 153 patients) were analysed and the histological findings compared with surgical excision histology results (54 lesions) to determine histological ...

  10. A prospective comparison between three-dimensional magnetic resonance imaging and ventriculography for target-coordinate determination in frame-based functional stereotactic neurosurgery

    NARCIS (Netherlands)

    Schuurman, P. R.; de Bie, R. M.; Majoie, C. B.; Speelman, J. D.; Bosch, D. A.

    1999-01-01

    OBJECT: The purpose of this prospective study was to compare stereotactic coordinates obtained with ventriculography with coordinates derived from stereotactic computer-reconstructed three-dimensional magnetic resonance (3D-MR) imaging in functional stereotactic procedures. METHODS: In 15

  11. Implantation metallurgy

    International Nuclear Information System (INIS)

    Picraux, S.T.

    1975-01-01

    Important changes in the near-surface physical properties of metals were obtained by high-fluence ion implantation. Recently there have been an increasing number of studies of the behavior of implanted species with the aim of understanding the detailed physical processes that occur in an implanted metal layer. A key aspect of these implantation metallurgy studies has been the ability to form uniquely controlled systems in the near-surface regions of metals that can be studied with accurate depth resolution. Metallurgical parameters that may be difficult or impossible to obtain by other means can be measured. Also, parameters that depend on the implantation process, due to the athermal introduction of atoms and defects can be determined. Thus the dual objective of implantation metallurgy is to obtain information to improve understanding of the microscopic aspects of metallurgy and to understand how to form controlled new metallurgical systems. Examples of parameters studied include implanted impurity location, diffusion, enhanced diffusion, solubility, precipitation, and dissolution. (auth)

  12. LINAC-based stereotactic radiosurgery for meningiomas

    International Nuclear Information System (INIS)

    Shin, Seong Soo; Kim, Dae Yong; Ahn, Yong Chan

    2001-01-01

    To evaluate the role of LINAC-based stereotactic radiosurgery (SRS) in the management of meningiomas, we reviewed clinical response, image response, neurological deficits for patients treated at our institution. Between February 1995 and December 1999, twenty-six patients were treated with SRS. Seven patients had undergone prior resection. Nineteen patients received SRS as the initial treatment. There were 7 male and 19 female patients. The median age was 51 years (range, 14-67 years). At least one clinical symptom presented at the time of SRS in 17 patients and cranial neuropathy was seen in 7 patients. The median tumor volume was 4.7 cm 3 (range, 0.7-16.5 cm 3 ). The mean marginal dose was 15 Gy (range, 10-20 Gy), delivered to the 80% isodose surface (ranger 46-90%). The median clinical and imaging follow-up periods were 27 months (range, 1-71 months) and 25 months (range, 1-52 months), respectively. Of 14 patients who had clinical follow-up of one year or longer, thirteen patients (93%) were improved clinically at follow-up examination. Clinical symptom worsened in one patient at 4 months after SRS as a result of intratumoral edema, who underwent surgical resection at 7 months. Of 14 patients who had radiologic follow-up of one year or longer, tumor volume decreased in 7 patients (50%) at a median of 11 months (range, 6-25 months), remained stable in 6 patients (43%), and increased in one patient (7%), who underwent surgical resection at 44 months. New radiation-induced neurological deficits developed in six patients (23%), Five patients (19%) had transient neurological deficits, completely resolved by conservative treatment including steroid therapy. Radiation-induced brain necrosis developed in one patient (3.8%) at 9 months after SRS who followed by surgical resection of tumor and necrotic tissue. LINAC-based SRS proves to be an effective and safe management strategy for small to moderate sized meningiomas, inoperable, residual, and recurrent, but longterm

  13. The NCI-atlas of dose distributions for regular 125I brain implants

    International Nuclear Information System (INIS)

    Rosenow, U.F.; Wright, D.C.

    1987-01-01

    In connection with the development of an optimization method for 125 I brain implants in irregulary shaped target volumes, a systematic study was conducted toward optimizing seed configurations for regular target volumes. The intention was to find basic rules for the positioning of strings of seeds in the cylindrical implant pattern of the stereotactic neurosurgical procedure in use, and in accordance with the following criteria: (i) steep dose fall-off outside the target volume; (ii) coverage of the target volume by making the prescribed dose surface coincident with the target volume surface within 1 mm; (iii) uniformity of the dose distribution in the target volume as far as achievable with a seed implant. As a result of this study, an atlas of optimized angular 125 I brain implant configurations was compiled. Regular implants were understood as being cylindrical or spherical. Diameters and heights from 2 to 5 cm were covered. 8 refs.; 11 figs.; 2 tabs

  14. Cochlear implant

    Science.gov (United States)

    ... made up of a microphone/receiver, a speech processor, and an antenna. This part of the implant ... ear. This sound is sent to a speech processor, which is most often connected to the microphone ...

  15. Stereotactic radiation therapy combined with immunotherapy: augmenting the role of radiation in local and systemic treatment.

    Science.gov (United States)

    Sharabi, Andrew B; Tran, Phuoc T; Lim, Michael; Drake, Charles G; Deweese, Theodore L

    2015-05-01

    Stereotactic radiosurgery and stereotactic body radiation therapy are two contemporary radiation modalities that can treat tumors in any area of the body using highly focused radiation. Recently, immunotherapy has established itself as a viable and powerful anticancer treatment. In this review we detail the rationale supporting a combination of immunotherapy and stereotactic radiation. Additionally, we discuss the evidence for the immune stimulatory effects of focused radiation and the role that radiation may play in enhancing the systemic treatment effects of immunotherapy.

  16. Initial clinical results of linac stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) for pituitary adenomas

    International Nuclear Information System (INIS)

    Mitsumori, Michihide; Shrieve, Dennis C.; Alexander, Eben; Kaiser, Ursula B.; Richardson, Gary E.; McL Black, Peter; Loeffler, Jay S.

    1997-01-01

    Purpose: To evaluate the initial clinical results of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) for pituitary adenomas with regard to tumor control and toxicity of the treatment, thus evaluate the feasibility of these technique for the treatment of pituitary adenomas. Subjects and Methods: 48 patients with either inoperable, recurrent or residual pituitary adenoma who underwent either SRS or SRT at the Brigham and Women's Hospital between 9/89 and 9/95 were analyzed. Of these, 18 received treatment with SRS, and 30 received SRT. SRS was contraindicated for the patients in whom the minimal distance of the target and optic chiasm or optic nerve was less than 5 mm. Patient characteristics were similar in the two groups, with the exception of tumor volume and previous irradiation. Median tumor volumes were 1.8 cm 3 and 7.7 cm 3 for SRS and SRT, respectively. Three of the SRS and none of the SRT patients had a history of previous external radiation therapy. Both SRS and SRT were performed by the use of dedicated stereotactic 6-MV linear accelerator with a treatment plan designed using a dedicated software. Doses were prescribed to the isodose distribution that covered the identified target. Dose and normalization used for SRS varied from 1000 cGy at 85 % isodose line to 1800 cGy at 80 % isodose line. For SRT patients, total dose of 4500 cGy was normalized at 90 or 95 % isodose line and this was delivered in 25 fractions of 180 cGy daily dose. Results: Local control: There was 1 case of local failure in each of SRS and SRT series (median follow up 42.5 months and 22 month, respectively). CNS adverse effects: There were 3 SRS cases in whom a ring enhancement in the temporal lobe was observed in follow-up MRI. (median follow up 32 months). Of these, one resolved spontaneously, whereas the other 2 lesion persisted and considered to be radiation necrosis. None of them required surgical intervention to date. These were observed in the

  17. Micro-stereotactic frame utilizing bone cement for individual fabrication: an initial investigation of its accuracy

    Science.gov (United States)

    Rau, Thomas S.; Lexow, G. Jakob; Blume, Denise; Kluge, Marcel; Lenarz, Thomas; Majdani, Omid

    2017-03-01

    A new method for template-guided cochlear implantation surgery is proposed which has been developed to create a minimally invasive access to the inner ear. A first design of the surgical template was drafted, built, and finally tested regarding its accuracy. For individual finalization of the micro-stereotactic frame bone cement is utilized as this well-known and well-established material suggests ease of use as well as high clinical acceptance and enables both sterile and rapid handling. The new concept includes an alignment device, based on a passive hexapod with manually adjustable legs for temporary fixation of the separate parts in the patient-specific pose until the bone cement is spread and finally cured. Additionally, a corresponding evaluation method was developed to determine the accuracy of the microstereotactic frame in some initial experiments. In total 18 samples of the surgical template were fabricated based on previously planned trajectories. The mean positioning error at the target point was 0.30 mm with a standard deviation of 0.25 mm.

  18. Stereotactic body radiotherapy in lung cancer: an update

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Carlos Eduardo Cintra Vita; Ferreira, Paula Pratti Rodrigues; Moraes, Fabio Ynoe de; Neves Junior, Wellington Furtado Pimenta; Carvalho, Heloisa de Andrade, E-mail: heloisa.carvalho@hc.fm.usp.br [Hospital Sirio-Libanes, Sao Paulo, SP (Brazil). Departamento de Radioterapia; Gadia, Rafael [Hospital Sirio-Libanes, Brasilia, DF (Brazil). Departamento de Radioterapia; Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Departamento de Radiologia e Oncologia. Servico de Radioterapia

    2015-07-15

    For early-stage lung cancer, the treatment of choice is surgery. In patients who are not surgical candidates or are unwilling to undergo surgery, radiotherapy is the principal treatment option. Here, we review stereotactic body radiotherapy, a technique that has produced quite promising results in such patients and should be the treatment of choice, if available. We also present the major indications, technical aspects, results, and special situations related to the technique. (author)

  19. CT-guided stereotactic surgery of brain abscess

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, Hiroto; Amano, Keiichi; Kawamura, Hirotsune (Tokyo Women' s Medical Coll. (Japan)) (and others)

    1991-02-01

    Seven patients with brain abscess underwent CT-guided stereotactic aspiration using Iseki's stereotactic apparatus. Three of them were under the age of fifteen and four were older than thirty. The lesions were single and round in four cases, multilobular in two and multiple in one patient. Operations were performed after systemic administration of antibiotics for more than two weeks and after capsule formation was confirmed on CTs. Preoperative volume of the abscesses was estimated from CTs. The target point chosen was the center of the ring of the largest diameter in the enhanced lesion. Abscess was aspirated under monitoring with intraoperative CT scan. No continuous drainage was performed and no antibiotics were given directly into the abscess cavity. In all cases the center of the abscess was punctured with a single trial. Average volume of the preoperative brain abscess was 18.8 ml. Aspirated volume at the time of the operation averaged 16.9 ml and all the abscesses decreased to unmeasurable size on CTs. In five of seven patients abscesses were cured after a single aspiraiton, and in one case after the second operation. One case required extirpation of the lesion. During the follow-up period of four months to five and a half years six patients showed no recurrence. One patient died of unrelated cause four and a half years after the operation. No operative complication was noted. There was no operative morbidity or mortality. Using a CT guided stereotactic method, brain abscess is punctured so accurately, regardless of its location and size, that damage to the surrounding brain during operation can be minimized. Therefore it is highly possible to aspirate absecesses completely. Operative complication such as bleeding into an abscess cavity is unlikely. CT-guided stereotactic aspiration is the treatment of first choice for brain abscess especially when it is small or deep seated. (author).

  20. Outcome in unipolar affective disorder after stereotactic tractotomy.

    Science.gov (United States)

    Lovett, L M; Crimmins, R; Shaw, D M

    1989-10-01

    An evaluation of 15 patients treated by subcaudate stereotactic tractotomy (SST) for treatment-resistant unipolar affective disorder was made for frequency and severity of recurrence of illness. One-third had died by the time of assessment, but none by suicide. Two-thirds of the sample experienced a reduction in the severity of depressive episodes after the operation; only one-third reported a reduction in frequency of episodes.

  1. Outcome in bipolar affective disorder after stereotactic tractotomy.

    Science.gov (United States)

    Lovett, L M; Shaw, D M

    1987-07-01

    Nine patients have been treated by subcaudate stereotactic tractotomy for bipolar affective disorder resistant to drug treatments. In the majority, after the operation there was a reduction in frequency and severity of depressive and manic episodes. There was a trend for the operation to have more effect on the manic than on the depressive phases. Drugs which had been inert previously sometimes became therapeutically useful after surgery.

  2. Implantable Cardioverter Defibrillator

    Science.gov (United States)

    ... To Health Topics / Implantable Cardioverter Defibrillators Implantable Cardioverter Defibrillators Also known as What Is an Implantable Cardioverter ... pacemakers and defibrillators. Comparison of an Implantable Cardioverter Defibrillator and a Pacemaker The image compares an ICD ...

  3. Breast reconstruction - implants

    Science.gov (United States)

    Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... to close the skin flaps. Breast reconstruction with implants is usually done in two stages, or surgeries. ...

  4. Frameless Angiogram-Based Stereotactic Radiosurgery for Treatment of Arteriovenous Malformations

    International Nuclear Information System (INIS)

    Lu Xingqi; Mahadevan, Anand; Mathiowitz, George; Lin, Pei-Jan P.; Thomas, Ajith; Kasper, Ekkehard M.; Floyd, Scott R.; Holupka, Edward; La Rosa, Salvatore; Wang, Frank; Stevenson, Mary Ann

    2012-01-01

    Purpose: Stereotactic radiosurgery (SRS) is an effective alternative to microsurgical resection or embolization for definitive treatment of arteriovenous malformations (AVMs). Digital subtraction angiography (DSA) is the gold standard for pretreatment diagnosis and characterization of vascular anatomy, but requires rigid frame (skull) immobilization when used in combination with SRS. With the advent of advanced proton and image-guided photon delivery systems, SRS treatment is increasingly migrating to frameless platforms, which are incompatible with frame-based DSA. Without DSA as the primary image, target definition may be less than optimal, in some cases precluding the ability to treat with a frameless system. This article reports a novel solution. Methods and Materials: Fiducial markers are implanted into the patient’s skull before angiography. Angiography is performed according to the standard clinical protocol, but, in contrast to the previous practice, without the rigid frame. Separate images of a specially designed localizer box are subsequently obtained. A target volume projected on DSA can be transferred to the localizer system in three dimensions, and in turn be transferred to multiple CT slices using the implanted fiducials. Combined with other imaging modalities, this “virtual frame” approach yields a highly precise treatment plan that can be delivered by frameless SRS technologies. Results: Phantom measurements for point and volume targets have been performed. The overall uncertainty of placing a point target to CT is 0.4 mm. For volume targets, deviation of the transformed contour from the target CT image is within 0.6 mm. The algorithm and software are robust. The method has been applied clinically, with reliable results. Conclusions: A novel and reproducible method for frameless SRS of AVMs has been developed that enables the use of DSA without the requirement for rigid immobilization. Multiple pairs of DSA can be used for better conformality

  5. Stereotactic minimally invasive tubular retractor system for deep brain lesions.

    Science.gov (United States)

    Greenfield, Jeffrey P; Cobb, William S; Tsouris, A John; Schwartz, Theodore H

    2008-10-01

    Deep-seated supratentorial intraparenchymal and intraventricular brain lesions can be difficult to access without causing significant trauma to the overlying cortex and intervening white matter tracts. Traditional brain retractors use multiple blades, which do not exert pressure in an equally distributed fashion. Tubular retractors offer an advantage. Although a commercially available frame-based tubular retractor system is on the market (COMPASS; Compass, Inc., Rochester, MN), we modified existing off-the-shelf equipment at our institution into a frameless tubular brain retractor. We used 14- to 22-mm METRx (Medtronic, Minneapolis, MN) tubular retractors in combination with a frameless stereotactic navigation system to remove 10 deep lesions. Histological findings included 6 periventricular metastases, 1 insular glioblastoma multiforme, 1 periventricular glioblastoma multiforme, 1 intraventricular meningioma, and 1 hippocampal cavernous malformation. Radiographic gross total resection was achieved in all patients. One patient experienced a transient worsening of an existing preoperative Wernicke's aphasia; otherwise, there were no intra- or postoperative complications. One patient with radiographic gross total resection of a metastatic lesion experienced a local recurrence of disease, requiring stereotactic radiosurgery. A frameless stereotactic tubular retractor system for deep brain lesions can be assembled with equipment already available at many institutions. Use of this system can decrease incision and craniotomy size, decrease retractor-induced trauma to overlying cortex, and help prevent damage to underlying white matter tracts.

  6. Stereotactic Radiotherapy for Adrenal Gland Metastases: University of Florence Experience

    International Nuclear Information System (INIS)

    Casamassima, Franco; Livi, Lorenzo; Masciullo, Stefano; Menichelli, Claudia; Masi, Laura; Meattini, Icro; Bonucci, Ivano; Agresti, Benedetta; Simontacchi, Gabriele; Doro, Raffaela

    2012-01-01

    Purpose: To evaluate a retrospective single-institution outcome after hypofractionated stereotactic body radiotherapy (SBRT) for adrenal metastases. Methods and Materials: Between February 2002 and December 2009, we treated 48 patients with SBRT for adrenal metastases. The median age of the patient population was 62.7 years (range, 43–77 years). In the majority of patients, the prescription dose was 36 Gy in 3 fractions (70% isodose, 17.14 Gy per fraction at the isocenter). Eight patients were treated with single-fraction stereotactic radiosurgery and forty patients with multi-fraction stereotactic radiotherapy. Results: Overall, the series of patients was followed up for a median of 16.2 months (range, 3–63 months). At the time of analysis, 20 patients were alive and 28 patients were dead. The 1- and 2-year actuarial overall survival rates were 39.7% and 14.5%, respectively. We recorded 48 distant failures and 2 local failures, with a median interval to local failure of 4.9 months. The actuarial 1-year disease control rate was 9%; the actuarial 1- and 2-year local control rate was 90%. Conclusion: Our retrospective study indicated that SBRT for the treatment of adrenal metastases represents a safe and effective option with a control rate of 90% at 2 years.

  7. Stereotactic biopsy of cerebellar lesions: straight versus oblique frame positioning.

    Science.gov (United States)

    Quick-Weller, Johanna; Brawanski, Nina; Dinc, Nazife; Behmanesh, Bedjahn; Kammerer, Sara; Dubinski, Daniel; Seifert, Volker; Marquardt, Gerhard; Weise, Lutz

    2017-10-26

    Biospies of brain lesions with unknown entity are an everyday procedure among many neurosurgical departments. Biopsies can be performed frame-guided or frameless. However, cerebellar lesions are a special entity with a more complex approach. All biopsies in this study were performed stereotactically frame guided. Therefore, only biopsies of cerebellar lesions were included in this study. We compared whether the frame was attached straight versus oblique and we focused on diagnostic yield and complication rate. We evaluated 20 patients who underwent the procedure between 2009 and 2017. Median age was 56.5 years. 12 (60%) Patients showed a left sided lesion, 6 (30%) showed a lesion in the right cerebellum and 2 (10%) patients showed a midline lesion. The stereotactic frame was mounted oblique in 12 (60%) patients and straight in 8 (40%) patients. Postoperative CT scan showed small, clinically silent blood collection in two (10%) of the patients, one (5%) patient showed haemorrhage, which caused a hydrocephalus. He received an external ventricular drain. In both patients with small haemorrhage the frame was positioned straight, while in the patient who showed a larger haemorrhage the frame was mounted oblique. In all patients a final histopathological diagnosis was established. Cerebellar lesions of unknown entity can be accessed transcerebellar either with the stereotactic frame mounted straight or oblique. Also for cerebellar lesions the procedure shows a high diagnostic yield with a low rate of severe complications, which need further treatment.

  8. Multiple brain metastases irradiation with Eleka Axesse stereotactic system

    Science.gov (United States)

    Filatov, P. V.; Polovnikov, E. S.; Orlov, K. Yu.; Krutko, A. V.; Kirilova, I. A.; Moskalev, A. V.; Filatova, E. V.; Zheravin, A. A.

    2017-09-01

    Brain metastases are one of the factors complicating the treatment of a malignant tumor. Radiation therapy, especially radiosurgery, plays an important role in the modern treatment practice. During 2011-2016, 32 patients (from 29 to 67 years old) with multiple brain metastases underwent the treatment with SRS or SRT in our center. The number of secondary lesions varied from 2 to 11. Eight patients underwent microsurgery resection. Seven patients had recurrence after whole brain radiotherapy. Thirty patient underwent single fraction SRS and two patients with large metastases (bigger than 3 cm) underwent fractionated SRT. The treatment was done with dedicated linear accelerator stereotactic system Elekta Axesse (Elekta AB, Stockholm, Sweden). Different stereotactic fixation devices were used, namely, Leksell G frame, non-invasive HeadFIX frame, and reinforced thermoplastic mask (IMRT perforation). All treatments included a volumetric modulated arc therapy (VMAT) technique and of Inage Guided Radiation Therapy (IGRT) technique. All lesions were treated from a single isocenter, which allowed reducing the treatment time and overall dose to the patient's body. All patients suffered the treatment satisfactorily. No adverse reactions or complications were met in any case during or right after the treatment. Different stereotactic fixation devices and modern treatment techniques allowed creating an optimal, safe and comfortable way for patient treatment. The treatment time was from 15 to 50 minutes. Patient position verification after or during the treatment demonstrated good accuracy for all fixation types and low level of intrafraction motion.

  9. Immune Modulation and Stereotactic Radiation: Improving Local and Abscopal Responses

    Directory of Open Access Journals (Sweden)

    Jing Zeng

    2013-01-01

    Full Text Available New and innovative treatment strategies for cancer patients in the fields of immunotherapy and radiotherapy are rapidly developing in parallel. Among the most promising preclinical treatment approaches is combining immunotherapy with radiotherapy where early data suggest synergistic effects in several tumor model systems. These studies demonstrate that radiation combined with immunotherapy can result in superior efficacy for local tumor control. More alluring is the emergence of data suggesting an equally profound systemic response also known as “abscopal” effects with the combination of radiation and certain immunotherapies. Studies addressing optimal radiation dose, fractionation, and modality to be used in combination with immunotherapy still require further exploration. However, recent anecdotal clinical reports combining stereotactic or hypofractionated radiation regimens with immunotherapy have resulted in dramatic sustained clinical responses, both local and abscopal. Technologic advances in clinical radiation therapy has made it possible to deliver hypofractionated regimens anywhere in the body using stereotactic radiation techniques, facilitating further clinical investigations. Thus, stereotactic radiation in combination with immunotherapy agents represents an exciting and potentially fruitful new space for improving cancer therapeutic responses.

  10. Fractionated stereotactic radiotherapy for skull base tumors: analysis of treatment accuracy using a stereotactic mask fixation system

    Directory of Open Access Journals (Sweden)

    Montagnoli Roberto

    2010-01-01

    Full Text Available Abstract Background To assess the accuracy of fractionated stereotactic radiotherapy (FSRT using a stereotactic mask fixation system. Patients and Methods Sixteen patients treated with FSRT were involved in the study. A commercial stereotactic mask fixation system (BrainLAB AG was used for patient immobilization. Serial CT scans obtained before and during FSRT were used to assess the accuracy of patient immobilization by comparing the isocenter position. Daily portal imaging were acquired to establish day to day patient position variation. Displacement errors along the different directions were calculated as combination of systematic and random errors. Results The mean isocenter displacements based on localization and verification CT imaging were 0.1 mm (SD 0.3 mm in the lateral direction, 0.1 mm (SD 0.4 mm in the anteroposterior, and 0.3 mm (SD 0.4 mm in craniocaudal direction. The mean 3D displacement was 0.5 mm (SD 0.4 mm, being maximum 1.4 mm. No significant differences were found during the treatment (P = 0.4. The overall isocenter displacement as calculated by 456 anterior and lateral portal images were 0.3 mm (SD 0.9 mm in the mediolateral direction, -0.2 mm (SD 1 mm in the anteroposterior direction, and 0.2 mm (SD 1.1 mm in the craniocaudal direction. The largest displacement of 2.7 mm was seen in the cranio-caudal direction, with 95% of displacements Conclusions The results indicate that the setup error of the presented mask system evaluated by CT verification scans and portal imaging are minimal. Reproducibility of the isocenter position is in the best range of positioning reproducibility reported for other stereotactic systems.

  11. Utility Estimation of the Manufactured Stereotactic Body Radiotherapy Immobilization

    International Nuclear Information System (INIS)

    Lee, Dong Hoon; Ahn, Jong Ho; Seo, Jeong Min; Shin, Eun Hyeak; Choi, Byeong Gi; Song, Gi Won

    2011-01-01

    Immobilizations used in order to maintain the reproducibility of a patient set-up and the stable posture for a long period are important more than anything else for the accurate treatment when the stereotactic body radiotherapy is underway. So the purpose of this study is to adapt the optimum immobilizations for the stereotactic body radiotherapy by comparing two commercial immobilizations with the self-manufactured immobilizations. Five people were selected for the experiment and three different immobilizations (A: Wing-board, B: BodyFix system, C: Arm up holder with vac-lock) were used to each target. After deciding on the target's most stable respiratory cycles, the targets were asked to wear a goggle monitor and maintain their respiration regularly for thirty minutes to obtain the respiratory signals. To analyze the respiratory signal, the standard deviation and the variation value of the peak value and the valley value of the respiratory signal were separated by time zone with the self-developed program at the hospital and each tie-downs were compared for the estimation by calculating a comparative index using the above. The stability of each immobilizations were measured in consideration of deviation changes studied in each respiratory time lapse. Comparative indexes of each immobilizations of each experimenter are shown to be A: 11.20, B: 4.87, C: 1.63 / A: 3.94, B: 0.67, C: 0.13 / A: 2.41, B: 0.29, C: 0.04 / A: 0.16, B: 0.19, C: 0.007 / A: 35.70, B: 2.37, C: 1.86. And when all five experimenters wore the immobilizations C, the test proved the most stable value while four people wearing A and one man wearing D expressed relatively the most unstable respiratory outcomes. The self-developed immobilizations, so called the arm up holder vac-lock for the stereotactic body radiotherapy is expected to improve the effect of the treatment by decreasing the intra-fraction organ motions because it keeps the respiration more stable than other two immobilizations

  12. Efficient and accurate stereotactic radiotherapy using flattening filter free beams and HexaPOD robotic tables

    DEFF Research Database (Denmark)

    Nielsen, Morten; Hansen, C. R.; Brink, C.

    2016-01-01

    Flattening filter free (FFF) high dose rate beam technique was introduced for brain stereotactic radiosurgery (SRS) and lung Stereotactic Body Radiotherapy (SBRT). Furthermore, a HexaPOD treatment table was introduced for the brain SRS to enable correction of rotational setup errors. 19 filter fl.......3 degrees (SD1.2 degrees) to 0.06 degrees (SD 0.3 degrees)....

  13. Measurement of relative dose distributions in stereotactic radiosurgery by the polymer-gel dosimeter

    Czech Academy of Sciences Publication Activity Database

    Novotný ml., J.; Spěváček, V.; Hrbáček, J.; Judas, L.; Novotný, J.; Dvořák, P.; Tlacháčová, D.; Schmitt, M.; Tintěra, J.; Vymazal, J.; Čechák, T.; Michálek, Jiří; Přádný, Martin; Liščák, R.

    2004-01-01

    Roč. 5, - (2004), s. 225-235 ISSN 1024-2651. [International Stereotactic Radiosurgery Society Meeting /6./. Kyoto, 22.06.2003-26.06.2003] R&D Projects: GA MZd NC7460 Institutional research plan: CEZ:AV0Z4050913 Keywords : stereotactic radiosurgery * polymer-gel dosimeter Subject RIV: FD - Oncology ; Hematology

  14. A study on CT-guided stereotactic technique for functional neurosurgery

    International Nuclear Information System (INIS)

    Uetsuhara, Koichi; Asakura, Tetsuhiko; Hirahara, Kazuho; Gondo, Masazumi; Oda, Hiroshige

    1987-01-01

    Recently, CT-guided stereotactic surgery has become of major interest, and some authors have discussed its potential in functional neurosurgery. The following is a comparative study of the CT-guided stereotactic technique and the conventional roentogenographic stereotactic technique. The Brown-Roberts-Wells apparatus was used for both types of procedures. 37 stereotactic procedures were performed on 35 patients under local anesthesia; 16 for stereotactic biopsy and 21 for stereotactic functional neurosurgery. Target points for stereotactic biopsy were determined by the CT-guided technique and target points for functional neurosurgery were determined by the conventional roentogenographic technique. The correlation with the position of target point determined by both techniques was investigated in the 21 functional neurosurgical procedures. On these occasions the authors used the reformatted horizontal and sagittal CT through the anterior and posterior commissure to determine the position of target point by the CT-guided technique. Results: It was found that the AC-PC line crossed with Reid's base line at angle of 11 ± 1 deg, and therefore it is important to obtain a CT images including AC-PC line at this angle. When applying the CT guided stereotactic procedure for functional surgery, it should be known that there could be a discrepancy within 2 mm from the conventional target determination. (author)

  15. 10 CFR 35.635 - Full calibration measurements on gamma stereotactic radiosurgery units.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Full calibration measurements on gamma stereotactic radiosurgery units. 35.635 Section 35.635 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT... decay; (ii) Following replacement of the sources or following reinstallation of the gamma stereotactic...

  16. Cochlear Implants

    Science.gov (United States)

    ... For young children who are deaf or severely hard-of-hearing, using a cochlear implant while they are young exposes them to sounds during an optimal period to develop speech and language skills. Research has shown that when these children receive ...

  17. Implant treatment software planning and guided flapless surgery with immediate provisional prosthesis delivery in the fully edentulous maxilla. A retrospective analysis of 15 consecutively treated patients.

    Science.gov (United States)

    Meloni, Silvio Mario; De Riu, Giacomo; Pisano, Miena; Cattina, Gavino; Tullio, Antonio

    2010-01-01

    To evaluate the clinical outcome of fully edentulous patients in the maxilla, who were treated with immediately loaded implant-supported cross-arch bridges using computer-aided implant surgery. The clinical outcome of 15 consecutive patients (5 males and 10 females) with a mean age of 52 years (range 40 to 70), with edentulous arches and treated with implant-supported cross-arch bridges was evaluated. Two computed tomography scans were performed, the first with the patient wearing the denture/radiographic guide and the radiographic index, and the second of the denture alone. The guided flapless surgical procedure was performed under local anaesthesia. Ninety implants were placed. The implant length ranged from 10 to 13 mm and the implant diameter was either 4.3 or 5 mm. All implants were immediately loaded with screw-retained provisional acrylic prostheses prepared in advance and delivered immediately after surgery. Clinical and radiographic follow-up visits were scheduled at 6, 12 and 18 months from surgery; implant survival rate, marginal bone levels, patient satisfaction and any complications were recorded. After the follow-up period of 18 months, two patients each lost one implant. After 18 months, patients lost, on average, 1.6 mm of peri-implant marginal bone. A patient satisfaction questionnaire at 18 months revealed a very high level of satisfaction with the treatment. Although limited by the number of patients, it can be concluded that software- and computed tomography-guided surgical planning for completely edentulous arches provides reliable results with high success rates.

  18. Short Implants: New Horizon in Implant Dentistry

    Science.gov (United States)

    Gulati, Manisha; Garg, Meenu; Pathak, Chetan

    2016-01-01

    The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration. PMID:27790598

  19. Short Implants: New Horizon in Implant Dentistry.

    Science.gov (United States)

    Jain, Neha; Gulati, Manisha; Garg, Meenu; Pathak, Chetan

    2016-09-01

    The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration.

  20. Accuracy of MRI-guided stereotactic thalamic functional neurosurgery

    International Nuclear Information System (INIS)

    Bourgeois, G.; Magnin, M.; Morel, A.; Jeanmonod, D.; Sartoretti, S.; Huisman, T.; Tuncdogan, E.; Meier, D.

    1999-01-01

    Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy. (orig.)

  1. Accuracy of MRI-guided stereotactic thalamic functional neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, G.; Magnin, M.; Morel, A.; Jeanmonod, D. [Laboratory for Functional Neurosurgery, Neurosurgical Clinic, University Hospital, Zurich (Switzerland); Sartoretti, S.; Huisman, T.; Tuncdogan, E. [Department of Neuroradiology, University Hospital, Zurich (Switzerland); Meier, D. [Institute of Biomedical Engineering and Medical Informatics, University and ETH, Zurich (Switzerland)

    1999-09-01

    Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy. (orig.)

  2. Accuracy of MRI-guided stereotactic thalamic functional neurosurgery.

    Science.gov (United States)

    Bourgeois, G; Magnin, M; Morel, A; Sartoretti, S; Huisman, T; Tuncdogan, E; Meier, D; Jeanmonod, D

    1999-09-01

    Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy.

  3. Review of long-term results of stereotactic psychosurgery.

    Science.gov (United States)

    Kim, Moon-Chan; Lee, Tae-Kyu; Choi, Chang-Rak

    2002-09-01

    Stereotactic psychosurgery is an effective method for treating some medically intractable psychiatric illnesses. However, it is unfamiliar and the long-term clinical results have not been reported in Asia. The long-term results of psychosurgery are evaluated and the neuroanatomical basis is discussed. Twenty-one patients underwent stereotactic psychosurgery for medically intractable psychiatric illnesses since 1993. All were referred from psychiatrists for these disorders. Two patients showed aggressive behavior, 12 had obsessive-compulsive disorder (OCD), and seven had depression with anxiety disorders. Bilateral amygdalotomy and subcaudate tractotomy were performed for aggressive behavior, limbic leucotomy was performed for OCD, and subcaudate tractotomy with or without cingulotomy was performed for depression with anxiety. OCD was evaluated with the Yale-Brown Obsessive Compulsive Scale (YBOCS), the visual analogue scale, the Clinical Global Impression Scale, and the Overt Aggression Scale (OAS). The Mini-Mental State Examination and the Wechsler Adult Intelligence Scale-Revised were used for the evaluation of aggressive behavior. The 17-item Hamilton Depression Rating Scale (HAMD) was used for evaluation of depression. Ventriculography was used in the first seven patients and magnetic resonance imaging-guided stereotaxy was used in the recent 14 cases for localization of the target. The lesions were made with a radiofrequency lesion generator. OAS scores in the two patients with aggressive behavior during follow up declined from 8 to 2 with clinical improvement. All 12 patients with OCD returned to their previous life and showed the mean YBOCS scores decreased from 34 to 3. Ten patients with OCD could be followed up (mean 45 months). All patients returned to their previous social life. In seven patients with depression with anxiety, HAMD scores declined from 28.5 to 16.5. There was no operative mortality and no significant morbidity except for one case of mild

  4. Single dose versus fractionated stereotactic radiotherapy for meningiomas

    International Nuclear Information System (INIS)

    Lo, S.S.; Cho, K.H.; Hall, W.A.

    2002-01-01

    To evaluate the safety and efficacy of stereotactic radiosurgery (SRS) compared to fractionated stereotactic radiation therapy (FSRT) for meningiomas treated over a seven year period. Of the 53 patients (15 male and 38 female) with 63 meningiomas, 35 were treated with SRS and the 18 patients with tumors adjacent to critical structures or with large tumors were treated with FSRT. The median doses for the SRS and the FSRT groups were 1400 cGy (500- 4500 cGy) and 5400 cGy (4000-6000 cGy) respectively. Median target volumes for SRS and FSRT were 6.8 ml and 8.8 ml respectively. The median follow-up for the SRS and FSRT groups were 38 months (4.1-97 months) and 30.5 months (6.0-63 months) respectively. The five-year tumor control probability (TC) for benign versus atypical meningiomas were 92.7% vs. 31% (P=.006). The three-year TC were 92.7% vs. 93.3% for SRS vs. FSRT groups respectively (P=.62). For benign meningiomas, the three-year TC were 92.9% vs. 92.3% for the SRS group (29 patients) vs. FSRT group (14 patients) respectively (P=.77). Two patients in the SRS group and one in the FSRT group developed late complications. Preliminary data suggest that SRS is a safe and effective treatment for patients with benign meningiomas. Fractionated stereotactic radiation therapy with conventional fractionation appeared to be an effective and safe treatment alternative for patients not appropriate for SRS. A longer follow-up is required to determine the long-term efficacy and the toxicity of these treatment modalities. (author)

  5. A computer assisted toolholder to guide surgery in stereotactic space.

    Science.gov (United States)

    Giorgi, C; Pluchino, F; Luzzara, M; Ongania, E; Casolino, D S

    1994-01-01

    A computer assisted toolholder, integrated with an anatomical graphic 3-D rendering programme, is presented. Stereotactic neuroanatomical images are acquired, and the same reference system is employed to represent the position of the toolholder on the monitor. The surgeon can check the orientation of different approach trajectories, moving the toolholder in a situation of virtual reality. Angular values expressed by high precision encoders on the five joints of the toolholder modify "on line" the representation of the configuration of the toolholder within the three dimensional representation of the patient's anatomy.

  6. A linac-based stereotactic irradiation technique of uveal melanoma

    International Nuclear Information System (INIS)

    Dieckmann, Karin; Bogner, Joachim; Georg, Dietmar; Zehetmayer, Martin; Kren, Gerhard; Poetter, Richard

    2001-01-01

    Purpose: To describe a stereotactic irradiation technique for uveal melanomas performed at a linac, based on a non-invasive eye fixation and eye monitoring system. Methods: For eye immobilization a light source system is integrated in a standard stereotactic mask system in front of the healthy eye: During treatment preparation (computed tomography/magnetic resonance imaging) as well as for treatment delivery, patients are instructed to gaze at the fixation light source. A mini-video camera monitors the pupil center position of the diseased eye. For treatment planning and beam delivery standard stereotactic radiotherapy equipment is used. If the pupil center deviation from a predefined 'zero-position' exceeds 1 mm (for more than 2 s), treatment delivery is interrupted. Between 1996 and 1999 60 patients with uveal melanomas, where (i) tumor height exceeded 7 mm, or (ii) tumor height was more than 3 mm, and the central tumor distance to the optic disc and/or the macula was less than 3 mm, have been treated. A total dose of 60 or 70 Gy has been given in 5 fractions within 10 days. Results: The repositioning accuracy in the mask system is 0.47±0.36 mm in rostral-occipital direction, 0.75±0.52 mm laterally, and 1.12±0.96 mm in vertical direction. An eye movement analysis performed for 23 patients shows a pupil center deviation from the 'zero' position<1 mm in 91% of all cases investigated. In a theoretical analysis, pupil center deviations are correlated with GTV 'movements'. For a pupil center deviation of 1 mm (rotation of the globe of 5 degree sign ) the GTV is still encompassed by the 80% isodose in 94%. Conclusion: For treatments of uveal melanomas, linac-based stereotactic radiotherapy combined with a non-invasive eye immobilization and monitoring system represents a feasible, accurate and reproducible method. Besides considerable technical requirements, the complexity of the treatment technique demands an interdisciplinary team continuously dedicated to this

  7. Resistant bipolar affective disorder treated by stereotactic subcaudate tractotomy.

    Science.gov (United States)

    Poynton, A; Bridges, P K; Bartlett, J R

    1988-03-01

    The results of stereotactic subcaudate tractotomy in nine patients with resistant bipolar affective disorder are presented in the form of a single case study with a summary of the other eight cases. Follow-up studies at 2-4 years showed substantial improvement in five patients and amelioration of symptoms in a further four patients, with a tendency for a greater improvement in the manic than in the depressive episodes. These preliminary results suggest that there is a place for this operation in the management of severe bipolar affective disorders which are not responding to any other treatment, although decisive recovery occurs less often than with unipolar depression.

  8. Stereotactic Body Radiation Therapy for Oligometastatic Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Muldermans, Jonathan L. [F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland (United States); Romak, Lindsay B. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Kwon, Eugene D. [Department of Urology, Mayo Clinic, Rochester, Minnesota (United States); Department of Immunology, Mayo Clinic, Rochester, Minnesota (United States); Park, Sean S. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Olivier, Kenneth R., E-mail: olivier.kenneth@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2016-06-01

    Purpose: To review outcomes of patients with oligometastatic prostate cancer (PCa) treated with stereotactic body radiation therapy (SBRT) and to identify variables associated with local failure. Methods and Materials: We retrospectively reviewed records of patients treated with SBRT for oligometastatic PCa. Metastasis control (ie, control of the treated lesion, MC), biochemical progression-free survival, distant progression-free survival, and overall survival were estimated with the Kaplan-Meier method. Results: Sixty-six men with 81 metastatic PCa lesions, 50 of which were castrate-resistant, were included in the analysis. Lesions were in bone (n=74), lymph nodes (n=6), or liver (n=1). Stereotactic body radiation therapy was delivered in 1 fraction to 71 lesions (88%), at a median dose of 16 Gy (range, 16-24 Gy). The remaining lesions received 30 Gy in 3 fractions (n=6) or 50 Gy in 5 fractions (n=4). Median follow-up was 16 months (range, 3-49 months). Estimated MC at 2 years was 82%. Biochemical progression-free survival, distant progression-free survival, and overall survival were 54%, 45%, and 83%, respectively. On multivariate analysis, only the dose of SBRT was significantly associated with MC; lesions treated with 16 Gy had 58% MC, and those treated with ≥18 Gy had 95% MC at 2 years (P≤.001). At 2 years, MC for lesions treated with 18 Gy (n=21) was 88%. No patient treated with ≥18 Gy in a single fraction or with any multifraction regimen had local failure. Six patients (9%) had grade 1 pain flare, and 2 (3%) had grade 2 pain flare. No grade 2 or greater late toxicities were reported. Conclusions: Stereotactic body radiation therapy for patients with oligometastatic prostate cancer provided optimal metastasis control and acceptable toxicity with doses ≥18 Gy. Biochemical progression-free survival was 54% at 16 months with the inclusion of SBRT in the treatment regimen. Stereotactic body radiation therapy should be considered in

  9. MR-guided stereotactic neurosurgery-comparison of fiducial-based and anatomical landmark transformation approaches

    International Nuclear Information System (INIS)

    Hunsche, S; Sauner, D; Maarouf, M; Hoevels, M; Luyken, K; Schulte, O; Lackner, K; Sturm, V; Treuer, H

    2004-01-01

    For application in magnetic resonance (MR) guided stereotactic neurosurgery, two methods for transformation of MR-image coordinates in stereotactic, frame-based coordinates exist: the direct stereotactic fiducial-based transformation method and the indirect anatomical landmark method. In contrast to direct stereotactic MR transformation, indirect transformation is based on anatomical landmark coregistration of stereotactic computerized tomography and non-stereotactic MR images. In a patient study, both transformation methods have been investigated with visual inspection and mutual information analysis. Comparison was done for our standard imaging protocol, including t2-weighted spin-echo as well as contrast enhanced t1-weighted gradient-echo imaging. For t2-weighted spin-echo imaging, both methods showed almost similar and satisfying performance with a small, but significant advantage for fiducial-based transformation. In contrast, for t1-weighted gradient-echo imaging with more geometric distortions due to field inhomogenities and gradient nonlinearity than t2-weighted spin-echo imaging, mainly caused by a reduced bandwidth per pixel, anatomical landmark transformation delivered markedly better results. Here, fiducial-based transformation yielded results which are intolerable for stereotactic neurosurgery. Mean Euclidian distances between both transformation methods were 0.96 mm for t2-weighted spin-echo and 1.67 mm for t1-weighted gradient-echo imaging. Maximum deviations were 1.72 mm and 3.06 mm, respectively

  10. Implantation, recoil implantation, and sputtering

    International Nuclear Information System (INIS)

    Kelly, R.

    1984-01-01

    Underlying ion-beam modification of surfaces is the more basic subject of particle-surface interaction. The ideas can be grouped into forward and backward features, i.e. those affecting the interior of the target and those leading to particle expulsion. Forward effects include the stopping of the incident particles and the deposition of energy, both governed by integral equations which are easily set up but difficult to solve. Closely related is recoil implantation where emphasis is placed not on the stopping of the incident particles but on their interaction with target atoms with resulting implantation of these atoms. Backward effects, all of which are denoted as sputtering, are in general either of collisional, thermal, electronic, or exfoliational origin. (Auth.)

  11. A dual computed tomography linear accelerator unit for stereotactic radiation therapy: a new approach without cranially fixated stereotactic frames

    International Nuclear Information System (INIS)

    Uematsu, Minoru; Fukui, Toshiharu; Shioda, Akira; Tokumitsu, Hideyuki; Takai, Kenji; Kojima, Tadaharu; Asai, Yoshiko; Kusano, Shoichi

    1996-01-01

    Purpose: To perform stereotactic radiation therapy (SRT) without cranially fixated stereotactic frames, we developed a dual computed tomography (CT) linear accelerator (linac) treatment unit. Methods and Materials: This unit is composed of a linac, CT, and motorized table. The linac and CT are set up at opposite ends of the table, which is suitable for both machines. The gantry axis of the linac is coaxial with that of the CT scanner. Thus, the center of the target detected with the CT can be matched easily with the gantry axis of the linac by rotating the table. Positioning is confirmed with the CT for each treatment session. Positioning and treatment errors with this unit were examined by phantom studies. Between August and December 1994, 8 patients with 11 lesions of primary or metastatic brain tumors received SRT with this unit. All lesions were treated with 24 Gy in three fractions to 30 Gy in 10 fractions to the 80% isodose line, with or without conventional external beam radiation therapy. Results: Phantom studies revealed that treatment errors with this unit were within 1 mm after careful positioning. The position was easily maintained using two tiny metallic balls as vertical and horizontal marks. Motion of patients was negligible using a conventional heat-flexible head mold and dental impression. The overall time for a multiple noncoplanar arcs treatment for a single isocenter was less than 1 h on the initial treatment day and usually less than 20 min on subsequent days. Treatment was outpatient-based and well tolerated with no acute toxicities. Satisfactory responses have been documented. Conclusion: Using this treatment unit, multiple fractionated SRT is performed easily and precisely without cranially fixated stereotactic frames

  12. MRI-guided stereotactic implantation of depth electrodes in epilepsy surgery

    OpenAIRE

    MENESES, MURILO S.; FOLLADOR, FLÁVIA R.; ARRUDA, WALTER O.; SANTOS, HERALDO L.; YONESAWA, DÉBORA; HUNHEVICZ, SONIVAL C.

    1999-01-01

    Apresentamos o caso de uma paciente com epilepsia refratária ao tratamento medicamentoso e submetida à monitorização em vídeo-eletrencefalografia por eletrodos de profundidade intracerebrais. A história, o exame clínico, a ressonância magnética (RM), a vídeo-eletrencefalografia e o estudo neuropsicológico não foram suficientes para a determinação da área cerebral de origem das crises convulsivas. Eletrodos de profundidade intracerebrais colocados por estereotaxia guiada por RM possibilitaram ...

  13. Target identification for stereotactic thalamotomy using diffusion tractography.

    Directory of Open Access Journals (Sweden)

    Zsigmond Tamás Kincses

    Full Text Available BACKGROUND: Stereotactic targets for thalamotomy are usually derived from population-based coordinates. Individual anatomy is used only to scale the coordinates based on the location of some internal guide points. While on conventional MR imaging the thalamic nuclei are indistinguishable, recently it has become possible to identify individual thalamic nuclei using different connectivity profiles, as defined by MR diffusion tractography. METHODOLOGY AND PRINCIPAL FINDINGS: Here we investigated the inter-individual variation of the location of target nuclei for thalamotomy: the putative ventralis oralis posterior (Vop and the ventral intermedius (Vim nucleus as defined by probabilistic tractography. We showed that the mean inter-individual distance of the peak Vop location is 7.33 mm and 7.42 mm for Vim. The mean overlap between individual Vop nuclei was 40.2% and it was 31.8% for Vim nuclei. As a proof of concept, we also present a patient who underwent Vop thalamotomy for untreatable tremor caused by traumatic brain injury and another patient who underwent Vim thalamotomy for essential tremor. The probabilistic tractography indicated that the successful tremor control was achieved with lesions in the Vop and Vim respectively. CONCLUSIONS: Our data call attention to the need for a better appreciation of the individual anatomy when planning stereotactic functional neurosurgery.

  14. Guidelines for safe practice of stereotactic body (ablative) radiation therapy

    International Nuclear Information System (INIS)

    Foote, Matthew; Barry, Tamara; Bailey, Michael; Smith, Leigh; Seeley, Anna; Siva, Shankar; Hegi-Johnson, Fiona; Booth, Jeremy; Ball, David; Thwaites, David

    2015-01-01

    The uptake of stereotactic ablative body radiation therapy (SABR) / stereotactic body radiation therapy (SBRT) worldwide has been rapid. The Australian and New Zealand Faculty of Radiation Oncology (FRO) assembled an expert panel of radiation oncologists, radiation oncology medical physicists and radiation therapists to establish guidelines for safe practice of SABR. Draft guidelines were reviewed by a number of international experts in the field and then distributed through the membership of the FRO. Members of the Australian Institute of Radiography and the Australasian College of Physical Scientists and Engineers in Medicine were also asked to comment on the draft. Evidence-based recommendations (where applicable) address aspects of departmental staffing, procedures and equipment, quality assurance measures, as well as organisational considerations for delivery of SABR treatments. Central to the guidelines is a set of key recommendations for departments undertaking SABR. These guidelines were developed collaboratively to provide an educational guide and reference for radiation therapy service providers to ensure appropriate care of patients receiving SABR.

  15. CT guided stereotactic evacuation of hypertensive and traumatic intracerebral hematomas

    International Nuclear Information System (INIS)

    Hondo, Hideki; Matsumoto, Keizo

    1983-01-01

    Recent advancement of CT system provides not only definite diagnosis and location of intracerebral hematoma but also coordinates of the center of the hematoma. Trials of stereotactic evacuation of the hematoma have been reported by some authors in the cases of subacute or chronic stages of hypertensive intracerebral hemorrhage. In this series, similar surgery has been performed in 33 cases of hypertensive intracerebral hematoma including 22 cases in acute stage, and 2 cases of traumatic hematoma. Clinical outcomes were investigated and the results were considered to be equivalent or rather better in the conventional microsurgery with evacuation of hematoma under direct vision. However, there still remained controversial problems in the cases of threatened herniation signs, because in these cases regular surgery with total evacuation of the hematoma at one time might have been preferable. The benefits of this CT guided stereotactic approach for the evacuation of the hematoma were thought to be as follow: 1) the procedure is simple and safe, 2) operation is readily performed under local anesthesia, and 3) the hematoma was drained out totally by means of urokinase activity. It is our impression that this surgery not only is indicated as emergency treatment for the patients of high-age or in high risk, but also can institute as a routine surgery for the intracerebral hematomas in patients showing no herniation sign. (J.P.N.)

  16. Local control after fractionated stereotactic radiation therapy for brain metastases.

    Science.gov (United States)

    Rajakesari, Selvan; Arvold, Nils D; Jimenez, Rachel B; Christianson, Laura W; Horvath, Margaret C; Claus, Elizabeth B; Golby, Alexandra J; Johnson, Mark D; Dunn, Ian F; Lee, Eudocia Q; Lin, Nancy U; Friesen, Scott; Mannarino, Edward G; Wagar, Matthew; Hacker, Fred L; Weiss, Stephanie E; Alexander, Brian M

    2014-11-01

    Stereotactic radiosurgery (SRS) is frequently used in the management of brain metastases, but concerns over potential toxicity limit applications for larger lesions or those in eloquent areas. Fractionated stereotactic radiation therapy (SRT) is often substituted for SRS in these cases. We retrospectively analyzed the efficacy and toxicity outcomes of patients who received SRT at our institution. Seventy patients with brain metastases treated with SRT from 2006-2012 were analyzed. The rates of local and distant intracranial progression, overall survival, acute toxicity, and radionecrosis were determined. The SRT regimen was 25 Gy in 5 fractions among 87 % of patients. The most common tumor histologies were non-small cell lung cancer (37 %), breast cancer (20 %) and melanoma (20 %), and the median tumor diameter was 1.7 cm (range 0.4-6.4 cm). Median survival after SRT was 10.7 months. Median time to local progression was 17 months, with a local control rate of 68 % at 6 months and 56 % at 1 year. Acute toxicity was seen in 11 patients (16 %), mostly grade 1 or 2 with the most common symptom being mild headache. Symptomatic radiation-induced treatment change was seen on follow-up MRIs in three patients (4.3 %). SRT appears to be a safe and reasonably effective technique to treat brain metastases deemed less suitable for SRS, though dose intensification strategies may further improve local control.

  17. Hypofractionated stereotactic radiation therapy for recurrent glioblastoma: single institutional experience

    International Nuclear Information System (INIS)

    Ciammella, Patrizia; Podgornii, Ala; Galeandro, Maria; D’Abbiero, Nunziata; Pisanello, Anna; Botti, Andrea; Cagni, Elisabetta; Iori, Mauro; Iotti, Cinzia

    2013-01-01

    Glioblastoma (GBM) is the most common malignant primary brain tumor in adults. Tumor control and survival have improved with the use of radiotherapy (RT) plus concomitant and adjuvant chemotherapy, but the prognosis remain poor. In most cases the recurrence occurs within 7–9 months after primary treatment. Currently, many approaches are available for the salvage treatment of patients with recurrent GBM, including resection, re-irradiation or systemic agents, but no standard of care exists. We analysed a cohort of patients with recurrent GBM treated with frame-less hypofractionated stereotactic radiation therapy with a total dose of 25 Gy in 5 fractions. Of 91 consecutive patients with newly diagnosed GBM treated between 2007 and 2012 with conventional adjuvant chemo-radiation therapy, 15 underwent salvage RT at recurrence. The median time interval between primary RT and salvage RT was 10.8 months (range, 6–54 months). Overall, patients undergoing salvage RT showed a longer survival, with a median survival of 33 vs. 9.9 months (p= 0.00149). Median overall survival (OS) from salvage RT was 9.5 months. No patients demonstrated clinically significant acute morbidity, and all patients were able to complete the prescribed radiation therapy without interruption. Our results suggest that hypofractionated stereotactic radiation therapy is effective and safe in recurrent GBM. However, until prospective randomized trials will confirm these results, the decision for salvage treatment should remain individual and based on a multidisciplinary evaluation of each patient

  18. Effectiveness of fractionated stereotactic radiotherapy for uveal melanoma

    International Nuclear Information System (INIS)

    Muller, Karin; Nowak, Peter; Pan, Connie de; Marijnissen, Johannes P.; Paridaens, Dion A.; Levendag, Peter; Luyten, Gre P.M.

    2005-01-01

    Purpose: To study the effectiveness and acute side effects of fractionated stereotactic radiation therapy (fSRT) for uveal melanoma. Methods and Materials: Between 1999 and 2003, 38 patients (21 male, 17 female) were included in a prospective, nonrandomized clinical trial (mean follow-up of 25 months). A total dose of 50 Gy was given in 5 consecutive days. A blinking light and a camera (to monitor the position of the diseased eye) were fixed to a noninvasive relocatable stereotactic frame. Primary end points were local control, best corrected visual acuity, and toxicity at 3, 6, 12, and 24 months, respectively. Results: After 3 months (38 patients), the local control was 100%; after 12 months (32 patients) and 24 months (15 patients), no recurrences were seen. The best corrected visual acuity declined from a mean of 0.21 at diagnosis to 0.06 2 years after therapy. The acute side effects after 3 months were as follows: conjunctival symptoms (10), loss of lashes or hair (6), visual symptoms (5), fatigue (5), dry eye (1), cataract (1), and pain (4). One eye was enucleated at 2 months after fSRT. Conclusions: Preliminary results demonstrate that fSRT is an effective and safe treatment modality for uveal melanoma with an excellent local control and mild acute side effects. The follow-up should be prolonged to study both long-term local control and late toxicity

  19. Extracranial stereotactic radiotherapy: Evaluation of PTV coverage and dose conformity

    International Nuclear Information System (INIS)

    Haedinger, U.; Thiele, W.; Wulf, J.

    2002-01-01

    During the past few years the concept of cranial sterotactic radiotherapy has been successfully extended to extracranial tumoral targets. In our department, hypofractionated treatment of tumours in lung, liver, abdomen, and pelvis is performed in the Stereotactic Body Frame (ELEKTA Instrument AB) since 1997. We present the evaluation of 63 consecutively treated targets (22 lung, 21 liver, 20 abdomen/pelvis) in 58 patients with respect to dose coverage of the planning target volume (PTV) as well as conformity of the dose distribution. The mean PTV coverage was found to be 96.3%±2.3% (lung), 95.0%±4.5% (liver), and 92.1%±5.2% (abdomen/pelvis). For the so-called conformation number we obtained values of 0.73±0.09 (lung), 0.77±0.10 (liver), and 0.70±0.08 (abdomen/pelvis). The results show that highly conformal treatment techniques can be applied also in extracranial stereotactic radiotherapy. This is primarily due to the relatively simple geometrical shape of most of the targets. Especially lung and liver targets turned out to be approximately spherically/cylindrically shaped, so that the dose distribution can be easily tailored by rotational fields. (orig.) [de

  20. Stereotactic radiation in primary brain tumors in children and adolescents.

    Science.gov (United States)

    Benk, V; Clark, B G; Souhami, L; Algan, O; Bahary, J; Podgorsak, E B; Freeman, C R

    1999-08-01

    To evaluate treatment outcome and morbidity of stereotactic external-beam irradiation (SEBI) in pediatric patients, we reviewed 14 children treated with SEBI, using a 10-MV isocentric linear accelerator at McGill University between 1988 and 1994. The median follow-up was 46 months (range 6-82 months). The median age was 14 years. There were 8 low-grade astrocytomas, 3 neuromas and 4 other histologies. Twelve patients received fractionated treatments. The median collimator diameter was 2.5 cm (range 1-5 cm). The median biological effective dose delivered to the entire tumor volume was 57 Gy for astrocytomas and 43 Gy for the other histologies. The overall actuarial survival rate and disease-free survival rate at 5 years were 83 and 62%, respectively. For the patients with low-grade astrocytomas, the 5-year survival and disease-free survival rates were 100 and 60%, respectively. Four children had recurrence at a median of 37 months. Four patients developed treatment-related complications: 1 had edema alone, 2 had necrosis and 1 had edema associated with necrosis. Neither the physical nor radiobiological parameters were predictive of the treatment outcome or the treatment complications. Stereotactic irradiation is a valid option for progressive nonresectable tumors in children. Copyright 1999 S. Karger AG, Basel

  1. Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Mehrnaz Karimi

    1993-03-01

    Full Text Available People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss. In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter, stimulator and receiver, and electrode array.

  2. Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Mehrnaz Karimi

    1992-04-01

    Full Text Available People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss . In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter, stimulator and receiver, and electrode array.

  3. Uncertainties associated with treatments of hepatic lesions in stereotactic body radiation therapy (SBRT) using respiratory tracking

    International Nuclear Information System (INIS)

    Charoy, Marie

    2014-01-01

    Oscar Lambret Center treated with Cyberknife R , since June 2007, liver lesions in stereotactic conditions with respiratory tracking using external LEDs correlated with seeds implanted near the target. Clinical results show excellent local control but there are still uncertainties in the preparation and delivery of treatment. The aims of this thesis are to identify and quantify these uncertainties, to define solutions and/or alternatives and to assess their added value. As a first step, the method of the target definition by the radiation oncologist is evaluated. Improvement of the method currently used in routine is considered, including the choice of the most appropriate imaging and the intervention of a second operator, expert in imaging (radiologist). The organ at risk and target movements induced by the respiratory motion are not taken into account in the treatment planning step, performed on the 3D images (the so-called planning CT). The dosimetric impact associated with this type of planning is evaluated using 4D Monte Carlo simulations that take into account patient and linear accelerator movements and the synchrony between both movements. The question of 4D planning as prospect of improvement is then investigated. Movements and deformations of the liver due to respiration are also implicated in the uncertainties involved in the treatment. The correlation model of external markers with the target, used for respiratory tracking, ignores eventual deformations and rotations within the liver. A study of the impact on the target tracking is performed. All these studies were conducted using real patient data sets. (author) [fr

  4. Complications after cardiac implantable electronic device implantations

    DEFF Research Database (Denmark)

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard

    2014-01-01

    Complications after cardiac implantable electronic device (CIED) treatment, including permanent pacemakers (PMs), cardiac resynchronization therapy devices with defibrillators (CRT-Ds) or without (CRT-Ps), and implantable cardioverter defibrillators (ICDs), are associated with increased patient...

  5. Stereotactic radiotherapy and radiosurgery in pediatric patients: analysis of indications and outcome

    DEFF Research Database (Denmark)

    Mirza, Bilal; Mønsted, Anne; Jensen, Josephine Harding

    2010-01-01

    We describe indications, outcomes, and risk profiles of fractionated stereotactic radiotherapy (SRT) and single fraction "radiosurgery" (SRS) in pediatric patients compared to the adult population and evaluate the causal role of SRS and SRT in inducing new neurological complications....

  6. Institutional experience in the treatment of colorectal liver metastases with stereotactic body radiation therapy

    NARCIS (Netherlands)

    Méndez Romero, Alejandra; Keskin-Cambay, Fatma; van Os, Rob M.; Nuyttens, Joost J.; Heijmen, Ben J. M.; Ijzermans, Jan N. M.; Verhoef, Cornelis

    2017-01-01

    To investigate whether the impact of dose escalation in our patient population represented an improvement in local control without increasing treatment related toxicity. A cohort of consecutive patients with colorectal liver metastases treated with stereotactic body radiation therapy (SBRT) between

  7. Stereotactic Image-Guided Intensity Modulated Radiotherapy Using the HI-ART II Helical Tomotherapy System

    International Nuclear Information System (INIS)

    Holmes, Timothy W.; Hudes, Richard; Dziuba, Sylwester; Kazi, Abdul; Hall, Mark; Dawson, Dana

    2008-01-01

    The highly integrated adaptive radiation therapy (HI-ART II) helical tomotherapy unit is a new radiotherapy machine designed to achieve highly precise and accurate treatments at all body sites. The precision and accuracy of the HI-ART II is similar to that provided by stereotactic radiosurgery systems, hence the historical distinction between external beam radiotherapy and stereotactic procedures based on differing precision requirements is removed for this device. The objectives of this work are: (1) to describe stereotactic helical tomotherapy processes (SRS, SBRT); (2) to show that the precision and accuracy of the HI-ART meet the requirements defined for SRS and SBRT; and (3) to describe the clinical implementation of a stereotactic image-guided intensity modulated radiation therapy (IG-IMRT) system that incorporates optical motion management

  8. Application of electronic endoscopy and CT-guided stereotactic aspiration to intracerebral hematoma

    International Nuclear Information System (INIS)

    Kusaka, Masahiko

    1991-01-01

    According to the development of computer technology and operative instruments, stereotactic neurosurgery became more precise, and extended as its indication. CT-guided stereotactic aspiration of intracerebral hematoma is superior operative procedure with rare complications. Using Stereotactic Aqua-Stream and Aspirator at the same time, hematoma was removed sufficiently. However, stereotactic neurosurgery had a major weak points, it was a blind operation. An endoscope (FVS-1000, M and M Co.) and SASA (Marui Medical Co.) were applied in 5 cases of intracerebral hematoma. In physiological saline, the endoscope had 32.9 deg angle of visual field, 1 mm - 25 mm depth of vision, and 16 pair/mm resolution. It was excellent ability for neurosurgery. Using for clinical cases, the bloody fluid in the hematoma cavity disturbed visibility. It was a difficult problem. Influence of bloody fluid concentration to depth of vision and resolution was investigated, and method of making clear visibility was described. (author)

  9. MRI guided stereotactic ventrointermediate thalamotomy for writer's cramp: two cases report and literature review

    Directory of Open Access Journals (Sweden)

    Chao-shi NIU

    2015-10-01

    Full Text Available Objective To explore the methods and curative effect of stereotactic surgery for treating writer's cramp (WC. Methods and Results Two patients with writer's cramp (tremor type underwent MRI guided stereotactic ventrointermediate (Vim thalamotomy on the left side. The symptoms of one patient disappeared immediately after operation, and the patient could write legibly. The tremor of right upper extremity in another patient was improved significantly. Two patients did not present obvious complications, and the previous symptoms were not found to recur during follow-up period respectively. Conclusions Stereotactic surgery for treatment of writer's cramp has definite therapeutic effect. MRI guided stereotactic technique can effectively avoid the complications of Vim thalamotomy. However, the indications of two methods in surgical treatment [thalamotomy and deep brain stimulation (DBS] and the respective merits still need further study. DOI: 10.3969/j.issn.1672-6731.2015.10.009

  10. Stereotactic biopsy for brainstem lesion: Comparison of approaches and reports of 10 cases

    Directory of Open Access Journals (Sweden)

    Se-Yi Chen

    2011-03-01

    Conclusion: A number of approaches are available for stereotactic brainstem biopsy. Surgical approach should be tailored, according to the location neurological function, with special concern for the patients’ safety. In selected condition, frameless stereotaxy biopsy also provides competed diagnostic yield.

  11. Efficacy and feasibility of stereotactic radiosurgery in the primary management of unfavorable pediatric ependymoma

    International Nuclear Information System (INIS)

    Aggarwal, Renu; Yeung, Daniel; Kumar, Parvesh; Muhlbauer, Michael; Kun, Larry E.

    1997-01-01

    Stereotactic radiosurgery was given as a boost in the initial radiation management of five children with localized intracranial ependymoma. Preliminary results in young children with high-risk tumors indicate good local control without excessive neurotoxicity

  12. A Prospective Cohort Study of Gated Stereotactic Liver Radiation Therapy Using Continuous Internal Electromagnetic Motion Monitoring.

    Science.gov (United States)

    Worm, Esben S; Høyer, Morten; Hansen, Rune; Larsen, Lars P; Weber, Britta; Grau, Cai; Poulsen, Per R

    2018-02-13

    Intrafraction motion can compromise the treatment accuracy in liver stereotactic body radiation therapy (SBRT). Respiratory gating can improve treatment delivery; however, gating based on external motion surrogates is inaccurate. The present study reports the use of Calypso-based internal electromagnetic motion monitoring for gated liver SBRT. Fifteen patients were included in a study of 3-fraction respiratory gated liver SBRT guided by 3 implanted electromagnetic transponders. The planning target volume was created by a 5-mm axial and 7-mm (n = 12) or 10-mm (n = 3) craniocaudal expansion of the clinical target volume (CTV) and covered with 67% of the prescribed CTV mean dose. Treatment was gated to the end-exhale phase of the respiratory cycle with beam-on when the target deviated 1 to 2 mm occurred. Log files of transponder motion were used to determine the geometric error and reconstruct the delivered CTV dose in the actual gated treatments and in simulated nongated treatments. No severe side effects were observed in relation to transponder implantation. All 45 treatment fractions were successfully guided using the Calypso system. The mean number of couch corrections during each gated fraction was 2.8 (range 0-7). The mean duty cycle during gated treatment was 62.5% (range 29.1%-84.9%). Without gating, the mean 3-dimensional geometric error during a fraction would have been 5.4 mm (range 2.7-12.1). Gating reduced this error to 2.0 mm (range 1.2-3.0). The patient mean reduction in minimum dose to 95% of the CTV relative to the planned dose was 6.0 percentage points (range 0.7-22.0) without gating and 0.8 percentage point (range 0.2-2.0) with gating. Gating using internal motion monitoring was successfully applied for liver SBRT. It markedly improved the geometric and dosimetric accuracy compared with nongated standard treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Stereotactic radiosurgery using the gamma knife for acoustic neuromas

    International Nuclear Information System (INIS)

    Foote, Robert L.; Coffey, Robert J.; Swanson, Jerry W.; Harner, Stephen G.; Beatty, Charles W.; Kline, Robert W.; Stevens, Lorna N.; Hu, Theresa C.

    1995-01-01

    Purpose: To assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas. Methods and Materials: Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompassed within the prescribed isodose line varied from 266 to 8,667 mm 3 (median: 3,135 mm 3 ). Tumors ≤ 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. The median number of isocenters per tumor was 5 (range: 1-12). Results: At a median follow-up of 16 months (range: 2.5-36 months), all patients were alive. Thirty-five patients had follow-up imaging studies. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% ± 17.3, respectively. Conclusion: Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients

  14. Complications from Stereotactic Body Radiotherapy for Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kylie H. [School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Okoye, Christian C.; Patel, Ravi B. [Department of Radiation Oncology, University Hospitals Seidman Cancer Center, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106 (United States); Siva, Shankar [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002 (Australia); Biswas, Tithi; Ellis, Rodney J.; Yao, Min; Machtay, Mitchell; Lo, Simon S., E-mail: Simon.Lo@uhhospitals.org [Department of Radiation Oncology, University Hospitals Seidman Cancer Center, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2015-06-15

    Stereotactic body radiotherapy (SBRT) has become a standard treatment option for early stage, node negative non-small cell lung cancer (NSCLC) in patients who are either medically inoperable or refuse surgical resection. SBRT has high local control rates and a favorable toxicity profile relative to other surgical and non-surgical approaches. Given the excellent tumor control rates and increasing utilization of SBRT, recent efforts have focused on limiting toxicity while expanding treatment to increasingly complex patients. We review toxicities from SBRT for lung cancer, including central airway, esophageal, vascular (e.g., aorta), lung parenchyma (e.g., radiation pneumonitis), and chest wall toxicities, as well as radiation-induced neuropathies (e.g., brachial plexus, vagus nerve and recurrent laryngeal nerve). We summarize patient-related, tumor-related, dosimetric characteristics of these toxicities, review published dose constraints, and propose strategies to reduce such complications.

  15. Anterior two-thirds corpus callosotomy via stereotactic laser ablation.

    Science.gov (United States)

    Karsy, Michael; Patel, Daxa M; Halvorson, Kyle; Mortimer, Vance; Bollo, Robert J

    2018-04-01

    Anterior two-thirds corpus callosotomy is a common palliative surgical intervention most commonly employed in patients with atonic or drop seizures. Recently, stereotactic laser ablation of the corpus callosum without a craniotomy has shown promise in achieving similar outcomes with fewer side effects and shorter hospitalizations. The authors demonstrate ablation of the anterior two-thirds corpus callosum in a patient with Lennox-Gastaut syndrome and drug-resistant drop seizures. Technical nuances of laser ablation with 3 laser fibers are described. Postoperatively, the patient showed a significant reduction in seizure frequency and severity over a 9-month follow-up period. The video can be found here: https://youtu.be/3-mMq5-PLiM .

  16. Stereotactic body radiotherapy: current strategies and future development

    Science.gov (United States)

    2016-01-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon. PMID:27606082

  17. Stereotactic body radiotherapy for de novo spinal metastases: systematic review.

    Science.gov (United States)

    Husain, Zain A; Sahgal, Arjun; De Salles, Antonio; Funaro, Melissa; Glover, Janis; Hayashi, Motohiro; Hiraoka, Masahiro; Levivier, Marc; Ma, Lijun; Martínez-Alvarez, Roberto; Paddick, J Ian; Régis, Jean; Slotman, Ben J; Ryu, Samuel

    2017-09-01

    OBJECTIVE The aim of this systematic review was to provide an objective summary of the published literature pertaining to the use of stereotactic body radiation therapy (SBRT) specific to previously untreated spinal metastases. METHODS The authors performed a systematic review, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, of the literature found in a search of Medline, PubMed, Embase, and the Cochrane Library up to March 2015. The search strategy was limited to publications in the English language. RESULTS A total of 14 full-text articles were included in the analysis. All studies were retrospective except for 2 studies, which were prospective. A total of 1024 treated spinal lesions were analyzed. The median follow-up time ranged from 9 to 49 months. A range of dose-fractionation schemes was used, the most common of which were 16-24 Gy/1 fraction (fx), 24 Gy/2 fx, 24-27 Gy/3 fx, and 30-35 Gy/5 fx. In studies that reported crude results regarding in-field local tumor control, 346 (85%) of 407 lesions remained controlled. For studies that reported actuarial values, the weighted average revealed a 90% 1-year local control rate. Only 3 studies reported data on complete pain response, and the weighted average of these results yielded a complete pain response rate of 54%. The most common toxicity was new or progressing vertebral compression fracture, which was observed in 9.4% of cases; 2 cases (0.2%) of neurologic injury were reported. CONCLUSION There is a paucity of prospective data specific to SBRT in patients with spinal metastases not otherwise irradiated. This systematic review found that SBRT is associated with favorable rates of local control (approximately 90% at 1 year) and complete pain response (approximately 50%), and low rates of serious adverse events were found. Practice guidelines are summarized based on these data and International Stereotactic Radiosurgery Society consensus.

  18. Hyperfractionated stereotactic reirradiation for recurrent head and neck cancer

    International Nuclear Information System (INIS)

    Cvek, Jakub; Knybel, Lukas; Skacelikova, Eva; Otahal, Bretislav; Molenda, Lukas; Feltl, David; Stransky, Jiri; Res, Oldrich; Matousek, Petr; Zelenik, Karol

    2016-01-01

    The goal of this work was to evaluate the efficacy and toxicity of hyperfractionated stereotactic reirradiation (re-RT) as a treatment for inoperable, recurrent, or second primary head and neck squamous cell cancer (HNSCC) that is not suitable for systemic treatment. Forty patients with recurrent or second primary HNSCC were included in this study. The patients had a median gross tumor volume of 76 ml (range 14-193 ml) and a previous radiotherapy dose greater than 60 Gy. Treatment was designed to cover 95 % of the planning target volume (PTV, defined as gross tumor volume [GTV] + 3 mm to account for microscopic spreading, with no additional set-up margin) with the prescribed dose (48 Gy in 16 fractions b.i.d.). Treatment was administered twice daily with a minimum 6 h gap. Uninvolved lymph nodes were not irradiated. Treatment was completed as planned for all patients (with median duration of 11 days, range 9-14 days). Acute toxicity was evaluated using the RTOG/EORTC scale. A 37 % incidence of grade 3 mucositis was observed, with recovery time of ≤ 4 weeks for all of these patients. Acute skin toxicity was never observed to be higher than grade 2. Late toxicity was also evaluated according to the RTOG/EORTC scale. Mandible radionecrosis was seen in 4 cases (10 %); however, neither carotid blowout syndrome nor other grade 4 late toxicity occurred. One-year overall survival (OS) and local progression-free survival (L-PFS) were found to be 33 and 44 %, respectively. Performance status and GTV proved to be significant prognostic factors regarding local control and survival. Hyperfractionated stereotactic re-RT is a reasonable treatment option for patients with recurrent/second primary HNSCC who were previously exposed to high-dose irradiation and who are not candidates for systemic treatment or hypofractionation. (orig.) [de

  19. CT-guided stereotactic evacuation of hypertensive intracerebral hematomas

    International Nuclear Information System (INIS)

    Hondo, Hideki

    1983-01-01

    Computerized tomography (CT) is now effective not only for definite diagnosis and location of intracerebral hematomas but also for coordination of the center of a hematoma. CT-guided stereotactic evacuation of hypertensive intracerebral hematoma was performed in 51 cases: 34 of basal ganglionic hematoma with or without ventricular perforation, 11 of subcortical hematoma, 3 of thalamic hematoma and 3 of cerebellar hematoma. Three dimensional CT images or biplane CT images were taken to determine the coordinates of the target point, which was the center of the hematoma. Then, a silicon tube (O.D. 3.5 phi, I.D. 2.1 phi) was inserted into the center of the hematoma through a burr-hole under local anesthesia, and the liquid or solid hematoma was aspirated as completely as possible with a syringe. Urokinase (6,000 I.U./5 ml saline) was administered through this silicon tube every 6 or 12 hours for several days until the hematoma had drained out competely. The silicon tube was taken out when repeated CT scanning revealed no hematoma. The results of clinical follow-ups indicated that this procedure is as good as, or rather better than conventional microsurgery with evacuation of hematoma under direct vision. Moreover this CT-guided stereotactic approach for evacuation of the hematoma has the following advantages: 1) the procedure is simple and safe, 2) operation can be performed under local anesthesia, and 3) the hematoma is drained out completely with the aid of urokinase. This surgery seems indicated as an emergency treatment for high-age or high risk patients and also as a routine surgery for intracerebral hematomas in patients showing no herination signs. (author)

  20. Robotic System for MRI-Guided Stereotactic Neurosurgery

    Science.gov (United States)

    Li, Gang; Cole, Gregory A.; Shang, Weijian; Harrington, Kevin; Camilo, Alex; Pilitsis, Julie G.; Fischer, Gregory S.

    2015-01-01

    Stereotaxy is a neurosurgical technique that can take several hours to reach a specific target, typically utilizing a mechanical frame and guided by preoperative imaging. An error in any one of the numerous steps or deviations of the target anatomy from the preoperative plan such as brain shift (up to 20 mm), may affect the targeting accuracy and thus the treatment effectiveness. Moreover, because the procedure is typically performed through a small burr hole opening in the skull that prevents tissue visualization, the intervention is basically “blind” for the operator with limited means of intraoperative confirmation that may result in reduced accuracy and safety. The presented system is intended to address the clinical needs for enhanced efficiency, accuracy, and safety of image-guided stereotactic neurosurgery for Deep Brain Stimulation (DBS) lead placement. The work describes a magnetic resonance imaging (MRI)-guided, robotically actuated stereotactic neural intervention system for deep brain stimulation procedure, which offers the potential of reducing procedure duration while improving targeting accuracy and enhancing safety. This is achieved through simultaneous robotic manipulation of the instrument and interactively updated in situ MRI guidance that enables visualization of the anatomy and interventional instrument. During simultaneous actuation and imaging, the system has demonstrated less than 15% signal-to-noise ratio (SNR) variation and less than 0.20% geometric distortion artifact without affecting the imaging usability to visualize and guide the procedure. Optical tracking and MRI phantom experiments streamline the clinical workflow of the prototype system, corroborating targeting accuracy with 3-axis root mean square error 1.38 ± 0.45 mm in tip position and 2.03 ± 0.58° in insertion angle. PMID:25376035

  1. Hypofractionation Regimens for Stereotactic Radiotherapy for Large Brain Tumors

    International Nuclear Information System (INIS)

    Yuan Jiankui; Wang, Jian Z.; Lo, Simon; Grecula, John C.; Ammirati, Mario; Montebello, Joseph F.; Zhang Hualin; Gupta, Nilendu; Yuh, William T.C.; Mayr, Nina A.

    2008-01-01

    Purpose: To investigate equivalent regimens for hypofractionated stereotactic radiotherapy (HSRT) for brain tumor treatment and to provide dose-escalation guidance to maximize the tumor control within the normal brain tolerance. Methods and Materials: The linear-quadratic model, including the effect of nonuniform dose distributions, was used to evaluate the HSRT regimens. The α/β ratio was estimated using the Gammaknife stereotactic radiosurgery (GKSRS) and whole-brain radiotherapy experience for large brain tumors. The HSRT regimens were derived using two methods: (1) an equivalent tumor control approach, which matches the whole-brain radiotherapy experience for many fractions and merges it with the GKSRS data for few fractions; and (2) a normal-tissue tolerance approach, which takes advantages of the dose conformity and fractionation of HSRT to approach the maximal dose tolerance of the normal brain. Results: A plausible α/β ratio of 12 Gy for brain tumor and a volume parameter n of 0.23 for normal brain were derived from the GKSRS and whole-brain radiotherapy data. The HSRT prescription regimens for the isoeffect of tumor irradiation were calculated. The normal-brain equivalent uniform dose decreased as the number of fractions increased, because of the advantage of fractionation. The regimens for potential dose escalation of HSRT within the limits of normal-brain tolerance were derived. Conclusions: The designed hypofractionated regimens could be used as a preliminary guide for HSRT dose prescription for large brain tumors to mimic the GKSRS experience and for dose escalation trials. Clinical studies are necessary to further tune the model parameters and validate these regimens

  2. Individual titanium zygomatic implant

    Science.gov (United States)

    Nekhoroshev, M. V.; Ryabov, K. N.; Avdeev, E. V.

    2018-03-01

    Custom individual implants for the reconstruction of craniofacial defects have gained importance due to better qualitative characteristics over their generic counterparts – plates, which should be bent according to patient needs. The Additive Manufacturing of individual implants allows reducing cost and improving quality of implants. In this paper, the authors describe design of zygomatic implant models based on computed tomography (CT) data. The fabrication of the implants will be carried out with 3D printing by selective laser melting machine SLM 280HL.

  3. Intraoperative MR-guided DBS implantation for treating PD and ET

    Science.gov (United States)

    Liu, Haiying; Maxwell, Robert E.; Truwit, Charles L.

    2001-05-01

    Deep brain stimulator (DBS) implantation is a promising treatment alternative for suppressing the motor tremor symptoms in Parkinson disease (PD) patient. The main objective is to develop a minimally invasive approach using high spatial resolution and soft-tissue contrast MR imaging techniques to guide the surgical placement of DBS. In the MR-guided procedure, the high spatial resolution MR images were obtained intra-operatively and used to target stereotactically a specific deep brain location. The neurosurgery for craniotomy was performed in the front of the magnet outside of the 10 Gauss line. Aided with positional registration assembly for the stereotactic head frame, the target location (VIM or GPi or STN) in deep brain areas was identified and measured from the MR images in reference to the markers in the calibration assembly of the head frame before the burrhole prep. In 20 patients, MR- guided DBS implantations have been performed according to the new methodology. MR-guided DBS implantation at high magnetic field strength has been shown to be feasible and desirable. In addition to the improved outcome, this offers a new surgical approach in which intra-operative visualization is possible during intervention, and any complications such as bleeding can be assessed in situ immediately prior to dural closure.

  4. SU-F-P-05: Initial Experience with an Independent Certification Program for Stereotactic Radiosurgery and Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Solberg, T [University of Pennsylvania, Philadelphia, PA (United States); Robar, J [Capital District Health Authority, Halifax, NS (Canada); Gevaert, T [University Hospital Brussels, Brussels (Belgium); Todorovic, M [Universitats-Klinikum Hamburg-Eppendorf, Hamburg (Germany); Howe, J [Associates In Medical Physics, Louisville, KY (United States)

    2016-06-15

    Purpose: The ASTRO document “Safety is no accident: A FRAMEWORK FOR QUALITY RADIATION ONCOLOGY AND CARE” recommends external reviews of specialized modalities. The purpose of this presentation is to describe the implementation of such a program for Stereotactic Radiosurgery (SRS) and Stereotactic Body radiation Therapy (SBRT). Methods: The margin of error for SRS and SBRT delivery is significantly smaller than that of conventional radiotherapy and therefore requires special attention and diligence. The Novalis Certified program was created to fill an unmet need for specialized SRS / SBRT credentialing. A standards document was drafted by a panel of experts from several disciplines, including medical physics, radiation oncology and neurosurgery. The document, based on national and international standards, covers requirements in program structure, personnel, training, clinical application, technology, quality management, and patient and equipment QA. The credentialing process was modeled after existing certification programs and includes an institution-generated self-study, extensive document review and an onsite audit. Reviewers generate a descriptive report, which is reviewed by a multidisciplinary expert panel. Outcomes of the review may include mandatory requirements and optional recommendations. Results: 15 institutions have received Novalis Certification, including 3 in the US, 7 in Europe, 4 in Australia and 1 in Asia. 87 other centers are at various stages of the process. Nine reviews have resulted in mandatory requirements, however all of these were addressed within three months of the audit report. All reviews have produced specific recommendations ranging from programmatic to technical in nature. Institutions felt that the credentialing process addressed a critical need and was highly valuable to the institution. Conclusion: Novalis Certification is a unique peer review program assessing safety and quality in SRS and SBRT, while recognizing

  5. Stereotactic Breast Core Needle Biopsy in a Tertiary Breast Center of Tehran University of Medical Sciences

    Directory of Open Access Journals (Sweden)

    Afsaneh Alikhassi

    2015-02-01

    Full Text Available Background: The purpose of this study was to evaluate the results of stereotactic breast core needle biopsy in a tertiary breast center of Tehran University of Medical Sciences.Methods: Patients who were candidates for mammography-guided stereotactic breast core biopsy from March 2011 to December 2013 were included in this study. Stereotactic biopsy was performed by a dedicated prone Hologic mammography unit employing an automatic biopsy device with a 14-gauge needle. Patients with malignant or premalignant biopsy results were followed up with surgical pathology reports and patients with benign core biopsy findings were followed up with mammograms.Results: Among the 150 patients who were included in the final analyses, 30 had malignant findings on stereotactic biopsy and 10 patients had a premalignant pathology result on stereotactic biopsy. The remaining 110 patients had benign results on histopathology; however, in 30 patients, wire localization and surgery of the same area were performed due to either discordant mammography-pathology findings or clinical suspicion of malignancy and in two of them, advancing pathologic grade was witnessed. A total of 80 patients with benign histopathologic results had follow-up mammograms and the follow-up period was between 12 months to 3 years. The sensitivity and specificity of stereotactic breast core biopsy in this study were 94% and 96%, respectively.Conclusions: Stereotactic breast core needle biopsy is an effective and safe method in evaluation of suspicious mammography-detected lesions but caution should be warranted when taking results into account, especially in mammography-pathology discordance and in patients with premalignant pathology reports.

  6. Fractionated stereotactic radiotherapy in brain tumors and cervical region. Experience of the Dean Funes Medical Center, first experience in stereotactic radiotherapy and radiosurgery inside the country

    International Nuclear Information System (INIS)

    Castro Vita, H.; Brunetto, M.; Derechinsky, V; Derechinsky, G.; Derechinsky, M.; Gonzalez, S.; Marinello, A.

    2004-01-01

    Purpose: A retrospective study to analyze the results of 53 patients treated with stereotactic radiotherapy in 'Centro Medico Dean Funes' was performed. The patients had brain and head and neck tumors. Patients and methods: From November 1997 to March 2003, 53 patients were treated with stereotactic radiotherapy in 'Centro Medico Dean Funes'. The daily dose administered varied from 1.8 to 2 Gy and the total dose from 30 to 70 Gy. The minimal follow up was 2 months, and the medium follow up 32 months. Local control and survival were analyzed in all patients, as well as tolerance and the complications of the treatment. Results: Since these series represented a very heterogeneous group of patients, the final results were very difficult to compare with other alternative treatments. However, an excellent tolerance to therapy was observed. Some subsets of patients had good results to treatment: patients with metastasis to the orbit, patients with lesions to the sellar and parasellar regions and some who relapsed following conventional radiotherapy, mainly lymphomas. Conclusions: Stereotactic radiotherapy is a valid therapeutic method to treat tumors of the brain and head and neck, as long as the tumor has a moderate size (6 cm. or less) and the shape is cylindrical or ellipsoid. Stereotactic radiation improves the therapeutic ratio as compared with the conventional radiotherapy. It has advantages over the 3D technique, and could compete with IMRT (Intensity modulated radiation therapy). (author) [es

  7. Breast Implants: Saline vs. Silicone

    Science.gov (United States)

    ... differ in material and consistency, however. Saline breast implants Saline implants are filled with sterile salt water. ... of any age for breast reconstruction. Silicone breast implants Silicone implants are pre-filled with silicone gel — ...

  8. [Biomaterials in cochlear implants].

    Science.gov (United States)

    Stöver, T; Lenarz, T

    2009-05-01

    Cochlear implants (CI) represent the "gold standard" for the treatment of congenitally deaf children and postlingually deafened adults. Thus, cochlear implantation is a success story of new bionic prosthesis development. Owing to routine application of cochlear implants in adults but also in very young children (below the age of one), high demands are placed on the implants. This is especially true for biocompatibility aspects of surface materials of implant parts which are in contact with the human body. In addition, there are various mechanical requirements which certain components of the implants must fulfil, such as flexibility of the electrode array and mechanical resistance of the implant housing. Due to the close contact of the implant to the middle ear mucosa and because the electrode array is positioned in the perilymphatic space via cochleostomy, there is a potential risk of bacterial transferral along the electrode array into the cochlea. Various requirements that have to be fulfilled by cochlear implants, such as biocompatibility, electrode micromechanics, and although a very high level of technical standards has been carried out there is still demand for the improvement of implants as well as of the materials used for manufacturing, ultimately leading to increased implant performance. General considerations of material aspects related to cochlear implants as well as potential future perspectives of implant development will be discussed.

  9. A simple implantation method for flexible, multisite microelectrodes into rat brains

    Directory of Open Access Journals (Sweden)

    Anja eRichter

    2013-07-01

    Full Text Available A long term functional and reliable coupling between neural tissue and implanted microelectrodes is the key issue in acquiring neural electrophysiological signals or therapeutically excite neural tissue. The currently often used rigid micro-electrodes are thought to cause a severe foreign body reaction resulting in a thick glial scar and consequently a poor tissue-electrode coupling in the chronic phase. We hypothesize, that this adverse effect might be remedied by probes compliant to the soft brain tissue, i.e. replacing rigid electrodes by flexible ones. Unfortunately, this flexibility comes at the price of a low stiffness, which makes targeted low trauma implantation very challenging. In this study, we demonstrate an adaptable and simple method to implant extremely flexible microprobes even to deep areas of rat’s brain. Implantation of flexible probes is achieved by rod supported stereotactic insertion fostered by a hydrogel (2% agarose in PBS cushion on the exposed skull. We were thus able to implant very flexible micro-probes in 70 rats as deep as the rodent's subthalamic nucleus. This work describes in detail the procedures and steps needed for minimal invasive, but reliable implantation of flexible probes.

  10. Stereotactic Radiation Therapy for Benign Meningioma: Long-Term Outcome in 318 Patients

    Energy Technology Data Exchange (ETDEWEB)

    Fokas, Emmanouil, E-mail: emmanouil.fokas@kgu.de [Department of Radiotherapy and Radiation Oncology, Philipps-University Marburg, Marburg (Germany); Department of Radiation Therapy and Oncology, Johann Wolfgang Goethe University, Frankfurt (Germany); Henzel, Martin [Department of Radiotherapy and Radiation Oncology, Philipps-University Marburg, Marburg (Germany); Surber, Gunar; Hamm, Klaus [Department for Stereotactic Neurosurgery and Radiosurgery, HELIOS Klinikum Erfurt, Erfurt (Germany); Engenhart-Cabillic, Rita [Department of Radiotherapy and Radiation Oncology, Philipps-University Marburg, Marburg (Germany)

    2014-07-01

    Purpose: To investigate the long-term outcome of stereotactic-based radiation therapy in a large cohort of patients with benign intracranial meningiomas. Methods and Materials: Between 1997 and 2010, 318 patients with histologically confirmed (44.7%; previous surgery) or imaging-defined (55.3%) benign meningiomas were treated with either fractionated stereotactic radiation therapy (79.6%), hypofractionated stereotactic radiation therapy (15.4%), or stereotactic radiosurgery (5.0%), depending on tumor size and location. Local control (LC), overall survival (OS), cause-specific survival (CSS), prognostic factors, and toxicity were analyzed. Results: The median follow-up was 50 months (range, 12-167 months). Local control, OS, and CSS at 5 years were 92.9%, 88.7%, and 97.2%, and at 10 years they were 87.5%, 74.1%, and 97.2%, respectively. In the multivariate analysis, tumor location (P=.029) and age >66 years (P=.031) were predictors of LC and OS, respectively. Worsening of pre-existing neurologic symptoms immediately after radiation therapy occurred in up to 2%. Clinically significant acute toxicity (grade 3°) occurred in 3%. Only grade 1-2 late toxicity was observed in 12%, whereas no new neurologic deficits or treatment-related mortality were encountered. Conclusions: Patients with benign meningiomas predominantly treated with standard fractionated stereotactic radiation therapy with narrow margins enjoy excellent LC and CSS, with minimal long-term morbidity.

  11. Percutaneous fiducial marker placement prior to stereotactic body radiotherapy for malignant liver tumors: an initial experience

    International Nuclear Information System (INIS)

    Ohta, Kengo; Shimohira, Masashi; Murai, Taro; Nishimura, Junichi; Iwata, Hiromitsu; Ogino, Hiroyuki; Hashizume, Takuya; Shibamoto, Yuta

    2016-01-01

    The aim of this study was to describe our initial experience with a gold flexible linear fiducial marker and to evaluate the safety and technical and clinical efficacy of stereotactic body radiotherapy using this marker for malignant liver tumors. Between July 2012 and February 2015, 18 patients underwent percutaneous fiducial marker placement before stereotactic body radiotherapy for malignant liver tumors. We evaluated the technical and clinical success rates of the procedure and the associated complications. Technical success was defined as successful placement of the fiducial marker at the target site, and clinical success was defined as the completion of stereotactic body radiotherapy without the marker dropping out of position. All 18 fiducial markers were placed successfully, so the technical success rate was 100% (18/18). All 18 patients were able to undergo stereotactic body radiotherapy without marker migration. Thus, the clinical success rate was 100% (18/18). Slight pneumothorax occurred as a minor complication in one case. No major complications such as coil migration or bleeding were observed. The examined percutaneous fiducial marker was safely placed in the liver and appeared to be useful for stereotactic body radiotherapy for malignant liver tumors

  12. Stereotactic image-guided navigation in the preoperative imaging of perforators for DIEP flap breast reconstruction.

    Science.gov (United States)

    Rozen, W M; Ashton, M W; Stella, D L; Phillips, T J; Taylor, G I

    2008-01-01

    Preoperative imaging is sought prior to DIEA (Deep Inferior Epigastric Artery) perforator flaps due to the potential for maximizing operative success and minimizing operative complications. Recent advances include the use of computed tomography (CT) angiography (CTA) and magnetic resonance angiography. Image-guided stereotactic surgery is a recent technique that has been used with success in several fields of surgery. The variability of perforator anatomy makes DIEA perforator flap surgery a suitable candidate for such technology, but as yet this has not been described. A study was undertaken to determine the feasibility of CT-guided stereotaxy technique in DIEA perforator flap surgery and to compare findings with both conventional CTA and operative findings. Five consecutive patients planned for an elective DIEA perforator flap were recruited. Each patient underwent preoperative imaging of the anterior abdominal wall vasculature with both conventional CTA and CT-guided stereotactic imaging. Imaging findings were compared to operative findings. In all cases, all the major perforators were accurately localized with stereotactic imaging and with conventional CTA. Stereotactic navigation demonstrated a slightly better (nonsignificant) correlation with perforator location than conventional CTA. As such, CT-guided stereotactic imaging is an accurate method for the preoperative planning of DIEA perforator flaps, providing additional and potentially more accurate data to conventional CTA. With no additional scanning required, the method described in this paper allows the combined use of both methods for preoperative planning. (c) 2008 Wiley-Liss, Inc.

  13. Confounding factors in diagnostics of MGMT promoter methylation status in glioblastomas in stereotactic biopsies.

    Science.gov (United States)

    Weise, Lutz M; Harter, Patrick N; Eibach, Sebastian; Braczynski, Anne K; Dunst, Maika; Rieger, Johannes; Bähr, Oliver; Hattingen, Elke; Steinbach, Joachim P; Plate, Karl H; Seifert, Volker; Mittelbronn, Michel

    2014-01-01

    In nonresectable glioblastoma (GBM), stereotactic biopsies are performed to retrieve tissue for diagnostic purposes. The analysis of O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation adds prognostic and predictive information. The aim of the study was to detect confounding factors that limit the number of conclusive MGMT promoter methylation results. We analyzed 71 consecutive GBM patients undergoing stereotactic biopsy on whom MGMT analysis was performed by methylation-specific polymerase chain reaction. Specimens were correlated to imaging by coregistration and prospective documentation of biopsy localization. Our findings were validated in an additional 62 GBM stereotactic biopsies. Our results demonstrate that the best MGMT promoter methylation results were obtained from samples (n = 71) taken in a tangential manner from tumor areas showing contrast enhancement in magnetic resonance imaging. In the additional validation series of 62 stereotactically biopsied GBM, we were able to increase the rate of conclusive MGMT promoter methylation results from 76.1 to 85.48% by strictly planning the route of biopsy in a tangential manner if possible. These results underline that within the contrast-enhanced tumor part, choosing the trajectory in a tangential manner increases the diagnostic yield for conclusive MGMT promoter methylation analyses in stereotactic biopsies as a basis for patient stratification and individualized therapy.

  14. Treatment of Five or More Brain Metastases With Stereotactic Radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, Grant K.; Suh, John H.; Reuther, Alwyn M. [Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH (United States); Vogelbaum, Michael A.; Barnett, Gene H.; Angelov, Lilyana; Weil, Robert J. [Department of Neurosurgery, Cleveland Clinic, Cleveland, OH (United States); Neyman, Gennady [Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH (United States); Chao, Samuel T., E-mail: chaos@ccf.org [Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH (United States)

    2012-08-01

    Purpose: To examine the outcomes of patients with five or more brain metastases treated in a single session with stereotactic radiosurgery (SRS). Methods and Materials: Sixty-four patients with brain metastases treated with SRS to five or more lesions in a single session were reviewed. Primary disease type, number of lesions, Karnofsky performance score (KPS) at SRS, and status of primary and systemic disease at SRS were included. Patients were treated using dosing as defined by Radiation Therapy Oncology Group Protocol 90-05, with adjustments for critical structures. We defined prior whole-brain radiotherapy (WBRT) as WBRT completed >1 month before SRS and concurrent WBRT as WBRT completed within 1 month before or after SRS. Kaplan-Meier estimates and Cox proportional hazard regression were used to determine which patient and treatment factors predicted overall survival (OS). Results: The median OS after SRS was 7.5 months. The median KPS was 80 (range, 60-100). A KPS of {>=}80 significantly influenced OS (median OS, 4.8 months for KPS {<=}70 vs. 8.8 months for KPS {>=}80, p = 0.0097). The number of lesions treated did not significantly influence OS (median OS, 6.6 months for eight or fewer lesions vs. 9.9 months for more than eight, p = nonsignificant). Primary site histology did not significantly influence median OS. On multivariate Cox modeling, KPS and prior WBRT significantly predicted for OS. Whole-brain radiotherapy before SRS compared with concurrent WBRT significantly influenced survival, with a risk ratio of 0.423 (95% confidence interval 0.191-0.936, p = 0.0338). No significant differences were observed when no WBRT was compared with concurrent WBRT or when the no WBRT group was compared with prior WBRT. A KPS of {<=}70 predicted for poorer outcomes, with a risk ratio of 2.164 (95% confidence interval 1.157-4.049, p = 0.0157). Conclusions: Stereotactic radiosurgery to five or more brain lesions is an effective treatment option for patients with

  15. A Study of Pseudoprogression After Spine Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bahig, Houda; Simard, Dany [Department of Radiation Oncology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada); Létourneau, Laurent [Department of Radiology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada); Wong, Philip; Roberge, David; Filion, Edith; Donath, David [Department of Radiation Oncology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada); Sahgal, Arjun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Masucci, Laura, E-mail: g.laura.masucci.chum@ssss.gouv.qc.ca [Department of Radiation Oncology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada)

    2016-11-15

    Purpose: To determine the incidence of pseudoprogression (PP) after spine stereotactic body radiation therapy based on a detailed and quantitative assessment of magnetic resonance imaging (MRI) morphologic tumor alterations, and to identify predictive factors distinguishing PP from local recurrence (LR). Methods and Materials: A retrospective analysis of 35 patients with 49 spinal segments treated with spine stereotactic body radiation therapy, from 2009 to 2014, was conducted. The median number of follow-up MRI studies was 4 (range, 2-7). The gross tumor volumes (GTVs) within each of the 49 spinal segments were contoured on the pretreatment and each subsequent follow-up T1- and T2-weighted MRI sagittal sequence. T2 signal intensity was reported as the mean intensity of voxels constituting each volume. LR was defined as persistent GTV enlargement on ≥2 serial MRI studies for ≥6 months or on pathologic confirmation. PP was defined as a GTV enlargement followed by stability or regression on subsequent imaging within 6 months. Kaplan-Meier analysis was used for estimation of actuarial local control, disease-free survival, and overall survival. Results: The median follow-up was 23 months (range, 1-39 months). PP was identified in 18% of treated segments (9 of 49) and LR in 29% (14 of 49). Earlier volume enlargement (5 months for PP vs 15 months for LR, P=.005), greater GTV to reference nonirradiated vertebral body T2 intensity ratio (+30% for PP vs −10% for LR, P=.005), and growth confined to 80% of the prescription isodose line (80% IDL) (8 of 9 PP cases vs 1 of 14 LR cases, P=.002) were associated with PP on univariate analysis. Multivariate analysis confirmed an earlier time to volume enlargement and growth within the 80% IDL as significant predictors of PP. LR involved the epidural space in all but 1 lesion, whereas PP was confined to the vertebral body in 7 of 9 cases. Conclusions: PP was observed in 18% of treated spinal segments. Tumor growth

  16. Implantable cardioverter-defibrillator

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007370.htm Implantable cardioverter-defibrillator To use the sharing features on this page, please enable JavaScript. An implantable cardioverter-defibrillator (ICD) is a device that detects any life- ...

  17. Implantable cardioverter defibrillator - discharge

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000108.htm Implantable cardioverter defibrillator - discharge To use the sharing features on this page, please enable JavaScript. An implantable cardioverter-defibrillator (ICD) is a device that detects a life- ...

  18. About Implantable Contraception

    Science.gov (United States)

    ... a tube was inserted, and get a new contraceptive implant on schedule or switch to another method ... STDs. Possible Side Effects Young women who get contraceptive implants might notice such side effects as: irregular ...

  19. Urinary incontinence - collagen implants

    Science.gov (United States)

    ... gov/ency/article/007373.htm Urinary incontinence - injectable implant To use the sharing features on this page, please enable JavaScript. Injectable implants are injections of material into the urethra to ...

  20. Moessbauer spectroscopy of implanted sources

    International Nuclear Information System (INIS)

    Niesen, L.

    1983-01-01

    A review is given of the field of Moessbauer spectroscopy of ion-implanted sources. After an introduction to the various aspects of the ion-implantation method, the following topics are treated: final site selection of implanted impurities; trapping of defects at implanted ions; on-line implantation; implantation in metals, semiconductors and insulators. (Auth.)

  1. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  2. COCHLEAR IMPLANTATION: MY EXPERIENCE

    OpenAIRE

    Shankar

    2015-01-01

    Cochlear implant is a small, surgically implanted complex electronic device that can help to provide a sense of sound to a person with severe to profound sensorineural hearing loss. This type of hearing loss, typically involves damage to hair cells in the cochlea, as a result sound cannot reach the auditory nerve which usually receives information from hair cells. A cochlear implant skips the damaged hair cells and to stimulate the auditory nerve directly. An implant does not rest...

  3. The use of a silicon strip detector dose magnifying glass in stereotactic radiotherapy QA and dosimetry

    International Nuclear Information System (INIS)

    Wong, J. H. D.; Knittel, T.; Downes, S.; Carolan, M.; Lerch, M. L. F.; Petasecca, M.; Perevertaylo, V. L.; Metcalfe, P.; Jackson, M.; Rosenfeld, A. B.

    2011-01-01

    Purpose: Stereotactic radiosurgery/therapy (SRS/SRT) is the use of radiation ablation in place of conventional surgical excision to remove or create fibrous tissue in small target volumes. The target of the SRT/SRS treatment is often located in close proximity to critical organs, hence the requirement of high geometric precision including a tight margin on the planning target volume and a sharp dose fall off. One of the major problems with quality assurance (QA) of SRT/SRS is the availability of suitable detectors with the required spatial resolution. The authors present a novel detector that they refer to as the dose magnifying glass (DMG), which has a high spatial resolution (0.2 mm) and is capable of meeting the stringent requirements of QA and dosimetry in SRS/SRT therapy. Methods: The DMG is an array of 128 phosphor implanted n + strips on a p-type Si wafer. The sensitive area defined by a single n + strip is 20x2000 μm 2 . The Si wafer is 375 μm thick. It is mounted on a 0.12 mm thick Kapton substrate. The authors studied the dose per pulse (dpp) and angular response of the detector in a custom-made SRS phantom. The DMG was used to determine the centers of rotation and positioning errors for the linear accelerator's gantry, couch, and collimator rotations. They also used the DMG to measure the profiles and the total scatter factor (S cp ) of the SRS cones. Comparisons were made with the EBT2 film and standard S cp values. The DMG was also used for dosimetric verification of a typical SRS treatment with various noncoplanar fields and arc treatments when applied to the phantom. Results: The dose per pulse dependency of the DMG was found to be cp agrees very well with the standard data with an average difference of 1.2±1.1%. Comparison of the relative intensity profiles of the DMG and EBT2 measurements for a simulated SRS treatment shows a maximum difference of 2.5%. Conclusions: The DMG was investigated for dose per pulse and angular dependency. Its

  4. Respiratory gating based on internal electromagnetic motion monitoring during stereotactic liver radiation therapy: First results.

    Science.gov (United States)

    Poulsen, Per Rugaard; Worm, Esben Schjødt; Hansen, Rune; Larsen, Lars Peter; Grau, Cai; Høyer, Morten

    2015-01-01

    Intrafraction motion may compromise the target dose in stereotactic body radiation therapy (SBRT) of tumors in the liver. Respiratory gating can improve the treatment delivery, but gating based on an external surrogate signal may be inaccurate. This is the first paper reporting on respiratory gating based on internal electromagnetic monitoring during liver SBRT. Two patients with solitary liver metastases were treated with respiratory-gated SBRT guided by three implanted electromagnetic transponders. The treatment was delivered in end-exhale with beam-on when the centroid of the three transponders deviated less than 3 mm [left-right (LR) and anterior-posterior (AP) directions] and 4mm [cranio-caudal (CC)] from the planned position. For each treatment fraction, log files were used to determine the transponder motion during beam-on in the actual gated treatments and in simulated treatments without gating. The motion was used to reconstruct the dose to the clinical target volume (CTV) with and without gating. The reduction in D95 (minimum dose to 95% of the CTV) relative to the plan was calculated for both treatment courses. With gating the maximum course mean (standard deviation) geometrical error in any direction was 1.2 mm (1.8 mm). Without gating the course mean error would mainly increase for Patient 1 [to -2.8 mm (1.6 mm) (LR), 7.1 mm (5.8 mm) (CC), -2.6 mm (2.8mm) (AP)] due to a large systematic cranial baseline drift at each fraction. The errors without gating increased only slightly for Patient 2. The reduction in CTV D95 was 0.5% (gating) and 12.1% (non-gating) for Patient 1 and 0.3% (gating) and 1.7% (non-gating) for Patient 2. The mean duty cycle was 55%. Respiratory gating based on internal electromagnetic motion monitoring was performed for two liver SBRT patients. The gating added robustness to the dose delivery and ensured a high CTV dose even in the presence of large intrafraction motion.

  5. Evaluation of stability of stereotactic space defined by cone-beam CT for the Leksell Gamma Knife Icon.

    Science.gov (United States)

    AlDahlawi, Ismail; Prasad, Dheerendra; Podgorsak, Matthew B

    2017-05-01

    The Gamma Knife Icon comes with an integrated cone-beam CT (CBCT) for image-guided stereotactic treatment deliveries. The CBCT can be used for defining the Leksell stereotactic space using imaging without the need for the traditional invasive frame system, and this allows also for frameless thermoplastic mask stereotactic treatments (single or fractionated) with the Gamma Knife unit. In this study, we used an in-house built marker tool to evaluate the stability of the CBCT-based stereotactic space and its agreement with the standard frame-based stereotactic space. We imaged the tool with a CT indicator box using our CT-simulator at the beginning, middle, and end of the study period (6 weeks) for determining the frame-based stereotactic space. The tool was also scanned with the Icon's CBCT on a daily basis throughout the study period, and the CBCT images were used for determining the CBCT-based stereotactic space. The coordinates of each marker were determined in each CT and CBCT scan using the Leksell GammaPlan treatment planning software. The magnitudes of vector difference between the means of each marker in frame-based and CBCT-based stereotactic space ranged from 0.21 to 0.33 mm, indicating good agreement of CBCT-based and frame-based stereotactic space definition. Scanning 4-month later showed good prolonged stability of the CBCT-based stereotactic space definition. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  6. Is mask-based stereotactic head-and-neck fixation as precise as stereotactic head fixation for precision radiotherapy?

    International Nuclear Information System (INIS)

    Georg, Dietmar; Bogner, Joachim; Dieckmann, Karin; Poetter, Richard

    2006-01-01

    Background: The aim of this study was to compare setup accuracy and reproducibility of a stereotactic head and a head-and-neck fixation system, both based on thermoplastic material. Methods and Material: Ten patients were immobilized with a head and a head-and-neck fixation system (both BrainLAB, Germany). Both mask systems were modified with a custom-made mouthpiece and a strip of thermoplastic material attached to the lower part of the mask. During the first treatment session, after positioning patients using room lasers, two orthogonal portal images were taken as reference. Later on, at least five sets of orthogonal portal images were acquired for each patient. The isocentric setup accuracy was determined by comparing field edges and anatomic landmarks and the repositioning accuracy in the mask was obtained by comparing individual anatomic landmarks with respect to the metal balls, fixed on the masks. Systematic and random deviations and resulting three-dimensional (3D) vectors were calculated. Additionally, margins were derived from the systematic and random component of the isocentric setup accuracy. Finally, inter- and intraobserver variations were analyzed. Results: The systematic variation of the isocentric setup accuracy was very similar for the two mask systems, but the random variations were slightly larger for the head-and-neck system, resulting in a 0.4-mm larger 3D vector. The repositioning variations for the head mask were smaller compared with the head-and-neck mask, resulting in smaller 3D vectors for the random (∼0.4 mm) and systematic variations (∼0.6 mm). For both mask systems, a 2-mm margin can be used in lateral and anteroposterior direction, whereas in craniocaudal direction, this margin should be extended to 2.5 mm for the head mask and to 3 mm for the head-and-neck mask. The average absolute differences between two observers were within 0.5 mm, maximum deviations around 1 mm. Conclusion: Thermoplastic mask-based stereotactic head

  7. Development of stereotactic radiosurgery using carbon beams (carbon-knife)

    Science.gov (United States)

    Keawsamur, Mintra; Matsumura, Akihiko; Souda, Hikaru; Kano, Yosuke; Torikoshi, Masami; Nakano, Takashi; Kanai, Tatsuaki

    2018-02-01

    The aim of this research is to develop a stereotactic-radiosurgery (SRS) technique using carbon beams to treat small intracranial lesions; we call this device the carbon knife. A 2D-scanning method is adapted to broaden a pencil beam to an appropriate size for an irradiation field. A Mitsubishi slow extraction using third order resonance through a rf acceleration system stabilized by a feed-forward scanning beam using steering magnets with a 290 MeV/u initial beam energy was used for this purpose. Ridge filters for spread-out Bragg peaks (SOBPs) with widths of 5 mm, 7.5 mm, and 10 mm were designed to include fluence-attenuation effects. The collimator, which defines field shape, was used to reduce the lateral penumbra. The lateral-penumbra width at the SOBP region was less than 2 mm for the carbon knife. The penumbras behaved almost the same when changing the air gap, but on the other hand, increasing the range-shifter thickness mostly broadened the lateral penumbra. The physical-dose rates were approximate 6 Gy s‑1 and 4.5 Gy s‑1 for the 10  ×  10 mm2 and 5  ×  5 mm2 collimators, respectively.

  8. Citation measures in stereotactic radiosurgery: publication across a discipline.

    Science.gov (United States)

    Kondziolka, Douglas

    2011-01-01

    It is possible to judge the impact of scientific research by the number of citations a publication has received. We identified the most cited works in the field of stereotactic radiosurgery to study the evolution of this field from the perspective of publication. A Web of Science search was performed for articles that included the word 'radiosurgery' in the title. We studied the reports with >100 citations. A total of 5,532 published works were available for study between 1951 and 2010. Eighty-five articles had ≥ 100 citations, and these were published in 19 separate journals. The majority were published in the International Journal of Radiation Oncology, Biology and Physics, the Journal of Neurosurgery and Neurosurgery. The most common topics included brain metastasis management (n = 20), arteriovenous malformations (n = 17), vestibular schwannomas (n = 9), technologies (n = 9), meningiomas (n = 8) and dose response/radiobiology (n = 6). Fifty-seven percent of the articles were published in the last 10 years. The first radiosurgery report by Leksell (1951) initiated the field. The 1980s were a period of new technology development followed in the 1990s by introductory articles on specific indications that consisted mainly of retrospective case series. More sophisticated higher level evidence reports were published in the last decade. The most significant works in radiosurgery include initial technology descriptions, multicenter studies with large numbers of patients, randomized clinical trials and reports that provide dose prescription guidelines. Copyright © 2011 S. Karger AG, Basel.

  9. In vivo biological effects of stereotactic radiosurgery: A primate model

    Energy Technology Data Exchange (ETDEWEB)

    Lunsford, L.D.; Altschuler, E.M.; Flickinger, J.C.; Wu, A.; Martinez, A.J. (Univ. of Pittsburgh School of Medicine, PA (USA))

    1990-09-01

    Single-fraction, closed skull, small-volume irradiation (radiosurgery) of intact intracranial structures requires accurate knowledge of radiation tolerance. We have developed a baboon model to assess the in vivo destructive radiobiological effects of stereotactic radiosurgery. Three baboons received a single-fraction, 150-Gy lesion of the caudate nucleus, the thalamus, or the pons using the 8-mm diameter collimator of the gamma unit. Serial standard neurodiagnostic tests (neurological examination, computed tomographic scan, magnetic resonance imaging, stable xenon-enhanced computed tomographic scan of cerebral blood flow, somatosensory and brain stem evoked potentials, and myelin basic protein levels of cerebrospinal fluid) were compared with preoperative studies. Magnetic resonance imaging revealed the development of a lesion at the target site between 45 and 60 days after irradiation. Deterioration of the brain stem evoked potentials preceded imaging changes when the lesion encroached on auditory pathways. Myelin basic protein levels increased subsequent to imaging changes. Postmortem neuropathological examination confirmed a well-demarcated radionecrosis of the target volume. The baboon model appears to be an excellent method to study the in vivo biological effects of radiosurgery.

  10. Stereotactic Body Radiation Therapy Boost in Locally Advanced Pancreatic Cancer

    International Nuclear Information System (INIS)

    Seo, Young Seok; Kim, Mi-Sook; Yoo, Sung Yul; Cho, Chul Koo; Yang, Kwang Mo; Yoo, Hyung Jun; Choi, Chul Won; Lee, Dong Han; Kim, Jin; Kim, Min Suk; Kang, Hye Jin; Kim, YoungHan

    2009-01-01

    Purpose: To investigate the clinical application of a stereotactic body radiation therapy (SBRT) boost in locally advanced pancreatic cancer patients with a focus on local efficacy and toxicity. Methods and Materials: We retrospectively reviewed 30 patients with locally advanced and nonmetastatic pancreatic cancer who had been treated between 2004 and 2006. Follow-up duration ranged from 4 to 41 months (median, 14.5 months). A total dose of 40 Gy was delivered in 20 fractions using a conventional three-field technique, and then a single fraction of 14, 15, 16, or 17 Gy SBRT was administered as a boost without a break. Twenty-one patients received chemotherapy. Overall and local progression-free survival were calculated and prognostic factors were evaluated. Results: One-year overall survival and local progression-free survival rates were 60.0% and 70.2%, respectively. One patient (3%) developed Grade 4 toxicity. Carbohydrate antigen 19-9 response was found to be an independent prognostic factor for survival. Conclusions: Our findings indicate that a SBRT boost provides a safe means of increasing radiation dose. Based on the results of this study, we recommend that a well controlled Phase II study be conducted on locally advanced pancreatic cancer.

  11. A Virtual Frame System for Stereotactic Radiosurgery Planning

    International Nuclear Information System (INIS)

    Ford, Eric; Purger, David; Tryggestad, Erik; McNutt, Todd; Christodouleas, John; Rigamonti, Daniele; Shokek, Ori; Won Sang; Zhou, Jessica; Lim, Michael; Wong, John; Kleinberg, Larry

    2008-01-01

    Purpose: We describe a computerized (or virtual) model of a stereotactic head frame to enable planning prior to the day of radiosurgery. The location of the virtual frame acts as a guide to frame placement on the day of the procedure. Methods and Materials: The software consists of a triangular mesh representation of the essential frame hardware that can be overlaid with any MR scan of the patient and manipulated in three dimensions. The software calculates regions of the head that will actually be accessible for treatment, subject to the geometric constraints of the Leksell Gamma Knife hardware. DICOM-compliant MR images with virtual fiducial markers overlaid onto the image can then be generated for recognition by the treatment planning system. Results: Retrospective evaluation of the software on 24 previously treated patients shows a mean deviation of the position of the virtual frame from the actual frame position of 1.6 ± 1.3 mm. Initial clinical use on five patients indicates an average discrepancy of the virtual frame location and the actual frame location of <1 mm. MR images with virtual fiducial markers can be imported into radiosurgical treatment planning software and used to generate an initial treatment plan. Conclusions: The virtual frame provides a tool for prospective determination of lesion accessibility, optimization of the frame placement, and treatment planning before the day of the procedure. This promises to shorten overall treatment times, improve patient comfort, and reduce the need for repeat treatments due to suboptimally placed frames

  12. Stereotactic radiotherapy of targets in the lung and liver

    Energy Technology Data Exchange (ETDEWEB)

    Wulf, J.; Haedinger, U.; Oppitz, U.; Thiele, W.; Ness-Dourdoumas, R.; Flentje, M. [Wuerzburg Univ. (Germany). Dept. of Radiotherapy

    2001-12-01

    Background: Stereotactic irradiation of extracranial targets offers a non-invasive treatment modality for patients with localized tumors, which are not amenable for surgery or other invasive approaches because of age or impaired medical condition. The purpose of the study was the evaluation of the method to achieve local control of irradiated targets in relation to treatment toxicity. Patients and Methods: Irradiation was performed as hypofractionated treatment in three fractions of 10 Gy each, normalized to the PTV enclosing 65% isodose with patient fixation in a stereotactic body frame. The isocenter was localized by stereotactic coordinates. Targets were circumscribed tumors in the lung (n = 27) and liver (n = 24) not amenable for other treatment modalities: primary lung cancer (n = 12), local recurrences of lung cancer (n = 4), lung metastases (n = 11), liver metastases (n = 23) and one cholangiocellular carcinoma. Median CTV/PTV for targets in the lung was 57/113 cm{sup 3} (min/max 5-277 cm{sup 3}/17-343 cm{sup 3}) and for targets in the liver 50/102 cm{sup 3} (min/max 9-516 cm{sup 3}/42-772 cm{sup 3}). Median follow-up for targets in the lung was 8 months (2-33) and 9 months (2-28) for liver targets. Local control was defined as complete or partial remission and stable disease, measured by repeated CT scans after 6 weeks and in 3 months intervals. Treatment toxicity was evaluated according to the WHO score. Results: Crude local control was 85% for pulmonary targets and 83% for hepatic targets. Actuarial local control after 1 and 2 years was 76% and 76% for lung tumors and 76% and 61% for liver tumors. Actuarial overall patient survival was 48% after 1 year and 21% after 2 years for targets in the lung and 71% and 43% for targets in the liver. No acute grade 3-5 side effects were observed. Serious late toxicity occurred in two patients: a chronic ulceration of the esophagus at a target close to the mediastinum after 3 months (grade 3) and fatal bleeding from

  13. Neuropsychological correlates of stereotactic subcaudate tractotomy. A prospective study.

    Science.gov (United States)

    Kartsounis, L D; Poynton, A; Bridges, P K; Bartlett, J R

    1991-12-01

    Stereotactic subcaudate tractotomy is a surgical procedure performed for the alleviation of intractable affective disorders. It involves the destruction of bifrontal pathways located beneath and in front of the head of the caudate nucleus. We report the first prospective study of the neuropsychological correlates of this operation in 23 patients. Tests of general intelligence, speed and attention, as well as a wide range of focal cognitive tests, including tasks which have been reported in the literature to be sensitive to frontal lobe dysfunction, were administered 1 wk before the operation, 2 wks after the operation and approximately 6 mths after the operation. The results indicated that this operation does not cause any significant, long-term adverse, cognitive deficits. In the post-operative assessment, however, patients show a significant deterioration in their performance on recognition memory tests and a large proportion of them present with a marked tendency to confabulate on recall tasks. In addition, their performance on some of the tasks which are considered to be sensitive to frontal lobe dysfunction is found to be significantly impaired. These deficits are interpreted to reflect frontal lobe dysfunction due to widespread post-operative oedema rather than damage to the subcaudate pathways. The potential for research on these transient effects of the operation for the advancement of our understanding of frontal lobe functions is discussed.

  14. A prospective clinical study of stereotactic subcaudate tractotomy.

    Science.gov (United States)

    Poynton, A M; Kartsounis, L D; Bridges, P K

    1995-07-01

    This study describes a cohort of 23 patients undergoing stereotactic subcaudate tractotomy. Research Diagnostic Criteria indicated that 70% suffered major depressive disorder; the remainder mostly had a bipolar affective disorder. There were serial assessments pre-operatively and at 2 weeks and 6 months post-operatively using the Hamilton Rating Scale for depression, the Present State Examination (PSE), Newcastle Scale, the Beck Depression Inventory, and the Taylor Manifest Anxiety Scale. Neuropsychological assessment included tests thought to be sensitive to frontal lobe dysfunction, as well as tests of general intelligence, attention, memory, language and visuo-spatial function. Post-operatively, depression rating scale scores decreased significantly but most patients continued to exhibit a number of PSE syndromes. Depression rating scale scores were correlated with 1 year global outcome: there was no significant correlation except for the 6 month assessment when lower Hamilton scores were found to be associated with better global outcome. Correlations between the neuropsychological tests and the Hamilton and Beck depression scales at 2 weeks post-operatively suggested that an improvement in psychiatric condition was associated with greater efficiency on some tests of attention and verbal recall, as well as faster performance on a sorting task. By contrast, the changes at 6 months suggested an association between improvement in psychiatric condition and less efficient performance on certain neuropsychological tests including verbal recognition memory, attention and two tests of frontal lobe dysfunction.

  15. Stereotactic Ablative Radiotherapy for Oligometastatic Disease in Liver

    Directory of Open Access Journals (Sweden)

    Myungsoo Kim

    2014-01-01

    Full Text Available Liver metastasis in solid tumors, including colorectal cancer, is the most frequent and lethal complication. The development of systemic therapy has led to prolonged survival. However, in selected patients with a finite number of discrete lesions in liver, defined as oligometastatic state, additional local therapies such as surgical resection, radiofrequency ablation, cryotherapy, and radiotherapy can lead to permanent local disease control and improve survival. Among these, an advance in radiation therapy made it possible to deliver high dose radiation to the tumor more accurately, without impairing the liver function. In recent years, the introduction of stereotactic ablative radiotherapy (SABR has offered even more intensive tumor dose escalation in a few fractions with reduced dose to the adjacent normal liver. Many studies have shown that SABR for oligometastases is effective and safe, with local control rates widely ranging from 50% to 100% at one or two years. And actuarial survival at one and two years has been reported ranging from 72% to 94% and from 30% to 62%, respectively, without severe toxicities. In this paper, we described the definition and technical aspects of SABR, clinical outcomes including efficacy and toxicity, and related parameters after SABR in liver oligometastases from colorectal cancer.

  16. Role of stereotactic body radiotherapy for oligometastasis from colorectal cancer.

    Science.gov (United States)

    Takeda, Atsuya; Sanuki, Naoko; Kunieda, Etsuo

    2014-04-21

    Systemic chemotherapy has enabled prolongation of survival in patients with stage IV colorectal cancer. This has subsequently increased the relative significance of local therapy for patients with oligometastases because they can be cured by removal of oligometastatic lesions. One of the most frequently reported tumor histologies for oligometastases is colorectal cancer. Resection is the standard therapy in most settings of oligometastases. Recently, studies have shown that stereotactic body radiotherapy (SBRT) may become a treatment option that provides high local control with minimal morbidity. Two-year local control rates following SBRT for hepatic and pulmonary oligometastases are almost over 80% and are even higher for patients treated with high-dose regimens. The indications of SBRT for other metastatic sites or conditions include isolated lymph nodes, spinal and adrenal metastasis, and post-surgical pelvic recurrence. Many retrospective studies have indicated that SBRT for various lesions results in good outcomes with low morbidity, both in the curative and palliative setting. However, few reports with a high level of evidence have indicated the efficacy of SBRT compared to standard therapy. Hereafter, the optimal indication of SBRT needs to be prospectively investigated to obtain convincing evidence.

  17. Stereotactic radiosurgery in the palliative treatment of brain metastases

    International Nuclear Information System (INIS)

    Faria, Sergio L.; Souhami, Luis; Bahary, Jean-Paul; Clark, Brenda; Adamson, Nelson; Podgorsak, Ervin B.; Caron, Jean-Louis; Villemure, Jean-Guy; Olivier, Andre

    1995-01-01

    Between October, 1988 and November, 1993, 57 patients with metastatic brain disease underwent stereotactic radiosurgery at McGill University, canada. Four patients were excluded from this analysis leaving a total of 53 evaluable patients (with 57 lesions). Radiosurgery was performed with the dynamic rotation technique which uses an isocentric, 10 MV, linear accelerator. A median dose of 1,800 c Gy was given in a single session. In 89% of the cases radiosurgery was used after failure to conventional brain radiotherapy. With a median follow-up of 6 months, the response rate was 65% . Treatments were well tolerated and only 4 patients (7%) developed late complications related to the therapy, with one patient requiring a surgical resection of an area of radionecrose. Radiosurgery appears to be and effective and safe treatment for selected patients with metastatic brain disease, recurrent post-conventional radiotherapy. Its value as a single treatment modality for patients with isolated brain metastasis is now being studied in prospective trials. (author). 29 refs., 4 figs., 4 tabs

  18. A Simple and Inexpensive Stereotactic Guidance Frame for MRI-Guided Brain Biopsy in Canines.

    Science.gov (United States)

    Squires, Alexander D; Gao, Yabiao; Taylor, Sean F; Kent, Marc; Tse, Zion Tsz Ho

    2014-01-01

    A magnetic resonance imaging (MRI) guided stereotactic system was developed to provide veterinarians a method to accomplish minimally invasive stereotactic brain biopsies and procedures involving the cerebrum in canines. While MR-guided procedures are prevalent for humans, they are less common in animal practices. The system was designed to minimize fabrication costs in an effort to make such procedures more accessible in the veterinary field. A frame constrained the head without the need for punctures and supported registration and guidance attachments. Location data for registration and relevant structures were selected by the clinician, and a reverse kinematic analysis program generated the settings of the stereotactic arch to guide a needle to the desired location. Phantom experiments and three cadaver trials showed an average targeting error of <3 mm using the system.

  19. Reirradiation of brain and skull base tumors with fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Tokuuye, Koichi; Akine, Yasuyuki; Sumi, Minako; Kagami, Yoshikazu; Ikeda, Hiroshi; Oyama, Hiroshi; Inou, Yasushi; Shibui, Soichiro; Nomura, Kazuhiro

    1998-01-01

    Purpose: We evaluated the feasibility of fractionated stereotactic radiotherapy for small intracranial recurrences after conventional radiotherapy. Methods and Materials: Nineteen patients who had initially undergone conventional radiotherapy to intracranial lesions, receiving a median total dose of 50 Gy in 5 weeks, were retreated with stereotactic radiotherapy for their recurrences and received a median total dose of 42 Gy in seven fractions over 2.3 weeks. Results: Of the 19 patients, 15 achieved local control 3-51 months after reirradiation. No patient suffered from acute reaction, but one patient with a history of extensive radiotherapy developed progressive radionecrosis 9 months after reirradiation. Conclusions: Fractionated stereotactic radiotherapy of intracranial recurrences appears to be effective in achieving in local control with negligible morbidity. We believe it merits further investigation in a prospective study

  20. Image-guided stereotactic surgery using ultrasonography and reconstructive three-dimensional CT-imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hirotsune; Iseki, Hiroshi; Umezawa, Yoshihiro (Tokyo Women' s Medical Coll. (Japan)) (and others)

    1991-12-01

    A new simulation and navigation system utilizing three-dimensional CT images has been developed for image-guided stereotactic surgery. Preoperative CT images are not always useful in predicting the intraoperative location of lesions, for cerebral lesions are easily displaced or distorted by gravity, brain retraction, and/or CSF aspiration during operative procedure. This new system, however, has the advantage that the intraoperative locations of intracranial lesions or the anatomical structures of the brain can be precisely confirmed during stereotactic surgery. Serial CT images were obtained from a patient whose head had been fixed to the ISEKI CT-guided stereotactic frame. The data of serial CT images were saved on a floppy disc and then transferred to the work station (IRIS) using the off line. In order to find the best approach angle for ultrasound-guided stereotactic surgery, three-dimenstional CT images were reconstructed using the work station. The site of the craniotomy or the angle of the trajectory of the ultrasound probe was measured preoperatively based on the three-dimensional CT images. Then, in the operating room, the patient's head was fixed to the ISEKI frame with the subframe at the same position as before according to the measurement of the CT images. In a case of cystic glioma, the predicable ultrasonograms from three-dimensional reconstructive CT images were ascertained to correspond well to the actual ultrasound images during ultrasound-guided stereotactic surgery. Therefore, the new simulation and navigation system can be judged to be a powerful operative supporting modality for correcting the locations of cerebral lesions; it allows one to perform stereotactic surgery more accurately and less invasively. (author).

  1. Diagnostic Imaging for Implants

    Directory of Open Access Journals (Sweden)

    Sanjay M Mallya

    2004-01-01

    Full Text Available Dental implants are a popular modality for permanent tooth replacement. The key to successful implant placement, its subsequent osseointegration and the final prosthetic rehabilitation is proper preoperative assessment. Diagnostic imaging plays an important role in the pre- and post-surgical evaluation process. Imaging is used to evaluate suitability of implant sites, aid in selection of appropriate implants, and finally evaluate implant placement and osseointegration. This article reviews the role of diagnostic imaging in the various phases and the advantages and limitations of the numerous imaging modalities.

  2. Anti-PD-1 Blockade and Stereotactic Radiation Produce Long-Term Survival in Mice With Intracranial Gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Jing [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); See, Alfred P.; Phallen, Jillian; Jackson, Christopher M.; Belcaid, Zineb; Ruzevick, Jacob [Department of Neurosurgery, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Durham, Nicholas [Department of Immunology, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Meyer, Christian [Department of Oncology, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Harris, Timothy J. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Albesiano, Emilia; Pradilla, Gustavo [Department of Neurosurgery, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Ford, Eric; Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Hammers, Hans-Joerg [Department of Immunology, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Mathios, Dimitris; Tyler, Betty; Brem, Henry [Department of Neurosurgery, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Tran, Phuoc T. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); Pardoll, Drew; Drake, Charles G. [Department of Immunology, Johns Hopkins Medical Institutes, Baltimore, Maryland (United States); and others

    2013-06-01

    Purpose: Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults, and radiation is one of the main treatment modalities. However, cure rates remain low despite best available therapies. Immunotherapy is a promising modality that could work synergistically with radiation, which has been shown to increase antigen presentation and promote a proinflammatory tumor microenvironment. Programmed-death-1 (PD-1) is a surface receptor expressed on activated and exhausted T cells, which mediate T cell inhibition upon binding with its ligand PD-L1, expressed on many tumor types including human GBMs. We tested the combination of anti-PD-1 immunotherapy with stereotactic radiosurgery in a mouse orthotopic GBM model. Methods and Materials: We performed intracranial implantation of mouse glioma cell line GL261 transfected with luciferase into C57BL/6 mice. Mice were stratified into 4 treatment groups: (1) control; (2) radiation only; (3) anti-PD-1 antibody only; and (4) radiation plus anti-PD-1 antibody. Overall survival was quantified. The mice were killed on day 21 after implantation to assess immunologic parameters in the brain/tumor, cervical lymph nodes, and spleen. Results: Improved survival was demonstrated with combination anti-PD-1 therapy plus radiation compared with either modality alone: median survival was 25 days in the control arm, 27 days in the anti-PD-1 antibody arm, 28 days in the radiation arm, and 53 days in the radiation plus anti-PD-1 therapy arm (P<.05 by log-rank Mantle-Cox). Long-term survival was seen only in the combined treatment arm, with a fraction (15%-40%) of animals alive at day 180+ after treatment. Immunologic data on day 21 after implantation showed increased tumor infiltration by cytotoxic T cells (CD8+/interferon-γ+/tumor necrosis factor-α+) and decreased regulatory T cells (CD4+/FOXP3) in the combined treatment group compared with the single modality arms. Conclusions: The combination of PD-1 blockade and localized

  3. Hypertensive thalamic hematoma treated by CT stereotactic evacuation (with two cases reports)

    International Nuclear Information System (INIS)

    Wang Hongsheng; Zhu Fengqing

    2002-01-01

    Objective: To investigate new surgical method to treat hypertensive thalamic hematoma. Methods: Two medial-degree coma patients with hypertensive thalamic hematoma were treated by CT stereotactic evacuation. Results: One week after operation the two patients regained consciousness. The function of paraplegic appendage restored partly, and one patient could take care of himself. Conclusion: CT stereotactic evacuation to treat hypertensive thalamic hematoma has the advantages of small trauma, little complication and good clinical results. The authors suggest that it be selected firstly in treating hypertensive thalamic hematoma

  4. Fractionated stereotactic irradiation by Cyberknife of choroid melanomas: repositioning validation, closed eyelids

    International Nuclear Information System (INIS)

    Horn, S.; Rezvoy, N.; Lacornerie, T.; Mirabel, X.; Labalette, P.; Lartigau, E.

    2009-01-01

    The fractionated stereotactic radiotherapy by Cyberknife is an option in the treatment of eyes tumors. The advantages of the Cyberknife in the choroid melanomas are in its infra-millimetric precision, to the automated repositioning on the skull bones and to the conformity brought by the stereotaxy. The objective of this study was to validate the quality of repositioning and the immobility of the eyes with closed eyelids. Conclusion: the reproducibility of the eye positioning with closed eyelids seems enough to consider the conservative treatment of choroid melanomas by fractionated stereotactic radiotherapy by Cyberknife without implementation of fiducials nor retrobulbar anaesthesia. (N.C.)

  5. Spinal metastases: multimodality imaging in diagnosis and stereotactic body radiation therapy planning.

    Science.gov (United States)

    Jabehdar Maralani, Pejman; Lo, Simon S; Redmond, Kristin; Soliman, Hany; Myrehaug, Sten; Husain, Zain A; Heyn, Chinthaka; Kapadia, Anish; Chan, Aimee; Sahgal, Arjun

    2017-01-01

    Due to increased effectiveness of cancer treatments and increasing survival rates, metastatic disease has become more frequent compared to the past, with the spine being the most common site of bony metastases. Diagnostic imaging is an integral part of screening, diagnosis and follow-up of spinal metastases. In this article, we review the principles of multimodality imaging for tumor detection with respect to their value for diagnosis and stereotactic body radiation therapy planning for spinal metastases. We will also review the current international consensus agreement for stereotactic body radiation therapy planning, and the role of imaging in achieving the best possible treatment plan.

  6. Low-cost phantoms for training of stereotactic vacuum-assisted biopsy of the breast.

    Science.gov (United States)

    Fischmann, Arne; Siegmann, Katja C

    2010-01-01

    To test low-cost phantoms for training in stereotactic breast biopsy, we prepared eggplant with calcium powder; gelatin and turkey breast with coarse salt, peppercorns, and calcium powder, respectively; and short-bread pastry with salt. Three to 12 cores were harvested with an 11-gauge vacuum biopsy unit. Mammography images were taken before and after biopsy and from the biopsy cores. The pastry phantom provided the best simulation of microcalcifications for stereotactic biopsy with realistic cores, long durability, and short preparation time. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Localization techniques in resection of deep seated cavernous angiomas - review and reevaluation of frame based stereotactic approaches.

    Science.gov (United States)

    Slotty, P J; Ewelt, C; Sarikaya-Seiwert, S; Steiger, H-J; Vesper, J; Hänggi, D

    2013-04-01

    Providing high accuracy is crucial in neurosurgery especially for resection of deep seated small cerebral pathologies such as cavernous angiomas. The goal of the present series was to reevaluate the feasibility, accuracy, efficacy and safety of frame-based, stereotactically guided resection for patients suffering from small deep-seated cavernous angiomas. Additionally a review of the literature on navigational tools in cavernoma surgery is provided comparing different navigation strategies. Ten patients with deep-seated, small intracranial, cavernous angiomas being subject to frame-based, stereotactically aided resection are included in this survey. Based on the stereotactic-fused image, set entry and target point aimed at the rim of the cavernoma were calculated. A minicraniotomy (Assets and drawbacks of the stereotactic-aided approach were evaluated, patients were analyzed for surgery-related neurological deficits and completeness of resection. Complete resection was achieved in all ten patients verified by post-surgery MRI imaging. The surgical procedure itself was only slightly aggravated by the stereotactic equipment. No adverse events such as bleedings or infections were observed in our series. Stereotactically guided, minimally invasive resection of deep seated and small cavernous angiomas is accurate and effective. The frame-based stereotactic guidance requires some additional time and effort which seems justified only for deep seated and small cavernous angiomas. Frameless neuronavigation is a common tool in cavernoma surgery and its spatial resolution is sufficient for the majority of cases.

  8. An analysis to compare the effects of stereotactic surgery and conservative medical treatment on hypertensive intracerebral hemorrhage

    Directory of Open Access Journals (Sweden)

    Wei-dong GUO

    2011-08-01

    Full Text Available Objective To analyze the therapeutic effects of stereotactic surgery and conservative medical treatment in patients with hypertensive intracerebral hemorrhage.Methods The clinical data of 100 patients with hypertensive intracerebral hemorrhage who underwent stereotactic surgery(stereotactic surgery group from June 2002 to October 2009 were retrospectively analyzed,and the result was compared with that of 80 contemporaneous patients with hypertensive intracerebral hemorrhage who received conservative medical treatment(medical treatment group.There was no significant difference of bleeding site,bleeding volume and state of consciousness on admission between two groups.Results The mortality rate of stereotactic surgery group was 21.0%,and of medical treatment group was 30.0%.The average hematoma absorption time in stereotactic surgery group was 4.8d,and that of medical treatment group was 15.1d.All of the surviving patients were followed-up for 6 months,the rate of cure and mild disability in stereotactic surgery group(37% was significantly higher than that of medical treatment group(26%,P 0.05.Conclusion Compared with conservative medical treatment,stereotactic surgery could decrease the mortality rate and improve the quality of life in patients with hypertensive intracerebral hemorrhage.

  9. Immediate side effects of stereotactic radiotherapy and radiosurgery

    International Nuclear Information System (INIS)

    Werner-Wasik, Maria; Rudoler, Shari; Preston, Peter E.; Downes, Beverly M.; Andrews, David; Corn, Benjamin W.; Rosenstock, Jeffrey; Curran, Walter J.

    1996-01-01

    Purpose/Objective: Despite increased utilization of fractionated stereotactic radiation therapy (SRT) or stereotactic radiosurgery (SRS), the incidence and nature of immediate side effects (ISE) associated with these treatment techniques is not well defined. Materials and Methods: Intracranial lesions in 78 adult patients were treated with SRT or SRS, using a dedicated linear accelerator. They comprised 13 gliomas, 2 ependymomas, 19 metastatic tumors, 15 meningiomas, 12 acoustic neuromas, 4 pituitary adenomas, 1 optic neuroma, 1 chondrosarcoma and 11 arteriovenous malformations (AVM). SRT was used in 51 and SRS in 27 patients. Mean target volume was 9.0 cc. Eleven patients received prior external beam radiation therapy within 2 months before SRT/SRS. Any side effects occurring during and up to two weeks after radiation course were defined as ISE and were graded as mild, moderate or severe. The incidence of ISE and the significance of their association with several pretreatment variables were analyzed. Results: Overall, (28(78)) (35%) patients experienced one or more ISE. Most of ISE (87%) were mild and consisted of nausea (5), dizziness/vertigo (5), seizures (7) and new persistent headaches (17). Two episodes of worsening neurological deficit and 2 of orbital pain were graded as moderate. Two patients experienced severe ISE, requiring hospitalization (1 seizure and 1 worsening neurological deficit). ISE in 5 cases prompted computerized tomography of the brain which revealed increased perilesional edema in 3 cases. The incidence of ISE by diagnosis was as follows: 46% ((6(13))) for gliomas, 50% ((6(12))) for acoustic neuromas, 36% ((4(11))) for AVM, 33% ((5(15))) for meningiomas and 21% ((4(19))) for metastases. Increasing dose to the margin and increasing maximum dose were associated with a higher incidence of ISE (p=0.02 and 0.005, respectively). Prior recent conventional external beam radiation therapy, target volume, number of isocenters, collimator size, dose

  10. Immediate side effects of stereotactic radiotherapy and radiosurgery

    International Nuclear Information System (INIS)

    Werner-Wasik, Maria; Rudoler, Shari; Preston, Peter E.; Hauck, Walter W.; Downes, Beverly M.; Leeper, Dennis; Andrews, David; Corn, Benjamin W.; Curran, Walter J.

    1999-01-01

    Purpose: Despite increased utilization of fractionated stereotactic radiation therapy (SRT) or stereotactic radiosurgery (SRS), the incidence and nature of immediate side effects (ISE) associated with these treatment techniques are not well defined. We report immediate side effects from a series of 78 patients. Materials and Methods: Intracranial lesions in 78 adult patients were treated with SRT or SRS, using a dedicated linear accelerator. Those lesions included 13 gliomas, 2 ependymomas, 19 metastatic tumors, 15 meningiomas, 12 acoustic neuromas, 4 pituitary adenomas, 1 optic neuroma, 1 chondrosarcoma, and 11 arteriovenous malformations (AVM). SRT was used in 51 and SRS in 27 patients. Mean target volume was 9.0 cc. Eleven patients received prior external-beam radiation therapy within 2 months before SRT/SRS. Any side effects occurring during and up to 2 weeks after the course of radiation were defined as ISE and were graded as mild, moderate, or severe. The incidence of ISE and the significance of their association with several treatment and pretreatment variables were analyzed. Results: Overall, 28 (35%) of 78 patients experienced one or more ISE. Most of the ISE (87%) were mild, and consisted of nausea (in 5), dizziness/vertigo (in 5), seizures (in 6), and new persistent headaches (in 17). Two episodes of worsening neurological deficit and 2 of orbital pain were graded as moderate. Two patients experienced severe ISE, requiring hospitalization (1 seizure and 1 worsening neurological deficit). ISE in 6 cases prompted computerized tomography of the brain, which revealed increased perilesional edema in 3 cases. The incidence of ISE by diagnosis was as follows: 46% (6 of 13) for gliomas, 50% (6 of 12) for acoustic neuromas, 36% (4 of 11) for AVM, 33% (5 of 15) for meningiomas, and 21% (4 of 19) for metastases. A higher incidence of dizziness/vertigo (4 of 12 = 33%) was seen among acoustic neuroma patients than among other patients (p < 0.01). There was no

  11. Hyperfractionated stereotactic reirradiation for recurrent head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cvek, Jakub; Knybel, Lukas; Skacelikova, Eva; Otahal, Bretislav; Molenda, Lukas; Feltl, David [University Hospital Ostrava, Department of Oncology, Ostrava (Czech Republic); Stransky, Jiri; Res, Oldrich [University Hospital Ostrava, Department of Maxilofacial Surgery, Ostrava (Czech Republic); Matousek, Petr; Zelenik, Karol [University Hospital Ostrava, Department of Otolaryngology, Ostrava (Czech Republic)

    2016-01-15

    The goal of this work was to evaluate the efficacy and toxicity of hyperfractionated stereotactic reirradiation (re-RT) as a treatment for inoperable, recurrent, or second primary head and neck squamous cell cancer (HNSCC) that is not suitable for systemic treatment. Forty patients with recurrent or second primary HNSCC were included in this study. The patients had a median gross tumor volume of 76 ml (range 14-193 ml) and a previous radiotherapy dose greater than 60 Gy. Treatment was designed to cover 95 % of the planning target volume (PTV, defined as gross tumor volume [GTV] + 3 mm to account for microscopic spreading, with no additional set-up margin) with the prescribed dose (48 Gy in 16 fractions b.i.d.). Treatment was administered twice daily with a minimum 6 h gap. Uninvolved lymph nodes were not irradiated. Treatment was completed as planned for all patients (with median duration of 11 days, range 9-14 days). Acute toxicity was evaluated using the RTOG/EORTC scale. A 37 % incidence of grade 3 mucositis was observed, with recovery time of ≤ 4 weeks for all of these patients. Acute skin toxicity was never observed to be higher than grade 2. Late toxicity was also evaluated according to the RTOG/EORTC scale. Mandible radionecrosis was seen in 4 cases (10 %); however, neither carotid blowout syndrome nor other grade 4 late toxicity occurred. One-year overall survival (OS) and local progression-free survival (L-PFS) were found to be 33 and 44 %, respectively. Performance status and GTV proved to be significant prognostic factors regarding local control and survival. Hyperfractionated stereotactic re-RT is a reasonable treatment option for patients with recurrent/second primary HNSCC who were previously exposed to high-dose irradiation and who are not candidates for systemic treatment or hypofractionation. (orig.) [German] Ziel der Studie war es, die Effektivitaet und Toxizitaet der hyperfraktionierten akzelerierten stereotaktischen Wiederbestrahlung (re

  12. Linear accelerator based stereotactic radiosurgery for melanoma brain metastases

    Directory of Open Access Journals (Sweden)

    Mark E Bernard

    2012-01-01

    Full Text Available Purpose: Melanoma is one of the most common malignancies to metastasize to the brain. Many patients with this disease will succumb to central nervous system (CNS disease, highlighting the importance of effective local treatment of brain metastases for both palliation and survival of the disease. Our objective was to evaluate the outcomes associated with stereotactic radiosurgery (SRS in the treatment of melanoma brain metastases. Materials and Methods: We retrospectively reviewed 54 patients with a total of 103 tumors treated with SRS. Twenty patients had prior surgical resection and nine patients underwent prior whole brain radiation therapy (WBRT. 71% of patients had active extracranial disease at the time of SRS. Median number of tumors treated with SRS was 1(range: 1-6 with median radiosurgery tumor volume 2.1 cm 3 (range: 0.05-59.7 cm 3 . The median dose delivered to the 80% isodose line was 24 Gy in a single fraction. Results: The median follow-up from SRS was five months (range:1-30 months. Sixty-five percent of patients had a follow-up MRI available for review. Actuarial local control at six months and 12 months was 87 and 68%, respectively. Eighty-one percent of patients developed new distant brain metastases at a median time of two months. The six-month and 12-month actuarial overall survival rates were 50 and 25%, respectively. The only significant predictor of overall survival was surgical resection prior to SRS. Post-SRS bleeding occurred in 18% of patients and at a median interval of 1.5 months. There was only one episode of radiation necrosis with no other treatment-related toxicity. Conclusion: SRS for brain metastases from melanoma is safe and achieves acceptable local control.

  13. Stereotactic body radiotherapy for primary prostate cancer: a systematic review

    International Nuclear Information System (INIS)

    Tan, Tze-Jian; Foroudi, Farsgad; Gill, Suki; Siva, Shankar

    2014-01-01

    Stereotactic body radiotherapy (SBRT) for prostate cancer allows overall treatment times to be reduced to as little as 1 week while maintaining a non-invasive approach. This study provides a comprehensive summary of the literature relating to SBRT in prostate cancer. A systematic review of the relevant literature was performed using structured search terms. Fourteen phase I–II trials and retrospective studies using SBRT for the treatment of prostate cancer were used. Three studies were identified which addressed cost. Dose fractionation, radiotherapy procedures, biochemical progression-free survival, toxicity, cost and quality of life were critically appraised. A total of 1472 patients were examined across studies. Median follow-up ranged from 11 to 60 months. The most common dose fractionation was 35–36.25Gy in five fractions, used in nine out of 14 studies. Ten of 14 studies used CyberKnife. The overall biochemical progression-free survival ranged 81–100%. Acute grade 2 urinary and rectal toxicities were reported in 5–42% and 0–27% of patients, respectively. Acute grade 3 or more urinary and rectal toxicity were 0.5% and 0%, respectively. Late grade 2 urinary toxicity was reported in 0–29% of patients, while 1.3% had a late grade 3 urinary toxicity. There were no late grade 4 urinary toxicities seen. Late grade 2 rectal toxicity was reported in 0–11%, while 0.5% had a late grade 3 rectal toxicity. Late grade 4 rectal toxicity was reported in 0.2% of patients.

  14. Fractionated Stereotactic Radiotherapy in Patients With Optic Nerve Sheath Meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Paulsen, Frank, E-mail: frank.paulsen@med.uni-tuebingen.de [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Doerr, Stefan [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Wilhelm, Helmut [Department of Ophthalmology, University of Tuebingen, Tuebingen (Germany); Becker, Gerd [Department of Radiation Oncology, Klinik am Eichert, Goeppingen (Germany); Bamberg, Michael [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Classen, Johannes [Department of Radiation Oncology, St. Vincentius-Kliniken, Karlsruhe (Germany)

    2012-02-01

    Purpose: To evaluate the effectiveness of fractionated stereotactic radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1993 and 2005, 109 patients (113 eyes) with primary (n = 37) or secondary (n = 76) ONSM were treated according to a prospective protocol with SFRT to a median dose of 54 Gy. All patients underwent radiographic, ophthalmologic, and endocrine analysis before and after SFRT. Radiographic response, visual control, and late side effects were endpoints of the analysis. Results: Median time to last clinical, radiographic, and ophthalmologic follow up was 30.2 months (n = 113), 42.7 months (n = 108), and 53.7 months (n = 91), respectively. Regression of the tumor was observed in 5 eyes and progression in 4 eyes, whereas 104 remained stable. Visual acuity improved in 12, deteriorated in 11, and remained stable in 68 eyes. Mean visual field defects reduced from 33.6% (n = 90) to 17.8% (n = 56) in ipsilateral and from 10% (n = 94) to 6.7% (n = 62) in contralateral eyes. Ocular motility improved in 23, remained stable in 65, and deteriorated in 3 eyes. Radiographic tumor control was 100% at 3 years and 98% at 5 years. Visual acuity was preserved in 94.8% after 3 years and in 90.9% after 5 years. Endocrine function was normal in 90.8% after 3 years and in 81.3% after 5 years. Conclusions: SFRT represents a highly effective treatment for ONSM. Interdisciplinary counseling of the patients is recommended. Because of the high rate of preservation of visual acuity we consider SFRT the standard approach for the treatment of ONSM. Prolonged observation is warranted to more accurately assess late visual impairment. Moderate de-escalation of the radiation dose might improve the preservation of visual acuity and pituitary gland function.

  15. Radiographer-performed stereotactic needle core biopsy: Making a difference

    International Nuclear Information System (INIS)

    Dixon, Anne-Marie; Dearnley, Christine

    2008-01-01

    This case study describes a qualitative investigation of the experiences of 14 experienced mammography radiographers who successfully undertook a formal programme of education and training in stereotactic needle core biopsy (SNCB) of the breast. They now routinely perform SNCB within symptomatic and screening breast services in a variety of NHS hospitals across the country. All 14 radiographers completed a semi-structured postal questionnaire approximately six months after the end of the course. A tentative theory derived from the data suggests that the professional challenge associated with radiographer-performed SNCB builds personal confidence and effects positive change. Three main categories emerging from the data - challenge, confidence and change are underpinned by two main themes - educational, professional and service drivers that promote the realisation of goals and vision; and personal, peer and external motivation sustained by respect, recognition and reward. SNCB role extension as explored in this study is having a positive and transformational impact on patient users of breast diagnostic clinical services and on the professional health carers providing them. The key drivers for this as identified in the study are a formal educational experience, professional role extension opportunities and the NHS modernisation process. The participants experienced positive change as individuals and as professional breast cancer multidisciplinary team members. Academic and financial rewards, respect and recognition from colleagues across professional disciplines and from patients, were key motivators that sustained the process. This study indicates that radiographer-performed SNCB can help deliver the NHS Plan and the NHS Cancer Plan and in doing so has the potential to improve the working lives of health care professionals and ultimately to improve the quality of care for patients

  16. Technical and anatomical aspects of novalis stereotactic radiosurgery sphenopalatine ganglionectomy

    International Nuclear Information System (INIS)

    De Salles, Antonio A.F.; Gorgulho, Alessandra; Golish, S. Raymond Ph.D.; Medin, Paul M.; Malkasian, Dennis; Solberg, Timothy D.; Selch, Michael T.

    2006-01-01

    Background: Several techniques have been applied for destruction of the sphenopalatine ganglion to control cluster headache and ocular pain with sympathetic component. Cluster headache has responded to radiofrequency ablation or phenol destruction. Radiosurgery of the sphenopalatine ganglion is promising due to the excellent visualization of the target on magnetic resonance imaging (MRI), computed tomography (CT), and skull X-rays. Material and Methods: Six patients and one cadaver head were analyzed in this study. The cadaver-head dissection confirmed the location of the sphenopalatine ganglion on X-rays and CT imaging. One patient undergoing radiofrequency sphenopalatine ablation participated for confirmation of the location of the ganglion on plain X-rays. Five patients received radiosurgery of the sphenopalatine ganglion. One patient had classic unilateral cluster headache. Two patients had neuropathic pain and 1 had bilateral migrainous neuralgia. The fifth patient had bilateral atypical facial pain. All received a single maximal dose of 90 Gy with a 5- or 7.5-mm circular collimator. MRI, CT, and skull X-rays identified and confirmed the target. Results: The sphenopalatine fossa is seen in the skull X-ray as an inverse tear drop just caudal to the sphenoid sinus. This location is readily correlated to the CT target by the stereotactic coordinates and confirmed with the presence of the ganglion visualized in the MRI scan. Only the patient with cluster headache experienced lasting pain relief. Conclusion: Multiple imaging modalities confirmed the location of the sphenopalatine ganglion for radiosurgery. The procedure was performed safely with CT and MRI fusion. Radiosurgery was significantly beneficial only on classic cluster headache

  17. Evaluation on usefulness of stereotactic radio surgery using Fraxion system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Won; Park, Kwang Woo; Ha, Jin Sook; Jeon, Mi Jin; Cho, Yoon Jin; Kim, Sei Joon; Kim, Jong Dae; Shin, Dong Bong [Dept. of Radiation Oncology, Gangnam Severance Hospital, Seoul (Korea, Republic of)

    2014-12-15

    We evaluated the usefulness of Fraxion system and s-thermoplastic mask by analyzing setup error when stereotactic radiousurgery (SRS) was treated for brain metastasis. 6 patients who received definite diagnosis as brain metastasis between May 2014 and October 2014 were selected. 3 patients were immobilized s-thermoplastic mask and mouthpiece (group1), while Fraxion system was used for the other 3 patients (group 2). Cone Beam Computerized Tomography (CBCT) scan was acquired to register planning CT scan. The registration offset was compared for each group. We compared and reported the errors using maximum, minimum, mean, and standard deviation of registration offsets. Furthermore, We used the same method as patient specific quality assurance to verify absorbed dose of PTV. The setup error which is registration offset was reduced 83% in x, 40% in y, and 92% in z-direction when Fraxion system was used compared to the case of using s-thermoplastic mask and mouthpiece. In addition, using Fraxion system showed improved results in rotational components, pitch (rotation along x-axis), roll (y), and yaw (z) which were reduced 64, 88, and 87% respectively compared to the case of using s-thermoplastic mask and mouthpiece. In dosimetry results, when sthermoplastic mask and mouthpiece used, absorbed dose was reduce 83% compared to before and after registration. However, using Fraxion system showed only 1.9%. All percentage were calculated with respect to average value. Using Fraxion system including mouthpiece, Fraxion frame, front piece, and thermoplastic mask, showed better repeatability and precision compared to using s-thermoplastic mask and mouthpiece, which is consequently considered as more improved immobilization system.

  18. Proton Stereotactic Radiosurgery for the Treatment of Benign Meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Halasz, Lia M., E-mail: lhalasz@partners.org [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States); Bussiere, Marc R.; Dennis, Elizabeth R.; Niemierko, Andrzej [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Chapman, Paul H. [Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States); Loeffler, Jay S.; Shih, Helen A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States)

    2011-12-01

    Purpose: Given the excellent prognosis for patients with benign meningiomas, treatment strategies to minimize late effects are important. One strategy is proton radiation therapy (RT), which allows less integral dose to normal tissue and greater homogeneity than photon RT. Here, we report the first series of proton stereotactic radiosurgery (SRS) used for the treatment of meningiomas. Methods and Materials: We identified 50 patients with 51 histologically proven or image- defined, presumed-benign meningiomas treated at our institution between 1996 and 2007. Tumors of <4 cm in diameter and located {>=}2 mm from the optic apparatus were eligible for treatment. Indications included primary treatment (n = 32), residual tumor following surgery (n = 8), and recurrent tumor following surgery (n = 10). The median dose delivered was 13 Gray radiobiologic equivalent (Gy[RBE]) (range, 10.0-15.5 Gy[RBE]) prescribed to the 90% isodose line. Results: Median follow-up was 32 months (range, 6-133 months). Magnetic resonance imaging at the most recent follow-up or time of progression revealed 33 meningiomas with stable sizes, 13 meningiomas with decreased size, and 5 meningiomas with increased size. The 3-year actuarial tumor control rate was 94% (95% confidence interval, 77%-98%). Symptoms were improved in 47% (16/ 34) of patients, unchanged in 44% (15/34) of patients, and worse in 9% (3/34) of patients. The rate of potential permanent adverse effects after SRS was 5.9% (3/51 patients). Conclusions: Proton SRS is an effective therapy for small benign meningiomas, with a potentially lower rate of long-term treatment-related morbidity. Longer follow-up is needed to assess durability of tumor control and late effects.

  19. Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders

    Science.gov (United States)

    Nuttin, Bart; Wu, Hemmings; Mayberg, Helen; Hariz, Marwan; Gabriëls, Loes; Galert, Thorsten; Merkel, Reinhard; Kubu, Cynthia; Vilela-Filho, Osvaldo; Matthews, Keith; Taira, Takaomi; Lozano, Andres M; Schechtmann, Gastón; Doshi, Paresh; Broggi, Giovanni; Régis, Jean; Alkhani, Ahmed; Sun, Bomin; Eljamel, Sam; Schulder, Michael; Kaplitt, Michael; Eskandar, Emad; Rezai, Ali; Krauss, Joachim K; Hilven, Paulien; Schuurman, Rick; Ruiz, Pedro; Chang, Jin Woo; Cosyns, Paul; Lipsman, Nir; Voges, Juergen; Cosgrove, Rees; Li, Yongjie; Schlaepfer, Thomas

    2014-01-01

    Background For patients with psychiatric illnesses remaining refractory to ‘standard’ therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups. Methods To expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments. Findings The proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered ‘established’ in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patient's capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-up evaluation, and reporting of effects and side effects for all patients. Interpretation This consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety. PMID:24444853

  20. Stereotactic Radiofrequency Ablation for Metastatic Melanoma to the Liver

    Energy Technology Data Exchange (ETDEWEB)

    Bale, Reto, E-mail: reto.bale@i-med.ac.at; Schullian, Peter [Medical University Innsbruck, Department of Radiology, Section of Interventional Oncology - Microinvasive Therapy (SIP) (Austria); Schmuth, Matthias [Medical University Innsbruck, Department of Dermatology (Austria); Widmann, Gerlig; Jaschke, Werner [Medical University Innsbruck, Department of Radiology, Section of Interventional Oncology - Microinvasive Therapy (SIP) (Austria); Weinlich, Georg [Medical University Innsbruck, Department of Dermatology (Austria)

    2016-08-15

    PurposeTo evaluate the outcome of patients with melanoma liver metastasis treated with stereotactic radiofrequency ablation (SRFA).Material and MethodFollowing IRB approval, a retrospective evaluation of the treatment of 20 patients with 75 melanoma liver metastases was performed.ResultsA median number of 2 lesions (range 1–14) per patient with a median size of 1.7 cm (range 0.5–14.5 cm) were treated. 67 lesions were <3 cm (89.3 %) and 8 lesions were >3 cm (10.7 %). Per patient a median of 1 ablation session was performed (range: 1–4) totaling 34 sessions. There were no procedure-related deaths and all major complications (n = 3) could be easily treated by pleural drainages. The primary and secondary success rates were 89.3 and 93.3 %, respectively. The overall local recurrence rate was 13.3 %. Four of ten local recurrences were re-treated successfully by SRFA. During follow-up, 9/20 patients developed extrahepatic metastatic disease and 10/20 had liver recurrence at any location. The median OS from the date of SRFA was 19.3 months, with an OS of 64, 41, and 17 % at 1, 3, and 5 years, with no significant difference for patients with cutaneous and ocular melanoma. The median DFS after SRFA for all 20 patients was 9.5 months, with 37, 9, and 0 % at 1, 3, and 5 years.ConclusionsDue to the high local curative potential and the promising long-term survival rates associated with minimal morbidity and mortality, radiofrequency ablation seems to be an attractive alternative to resection in patients with melanoma liver metastases.

  1. Stereotactic Body Radiotherapy and Gemcitabine for Locally Advanced Pancreatic Cancer

    International Nuclear Information System (INIS)

    Mahadevan, Anand; Jain, Sanjay; Goldstein, Michael; Miksad, Rebecca; Pleskow, Douglas; Sawhney, Mandeep; Brennan, Darren M.D.; Callery, Mark; Vollmer, Charles

    2010-01-01

    Purpose: Patients with nonmetastatic locally advanced unresectable pancreatic cancer have a dismal prognosis. Conventional concurrent chemoradiotherapy requires 6 weeks of daily treatment and can be arduous. We explored the safety and effectiveness of a 3-day course of hypofractionated stereotactic body radiotherapy (SBRT) followed by gemcitabine in this population. Patients and Methods: A total of 36 patients with nonmetastatic, locally advanced, unresectable pancreatic cancer with ≥12 months of follow-up were included. They received three fractions of 8, 10, or 12 Gy (total dose, 24-36 Gy) of SBRT according to the tumor location in relation to the stomach and duodenum, using fiducial-based respiratory motion tracking on a robotic radiosurgery system. The patients were then offered gemcitabine for 6 months or until tolerance or disease progression. Results: With an overall median follow-up of 24 months (range, 12-33), the local control rate was 78%, the median overall survival time was 14.3 months, the median carbohydrate antigen 19-9-determined progression-free survival time was 7.9 months, and the median computed tomography-determined progression-free survival time was 9.6 months. Of the 36 patients, 28 (78%) eventually developed distant metastases. Six patients (17%) were free of progression at the last follow-up visit (range, 13-30 months) as determined by normalized tumor markers with stable computed tomography findings. Nine Grade 2 (25%) and five Grade 3 (14%) toxicities attributable to SBRT occurred. Conclusion: Hypofractionated SBRT can be delivered quickly and effectively in patients with nonmetastatic, locally advanced, unresectable pancreatic cancer with acceptable side effects and minimal interference with gemcitabine chemotherapy.

  2. Bilateral Stereotactic Thalamotomy for Bilateral Musician's Hand Dystonia.

    Science.gov (United States)

    Horisawa, Shiro; Goto, Shinichi; Nakajima, Takeshi; Kawamata, Takakazu; Taira, Takaomi

    2016-08-01

    Focal hand dystonia in musicians, also known as musician's dystonia, is a task-specific movement disorder characterized by unwanted involuntary muscle contractions occurring only when playing a musical instrument. Case 1 was a 50-year-old female professional pianist who underwent staged bilateral ventro-oral (Vo) thalamotomy, with an interval between the first and second surgery of 4 years. The first surgery (right Vo thalamotomy) led to significant improvements in dystonic symptoms without any complications. Pre- and postoperative Tubiana's musician's dystonia scale (TMDS) scores were 2 and 5, respectively. The second surgery (left Vo thalamotomy) also led to significant improvements in dystonic symptoms, with dysarthria and verbal recall disturbance resolving within 3 months. Pre- and postoperative TMDS scores were 2 and 5, respectively. The patient was subsequently able to return to live-stage performances. Case 2 was a 48-year-old male clarinet repair technician who underwent staged bilateral Vo thalamotomy, with an interval between the first and second surgery of 13 months. The first surgery (right Vo thalamotomy) led to dramatic improvements in symptoms without any complications. Pre- and postoperative TMDS scores were 2 and 5, respectively. The second surgery (left Vo thalamotomy) also led to significant improvements in symptoms with transient hypophonia. Pre- and postoperative TMDS scores were 2 and 5, respectively. The patient was subsequently able to return to work without difficulty. The findings in these 2 cases indicate the utility of bilateral stereotactic Vo thalamotomy in the treatment of medically intractable musician's dystonia affecting both hands. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. [Possibility of 3D Printing in Ophthalmology - First Experiences by Stereotactic Radiosurgery Planning Scheme of Intraocular Tumor].

    Science.gov (United States)

    Furdová, A; Furdová, Ad; Thurzo, A; Šramka, M; Chorvát, M; Králik, G

    Nowadays 3D printing allows us to create physical objects on the basis of digital data. Thanks to its rapid development the use enormously increased in medicine too. Its creations facilitate surgical planning processes, education and research in context of organ transplantation, individualization prostheses, breast forms, and others.Our article describes the wide range of applied 3D printing technology possibilities in ophthalmology. It is focusing on innovative implementation of eye tumors treatment planning in stereotactic radiosurgery irradiation.We analyze our first experience with 3D printing model of the eye in intraocular tumor planning stereotactic radiosurgery. 3D printing, model, Fused Deposition Modelling, stereotactic radiosurgery, prostheses, intraocular tumor.

  4. Five-Year Neuropsychological Outcome after Stereotactic Radiofrequency Amygdalohippocampectomy for Mesial Temporal Lobe Epilepsy: Longitudinal Study

    Czech Academy of Sciences Publication Activity Database

    Krámská, L.; Vojtěch, Z.; Lukavský, Jiří; Stará, M.; Malíková, H.

    Roč. 95, č. 3 ( 2017 ), s. 149-157 ISSN 1011-6125 Institutional support: RVO:68081740 Keywords : Cognitive outcome * Memory * Temporal lobe epilepsy * Stereotactic surgery Subject RIV: FH - Neurology OBOR OECD: Psychology (including human - machine relations) Impact factor: 1.692, year: 2016

  5. Remission spectrometry for blood vessel detection during stereotactic biopsy of brain tumors.

    Science.gov (United States)

    Markwardt, Niklas A; Stepp, Herbert; Franz, Gerhard; Sroka, Ronald; Goetz, Marcus; Zelenkov, Petr; Rühm, Adrian

    2017-08-01

    Stereotactic biopsy is used to enable diagnostic confirmation of brain tumors and treatment planning. Despite being a well-established technique, it is related to significant morbidity and mortality rates mostly caused by hemorrhages due to blood vessel ruptures. This paper presents a method of vessel detection during stereotactic biopsy that can be easily implemented by integrating two side-view fibers into a conventional side-cutting biopsy needle. Tissue within the needle window is illuminated through the first fiber; the second fiber detects the remitted light. By taking the ratio of the intensities at two wavelengths with strongly differing hemoglobin absorption, blood vessels can be recognized immediately before biopsy sampling. Via ray tracing simulations and phantom experiments, the dependency of the remission ratio R = I 578 /I 650 on various parameters (blood oxygenation, fiber-to-vessel and inter-fiber distance, vessel diameter and orientation) was investigated for a bare-fiber probe. Up to 800-1200 µm away from the probe, a vessel can be recognized by a considerable reduction of the remission ratio from the background level. The technique was also successfully tested with a real biopsy needle probe on both optical phantoms and ex-vivo porcine brain tissue, thus showing potential to improve the safety of stereotactic biopsy. Dual-wavelength remission measurement for the detection of blood vessels during stereotactic biopsy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Stereotactic radiotherapy for wet age-related macular degeneration: current perspectives

    Directory of Open Access Journals (Sweden)

    Neffendorf JE

    2015-09-01

    Full Text Available James E Neffendorf, Timothy L Jackson Department of Ophthalmology, School of Medicine, King’s College London, London, United Kingdom Abstract: Neovascular age-related macular degeneration is a leading cause of blindness in the developed world. Currently, the treatment of choice is intravitreal injections of anti-VEGF medications. These require frequent dosing, up to monthly, and impose a substantial burden on patients and the health economy. Ionizing radiation was proposed as a possible treatment for age-related macular degeneration due to its anti-inflammatory and anti-fibrotic properties. Stereotactic radiotherapy is an outpatient-based radiotherapy platform that provides stereotactic application of low energy X-ray to the retina in three highly collimated beams that cross the inferior sclera to overlap at the macula. A randomized, double-masked, sham-controlled trial of 230 patients (INTREPID showed that a single dose of stereotactic radiotherapy significantly reduces the number of intravitreal anti-VEGF injections needed over 2 years. A larger randomized controlled trial (STAR is underway. Keywords: wet age-related macular degeneration, radiation therapy, stereotactic radiotherapy, vascular endothelial growth factor

  7. Enhanced intrinsic radiosensitivity after treatment with stereotactic radiosurgery for an acoustic neuroma

    International Nuclear Information System (INIS)

    Adams, Gerard; Martin, Olga A.; Roos, Daniel E.; Lobachevsky, Pavel N.; Potter, Andrew E.; Zacest, Andrew C.; Bezak, Eva; Bonner, William M.; Martin, Roger F.; Leong, Trevor

    2012-01-01

    Enhanced radiosensitivity is an uncommon phenomenon attributable to deficient DNA repair after radiotherapy which can be assessed with the γ-H2AX assay. Reports of radiosensitivity after stereotactic radiosurgery (SRS) are uncommon. We describe a case where the clinical, radiological and laboratory findings suggest enhanced radiosensitivity after SRS for an acoustic neuroma.

  8. Quality of life after stereotactic body radiation therapy for primary and metastatic liver tumors

    NARCIS (Netherlands)

    Romero, Alejandra Mendez; Wunderink, Wouter; van Os, Rob M.; Nowak, Peter J. C. M.; Helimen, Ben J. M.; Nuyttens, Joost J.; Brandwijk, Rene P.; Verhoef, Cornelis; Ijzermans, Jan N. M.; Levendag, Peter C.

    2008-01-01

    Purpose: Stereotactic body radiation therapy (SBRT) provides a high local control rate for primary and metastatic liver tumors. The aim of this study is to assess the impact of this treatment on the patient's quality of life. This is the first report of quality of life associated with liver SBRT.

  9. Optimizing dose prescription in stereotactic body radiotherapy for lung tumours using Monte Carlo dose calculation

    NARCIS (Netherlands)

    Widder, Joachim; Hollander, Miranda; Ubbels, Jan F.; Bolt, Rene A.; Langendijk, Johannes A.

    Purpose: To define a method of dose prescription employing Monte Carlo (MC) dose calculation in stereotactic body radiotherapy (SBRT) for lung tumours aiming at a dose as low as possible outside of the PTV. Methods and materials: Six typical T1 lung tumours - three small, three large - were

  10. A new lesion for the psychosurgical operation of stereotactic subcaudate tractotomy (SST)

    Science.gov (United States)

    Malhi, G S; Bartlett, J R

    1998-08-01

    The psychosurgical treatment of psychiatric illnesses, using stereotactic subcaudate tractotomy (SST), has been carried out at the Geoffrey Knight Unit since 1961. Recently, the procedure has had to be modified. This paper describes the manner in which this has been achieved and the clinical implications of this change.

  11. Clinical treatment planning for stereotactic radiotherapy, evaluation by Monte Carlo simulation

    International Nuclear Information System (INIS)

    Kairn, T.; Aland, T.; Kenny, J.; Knight, R.T.; Crowe, S.B.; Langton, C.M.; Franich, R.D.; Johnston, P.N.

    2010-01-01

    Full text: This study uses re-evaluates the doses delivered by a series of clinical stereotactic radiotherapy treatments, to test the accuracy of treatment planning predictions for very small radiation fields. Stereotactic radiotherapy treatment plans for meningiomas near the petrous temporal bone and the foramen magnum (incorp rating fields smaller than I c m2) were examined using Monte Carlo simulations. Important differences between treatment planning predictions and Monte Carlo calculations of doses delivered to stereotactic radiotherapy patients are apparent. For example, in one case the Monte Carlo calculation shows that the delivery a planned meningioma treatment would spare the patient's critical structures (eyes, brainstem) more effectively than the treatment plan predicted, and therefore suggests that this patient could safely receive an increased dose to their tumour. Monte Carlo simulations can be used to test the dose predictions made by a conventional treatment planning system, for dosimetrically challenging small fields, and can thereby suggest valuable modifications to clinical treatment plans. This research was funded by the Wesley Research Institute, Australia. The authors wish to thank Andrew Fielding and David Schlect for valuable discussions of aspects of this work. The authors are also grateful to Muhammad Kakakhel, for assisting with the design and calibration of our linear accelerator model, and to the stereotactic radiation therapy team at Premion, who designed the treatment plans. Computational resources and services used in this work were provided by the HPC and Research Support Unit, QUT, Brisbane, Australia. (author)

  12. Five-Year Neuropsychological Outcome after Stereotactic Radiofrequency Amygdalohippocampectomy for Mesial Temporal Lobe Epilepsy: Longitudinal Study

    Czech Academy of Sciences Publication Activity Database

    Krámská, L.; Vojtěch, Z.; Lukavský, Jiří; Stará, M.; Malíková, H.

    2017-01-01

    Roč. 95, č. 3 (2017), s. 149-157 ISSN 1011-6125 Institutional support: RVO:68081740 Keywords : Cognitive outcome * Memory * Temporal lobe epilepsy * Stereotactic surgery Subject RIV: FH - Neurology OBOR OECD: Psychology (including human - machine relations) Impact factor: 1.692, year: 2016

  13. Stereotactic radiotherapy of benign meningioma in the elderly: Clinical outcome and toxicity in 121 patients

    International Nuclear Information System (INIS)

    Fokas, Emmanouil; Henzel, Martin; Surber, Gunar; Hamm, Klaus; Engenhart-Cabillic, Rita

    2014-01-01

    Background and purpose: To investigate the outcome of definitive stereotactic-based radiotherapy in elderly patients (⩾70 years of age) with benign intracranial meningiomas. Materials and methods: 121 patients were treated with either fractionated stereotactic radiotherapy (FRTS; n = 74), hypofractionated FSRT (hFSRT; n = 35) or stereotactic radiosurgery (SRS; n = 12), depending on tumor size and location. Local control (LC), overall survival (OS), cause-specific survival (CSS), symptomatology and acute and late toxicity were assessed. The prognostic value of factors such as age, sex, tumor location, Karnofsky performance scale, target volume and radiotherapy schedule was examined. Results: The median follow-up was 40 months (range, 12–124 months). LC, OS and CSS at 3 years were 98.3%, 92% and 99% and at 5 years they accounted 94.7%, 79% and 94.3%, respectively. We failed to identify any significant prognostic factor for outcome. Only Grade I–II toxicity was observed, whereas no new neurologic deficits or treatment-related mortality were encountered. Conclusion: This is the first study to assess the outcome following radiotherapy in elderly patients with intracranial meningiomas. The high local control, the low toxicity and the lack of treatment-associated mortality make stereotactic radiotherapy an attractive option in an age population where neurosurgery is often correlated with some mortality

  14. Stereotactic Body Radiaton Therapy for 15 Patients with Small Lung Neoplasms

    Directory of Open Access Journals (Sweden)

    Rong YU

    2011-03-01

    Full Text Available Background and objective It has been known that stereotactic radiotherapy has been widely used in clinical practice. The aim of this study is to evaluate the feasibility to treat small lung neoplasms with hypofraction stereotactic radiotherapy. Methods From September 2005 to November 2009, 15 patients with non-small cell lung cancer and solitary metastatic lung cancer were treated with hypofration stereotactic radiotherapy. Dose volume histogram was used to evaluated treatment plans. Lesion diameter 1.5 cm-4.0 cm. Toxicity was evaluated with the NCI-CTCAE 3.0 version. A dose 48 Gy-50 Gy was given in 4-10 fractions. Results The short-term results showed that the complete response (CR rate, the partial response (PR rate, the overall response (CR+PR rate, the one-year local control rate, the one-year survival rate was 60%, 20%, 80%, 100% and 86.67% respectively. Two patients had radiation pneumonitis of 0 grade. Acute radiation pneumonitis of grade I occurred in 9 patients, 4 patients had radiation pneumonitis of grade II and no patient developed serious (grade III radiation pneumonitis. Conclusion The hypofraction stereotactic radiotherapy is safe for small lung neoplasms.

  15. Effects of stereotactic neurosurgery on postural instability and gait in Parkinson's disease

    NARCIS (Netherlands)

    Bakker, Maaike; Esselink, Rianne A. J.; Munneke, Marten; Limousin-Dowsey, Patricia; Speelman, Hans D.; Bloem, Bastiaan R.

    2004-01-01

    Postural instability and gait disability (PIGD) are disabling signs of Parkinson's disease. Stereotactic surgery aimed at the internal globus pallidus (GPi) or subthalamic nucleus (STN) might improve PIGD, but the precise effects remain unclear. We performed a systematic review of studies that

  16. 10 CFR 35.655 - Five-year inspection for teletherapy and gamma stereotactic radiosurgery units.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Five-year inspection for teletherapy and gamma stereotactic radiosurgery units. 35.655 Section 35.655 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF... and serviced during source replacement or at intervals not to exceed 5 years, whichever comes first...

  17. A step towards stereotactic navigation during pelvic surgery: 3D nerve topography

    NARCIS (Netherlands)

    A.R. Wijsmuller; Giraudeau, C. (C.); Leroy, J. (J.); G.J. Kleinrensink (Gert Jan); E. Rociu (Elena); Romagnolo, L.G. (L. G.); Melani, A.G.F. (A. G.F.); Agnus, V. (V.); Diana, M. (M.); Soler, L. (L.); Dallemagne, B. (B.); Marescaux, J. (J.); Mutter, D. (D.)

    2018-01-01

    textabstractBackground: Long-term morbidity after multimodal treatment for rectal cancer is suggested to be mainly made up by nerve-injury-related dysfunctions. Stereotactic navigation for rectal surgery was shown to be feasible and will be facilitated by highlighting structures at risk of

  18. Dose delivery verification and accuracy assessment of stereotaxy in stereotactic radiotherapy and radiosurgery

    International Nuclear Information System (INIS)

    Pelagade, S.M.; Bopche, T.T.; Namitha, K.; Munshi, M.; Bhola, S.; Sharma, H.; Patel, B.K.; Vyas, R.K.

    2008-01-01

    The outcome of stereotactic radiotherapy (SRT) and stereotactic radiosurgery (SRS) in both benign and malignant tumors within the cranial region highly depends on precision in dosimetry, dose delivery and the accuracy assessment of stereotaxy associated with the unit. The frames BRW (Brown-Roberts-Wells) and GTC (Gill- Thomas-Cosman) can facilitate accurate patient positioning as well as precise targeting of tumours. The implementation of this technique may result in a significant benefit as compared to conventional therapy. As the target localization accuracy is improved, the demand for treatment planning accuracy of a TPS is also increased. The accuracy of stereotactic X Knife treatment planning system has two components to verify: (i) the dose delivery verification and the accuracy assessment of stereotaxy; (ii) to ensure that the Cartesian coordinate system associated is well established within the TPS for accurate determination of a target position. Both dose delivery verification and target positional accuracy affect dose delivery accuracy to a defined target. Hence there is a need to verify these two components in quality assurance protocol. The main intention of this paper is to present our dose delivery verification procedure using cylindrical wax phantom and accuracy assessment (target position) of stereotaxy using Geometric Phantom on Elekta's Precise linear accelerator for stereotactic installation

  19. Evaluation of initial setup accuracy and intrafraction motion for spine stereotactic body radiation therapy using stereotactic body frames.

    Science.gov (United States)

    Han, Zhaohui; Bondeson, John C; Lewis, John H; Mannarino, Edward G; Friesen, Scott A; Wagar, Matthew M; Balboni, Tracy A; Alexander, Brian M; Arvold, Nils D; Sher, David J; Hacker, Fred L

    2016-01-01

    The purposes of this study were (1) to evaluate the initial setup accuracy and intrafraction motion for spine stereotactic body radiation therapy (SBRT) using stereotactic body frames (SBFs) and (2) to validate an in-house-developed SBF using a commercial SBF as a benchmark. Thirty-two spine SBRT patients (34 sites, 118 fractions) were immobilized with the Elekta and in-house (BHS) SBFs. All patients were set up with the Brainlab ExacTrac system, which includes infrared and stereoscopic kilovoltage x-ray-based positioning. Patients were initially positioned in the frame with the use of skin tattoos and then shifted to the treatment isocenter based on infrared markers affixed to the frame with known geometry relative to the isocenter. ExacTrac kV imaging was acquired, and automatic 6D (6 degrees of freedom) bony fusion was performed. The resulting translations and rotations gave the initial setup accuracy. These translations and rotations were corrected for by use of a robotic couch, and verification imaging was acquired that yielded residual setup error. The imaging/fusion process was repeated multiple times during treatment to provide intrafraction motion data. The BHS SBF had greater initial setup errors (mean±SD): -3.9±5.5mm (0.2±0.9°), -1.6±6.0mm (0.5±1.4°), and 0.0±5.3mm (0.8±1.0°), respectively, in the vertical (VRT), longitudinal (LNG), and lateral (LAT) directions. The corresponding values were 0.6±2.7mm (0.2±0.6°), 0.9±5.3mm (-0.2±0.9°), and -0.9±3.0mm (0.3±0.9°) for the Elekta SBF. The residual setup errors were essentially the same for both frames and were -0.1±0.4mm (0.1±0.5°), -0.2±0.4mm (0.0±0.4°), and 0.0±0.4mm (0.0±0.4°), respectively, in VRT, LNG, and LAT. The intrafraction shifts in VRT, LNG, and LAT were 0.0±0.4mm (0.0±0.3°), 0.0±0.5mm (0.0±0.4°), and 0.0±0.4mm (0.0±0.3°), with no significant difference observed between the 2 frames. These results showed that the combination of the ExacTrac system with either

  20. Salvage whole brain radiotherapy or stereotactic radiosurgery after initial stereotactic radiosurgery for 1-4 brain metastases.

    Science.gov (United States)

    Liu, Yufei; Alexander, Brian M; Chen, Yu-Hui; Horvath, Margaret C; Aizer, Ayal A; Claus, Elizabeth B; Dunn, Ian F; Golby, Alexandra J; Johnson, Mark D; Friesen, Scott; Mannarino, Edward G; Wagar, Matthew; Hacker, Fred L; Arvold, Nils D

    2015-09-01

    Patients with limited brain metastases are often candidates for stereotactic radiosurgery (SRS) or whole brain radiotherapy (WBRT). Among patients who receive SRS, the likelihood and timing of salvage WBRT or SRS remains unclear. We examined rates of salvage WBRT or SRS among 180 patients with 1-4 newly diagnosed brain metastases who received index SRS from 2008-2013. Competing risks multivariable analysis was used to examine factors associated with time to WBRT. Patients had non-small cell lung (53 %), melanoma (23 %), breast (10 %), renal (6 %), or other (8 %) cancers. Median age was 62 years. Patients received index SRS to 1 (60 %), 2 (21 %), 3 (13 %), or 4 (7 %) brain metastases. Median survival after SRS was 9.7 months (range, 0.3-67.6 months). No further brain-directed radiotherapy was delivered after index SRS in 55 % of patients. Twenty-seven percent of patients ever received salvage WBRT, and 30 % ever received salvage SRS; 12 % of patients received both salvage WBRT and salvage SRS. Median time to salvage WBRT or salvage SRS were 5.6 and 6.1 months, respectively. Age ≤60 years (adjusted hazard ratio [AHR] = 2.80; 95 % CI 1.05-7.51; P = 0.04) and controlled/absent extracranial disease (AHR = 6.76; 95 % CI 1.60-28.7; P = 0.01) were associated with shorter time to salvage WBRT. Isolated brain progression caused death in only 11 % of decedents. In summary, most patients with 1-4 brain metastases receiving SRS never require salvage WBRT or SRS, and the remainder do not require salvage treatment for a median of 6 months.

  1. INTER- AND INTRAFRACTION MOTION FOR STEREOTACTIC RADIOSURGERY IN DOGS AND CATS USING A MODIFIED BRAINLAB FRAMELESS STEREOTACTIC MASK SYSTEM.

    Science.gov (United States)

    Dieterich, Sonja; Zwingenberger, Allison; Hansen, Katherine; Pfeiffer, Isabella; Théon, Alain; Kent, Michael S

    2015-01-01

    Precise and accurate patient positioning is necessary when doing stereotactic radiosurgery (SRS) to ensure adequate dosing to the tumor and sparing of normal tissues. This prospective cross-sectional study aimed to assess feasibility of a commercially available modified frameless SRS positioning system for use in veterinary radiotherapy patients with brain tumors. Fifty-one dogs and 12 cats were enrolled. Baseline and verification CT images were acquired. The verification CT images from 32 dogs and five cats had sufficient images for fusion to baseline CT images. A rigid box-based fusion was performed to determine interfraction motion. Forty-eight dogs and 11 cats were assessed for intrafraction motion by cine CT. Seventy percent of dogs and 60% of cats had interfraction 3D vector translational shifts >1 mm, with mean values of 1.9 mm in dogs, and 1.8 mm in cats. In dogs muscle wasting was weakly correlated with translational shifts. The maximum angular interfraction motion observed was 6.3° (roll), 3.5° (pitch), and 3.3° (yaw). There was no correlation between angular interfraction motion and weight, brachycephaly, or muscle wasting. Fifty-seven percent of dogs and 50% of cats had respiration-related intrafraction motion. Of these, 4.5% of dogs and 10% of cats had intrafraction motion >1 mm. This study demonstrates the modified Brainlab system is feasible for SRS in dogs and cats. The smaller cranial size and difference in anatomy increases setup uncertainty in some animals beyond limits usually accepted in SRS. Image-guided positioning is recommended to achieve clinically acceptable setup accuracy (<1 mm) for SRS. © 2015 American College of Veterinary Radiology.

  2. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...... of improving the fixation of implants. Of these, hydroxyapatite (HA) is the most widely used and most extensively investigated. HA is highly osseoconductive, and the positive effect is well documented in both basic and long-term clinical research [1–6]. This chapter describes experimental and clinical studies...... evaluating bone-implant fixation with HA coatings....

  3. Ion implantation technology

    CERN Document Server

    Downey, DF; Jones, KS; Ryding, G

    1993-01-01

    Ion implantation technology has made a major contribution to the dramatic advances in integrated circuit technology since the early 1970's. The ever-present need for accurate models in ion implanted species will become absolutely vital in the future due to shrinking feature sizes. Successful wide application of ion implantation, as well as exploitation of newly identified opportunities, will require the development of comprehensive implant models. The 141 papers (including 24 invited papers) in this volume address the most recent developments in this field. New structures and possible approach

  4. Single-Fraction Spine Stereotactic Body Radiation Therapy for the Treatment of Chordoma.

    Science.gov (United States)

    Jung, Edward W; Jung, David L; Balagamwala, Ehsan H; Angelov, Lilyana; Suh, John H; Djemil, Toufik; Magnelli, Anthony; Chao, Samuel T

    2017-06-01

    Chordoma is a radioresistant tumor that presents a therapeutic challenge with spine involvement, as high doses of radiation are needed for local control while limiting dose to the spinal cord. The purpose of this study is to determine the efficacy and safety of single-fraction spine stereotactic body radiation therapy for the treatment of spine chordoma. A retrospective review of our institutional database from 2006 to 2013 identified 8 patients (12 cases) with chordoma of the spine who were treated with spine stereotactic body radiation therapy. Surgical resection was performed in 7 of the 12 cases. The treatment volume was defined by the bony vertebral level of the tumor along with soft tissue extension appreciated on magnetic resonance imaging fusion. Medical records and imaging were assessed for pain relief and local control. Treatment toxicity was evaluated using Common Terminology Criteria for Adverse Events version 4.0. Median age was 59 years (range, 17-91). Median target volume was 48 cm 3 (1-304), and median prescription dose was 16 Gy (11-16). Median conformality index was 1.44 (1.14-3.21), and homogeneity index was 1.12 (1.05-1.19). With a median follow-up time of 9.7 months (.5-84), local control was achieved in 75% of the cases treated. One patient developed limited grade 2 spinal cord myelopathy that resolved with steroids. There were no other treatment toxicities from spine stereotactic body radiation therapy. Single-fraction spine stereotactic body radiation therapy can be safely delivered to treat chordoma of the spine with the potential to improve pain symptoms. Although the early data are suggestive, long-term follow-up with more patients is necessary to determine the efficacy of spine stereotactic body radiation therapy in the treatment of chordoma of the spine.

  5. Early experiences of planning stereotactic radiosurgery using 3D printed models of eyes with uveal melanomas

    Directory of Open Access Journals (Sweden)

    Furdová A

    2017-01-01

    Full Text Available Alena Furdová,1 Miron Sramka,2 Andrej Thurzo,3 Adriana Furdová3 1Department of Ophthalmology, Faculty of Medicine, Comenius University, 2Department of Stereotactic Radiosurgery, St Elisabeth Cancer Inst and St Elisabeth University College of Health and Social Work, 3Department of Simulation and Virtual Medical Education, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic Objective: The objective of this study was to determine the use of 3D printed model of an eye with intraocular tumor for linear accelerator-based stereotactic radiosurgery.Methods: The software for segmentation (3D Slicer created virtual 3D model of eye globe with tumorous mass based on tissue density from computed tomography and magnetic resonance imaging data. A virtual model was then processed in the slicing software (Simplify3D® and printed on 3D printer using fused deposition modeling technology. The material that was used for printing was polylactic acid.Results: In 2015, stereotactic planning scheme was optimized with the help of 3D printed model of the patient’s eye with intraocular tumor. In the period 2001–2015, a group of 150 patients with uveal melanoma (139 choroidal melanoma and 11 ciliary body melanoma were treated. The median tumor volume was 0.5 cm3 (0.2–1.6 cm3. The radiation dose was 35.0 Gy by 99% of dose volume histogram.Conclusion: The 3D printed model of eye with tumor was helpful in planning the process to achieve the optimal scheme for irradiation which requires high accuracy of defining the targeted tumor mass and critical structures. Keywords: 3D printing, uveal melanoma, stereotactic radiosurgery, linear accelerator, intraocular tumor, stereotactic planning scheme

  6. Antimicrobial coatings for implant surfaces

    OpenAIRE

    Brunetto, Priscilla S.; Fromm, Katharina M.

    2008-01-01

    Body-foreign materials are used more and more frequently in our lives: joint implants (hips, knees, fingers, etc.), catheters, pacemakers, dental and aesthetic implants, etc. The increasing numbers of patients requiring such implants also raises the absolute numbers of implant-related infections. Thus, it is known that body-foreign materials are prone to bacterial adhesion and subsequent biofilm formation, either via bacterial debris on implant materials, infections during implantation or, la...

  7. Stereotactic body radiotherapy for organ-confined prostate cancer

    Directory of Open Access Journals (Sweden)

    Diblasio Ferdinand

    2010-02-01

    Full Text Available Abstract Background Improved understanding of prostate cancer radiobiology combined with advances in delivery of radiation to the moving prostate offer the potential to reduce treatment-related morbidity and maintain quality of life (QOL following prostate cancer treatment. We present preliminary results following stereotactic body radiotherapy (SBRT treatment for organ-confined prostate cancer. Methods SBRT was performed on 304 patients with clinically localized prostate cancer: 50 received 5 fractions of 7 Gy (total dose 35 Gy and 254 received 5 fractions of 7.25 Gy (total dose 36.25 Gy. Acute and late toxicity was assessed using the Radiation Therapy Oncology Group scale. The Expanded Prostate Cancer Index Composite questionnaire was used to assess QOL. Prostate-specific antigen response was monitored. Results At a median 30-month (26 - 37 month, range follow-up there were no biochemical failures for the 35-Gy dose level. Acute Grade II urinary and rectal toxicities occurred in 4% of patients with no higher Grade acute toxicities. One Grade II late urinary toxicity occurred with no other Grade II or higher late toxicities. At a median 17-month (8 - 27 month, range follow-up the 36.25 Gy dose level had 2 low- and 2 high-risk patients fail biochemically (biopsy showed 2 low- and 1 high-risk patients were disease-free in the gland. Acute Grade II urinary and rectal toxicities occurred in 4.7% (12/253 and 3.6% (9/253 of patients, respectively. For those patients with a minimum of 12 months follow-up, 5.8% (12/206 had late Grade II urinary toxicity and 2.9% (6/206 had late Grade II rectal toxicities. One late Grade III urinary toxicity occurred; no Grade IV toxicities occurred. For both dose levels at 17 months, bowel and urinary QOL returned to baseline values; sexual QOL decreased by 10%. Conclusions The low toxicity and maintained QOL are highly encouraging. Additional follow-up is needed to determine long-term biochemical control and

  8. Adaptive Stereotactic Body Radiation Therapy Planning for Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yujiao [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Zhang, Fan [Occupational and Environmental Safety Office, Duke University Medical Center, Durham, North Carolina (United States); Yoo, David S.; Kelsey, Chris R. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Cai, Jing, E-mail: jing.cai@duke.edu [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2013-09-01

    Purpose: To investigate the dosimetric effects of adaptive planning on lung stereotactic body radiation therapy (SBRT). Methods and Materials: Forty of 66 consecutive lung SBRT patients were selected for a retrospective adaptive planning study. CBCT images acquired at each fraction were used for treatment planning. Adaptive plans were created using the same planning parameters as the original CT-based plan, with the goal to achieve comparable comformality index (CI). For each patient, 2 cumulative plans, nonadaptive plan (P{sub NON}) and adaptive plan (P{sub ADP}), were generated and compared for the following organs-at-risks (OARs): cord, esophagus, chest wall, and the lungs. Dosimetric comparison was performed between P{sub NON} and P{sub ADP} for all 40 patients. Correlations were evaluated between changes in dosimetric metrics induced by adaptive planning and potential impacting factors, including tumor-to-OAR distances (d{sub T-OAR}), initial internal target volume (ITV{sub 1}), ITV change (ΔITV), and effective ITV diameter change (Δd{sub ITV}). Results: 34 (85%) patients showed ITV decrease and 6 (15%) patients showed ITV increase throughout the course of lung SBRT. Percentage ITV change ranged from −59.6% to 13.0%, with a mean (±SD) of −21.0% (±21.4%). On average of all patients, P{sub ADP} resulted in significantly (P=0 to .045) lower values for all dosimetric metrics. Δd{sub ITV}/d{sub T-OAR} was found to correlate with changes in dose to 5 cc (ΔD5cc) of esophagus (r=0.61) and dose to 30 cc (ΔD30cc) of chest wall (r=0.81). Stronger correlations between Δd{sub ITV}/d{sub T-OAR} and ΔD30cc of chest wall were discovered for peripheral (r=0.81) and central (r=0.84) tumors, respectively. Conclusions: Dosimetric effects of adaptive lung SBRT planning depend upon target volume changes and tumor-to-OAR distances. Adaptive lung SBRT can potentially reduce dose to adjacent OARs if patients present large tumor volume shrinkage during the treatment.

  9. CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

    International Nuclear Information System (INIS)

    Wood, Bradford J.; Frenkel, V.; Viswanathan, A.; Dromi, S.; Oh, K.; Kam, A.; Li, K. C. P.; Yanof, J.; Bauer, C.; Kruecker, J.; Seip, R.

    2006-01-01

    To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large

  10. Design of a modulated orthovoltage stereotactic radiosurgery system.

    Science.gov (United States)

    Fagerstrom, Jessica M; Bender, Edward T; Lawless, Michael J; Culberson, Wesley S

    2017-07-01

    To achieve stereotactic radiosurgery (SRS) dose distributions with sharp gradients using orthovoltage energy fluence modulation with inverse planning optimization techniques. A pencil beam model was used to calculate dose distributions from an orthovoltage unit at 250 kVp. Kernels for the model were derived using Monte Carlo methods. A Genetic Algorithm search heuristic was used to optimize the spatial distribution of added tungsten filtration to achieve dose distributions with sharp dose gradients. Optimizations were performed for depths of 2.5, 5.0, and 7.5 cm, with cone sizes of 5, 6, 8, and 10 mm. In addition to the beam profiles, 4π isocentric irradiation geometries were modeled to examine dose at 0.07 mm depth, a representative skin depth, for the low energy beams. Profiles from 4π irradiations of a constant target volume, assuming maximally conformal coverage, were compared. Finally, dose deposition in bone compared to tissue in this energy range was examined. Based on the results of the optimization, circularly symmetric tungsten filters were designed to modulate the orthovoltage beam across the apertures of SRS cone collimators. For each depth and cone size combination examined, the beam flatness and 80-20% and 90-10% penumbrae were calculated for both standard, open cone-collimated beams as well as for optimized, filtered beams. For all configurations tested, the modulated beam profiles had decreased penumbra widths and flatness statistics at depth. Profiles for the optimized, filtered orthovoltage beams also offered decreases in these metrics compared to measured linear accelerator cone-based SRS profiles. The dose at 0.07 mm depth in the 4π isocentric irradiation geometries was higher for the modulated beams compared to unmodulated beams; however, the modulated dose at 0.07 mm depth remained central, maximum dose. The 4π profiles irradiating a constant target volume showed improved statistics for the modulated, filtered distribution compared

  11. Dysuria Following Stereotactic Body Radiation Therapy for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Einsley-Marie eJanowski

    2015-07-01

    Full Text Available Background: Dysuria following prostate radiation therapy is a common toxicity that adversely affects patients’ quality of life and may be difficult to manage. Methods: 204 patients treated with stereotactic body radiation therapy (SBRT from 2007 to 2010 for localized prostate carcinoma with a minimum follow up of three years were included in this retrospective review of prospectively collected data. All patients were treated to 35-36.25Gy in 5 fractions delivered with robotic SBRT with real time fiducial tracking. Dysuria and other lower urinary tract symptoms were assessed via Question 4b (Pain or burning on urination of the Expanded Prostate Index Composite (EPIC-26 and the American Urological Association (AUA Symptom Score at baseline and at routine follow up. Results: 204 patients (82 low-, 105 intermediate-, and 17 high risk according to the D’Amico classification at a median age of 69 years (range 48-91 received SBRT for their localized prostate cancer with a median follow up of 47 months. Bother associated with dysuria significantly increased from a baseline of 12% to a maximum of 43% at one month (p<0.0001. There were two distinct peaks of moderate to severe dysuria bother at 1 month and at 6-12 months, with 9% of patients experiencing a late transient dysuria flare. While a low level of dysuria was seen through the first two years of follow-up, it returned to below baseline by two years (p=0.91. The median baseline AUA score of 7.5 significantly increased to 11 at 1 month (p<0.0001 and returned to 7 at 3 months (p= 0.54. Patients with dysuria had a statistically higher AUA score at baseline and at all follow-ups up to 30 months. Dysuria significantly correlated with dose and AUA score on multivariate analysis. Frequency and strain significantly correlated with dysuria on stepwise multivariate analysis.Conclusions: The rate and severity of dysuria following SBRT is comparable to patients treated with other radiation modalities.

  12. Knowledge Modeling for the Outcome of Brain Stereotactic Radiosurgery

    Science.gov (United States)

    Hauck, Jillian E.

    Purpose: To build a model that will predict the survival time for patients that were treated with stereotactic radiosurgery for brain metastases using support vector machine (SVM) regression. Methods and Materials: This study utilized data from 481 patients, which were equally divided into training and validation datasets randomly. The SVM model used a Gaussian RBF function, along with various parameters, such as the size of the epsilon insensitive region and the cost parameter (C) that are used to control the amount of error tolerated by the model. The predictor variables for the SVM model consisted of the actual survival time of the patient, the number of brain metastases, the graded prognostic assessment (GPA) and Karnofsky Performance Scale (KPS) scores, prescription dose, and the largest planning target volume (PTV). The response of the model is the survival time of the patient. The resulting survival time predictions were analyzed against the actual survival times by single parameter classification and two-parameter classification. The predicted mean survival times within each classification were compared with the actual values to obtain the confidence interval associated with the model's predictions. In addition to visualizing the data on plots using the means and error bars, the correlation coefficients between the actual and predicted means of the survival times were calculated during each step of the classification. Results: The number of metastases and KPS scores, were consistently shown to be the strongest predictors in the single parameter classification, and were subsequently used as first classifiers in the two-parameter classification. When the survival times were analyzed with the number of metastases as the first classifier, the best correlation was obtained for patients with 3 metastases, while patients with 4 or 5 metastases had significantly worse results. When the KPS score was used as the first classifier, patients with a KPS score of 60 and

  13. Stereotactic Radiation Therapy for Liver Tumours. Technological evaluation report

    International Nuclear Information System (INIS)

    Zeghari-Squalli, Nadia

    2016-09-01

    The purpose of this report was to analyse the efficacy and safety data of Stereotactic Body Radiation Therapy (SBRT) in patients with inoperable primary (hepatocellular carcinoma (HCC) and metastatic liver tumors (LM), to define the indications and the place of SBRT in the therapeutic strategy with the aim of its inclusion in the CCAM (French National list of reimbursement). The key points that arose from this assessment are the following: - The results are preliminary and the literature is inconclusive about safety and efficacy; - There are no standardised guidelines for: the indications, the eligibility criteria, the treatment protocols or the place of SBRT in the therapeutic strategy; - SBRT is a technique that requires great rigorous radioprotection and quality assurance procedures; the professionals and National institutions concerned recommend that SBRT only be performed in centres with sufficient resources, specific expertise and an organisation which guarantees that the quality assurance procedures will be respected. Recommendations HAS believes it is premature to recommend SBRT for the routine treatment of liver tumors and its reimbursement by the National Health Insurance (Assurance Maladie). HAS recommends its use in the strict context of clinical research by centres with sufficient resources, specific expertise and an organisation which guarantees that the quality assurance procedures will be respected. The literature search strategy prioritized randomised comparative studies and systematic reviews; If these were not available then non-randomised controlled trials, prospective studies were to be used and finally retrospective studies and case series were to be used. The assessment of SRBT for liver tumors was based on the critical analysis of clinical data from: - Three prospective case series, five retrospective case series, four health technology evaluation reports and 11 good practice recommendations, for primary liver tumors (HCC) - One prospective

  14. CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

    Science.gov (United States)

    Wood, Bradford J.; Yanof, J.; Frenkel, V.; Viswanathan, A.; Dromi, S.; Oh, K.; Kruecker, J.; Bauer, C.; Seip, R.; Kam, A.; Li, K. C. P.

    2006-05-01

    To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large

  15. Pulmonary Function Testing After Stereotactic Body Radiotherapy to the Lung

    Energy Technology Data Exchange (ETDEWEB)

    Bishawi, Muath [Division of Cardiothoracic Surgery, Stony Brook University Medical Center, Stony Brook, NY (United States); Kim, Bong [Division of Radiology, Stony Brook University Medical Center, Stony Brook, NY (United States); Moore, William H. [Division of Radiation Oncology, Stony Brook University, Stony Brook, NY (United States); Bilfinger, Thomas V., E-mail: Thomas.bilfinger@stonybrook.edu [Division of Cardiothoracic Surgery, Stony Brook University Medical Center, Stony Brook, NY (United States)

    2012-01-01

    Purpose: Surgical resection remains the standard of care for operable early-stage non-small-cell lung cancer (NSCLC). However, some patients are not fit for surgery because of comorbidites such as chronic obstructive pulmonary disease (COPD) and other medical conditions. We aimed to evaluate pulmonary function and tumor volume before and after stereotactic body radiotherapy (SBRT) for patients with and without COPD in early-stage lung cancer. Methods and Materials: A review of prospectively collected data of Stage I and II lung cancers, all treated with SBRT, was performed. The total SBRT treatment was 60 Gy administered in three 20 Gy fractions. The patients were analyzed based on their COPD status, using their pretreatment pulmonary function test cutoffs as established by the American Thoracic Society guidelines (forced expiratory volume [FEV]% {<=}50% predicted, FEV%/forced vital capacity [FVC]% {<=}70%). Changes in tumor volume were also assessed by computed tomography. Results: Of a total of 30 patients with Stage I and II lung cancer, there were 7 patients in the COPD group (4 men, 3 women), and 23 in t he No-COPD group (9 men, 14 women). At a mean follow-up time of 4 months, for the COPD and No-COPD patients, pretreatment and posttreatment FEV% was similar: 39 {+-} 5 vs. 40 {+-} 9 (p = 0.4) and 77 {+-} 0.5 vs. 73 {+-} 24 (p = 0.9), respectively. The diffusing capacity of the lungs for carbon monoxide (DL{sub CO}) did significantly increase for the No-COPD group after SBRT treatment: 60 {+-} 24 vs. 69 {+-} 22 (p = 0.022); however, DL{sub CO} was unchanged for the COPD group: 49 {+-} 13 vs. 50 {+-} 14 (p = 0.8). Although pretreatment tumor volume was comparable for both groups, tumor volume significantly shrank in the No-COPD group from 19 {+-} 24 to 9 {+-} 16 (p < 0.001), and there was a trend in the COPD patients from 12 {+-} 9 to 6 {+-} 5 (p = 0.06). Conclusion: SBRT did not seem to have an effect on FEV{sub 1} and FVC, but it shrank tumor volume and

  16. Stereotactic Robotic Body Radiotherapy for Patients With Unresectable Hepatic Oligorecurrence.

    Science.gov (United States)

    Berkovic, Patrick; Gulyban, Akos; Nguyen, Paul Viet; Dechambre, David; Martinive, Philippe; Jansen, Nicolas; Lakosi, Ferenc; Janvary, Levente; Coucke, Philippe A

    2017-12-01

    The purpose of this study was to analyze local control (LC), liver progression-free survival (PFS), and distant PFS (DFS), overall survival (OS), and toxicity in a cohort of patients treated with stereotactic body radiotherapy (SBRT) with fiducial tracking for oligorecurrent liver lesions; and to evaluate the potential influence of lesion size, systemic treatment, physical and biologically effective dose (BED), treatment calculation algorithms and other parameters on the obtained results. Unoperable patients with sufficient liver function had [18F]-fluorodeoxyglucose-positron emission tomography-computed tomography and liver magnetic resonance imaging to confirm the oligorecurrent nature of the disease and to further delineate the gross tumor volume (GTV). An intended dose of 45 Gy in 3 fractions was prescribed on the 80% isodose and adapted if risk-related. Treatment was executed with the CyberKnife system (Accuray Inc) platform using fiducials tracking. Initial plans were recalculated using the Monte Carlo algorithm. Patient and treatment data were processed using the Kaplan-Meier method and log rank test for survival analysis. Between 2010 and 2015, 42 patients (55 lesions) were irradiated. The mean GTV and planning target volume (PTV) were 30.5 cc and 96.8 cc, respectively. Treatments were delivered 3 times per week in a median of 3 fractions to a PTV median dose of 54.6 Gy. The mean GTV and PTV D98% were 51.6 Gy and 51.2 Gy, respectively. Heterogeneity corrections did not influence dose parameters. After a median follow-up of 18.9 months, the 1- and 2-year LC/liver PFS/DFS/OS were 81.3%/55%/62.4%/86.9%, and 76.3%/42.3%/52%/78.3%, respectively. Performance status and histology had a significant effect on LC, whereas age (older than 65 years) marginally influenced liver PFS. Clinical target volume physical dose V45 Gy > 95%, generalized equivalent uniform dose (a = -30) > 45 Gy and a BED (α/β = 10) V105 Gy > 96% showed statistically significant effect on

  17. Is stereotactic large-core needle biopsy beneficial prior to surgical treatment in BI-RADS 5 lesions?

    NARCIS (Netherlands)

    Hoorntje, LE; Peeters, PHM; Mali, WPTM; Rinkes, IHMB

    Introduction. Due to screening mammography, more nonpalpable mammographic lesions warrant histological evaluation. Stereotactic large-core needle biopsy (SLCNB) has been shown to be as effective in diagnosing these lesions as diagnostic surgical excision, and has become the preferred diagnostic

  18. Time-Resolved Intrafraction Target Translations and Rotations During Stereotactic Liver Radiation Therapy: Implications for Marker-based Localization Accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Bertholet, Jenny, E-mail: jennbe@rm.dk [Department of Oncology, Aarhus University Hospital, Aarhus C (Denmark); Worm, Esben S. [Department of Medical Physics, Aarhus University Hospital, Aarhus C (Denmark); Fledelius, Walther; Høyer, Morten; Poulsen, Per R. [Department of Oncology, Aarhus University Hospital, Aarhus C (Denmark)

    2016-06-01

    Purpose: Image guided liver stereotactic body radiation therapy (SBRT) often relies on implanted fiducial markers. The target localization accuracy decreases with increased marker-target distance. This may occur partly because of liver rotations. The aim of this study was to examine time-resolved translations and rotations of liver marker constellations and investigate if time-resolved intrafraction rotational corrections can improve localization accuracy in liver SBRT. Methods and Materials: Twenty-nine patients with 3 implanted markers received SBRT in 3 to 6 fractions. The time-resolved trajectory of each marker was estimated from the projections of 1 to 3 daily cone beam computed tomography scans and used to calculate the translation and rotation of the marker constellation. In all cone beam computed tomography projections, the time-resolved position of each marker was predicted from the position of another surrogate marker by assuming that the marker underwent either (1) the same translation as the surrogate marker; or (2) the same translation as the surrogate marker corrected by the rotation of the marker constellation. The localization accuracy was quantified as the root-mean-square error (RMSE) between the estimated and the actual marker position. For comparison, the RMSE was also calculated when the marker's position was estimated as its mean position for all the projections. Results: The mean translational and rotational range (2nd-98th percentile) was 2.0 mm/3.9° (right-left), 9.2 mm/2.9° (superior-inferior), 4.0 mm/4.0° (anterior-posterior), and 10.5 mm (3-dimensional). Rotational corrections decreased the mean 3-dimensional RMSE from 0.86 mm to 0.54 mm (P<.001) and halved the RMSE increase per millimeter increase in marker distance. Conclusions: Intrafraction rotations during liver SBRT reduce the accuracy of marker-guided target localization. Rotational correction can improve the localization accuracy with a factor of approximately 2

  19. Percutaneous and skeletal biocarbon implants

    Science.gov (United States)

    Mooney, V.

    1977-01-01

    Review of carbon implants developed by NASA discussed four different types of implants and subsequent improvements. Improvements could be of specific interest to rehabilitation centers and similar organizations.

  20. Peri-Implant Diseases

    Science.gov (United States)

    ... Dentists about How Often They Floss Their Teeth Oral Hygiene Habits and Hypertension Risk Alcohol Consumption and Gum ... peri-implant disease include previous periodontal disease diagnosis, poor ... tooth. With a proper oral health routine, your dental implant can last a ...

  1. Biocompatible implant surface treatments

    Directory of Open Access Journals (Sweden)

    Bikash Pattanaik

    2012-01-01

    Limitation of this study is that we tried to give a broader overview related to implant surface treatments. It does not give any conclusion regarding the best biocompatible implant surface treatment investigated till date. Unfortunately, the eventually selected studies were too heterogeneous for inference of data.

  2. Ion implantation into diamond

    International Nuclear Information System (INIS)

    Sato, Susumu

    1994-01-01

    The graphitization and the change to amorphous state of diamond surface layer by ion implantation and its characteristics are reported. In the diamond surface, into which more than 10 16 ions/cm 2 was implanted, the diamond crystals are broken, and the structure changes to other carbon structure such as amorphous state or graphite. Accompanying this change of structure, the electric conductivity of the implanted layer shows two discontinuous values due to high resistance and low resistance. This control of structure can be done by the temperature of the base during the ion implantation into diamond. Also it is referred to that by the base temperature during implantation, the mutual change of the structure between amorphous state and graphite can be controlled. The change of the electric resistance and the optical characteristics by the ion implantation into diamond surface, the structural analysis by Raman spectroscopy, and the control of the structure of the implanted layer by the base temperature during implantation are reported. (K.I.)

  3. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...

  4. Dynamic ion implantation

    International Nuclear Information System (INIS)

    Oppenheim, I.F.C.

    1988-01-01

    The Dynamic Ion Implantation Technique consists of ion implantation of a film during the film-deposition process. This technique was investigated theoretically and experimentally with ions whose incident energy is of the order of a few times 100 keV. It was found to be a viable alternative low-temperature method for the preparation of thick zirconium nitride films (∼1 μm) with good mechanical properties. Theoretical modeling of the processes involved during dynamic ion implantation lead to analytical expressions for the ions' depth-profile distributions. Numerical evaluations of these equations indicated that the depth distributions of dynamically implanted ions are in general more uniform than those predicted by the model for ions implanted by more conventional techniques. Mechanical properties of stoichiometric RF sputter-deposited zirconium nitride films post implanted with krypton and rubidium ions were investigated. Scratch-adhesion critical load and Vickers microhardness of samples implanted with doses varying from 1 x 10 15 to 5 x 10 16 ions/cm 2 and energies ranging from 300 to 500 keV were studied. In general, best mechanical properties were observed for 300- keV krypton implantations

  5. CT perfusion imaging as an early biomarker of differential response to stereotactic radiosurgery in C6 rat gliomas.

    Directory of Open Access Journals (Sweden)

    Timothy Pok Chi Yeung

    Full Text Available The therapeutic efficacy of stereotactic radiosurgery for glioblastoma is not well understood, and there needs to be an effective biomarker to identify patients who might benefit from this treatment. This study investigated the efficacy of computed tomography (CT perfusion imaging as an early imaging biomarker of response to stereotactic radiosurgery in a malignant rat glioma model.Rats with orthotopic C6 glioma tumors received either mock irradiation (controls, N = 8 or stereotactic radiosurgery (N = 25, 12 Gy in one fraction delivered by Helical Tomotherapy. Twelve irradiated animals were sacrificed four days after stereotactic radiosurgery to assess acute CT perfusion and histological changes, and 13 irradiated animals were used to study survival. Irradiated animals with survival >15 days were designated as responders while those with survival ≤15 days were non-responders. Longitudinal CT perfusion imaging was performed at baseline and regularly for eight weeks post-baseline.Early signs of radiation-induced injury were observed on histology. There was an overall survival benefit following stereotactic radiosurgery when compared to the controls (log-rank P<0.04. Responders to stereotactic radiosurgery showed lower relative blood volume (rBV, and permeability-surface area (PS product on day 7 post-stereotactic radiosurgery when compared to controls and non-responders (P<0.05. rBV and PS on day 7 showed correlations with overall survival (P<0.05, and were predictive of survival with 92% accuracy.Response to stereotactic radiosurgery was heterogeneous, and early selection of responders and non-responders was possible using CT perfusion imaging. Validation of CT perfusion indices for response assessment is necessary before clinical implementation.

  6. Spatial Distortion in MRI-Guided Stereotactic Procedures: Evaluation in 1.5-, 3- and 7-Tesla MRI Scanners.

    Science.gov (United States)

    Neumann, Jan-Oliver; Giese, Henrik; Biller, Armin; Nagel, Armin M; Kiening, Karl

    2015-01-01

    Magnetic resonance imaging (MRI) is replacing computed tomography (CT) as the main imaging modality for stereotactic transformations. MRI is prone to spatial distortion artifacts, which can lead to inaccuracy in stereotactic procedures. Modern MRI systems provide distortion correction algorithms that may ameliorate this problem. This study investigates the different options of distortion correction using standard 1.5-, 3- and 7-tesla MRI scanners. A phantom was mounted on a stereotactic frame. One CT scan and three MRI scans were performed. At all three field strengths, two 3-dimensional sequences, volumetric interpolated breath-hold examination (VIBE) and magnetization-prepared rapid acquisition with gradient echo, were acquired, and automatic distortion correction was performed. Global stereotactic transformation of all 13 datasets was performed and two stereotactic planning workflows (MRI only vs. CT/MR image fusion) were subsequently analysed. Distortion correction on the 1.5- and 3-tesla scanners caused a considerable reduction in positional error. The effect was more pronounced when using the VIBE sequences. By using co-registration (CT/MR image fusion), even a lower positional error could be obtained. In ultra-high-field (7 T) MR imaging, distortion correction introduced even higher errors. However, the accuracy of non-corrected 7-tesla sequences was comparable to CT/MR image fusion 3-tesla imaging. MRI distortion correction algorithms can reduce positional errors by up to 60%. For stereotactic applications of utmost precision, we recommend a co-registration to an additional CT dataset. © 2015 S. Karger AG, Basel.

  7. Risk Factors Associated With Symptomatic Radiation Pneumonitis After Stereotactic Body Radiation Therapy for Stage I Non–Small Cell Lung Cancer

    OpenAIRE

    Shi, Shiming; Zeng, Zhaochong; Ye, Luxi; Huang, Yan; He, Jian

    2016-01-01

    Radiation pneumonitis is the most frequent acute pulmonary toxicity following stereotactic body radiation therapy for lung cancer. Here, we investigate clinical and dosimetric factors associated with symptomatic radiation pneumonitis in patients with stage I non–small cell lung cancer treated with stereotactic body radiation therapy. A total of 67 patients with stage I non–small cell lung cancer who received stereotactic body radiation therapy at our institution were enrolled, and their clini...

  8. Hypofractionated stereotactic radiation therapy in three to five fractions for vestibular schwannoma

    International Nuclear Information System (INIS)

    Morimoto, Masahiro; Yoshioka, Yasuo; Kotsuma, Tadayuki

    2013-01-01

    The objective of this study was to retrospectively examine the outcomes of hypofractionated stereotactic radiation therapy in three to five fractions for vestibular schwannomas. Twenty-five patients with 26 vestibular schwannomas were treated with hypofractionated stereotactic radiation therapy using a CyberKnife. The vestibular schwannomas of 5 patients were associated with type II neurofibromatosis. The median follow-up time was 80 months (range: 6-167); the median planning target volume was 2.6 cm 3 (0.3-15.4); and the median prescribed dose (≥D90) was 21 Gy in three fractions (18-25 Gy in three to five fractions). Progression was defined as ≥2 mm 3-dimensional post-treatment tumor enlargement excluding transient expansion. Progression or any death was counted as an event in progression-free survival rates, whereas only progression was counted in progression-free rates. The 7-year progression-free survival and progression-free rates were 78 and 95%, respectively. Late adverse events (≥3 months) with grades based on Common Terminology Criteria for Adverse Events, v4.03 were observed in 6 patients: Grade 3 hydrocephalus in one patient, Grade 2 facial nerve disorders in two and Grade 1-2 tinnitus in three. In total, 12 out of 25 patients maintained pure tone averages ≤50 dB before hypofractionated stereotactic radiation therapy, and 6 of these 12 patients (50%) maintained pure tone averages at this level at the final audiometric follow-up after hypofractionated stereotactic radiation therapy. However, gradient deterioration of pure tone average was observed in 11 of these 12 patients. The mean pure tone averages before hypofractionated stereotactic radiation therapy and at the final follow-up for the aforementioned 12 patients were 29.8 and 57.1 dB, respectively. Treating vestibular schwannomas with hypofractionated stereotactic radiation therapy in three to five fractions may prevent tumor progression with tolerable toxicity. However, gradient

  9. Maintenance in dental implants

    Directory of Open Access Journals (Sweden)

    Giselle Póvoa Gomes

    2008-01-01

    Full Text Available In implants, maintenance is a decisive factor for obtaining success when implant supported overdentures and dentures are used. The present stud presents, a clinical case of a patient, a 70 year-old white man, with a completely edentulous mandibular alveolar ridge, severe bone resorption with presence of basal bone only, and absence of vestibule. Initially, treatment consisted of the placement of a mandibular overdenture, supported on three implants in the anterior inter-foramen region, as the left implant was transfixed in the basal bone of 2 to 3 millimeters. Eleven years later, another two implants were placed in the anterior area and an immediate load was performed up to the first molars, for the placement of an implant supported fixed. Throughout the entire treatment, meticulous maintenance was carried out, with follow-up for fourteen years, interrupted by the patient’s death. From the third month after the opening the three implants initially placed, the presence of keratinized mucosa, definition of the vestibule, maturation of the alveolar ridge and bone formation in the mento region were observed. It was concluded that good planning, allied to mastery of the technique and adequate maintenance were the prerequisites necessary for obtaining favorable results, success of the present case, and for the patient to have a better quality of life.

  10. Implants in the hand; Implantate der Hand

    Energy Technology Data Exchange (ETDEWEB)

    Wanivenhaus, A. [Medizinische Universitaet, Universitaetsklinik fuer Orthopaedie, Wien (Austria)

    2006-09-15

    Increasingly, implants in the region of hand joints and the wrist represent an alternative for the treatment of post-traumatic, inflamed, or degenerative joint damage. The diversity of hand functions also results in varied solutions, which are effective in their stability, mobility, and distraction. Different materials are necessary for this, and they require subtile radiological control. The native X-ray represents the substantial method to observe migration of the implants. Each interface between titanium, ceramic, zirconium, pyrocarbon, and silicon to the bone has to be assessed differently in order to obtain a relevant statement. The finger joints and to a limited extent the wrist represent the artificial joints with limited alternative therapy. Other implants in the hand should only be applied after strict indication and patient compliance, as arthrodesis and resection arthroplasty have shown very good long-term results. (orig.) [German] Implantate im Bereich der Gelenke der Hand und des Handgelenks stellen zunehmend Alternativen bei der Versorgung posttraumatischer, entzuendlicher oder degenerativer Gelenkschaeden dar. Die Vielfalt der Handfunktionen fuehrt auch zu unterschiedlichen Loesungen, die durch Stabilitaet, Mobilitaet und Distraktion wirksam werden. Dafuer sind unterschiedliche Materialien erforderlich, die eine subtile radiologische Kontrolle erfordern. Das Nativroentgen stellt das wesentlichste Verfahren zur Verlaufsbeobachtung von Implantaten dar. Das Interface zwischen Titan, Keramik, Zirkonium, Pyrokarbon und Silikon zum Knochen muss unterschiedlich bewertet werden, um relevante Aussagen treffen zu koennen. Die Fingergelenke und in begrenztem Ausmass auch das Handgelenk stellen Kunstgelenke mit geringen Alternativtherapiemoeglichkeiten dar. Die uebrigen Implantate der Hand sollten nur bei strenger Indikationsstellung und hoher Patientencompliance Anwendung finden, da Arthrodese oder Resektionsarthroplastik gute Langzeitresultate aufweisen. (orig.)

  11. Adaptive fractionated stereotactic Gamma Knife radiotherapy of meningioma using integrated stereotactic cone-beam-CT and adaptive re-planning (a-gkFSRT)

    International Nuclear Information System (INIS)

    Stieler, F.; Wenz, F.; Abo-Madyan, Y.; Schweizer, B.; Polednik, M.; Herskind, C.; Giordano, F.A.; Mai, S.

    2016-01-01

    The Gamma Knife Icon (Elekta AB, Stockholm, Sweden) allows frameless stereotactic treatment using a combination of cone beam computer tomography (CBCT), a thermoplastic mask system, and an infrared-based high-definition motion management (HDMM) camera system for patient tracking during treatment. We report on the first patient with meningioma at the left petrous bone treated with adaptive fractionated stereotactic radiotherapy (a-gkFSRT). The first patient treated with Gamma Knife Icon at our institute received MR imaging for preplanning before treatment. For each treatment fraction, a daily CBCT was performed to verify the actual scull/tumor position. The system automatically adapted the planned shot positions to the daily position and recalculated the dose distribution (online adaptive planning). During treatment, the HDMM system recorded the intrafractional patient motion. Furthermore, the required times were recorded to define a clinical treatment slot. Total treatment time was around 20 min. Patient positioning needed 0.8 min, CBCT positioning plus acquisition 1.65 min, CT data processing and adaptive planning 2.66 min, and treatment 15.6 min. The differences for the five daily CBCTs compared to the reference are for rotation: -0.59 ± 0.49 /0.18 ± 0.20 /0.05 ± 0.36 and for translation: 0.94 ± 0.52 mm/-0.08 ± 0.08 mm/-1.13 ± 0.89 mm. Over all fractions, an intrafractional movement of 0.13 ± 0.04 mm was observed. The Gamma Knife Icon allows combining the accuracy of the stereotactic Gamma Knife system with the flexibility of fractionated treatment with the mask system and CBCT. Furthermore, the Icon system introduces a new online patient tracking system to the clinical routine. The interfractional accuracy of patient positioning was controlled with a thermoplastic mask and CBCT. (orig.) [de

  12. Nanotechnology for dental implants.

    Science.gov (United States)

    Tomsia, Antoni P; Lee, Janice S; Wegst, Ulrike G K; Saiz, Eduardo

    2013-01-01

    With the advent of nanotechnology, an opportunity exists for the engineering of new dental implant materials. Metallic dental implants have been successfully used for decades, but they have shortcomings related to osseointegration and mechanical properties that do not match those of bone. Absent the development of an entirely new class of materials, faster osseointegration of currently available dental implants can be accomplished by various surface modifications. To date, there is no consensus regarding the preferred method(s) of implant surface modification, and further development will be required before the ideal implant surface can be created, let alone become available for clinical use. Current approaches can generally be categorized into three areas: ceramic coatings, surface functionalization, and patterning on the micro- to nanoscale. The distinctions among these are imprecise, as some or all of these approaches can be combined to improve in vivo implant performance. These surface improvements have resulted in durable implants with a high percentage of success and long-term function. Nanotechnology has provided another set of opportunities for the manipulation of implant surfaces in its capacity to mimic the surface topography formed by extracellular matrix components of natural tissue. The possibilities introduced by nanotechnology now permit the tailoring of implant chemistry and structure with an unprecedented degree of control. For the first time, tools are available that can be used to manipulate the physicochemical environment and monitor key cellular events at the molecular level. These new tools and capabilities will result in faster bone formation, reduced healing time, and rapid recovery to function.

  13. Automatic metastatic brain tumor segmentation for stereotactic radiosurgery applications

    Science.gov (United States)

    Liu, Yan; Stojadinovic, Strahinja; Hrycushko, Brian; Wardak, Zabi; Lu, Weiguo; Yan, Yulong; Jiang, Steve B.; Timmerman, Robert; Abdulrahman, Ramzi; Nedzi, Lucien; Gu, Xuejun

    2016-12-01

    The objective of this study is to develop an automatic segmentation strategy for efficient and accurate metastatic brain tumor delineation on contrast-enhanced T1-weighted (T1c) magnetic resonance images (MRI) for stereotactic radiosurgery (SRS) applications. The proposed four-step automatic brain metastases segmentation strategy is comprised of pre-processing, initial contouring, contour evolution, and contour triage. First, T1c brain images are preprocessed to remove the skull. Second, an initial tumor contour is created using a multi-scaled adaptive threshold-based bounding box and a super-voxel clustering technique. Third, the initial contours are evolved to the tumor boundary using a regional active contour technique. Fourth, all detected false-positive contours are removed with geometric characterization. The segmentation process was validated on a realistic virtual phantom containing Gaussian or Rician noise. For each type of noise distribution, five different noise levels were tested. Twenty-one cases from the multimodal brain tumor image segmentation (BRATS) challenge dataset and fifteen clinical metastases cases were also included in validation. Segmentation performance was quantified by the Dice coefficient (DC), normalized mutual information (NMI), structural similarity (SSIM), Hausdorff distance (HD), mean value of surface-to-surface distance (MSSD) and standard deviation of surface-to-surface distance (SDSSD). In the numerical phantom study, the evaluation yielded a DC of 0.98  ±  0.01, an NMI of 0.97  ±  0.01, an SSIM of 0.999  ±  0.001, an HD of 2.2  ±  0.8 mm, an MSSD of 0.1  ±  0.1 mm, and an SDSSD of 0.3  ±  0.1 mm. The validation on the BRATS data resulted in a DC of 0.89  ±  0.08, which outperform the BRATS challenge algorithms. Evaluation on clinical datasets gave a DC of 0.86  ±  0.09, an NMI of 0.80  ±  0.11, an SSIM of 0.999  ±  0.001, an HD of 8

  14. Potency preservation following stereotactic body radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Obayomi-Davies, Olusola; Pahira, John; McGeagh, Kevin G; Collins, Brian T; Kowalczyk, Keith; Bandi, Gaurav; Kumar, Deepak; Suy, Simeng; Dritschilo, Anatoly; Lynch, John H; Collins, Sean P; Chen, Leonard N; Bhagat, Aditi; Wright, Henry C; Uhm, Sunghae; Kim, Joy S; Yung, Thomas M; Lei, Siyuan; Batipps, Gerald P

    2013-01-01

    Erectile dysfunction after prostate radiation therapy remains an ongoing challenge and critical quality of life issue. Given the higher dose of radiation per fraction using stereotactic body radiation therapy (SBRT) there is concern that post-SBRT impotency would be higher than conventional radiation therapy approaches. This study sought to evaluate potency preservation and sexual function following SBRT for prostate cancer. Between February 2008 and March 2011, 216 men with clinically localized prostate cancer were treated definitively with SBRT monotherapy at Georgetown University Hospital. Potency was defined as the ability to have an erection firm enough for intercourse with or without sexual aids while sexual activity was defined as the ability to have an erection firm enough for masturbation and foreplay. Patients who received androgen deprivation therapy (ADT) were excluded from this study. Ninety-seven hormone-naïve men were identified as being potent at the initiation of therapy and were included in this review. All patients were treated to 35–36.25 Gy in 5 fractions delivered with the CyberKnife Radiosurgical System (Accuray). Prostate specific antigen (PSA) and total testosterone levels were obtained pre-treatment, every 3 months for the first year and every 6 months for the subsequent year. Sexual function was assessed with the Sexual Health Inventory for Men (SHIM), the Expanded Prostate Index Composite (EPIC)-26 and Utilization of Sexual Medication/Device questionnaires at baseline and all follow-up visits. Ninety-seven men (43 low-, 50 intermediate- and 4 high-risk) at a median age of 68 years (range, 48–82 years) received SBRT. The median pre-treatment PSA was 5.9 ng/ml and the minimum follow-up was 24 months. The median pre-treatment total serum testosterone level was 11.4 nmol/L (range, 4.4-27.9 nmol/L). The median baseline SHIM was 22 and 36% of patients utilized sexual aids prior to treatment. Although potency rates declined following

  15. Optimization of dental implantation

    Science.gov (United States)

    Dol, Aleksandr V.; Ivanov, Dmitriy V.

    2017-02-01

    Modern dentistry can not exist without dental implantation. This work is devoted to study of the "bone-implant" system and to optimization of dental prostheses installation. Modern non-invasive methods such as MRI an 3D-scanning as well as numerical calculations and 3D-prototyping allow to optimize all of stages of dental prosthetics. An integrated approach to the planning of implant surgery can significantly reduce the risk of complications in the first few days after treatment, and throughout the period of operation of the prosthesis.

  16. Radiology of Implant Dentistry.

    Science.gov (United States)

    Al-Ekrish, Asma'a Abdurrahman

    2018-01-01

    The article presents an overview of the goal of imaging at each stage of implant therapy and the usefulness and limitations of multidetector computed tomography (MDCT) in achieving those goals. Various MDCT protocols of use in implant imaging also are presented, with an emphasis on dose reduction and the use of iterative reconstruction techniques. Also discussed are options for viewing and analysis of CT images, issues related to appropriate image reformatting and interpretation, interactive treatment planning, and transfer of information from the images to the surgical field during implant surgery using surgical guides and CT-guided navigation systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Hypofractionated Stereotactic Radiosurgery in a Large Bilateral Thalamic and Basal Ganglia Arteriovenous Malformation

    Directory of Open Access Journals (Sweden)

    Janet Lee

    2013-01-01

    Full Text Available Purpose. Arteriovenous malformations (AVMs in the basal ganglia and thalamus have a more aggressive natural history with a higher morbidity and mortality than AVMs in other locations. Optimal treatment—complete obliteration without new neurological deficits—is often challenging. We present a patient with a large bilateral basal ganglia and thalamic AVM successfully treated with hypofractionated stereotactic radiosurgery (HFSRS with intensity modulated radiotherapy (IMRT. Methods. The patient was treated with hypofractionated stereotactic radiosurgery to 30 Gy at margin in 5 fractions of 9 static fields with a minimultileaf collimator and intensity modulated radiotherapy. Results. At 10 months following treatment, digital subtraction angiography showed complete obliteration of the AVM. Conclusions. Large bilateral thalamic and basal ganglia AVMs can be successfully treated with complete obliteration by HFSRS with IMRT with relatively limited toxicity. Appropriate caution is recommended.

  18. Stereotactic radiation therapy: a second gold standard in the treatment of early-stage lung cancer?

    International Nuclear Information System (INIS)

    Santini B, Alejandro; Valdez C, Cristian; Sepulveda A, Veronica; Baeza L, Ricardo; Bustos, Sergio

    2016-01-01

    Lung cancer is still the leading cause of cancer death in the world. Although in Chile this is not the case, the northern regions of the country show higher incidence and mortality rates than the other Chilean regions. In recent years screening guides for lung cancer with low-dose scanner have begun to be established, and most of the medical societies involved in this subject have already settled the selection criteria. At the same time new techniques of treatment for these patients have developed, with highly sophisticated radiotherapy such as SBRT (Stereotactic Body Radiotherapy) and SBART (Stereotactic ablative body radiation therapy) that are revealing extremely encouraging results and augur significant changes in the coming years. In the present review we analyze the current work, their results, and the future of this treatment modality

  19. Clinical-radiological evaluation of sequelae of stereotactic radiosurgery for intracranial arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Levy, R.P.; Fabrikant, J.I.; Frankel, K.A.; Phillips, M.H.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.

    1989-12-01

    Stereotactic heavy-charged-particle Bragg peak radiosurgery has been used to treat 322 patients with surgically-inaccessible intracranial vascular malformations. (The clinical results of this method for the treatment of angiographically demonstrable arteriovenous malformations (AVMs) and angiographically occult vascular malformations (AOVMs) of the brain are described in separate reports of this symposium). The great majority of patients have had an uneventful post-treatment course with satisfactory health outcomes. However, several categories of delayed sequelae of stereotactic radiosurgery have been identified, involving the vascular structures essential for the integrity of the brain tissue and the brain parenchyma directly. These categories reflect both reaction to injury and to alterations in regional hemodynamic status, and include vasogenic edema, occlusion of functional vasculature, radiation necrosis, and local or remote effects on cerebral arterial aneurysms. 10 refs., 7 figs., 1 tab.

  20. Treatment of Chushing's disease in childhood and adolescence by stereotactic pituitary irradiation

    International Nuclear Information System (INIS)

    Thoren, M.; Raehn, T.; Ritzen, M.; Hallengren, B.; Nilsson, K.O.; Kaad, P.H.; Ravn, H.; Petersen, K.E.; Aarskog, D.

    1986-01-01

    Eight children with Cushing's disease aged 6-18 years were treated with external radiation to the pituitary gland using /sup60/Co gamma radiation given with stereotactic technique. The dose given varied between 50 and 70 Gy. The observation time was 2.6 to 6.75 years. Seven children had a clinical remission with normal urinary cortisol excretion. One child had insufficent effect of two irriadiations and underwent bilateral adrenalectomy. In the patients in remission the growth velocity increased during the first year after treatment but growth retardation occurred again during the second year. Insufficient growth hormone secretion was demonstrated in all subjects. Two patients were given thyroxine substitution and three showed evidence for secondary hypogonadism. In conclusion, stereotactic pituitary irradiation was effective in normalizing the excessive glucocorticoid production in children with Cushing's disease. However, with the doses used, it was not possible to maintain a normal anterior pituitary function

  1. Treatment of Chushing's disease in childhood and adolescence by stereotactic pituitary irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Thoren, M.; Raehn, T.; Ritzen, M.; Hallengren, B.; Nilsson, K.O.; Kaad, P.H.; Ravn, H.; Petersen, K.E.; Aarskog, D.

    1986-01-01

    Eight children with Cushing's disease aged 6-18 years were treated with external radiation to the pituitary gland using /sup60/Co gamma radiation given with stereotactic technique. The dose given varied between 50 and 70 Gy. The observation time was 2.6 to 6.75 years. Seven children had a clinical remission with normal urinary cortisol excretion. One child had insufficent effect of two irriadiations and underwent bilateral adrenalectomy. In the patients in remission the growth velocity increased during the first year after treatment but growth retardation occurred again during the second year. Insufficient growth hormone secretion was demonstrated in all subjects. Two patients were given thyroxine substitution and three showed evidence for secondary hypogonadism. In conclusion, stereotactic pituitary irradiation was effective in normalizing the excessive glucocorticoid production in children with Cushing's disease. However, with the doses used, it was not possible to maintain a normal anterior pituitary function.

  2. Phase-II study on stereotactic radiotherapy of locally advanced pancreatic carcinoma

    DEFF Research Database (Denmark)

    Høyer, Morten; Roed, Henrik; Sengeløv, Lisa

    2005-01-01

    in the present phase-II trial. PATIENTS AND METHODS: Twenty-two patients with locally advanced and surgically non-resectable, histological proven pancreatic carcinoma were included into the trial. The patients were immobilized by the Elekta stereotactic body frame (SBF) or a custom made body frame. SRT was given......BACKGROUND AND PURPOSE: The majority of patients with pancreatic cancer have advanced disease at the time of diagnosis and are not amenable for surgery. Stereotactic radiotherapy (SRT) may be an alternative treatment for patients with locally advanced disease. The effect of SRT was investigated...... on standard LINAC with standard multi-leaf collimator. Central dose was 15 Gyx3 within 5-10 days. RESULTS: Evaluation of response was found to be very difficult due to radiation and tumour related tissue reaction. Only two patients (9%) were found to have a partial response (PR), the remaining had no change...

  3. Prospective study on stereotactic radiotherapy of limited-stage non-small-cell lung cancer

    DEFF Research Database (Denmark)

    Høyer, Morten; Roed, Henrik; Hansen, Anders Traberg

    2006-01-01

    Purpose: To test the effect of stereotactic body radiotherapy (SBRT) in       the treatment of medically inoperable patients with limited-stage       non-small-cell lung cancer (NSCLC) in a Phase II trial. Methods and       Materials: Forty patients with Stage I NSCLC were treated with SBRT......%. At 2       years, 54% were without local or distant progression, and overall survival       was 47%. Within 6 months after treatment, one or more Grade >/=2 reactions       were observed in 48% of the patients. Conclusions: Stereotactic body       radiotherapy in patients with limited-stage NSCLC...

  4. Neuropsychological processing associated with recovery from depression after stereotactic subcaudate tractotomy.

    Science.gov (United States)

    Dalgleish, Tim; Yiend, Jenny; Bramham, Jessica; Teasdale, John D; Ogilvie, Alan D; Malhi, Gin; Howard, Robert

    2004-10-01

    The authors compared patients who underwent stereotactic subcaudate tractotomy for depression, who were still depressed or recovered from depression, to identify therapeutic mechanisms. Ten depressed and eight recovered psychosurgery patients, along with nine never-depressed subjects and nine who had recovered from depression with medication, completed the Iowa Gambling Task, a measure of decision making in the face of feedback. Psychosurgery patients also completed general neuropsychological testing. Recovered psychosurgery patients exhibited insensitivity to negative feedback on the Iowa Gambling Task compared to the other three groups. This difference between the groups remained when general neuropsychological performance was covaried out. These findings suggest acquired relative insensitivity to negative information as a specific mechanism mediating the antidepressant effect of stereotactic subcaudate tractotomy. Such insensitivity is not secondary to deficits in general neuropsychological functioning and is not a function of recovery from depression per se.

  5. Efficiency of Stereotactic Conformal Radiotherapy in Lung Metastases with Active Breathing Control

    Directory of Open Access Journals (Sweden)

    Olga Yu. Anikeeva, PhD

    2013-06-01

    Full Text Available Twenty four patients with lung metastases underwent radiosurgery treatment between October 2010 and December 2012. Stereotactic conformal high-dose radiation therapy with Active Breathing Control (ABC was conducted using the volumetric modulated arc therapy (VMAT technique. The median overall follow-up was 18 months (range 6-24 months, overall survival was 75%, and local control rate was 92%. The median time to progression was 4 months (range 1-18 months.There have been no cases of leucopenia, radiation esophagitis, mediastinitis or severe acute radiation pneumonitis. The late radiation effects Grade 2, according to the LENT SOMA scales, was observed in one patient (4%. The results of this study indicate that the usage of the stereotactic high-dose radiation therapy with ABC is safe and effective in the treatment of lung metastases.

  6. Clinical-radiological evaluation of sequelae of stereotactic radiosurgery for intracranial arteriovenous malformations

    International Nuclear Information System (INIS)

    Levy, R.P.; Fabrikant, J.I.; Frankel, K.A.; Phillips, M.H.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.

    1989-12-01

    Stereotactic heavy-charged-particle Bragg peak radiosurgery has been used to treat 322 patients with surgically-inaccessible intracranial vascular malformations. (The clinical results of this method for the treatment of angiographically demonstrable arteriovenous malformations (AVMs) and angiographically occult vascular malformations (AOVMs) of the brain are described in separate reports of this symposium). The great majority of patients have had an uneventful post-treatment course with satisfactory health outcomes. However, several categories of delayed sequelae of stereotactic radiosurgery have been identified, involving the vascular structures essential for the integrity of the brain tissue and the brain parenchyma directly. These categories reflect both reaction to injury and to alterations in regional hemodynamic status, and include vasogenic edema, occlusion of functional vasculature, radiation necrosis, and local or remote effects on cerebral arterial aneurysms. 10 refs., 7 figs., 1 tab

  7. Dealing with dental implant failures

    Directory of Open Access Journals (Sweden)

    Liran Levin

    2008-06-01

    Full Text Available An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options.When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them.

  8. Stereotactic helium-ion radiosurgery for the treatment of intracranial arteriovenous malformations

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Levy, R.P.; Frankel, K.A.; Phillips, M.H.; Lyman, J.T.; Chuang, F.Y.S.; Steinberg, G.K.; Marks, M.P.

    1989-12-01

    One of the more challenging problems of vascular neurosurgery is the management of surgically-inaccessible arteriovenous malformations (AVMs) of the brain. At Lawrence Berkeley Laboratory, we have developed the method of stereotactic heavy-charged-particle (helium-ion) Bragg peak radiosurgery for treatment of inoperable intracranial AVMs in over 300 patients since 1980 [Fabrikant et al. 1989, Fabrikant et al. 1985, Levy et al. 1989]. This report describes patient selection, treatment method, clinical and neuroradiologic results and complications encountered. 4 refs

  9. Fractionated stereotactic radiotherapy boost after post-operative radiotherapy in patients with high-grade gliomas

    International Nuclear Information System (INIS)

    Baumert, Brigitta G.; Lutterbach, Johannes; Bernays, Rene; Davis, J. Bernard; Heppner, Frank L.

    2003-01-01

    Purpose: To determine the value and the toxicity of an additional fractionated stereotactic boost as used in the joint randomized EORTC-22972/MRC-BR10 study in patients with malignant gliomas. Materials and methods: Seventeen patients (11 male, six female) with a high-grade glioma (two WHO III, 15 WHO IV) ≤4 cm in maximum diameter, with a good performance status (WHO ≥2), were treated with a fractionated stereotactic radiotherapy (SRT) boost to 20 Gy in four fractions following partial brain irradiation to a dose of 60 Gy in 30 fractions. This patient group was compared with historical data in a matched-pair analysis. Results: All patients were treated by conventional radiotherapy and a SRT boost (15 patients received 20 Gy and two patients 10 Gy). Acute side effects included fatigue (two), impairment of short-term memory (one) and worsening of pre-existing symptoms (one). No patient developed steroid dependence after SRT. One patient was re-operated for radiation necrosis. At a median follow-up of 25 months (9-50 months) 14 patients recurred locally. Survival was 77% at 1 year and 42% at 2 years; progression-free survival was 70% at 1 year and 35% at 2 years for all patients, respectively. Median survival for the whole patient group is 20 months. Comparison with a matched historical group showed a significantly better survival for the group treated with a stereotactic boost (P<0.0001). Conclusion: A fractionated stereotactic boost after standard external beam radiotherapy in selected patients with high-grade glioma is feasible and well tolerated with low toxicity. Compared to historical data survival is significantly better with an additional SRT boost. However, its effectiveness has to be proven in a randomized trial

  10. Effects on Cognition of Stereotactic Lesional Surgery For the Treatment of Tremor in Multiple Sclerosis

    OpenAIRE

    Jahanshahi, Marjan; Pieter, Socorro; Alusi, Sundus H.; Jones, Catherine R. G.; Glickman, Scott; Stein, John; Aziz, Tipu; Bain, Peter G.

    2008-01-01

    Objective: To assess the effect of stereotactic lesional surgery for treatment of tremor in multiple sclerosis on cognition. Methods: Eleven patients (3 males, 8 females) with multiple sclerosis participated in the study. Six subjects comprised the surgical group and five the matched control group. All patients were assessed at baseline and three months using a neuropsychological test battery that included measures of intellectual ability, memory, language, perception and executive function. ...

  11. Stereotactic radiosurgery may contribute to overall survival for patients with recurrent head and neck carcinoma

    International Nuclear Information System (INIS)

    Kawaguchi, Koji; Sato, Kengo; Horie, Akihisa; Iketani, Susumu; Yamada, Hiroyuki; Nakatani, Yasunori; Sato, Junichi; Hamada, Yoshiki

    2010-01-01

    The aim of this study is to examine the effect of stereotactic radiosurgery (SRS) in the treatment of advanced, recurrent lesions for head and neck carcinoma both with and without lymph node involvement. Between April 2006 and July 2007, 22 patients (mean age 67 years) with advanced, recurrent head and neck carcinoma were treated with stereotactic radiosurgery. All of the patients except one had biopsy confirmed disease prior to stereotactic radiosurgery. Patients included 3 rT2, 8 rT3, and 9 rT4; 8 of the patients had lymph node metastases. Marginal SRS doses were 20-42 Gy delivered in two to five fractions. Starting one month after SRS, all patients received S-1 oral chemotherapy for one year. At an overall median follow-up of 24 months (range, 4-39 months), for the 14 locally recurrent patients without lymph node metastases, 9 patients (64.3%) had a complete response (CR), 1 patient (7.1%) had a partial response (PR), 1 patient (7.1%) had stable disease (SD), and 3 patients (21.4%) had progressive disease (PD). For the 8 patients with lymph node metastases, 1 patient with a single retropharyngeal (12.5%) had CR; the remaining 7 patients (87.5%) all progressed. Nine patients have died from their cancer. The overall actuarial 2-year survival for the patients with and without lymph node metastases is 12.5% and 78.6%, respectively. These results show the benefit of stereotactic radiosurgery salvage treatment for advanced, recurrent lesions, without lymph node metastases in previously irradiated head and neck cancer

  12. A community-centric internet portal for stereotactic and functional neurosurgery with a probabilistic functional atlas.

    Science.gov (United States)

    Nowinski, Wieslaw L; Belov, Dmitry; Benabid, Alim-Louis

    2002-01-01

    This paper describes an Internet portal for stereotactic and functional neurosurgery with a probabilistic functional atlas (PFA) calculated from electrophysiological and neuroimaging data. This portal enables (1) data sharing among neurosurgeons; (2) the calculation of probabilistic functional maps of stereotactic target structures from a neurosurgeon's own data, optionally combined with data from other neurosurgeons, and (3) the construction and development of a PFA of the human brain by the neurosurgical community via the Internet. The overall approach is done in three steps: (1) development and validation of the algorithm for PFA generation; (2) design and development of the portal for stereotactic and functional neurosurgery with tools for the rapid calculation, presentation, and use of the PFA, and (3) portal testing with the initial data acquired for 274 Parkinson's disease patients, 487 hemispheres, and 500 best contacts. This paper covers step 2 and some results from step 3. The Internet portal has been developed in Java and tested with the available data. Functions have been developed for: (1) data input, transfer, and editing; (2) data selection for PFA generation; (3) PFA generation; (4) PFA display and interactive manipulation, and (5) target planning. The portal has been put on the Internet for public use and so far more than 100 users downloaded it. The Internet portal for stereotactic and functional neurosurgery with a PFA potentially increases both the accuracy of targeting and the neurosurgeon's confidence. The portal may be useful for both experienced functional neurosurgeons who have studied numerous cases and novices in the field. The use of the PFA through this portal, and sharing and expanding its content by neurosurgeons represents a paradigm shift from manufacturer centric to community centric. Copyright 2002 S. Karger AG, Basel

  13. Gemella morbillorum deep brain abscess successfully treated with combined stereotactic, medical, and imaging approach

    Energy Technology Data Exchange (ETDEWEB)

    Messori, Anna; Bartolucci, Francesca; Dini, Marco; Paggi, Alessandra Mataloni; Ricciuti, Riccardo A.; Rychlicki, Franco; Salvolini, Ugo E-mail: u.salvolini@popcsi.unian.it

    2002-11-01

    A rare case of brain abscess due to Gemella morbillorum, a normal inhabitant of the oral cavity, is presented. The aim of this report is to draw the attention of radiology literature readers to this little known pathogen, which caused a potentially life-threatening condition in an immunocompetent young man, and to emphasise the usefulness of a combined stereotactic, medical, and imaging approach to deep-located brain abscesses.

  14. Gemella morbillorum deep brain abscess successfully treated with combined stereotactic, medical, and imaging approach

    International Nuclear Information System (INIS)

    Messori, Anna; Bartolucci, Francesca; Dini, Marco; Paggi, Alessandra Mataloni; Ricciuti, Riccardo A.; Rychlicki, Franco; Salvolini, Ugo

    2002-01-01

    A rare case of brain abscess due to Gemella morbillorum, a normal inhabitant of the oral cavity, is presented. The aim of this report is to draw the attention of radiology literature readers to this little known pathogen, which caused a potentially life-threatening condition in an immunocompetent young man, and to emphasise the usefulness of a combined stereotactic, medical, and imaging approach to deep-located brain abscesses

  15. Stereotactic core biopsy of an impalpable screen-detected breast lesion using acupuncture-analgesia

    OpenAIRE

    English, R E; Chen, J H

    2010-01-01

    Chinese acupuncture-analgesia is used for pain management during various surgical procedures. Over the past 40 years this approach has been introduced in many countries and has been particularly helpful in the investigation and treatment of patients who are unable to tolerate conventional analgesia. We report here the case of a woman with a 17-year history of myalgic encephalitis who underwent a stereotactic core biopsy of the breast under acupuncture-analgesia. A planning session was needed ...

  16. Stereotactic aspiration versus craniotomy for primary intracerebral hemorrhage: a meta-analysis of randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Jia-Wei Wang

    Full Text Available BACKGROUND: A wealth of evidence based on the randomized controlled trials (RCTs has indicated that surgery may be a better choice in the management of primary intracerebral hemorrhage (ICH compared to conservative treatment. However, there is considerable controversy over selecting appropriate surgical procedures for ICH. Thus, this meta-analysis was performed to assess the effects of stereotactic aspiration compared to craniotomy in patients with ICH. METHODS: According to the study strategy, we searched PUBMED, EMBASE and Cochrane Central Register of Controlled Trials. Other sources such as the internet-based clinical trial registries, relevant journals and the lists of references were also searched. After literature searching, two investigators independently performed literature screening, assessment of quality of the included trials and data extraction. The outcome measures included death or dependence, total risk of complication, and the risk of rebleeding, gastrointestinal hemorrhage and systematic infection. RESULTS: Four RCTs with 2996 participants were included. The quality of the included trials was acceptable. Stereotactic aspiration significantly decreased the odds of death or dependence at the final follow-up (odds ratio (OR: 0.80, 95% confidence interval (CI: 0.69-0.93; P = 0.004 and the risk of intracerebral rebleeding (OR: 0.44, 95% CI: 0.26-0.74; P = 0.002 compared to craniotomy with no significant heterogeneity among the study results. CONCLUSIONS: The present meta-analysis provides evidence that the stereotactic aspiration may be associated with a reduction in the odds of being dead or dependent in primary ICH, which should be interpreted with caution. Further trials are needed to identify those patients most likely to benefit from the stereotactic aspiration.

  17. A new non-invasive and relocatable immobilization frame for fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Theodorou, K.; Kappas, C.; Tsokas, C.

    1998-01-01

    Purpose: A newly developed non-invasive immobilization frame for stereotactic radiotherapy is presented, which is intended to be used for both imaging (computed tomography (CT) and angiography) and radiotherapeutic procedures. Materials and methods: The frame is made of duraluminium so as to be stable and light and it has an elliptical shape. The immobilization is achieved using three stable locations on the patient's head, i.e. the upper dentition, the nose and the back of the neck. The fixation on the three locations ensures complete immobilization in all directions. Results: The immobilization frame can be fitted as many times as is needed to most heads. In order to assess the accuracy of relocation, repeated fittings on two volunteers and on 22 patients undergoing stereotactic treatment were performed (more than 200 mountings in total), which showed maximum anterior-posterior, inferior-superior and lateral reproducibility in positioning of less than 1 mm in all cases. Conclusions and discussion: The in-house-constructed stereotactic frame is simple to use, easily made, non-invasive, relocatable and well tolerated by the patients, providing the possibility of multiple fractions. The major advantage of using such a non-invasive stereotactic frame is the flexibility in timing the different diagnostic procedures (CT and angiography) as well as providing the possibility to extend the use to large brain lesions (treatment without an additional collimator) where a high precision is also required. It also offers significant labour and cost saving over the invasive frames and the majority of the non-invasive frames. To date, 22 patients with ages varying between 12 and 70 years have been treated using this method. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. Outcome after the psychosurgical operation of stereotactic subcaudate tractotomy, 1979-1991.

    Science.gov (United States)

    Hodgkiss, A D; Malizia, A L; Bartlett, J R; Bridges, P K

    1995-01-01

    The outcome of all psychosurgical operations (stereotactic subcaudate tractotomies) performed at the Geoffrey Knight National Unit for Affective Disorders in London since 1979 is reviewed. Of patients who had suffered severe mood or obsessive-compulsive disorders before surgery, 84 of 249 (34%) were well 1 year after. The effects of gender, psychiatric diagnosis, and age on outcome are assessed. The findings are compared with a 1975 outcome study, and explanations for apparent differences are proposed.

  19. Linear accelerator based stereotactic radiosurgery with micro multi-leaf collimator : technological advancement in precision radiotherapy

    International Nuclear Information System (INIS)

    Dayananda, S.; Kinhikar, R.A.; Saju, Sherley; Deshpande, D.D.; Jalali, R.; Sarin, R.; Shrivastava, S.K.; Dinshaw, K.A.

    2003-01-01

    Stereotactic Radiosurgery (SRS) is an advancement on precision radiotherapy, in which stereo tactically guided localized high dose is delivered to the lesion (target) in a single fraction, while sparing the surrounding normal tissue. Radiosurgery has been used to treat variety of benign and malignant lesions as well as functional disorders in brain such as arteriovenous malformation (AVM), acoustic neuroma, solitary primary brain tumor, single metastasis, pituitary adenoma etc

  20. Stereotactic Aspiration versus Craniotomy for Primary Intracerebral Hemorrhage: A Meta-Analysis of Randomized Controlled Trials

    Science.gov (United States)

    Wang, Jia-Wei; Li, Jin-Ping; Song, Ying-Lun; Tan, Ke; Wang, Yu; Li, Tao; Guo, Peng; Li, Xiong; Wang, Yan; Zhao, Qi-Huang

    2014-01-01

    Background A wealth of evidence based on the randomized controlled trials (RCTs) has indicated that surgery may be a better choice in the management of primary intracerebral hemorrhage (ICH) compared to conservative treatment. However, there is considerable controversy over selecting appropriate surgical procedures for ICH. Thus, this meta-analysis was performed to assess the effects of stereotactic aspiration compared to craniotomy in patients with ICH. Methods According to the study strategy, we searched PUBMED, EMBASE and Cochrane Central Register of Controlled Trials. Other sources such as the internet-based clinical trial registries, relevant journals and the lists of references were also searched. After literature searching, two investigators independently performed literature screening, assessment of quality of the included trials and data extraction. The outcome measures included death or dependence, total risk of complication, and the risk of rebleeding, gastrointestinal hemorrhage and systematic infection. Results Four RCTs with 2996 participants were included. The quality of the included trials was acceptable. Stereotactic aspiration significantly decreased the odds of death or dependence at the final follow-up (odds ratio (OR): 0.80, 95% confidence interval (CI): 0.69–0.93; P = 0.004) and the risk of intracerebral rebleeding (OR: 0.44, 95% CI: 0.26–0.74; P = 0.002) compared to craniotomy with no significant heterogeneity among the study results. Conclusions The present meta-analysis provides evidence that the stereotactic aspiration may be associated with a reduction in the odds of being dead or dependent in primary ICH, which should be interpreted with caution. Further trials are needed to identify those patients most likely to benefit from the stereotactic aspiration. PMID:25237813

  1. Stereotactic helium-ion radiosurgery for the treatment of intracranial arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.; Levy, R.P.; Frankel, K.A.; Phillips, M.H.; Lyman, J.T.; Chuang, F.Y.S.; Steinberg, G.K.; Marks, M.P.

    1989-12-01

    One of the more challenging problems of vascular neurosurgery is the management of surgically-inaccessible arteriovenous malformations (AVMs) of the brain. At Lawrence Berkeley Laboratory, we have developed the method of stereotactic heavy-charged-particle (helium-ion) Bragg peak radiosurgery for treatment of inoperable intracranial AVMs in over 300 patients since 1980 (Fabrikant et al. 1989, Fabrikant et al. 1985, Levy et al. 1989). This report describes patient selection, treatment method, clinical and neuroradiologic results and complications encountered. 4 refs.

  2. Stereotactic core needle breast biopsy marker migration: An analysis of factors contributing to immediate marker migration.

    Science.gov (United States)

    Jain, Ashali; Khalid, Maria; Qureshi, Muhammad M; Georgian-Smith, Dianne; Kaplan, Jonah A; Buch, Karen; Grinstaff, Mark W; Hirsch, Ariel E; Hines, Neely L; Anderson, Stephan W; Gallagher, Katherine M; Bates, David D B; Bloch, B Nicolas

    2017-11-01

    To evaluate breast biopsy marker migration in stereotactic core needle biopsy procedures and identify contributing factors. This retrospective study analyzed 268 stereotactic biopsy markers placed in 263 consecutive patients undergoing stereotactic biopsies using 9G vacuum-assisted devices from August 2010-July 2013. Mammograms were reviewed and factors contributing to marker migration were evaluated. Basic descriptive statistics were calculated and comparisons were performed based on radiographically-confirmed marker migration. Of the 268 placed stereotactic biopsy markers, 35 (13.1%) migrated ≥1 cm from their biopsy cavity. Range: 1-6 cm; mean (± SD): 2.35 ± 1.22 cm. Of the 35 migrated biopsy markers, 9 (25.7%) migrated ≥3.5 cm. Patient age, biopsy pathology, number of cores, and left versus right breast were not associated with migration status (P> 0.10). Global fatty breast density (P= 0.025) and biopsy in the inner region of breast (P = 0.031) were associated with marker migration. Superior biopsy approach (P= 0.025), locally heterogeneous breast density, and t-shaped biopsy markers (P= 0.035) were significant for no marker migration. Multiple factors were found to influence marker migration. An overall migration rate of 13% supports endeavors of research groups actively developing new biopsy marker designs for improved resistance to migration. • Breast biopsy marker migration is documented in 13% of 268 procedures. • Marker migration is affected by physical, biological, and pathological factors. • Breast density, marker shape, needle approach etc. affect migration. • Study demonstrates marker migration prevalence; marker design improvements are needed.

  3. Precipitation processes in implanted materials

    International Nuclear Information System (INIS)

    Borders, J.A.

    1978-01-01

    Ion implantation is a nonequilibrium process. It is possible to implant materials with impurities to concentration levels which exceed the solid solubilities. The return of the system to thermodynamic equilibrium is often accomplished by precipitation of the implanted species or a compound involving atoms of both the host and the implanted species. This may involve long time scales when taking place at room temperature or it may take place during the implantation

  4. Implant treatment planning: endodontic considerations.

    Science.gov (United States)

    Simonian, Krikor; Frydman, Alon; Verdugo, Fernando; Roges, Rafael; Kar, Kian

    2014-12-01

    Implants are a predictable and effective method for replacing missing teeth. Some clinicians have advocated extraction and replacement of compromised but treatable teeth on the assumption that implants will outperform endodontically and/or periodontally treated teeth. However, evidence shows that conventional therapy is as effective as implant treatment. With data on implants developing complications long term and a lack of predictable treatment for peri-implantitis, retaining and restoring the natural dentition should be the first choice when possible.

  5. Recent advances in dental implants

    OpenAIRE

    Hong, Do Gia Khang; Oh, Ji-hyeon

    2017-01-01

    Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar c...

  6. The implantable artificial kidney.

    Science.gov (United States)

    Fissell, William H; Roy, Shuvo

    2009-01-01

    The confluence of an increasing prevalence of end-stage renal disease (ESRD), clinical trial data suggestive of benefit from quotidian dialysis, and ongoing cost/benefit reanalysis of healthcare spending have stimulated interest in technological improvements in provision of ESRD care. For the last decade, our group has focused on enabling technologies that would permit a paradigm shift in dialysis care similar to that brought by implantable defibrillators to arrhythmia management. Two significant barriers to wearable or implantable dialysis persist: package size of the dialyzer and water requirements for preparation of dialysate. Decades of independent research into highly efficient membranes and cell-based bioreactors culminated in a team effort to develop an implantable version of the University of Michigan Renal Assist Device. In this review, the rationale for the design of the implantable artificial kidney is described.

  7. Wireless cortical implantable systems

    CERN Document Server

    Majidzadeh Bafar, Vahid

    2013-01-01

    Wireless Cortical Implantable Systems examines the design for data acquisition and transmission in cortical implants. The first part of the book covers existing system-level cortical implants, as well as future devices. The authors discuss the major constraints in terms of microelectronic integration. The second part of the book focuses on system-level as well as circuit and system level solutions to the development of ultra low-power and low-noise microelectronics for cortical implants. Existing solutions are presented and novel methods and solutions proposed. The third part of the book focuses on the usage of digital impulse radio ultra wide-band transmission as an efficient method to transmit cortically neural recorded data at high data-rate to the outside world. Original architectural and circuit and system solutions are discussed.

  8. Hip Implant Systems

    Science.gov (United States)

    ... Orthopaedic Surgeons Information about Soft Tissue Imaging and Metal Ion Testing Information for All Health Care Professionals who Provide Treatment to Patients with a Metal-on-Metal Hip Implant Metal-on-Metal Hip ...

  9. [Implant supported prostheses (1)].

    Science.gov (United States)

    del Río Highsmith, J; López Lozano, J F

    1988-11-01

    In the present article deals with a number of general considerations in the realization of prostheses over endosseous implants. The different principles to study in the construction of a fixed protesic rehabilitation implanto-supported are analyzed.

  10. Breast Reconstruction with Implants

    Science.gov (United States)

    ... What you can expect Breast reconstruction begins with placement of a breast implant or tissue expander, either at the time of your mastectomy surgery (immediate reconstruction) or during a later procedure (delayed reconstruction). ...

  11. Superelastic Orthopedic Implant Coatings

    Science.gov (United States)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  12. Risks of Breast Implants

    Science.gov (United States)

    ... them or to undergo additional reconstructive surgery. Photo courtesy of Walter Peters, Ph.D., M.D., F. ... placement of silicone gel-filled breast implants. Photo courtesy of Walter Peters, Ph.D., M.D., F. ...

  13. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2011-01-01

    Studies of complications following reconstructive surgery with implants among women with breast cancer are needed. As the, to our knowledge, first prospective long-term study we evaluated the occurrence of complications following delayed breast reconstruction separately for one- and two......-stage procedures. From the Danish Registry for Plastic Surgery of the Breast, which has prospectively registered data for women undergoing breast implantations since 1999, we identified 559 women without a history of radiation therapy undergoing 592 delayed breast reconstructions following breast cancer during...... of reoperation was significantly higher following the one-stage procedure. For both procedures, the majority of reoperations were due to asymmetry or displacement of the implant. In conclusion, non-radiated one- and two-stage delayed breast implant reconstructions are associated with substantial risks...

  14. Ion implantation for semiconductors

    International Nuclear Information System (INIS)

    Grey-Morgan, T.

    1995-01-01

    Full text: Over the past two decades, thousands of particle accelerators have been used to implant foreign atoms like boron, phosphorus and arsenic into silicon crystal wafers to produce special embedded layers for manufacturing semiconductor devices. Depending on the device required, the atomic species, the depth of implant and doping levels are the main parameters for the implantation process; the selection and parameter control is totally automated. The depth of the implant, usually less than 1 micron, is determined by the ion energy, which can be varied between 2 and 600 keV. The ion beam is extracted from a Freeman or Bernas type ion source and accelerated to 60 keV before mass analysis. For higher beam energies postacceleration is applied up to 200 keV and even higher energies can be achieved by mass selecting multiplycharged ions, but with a corresponding reduction in beam output. Depending on the device to be manufactured, doping levels can range from 10 10 to 10 15 atoms/cm 2 and are controlled by implanter beam currents in the range up to 30mA; continuous process monitoring ensures uniformity across the wafer of better than 1 % . As semiconductor devices get smaller, additional sophistication is required in the design of the implanter. The silicon wafers charge electrically during implantation and this charge must be dissipated continuously to reduce the electrical stress in the device and avoid destructive electrical breakdown. Electron flood guns produce low energy electrons (below 10 electronvolts) to neutralize positive charge buildup and implanter design must ensure minimum contamination by other isotopic species and ensure low internal sputter rates. The pace of technology in the semiconductor industry is such that implanters are being built now for 256 Megabit circuits but which are only likely to be widely available five years from now. Several specialist companies manufacture implanter systems, each costing around US$5 million, depending on the

  15. Stereotactic Body Radiosurgery for Spinal Metastatic Disease: An Evidence-Based Review

    Directory of Open Access Journals (Sweden)

    William A. Hall

    2011-01-01

    Full Text Available Spinal metastasis is a problem that afflicts many cancer patients. Traditionally, conventional fractionated radiation therapy and/or surgery have been the most common approaches for managing such patients. Through technical advances in radiotherapy, high dose radiation with extremely steep drop off can now be delivered to a limited target volume along the spine under image-guidance with very high precision. This procedure, known as stereotactic body radiosurgery, provides a technique to rapidly treat selected spinal metastasis patients with single- or limited-fraction treatments that have similar to superior efficacies compared with more established approaches. This review describes current treatment systems in use to deliver stereotactic body radiosurgery as well as results of some of the larger case series from a number of institutions that report outcomes of patients treated for spinal metastatic disease. These series include nearly 1400 patients and report a cumulative local control rate of 90% with myelopathy risk that is significantly less than 1%. Based on this comprehensive review of the literature, we believe that stereotactic body radiosurgery is an established treatment modality for patients with spinal metastatic disease that is both safe and highly effective.

  16. Inter- and intrafractional movement of the tumour in extracranial stereotactic radiotherapy of NSCLC

    DEFF Research Database (Denmark)

    Jensen, Henrik R; Hansen, Olfred; Hjelm-Hansen, Mogens

    2008-01-01

    PURPOSE: The purpose of this study is to determine the inter- and intra-fractional respiration induced tumour movements as well as setup accuracy in a stereotactic body frame for stereotactic treatments of NSCLC patients. PATIENTS AND METHODS: From August 2005 to March 2008, 26 patients with NSCLC....... These coordinate constitute the data of this study. RESULTS: The standard deviations of the respiration induced intra-fractional movements were: LR: 0.9 mm, AP: 1.6 mm and CC: 2.0 mm (1 SD). The inter-fractional movements were: LR: 1.1 mm, AP: 1.3 mm and CC: 1.7 mm (1 SD). Finally the set up accuracies in the body...... frame were LR: 1.5 mm, AP: 1.1 mm and CC: 1.7 mm (1 SD). DISCUSSION AND CONCLUSIONS: Consecutive CT scans can be used to evaluate the respiration induced tumour movement. For patients immobilized in a stereotactic body frame, large movements of the tumour are rarely seen within the lung...

  17. Upright stereotactic vacuum-assisted needle biopsy of suspicious breast microcalcification

    International Nuclear Information System (INIS)

    Sim, L. S. J.; Kei, P. L.

    2008-01-01

    Full text: Stereotactic core needle biopsy is a useful technique for evaluation of suspicious breast microcalcifications. Thf development of the 11-G vacuum-assisted biopsy system offers another method of minimally invasive biopsy carried out on a conventional mammography unit. We evaluate its usefulness, efficacy and safety in Asian women.. Vacuum-assisted biopsy was carried out through the lateral approach using an add-on stereotactic device attached to a mammography unit. One hundred and five lesions were sampled in 97 patients. Excisional biopsy was subsequently Carried out for diagnosis of atypical ductal hyperplasia or carcinoma in high-risk patients. Patients with benign diagnosis underwent mammographic follow up. The technical success rate was 97%. An average of 13.5 tissue cores were retrieved for each lesion. The histopathological result obtained from mammotome was benign in 84.8% and malignant in 15.2%. The benign microcalcifications were predominantly fibrocystic change (n = 42)| whereas the malignant microcalcifications included ductal carcinoma in situ (n = 15) and invasive carcinoma (n = 1). Twenty-two patients underwent subsequent open surgical biopsy but no underestimation of disease was seen. Only two patients had vasovagal syncope and three others felt unwell during the biopsy. Nine patients had small haema-1 tomas, which resolved spontaneously. Vacuum-assisted biopsy carried out on an upright stereotactic mammography] unit is a safe and effective method for evaluation of suspicious microcalcifications.

  18. Gamma knife stereotactic radiosurgical thalamotomy for intractable tremor: A systematic review of the literature

    International Nuclear Information System (INIS)

    Campbell, Allison M.; Glover, Janis; Chiang, Veronica L.S.; Gerrard, Jason; Yu, James B.

    2015-01-01

    Tremor markedly reduces quality of life and causes a significant psychological burden for patients who are severely affected by this movement disorder. Pharmacologic and surgical treatments for tremor exist, but for patients who have failed medical therapy and are not surgical candidates, stereotactic radiosurgery is the only available treatment option. Of available stereotactic radiosurgical techniques for intractable tremor, the authors chose to evaluate the safety and efficacy of gamma knife stereotactic radiosurgical thalamotomy. In order to qualitatively synthesize available data a systematic review was conducted by searching MEDLINE (OvidSP 1946–January Week 1 2014) and Embase (OvidSP 1974–2014 January). The search strategy was not limited by study design or language of publication. All searches were conducted on January 7, 2014. Treatment efficacy, adverse outcomes, and patient deaths were reviewed and tabulated. Complications appeared months to years post procedure and most commonly consisted of mild contralateral numbness and transient hemiparesis. Rarely, more severe complications were reported, including dysphagia and death. Though no data from randomized controlled trials are available, our analysis of the literature indicates that unilateral gamma knife thalamotomy using doses from 130 to 150 Gy appears safe and well tolerated

  19. [Doses to organs at risk in conformational and stereotactic body radiation therapy: Liver].

    Science.gov (United States)

    Debbi, K; Janoray, G; Scher, N; Deutsch, É; Mornex, F

    2017-10-01

    The liver is an essential organ that ensures many vital functions such as metabolism of bilirubin, glucose, lipids, synthesis of coagulation factors, destruction of many toxins, etc. The hepatic parenchyma can be irradiated during the management of digestive tumors, right basithoracic, esophagus, abdomen in toto or TBI. In addition, radiotherapy of the hepatic area, which is mainly stereotactic, now occupies a central place in the management of primary or secondary hepatic tumors. Irradiation of the whole liver, or part of it, may be complicated by radiation-induced hepatitis. It is therefore necessary to respect strict dosimetric constraints both in stereotactic and in conformational irradiation in order to limit the undesired irradiation of the hepatic parenchyma which may vary according to the treatment techniques, the basic hepatic function or the lesion size. The liver is an organ with a parallel architecture, so the average tolerable dose in the whole liver should be considered rather than the maximum tolerable dose at one point. The purpose of this article is to propose a development of dose recommendations during conformation or stereotactic radiotherapy of the liver. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  20. [Stereotactic vacuum-assisted breast biopsy (Mammotome biopsy) for non-palpable microcalcification on mammography].

    Science.gov (United States)

    Matsuzaki, Saeko; Shiba, Eiichi; Kobayashi, Yasushi; Kawai, Mieko; Kitamura, Kaeko; Nishita, Toshiyuki; Nishio, Hiroshi; Kobayashi, Nobuyuki

    2005-01-01

    The purpose of this study was to assess the benefits of stereotactic vacuum-assisted breast biopsy in patients with non-palpable microcalcification detected on mammography. Between October 2001 and November 2003, stereotactic Mammotome biopsies were performed for 150 microcalcified lesions on mammography using the prone-type stereotactic vacuum-assisted breast biopsy system (Mammotest and Mammovision, Fischer, Denver, USA) . The mammography findings were classified according to the guidelines of The Japan Radiological Society/The Japan Association of Radiological Technologists. Ninety-eight cases were category 3, 38 were category 4, and 14 were category 5. All cases were determined to be cases of microcalcification by specimen radiography or histology. Complications were negligible. One hundred twenty of the cases were mastopathy, and 30 of them were breast cancer (14 were ductal carcinoma in situ, 7 were ductal carcinoma in situ with microinvasion, and 9 were invasive ductal carcinoma). Twenty-seven breast cancers were diagnosed as category 4 or 5 (51.9%) on mammography. The operative stages of 27 cases were as follows: 7 were stage 0, 17 were stage 1, and 3 were stage 2A. Twenty-four of 27 (88.9%) were early breast cancers. Mammotome biopsy is a safe and useful modality for the histological diagnosis of non-palpable microcalcifications.

  1. Primary lung sarcoma treated with stereotactic ablative radiotherapy: a case report

    Directory of Open Access Journals (Sweden)

    Yeo SG

    2017-07-01

    Full Text Available Seung-Gu Yeo Department of Radiation Oncology, Soonchunhyang University College of Medicine, Soonchunhyang University Hospital, Cheonan, Republic of Korea Abstract: Primary lung sarcoma (PLS is an extremely rare, very aggressive malignancy. Surgical removal is considered the treatment of choice, and patients who have been given conventional radiotherapy have had inferior outcomes. This study is the first describing a case of PLS treated with stereotactic ablative radiotherapy (SABR, which precisely targets a small tumor with a markedly higher biologically effective dose than conventional radiotherapy. The patient was an 82-year-old man who was diagnosed with primary lung leiomyosarcoma based on radiology, pathology, and immunohistochemical examinations. The PLS was located in the right lower lobe and measured 2.5 cm. No regional nodal or distant organ metastasis was observed. He was inoperable medically. The SABR was performed using volumetric modulated arc therapy and a dose of 56 Gy in four fractions. Follow-up computed tomography 2 months after SABR revealed a complete tumor response. The toxicity was limited to mild respiratory symptoms. The patient is alive and has had no evidence of disease for 2 years. This study suggests that SABR can be a safe and effective treatment option for PLS. Keywords: primary lung sarcoma, leiomyosarcoma, stereotactic ablative radiotherapy, stereotactic body radiotherapy, radiation therapy, sarcoma 

  2. Stereotactically-navigated percutaneous Irreversible Electroporation (IRE compared to conventional IRE: a prospective trial

    Directory of Open Access Journals (Sweden)

    Lukas P. Beyer

    2016-08-01

    Full Text Available Purpose. The purpose of this study was to compare CT-navigated stereotactic IRE (SIRE needle placement to non-navigated conventional IRE (CIRE for percutaneous ablation of liver malignancies. Materials and Methods. A prospective trial including a total of 20 patients was conducted with 10 patients in each arm of the study. IRE procedures were guided using either CT fluoroscopy (CIRE or a stereotactic planning and navigation system (SIRE. Primary endpoint was procedure time. Secondary endpoints were accuracy of needle placement, technical success rate, complication rate and dose-length product (DLP. Results. A total of 20 IRE procedures were performed to ablate hepatic malignancies (16 HCC, 4 liver metastases, 10 procedures in each arm. Mean time for placement of IRE electrodes in SIRE was significantly shorter with 27 ± 8 min compared to 87 ± 30 min for CIRE (p < 0.001. Accuracy of needle placement for SIRE was higher than CIRE (2.2 mm vs. 3.3 mm mean deviation, p < 0.001. The total DLP and the fluoroscopy DLP were significantly lower in SIRE compared to CIRE. Technical success rate and complication rates were equal in both arms. Conclusion. SIRE demonstrated a significant reduction of procedure length and higher accuracy compared to CIRE. Stereotactic navigation has the potential to reduce radiation dose for the patient and the radiologist without increasing the risk of complications or impaired technical success compared to CIRE.

  3. Radiocromic film, TLD, OSL and 'Paracas Phantom' by dosimetric intercomparation in stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Paucar Jauregui, R.; Condori Marcos, P.; Vidarte Garcia, F.

    2008-01-01

    Full text: In Peru, one deals to patients with arteriovenous malformations or cerebral tumors by means of stereotactic radiosurgery, using fine photon beams of high energy of 6 MeV, generated by a linear accelerator Varian 2100 Clinac CD of the Complejo Hospitalario San Pablo in Lima, Peru. In this work we describes the 'Dosimetric Intercomparation System of the Quality Assurance Program in Stereotactic Radiosurgery of the Complejo Hospitalario San Pablo (DIS)'. The DIS allows to guarantee application of the doses with high accuracy. It shows the good performance of the Local DIS's components: dosimetry of radiocromics films, dosimetry termoluminiscent (TLD), dosimetry of optically stimulated luminescence (OSL) and an anthropomorphic phantom of head constructed locally, denominated 'Paracas Phantom'. Also, in the International DIS practiced with The University of Texas Md Anderson Cancer Center, stands out results within the ranges: a) Dose to the center of the target (RDS/Institution): 0,95-1,05; b) Treated volumen (Measured/Institution): 0,75 - 1,05; c) Ratio of measure treated volume to target volume: 1,00 - 2,00; and d) Minimum dose to target (Minimum dose/Prescription dose): >0,90. It concludes that the DIS is important for the good decision making on the radiological safety of the patients dealt with stereotactic radiosurgery. (author)

  4. Simple Implant Augmentation Rhinoplasty

    OpenAIRE

    Nguyen, Anh H.; Bartlett, Erica L.; Kania, Katarzyna; Bae, Sang Mo

    2015-01-01

    Augmentation rhinoplasty among Asian patients is often performed to improve the height of the nasal dorsum. As the use of autogenous tissues poses certain limitations, alloplastic materials are a viable alternative with a long history of use in Asia. The superiority of one implant prosthesis over another for augmentation rhinoplasty is a matter of debate, with each material representing varying strengths and weaknesses, indications for use, and precautions to consider in nasal implant placeme...

  5. Quantitative ion implantation

    International Nuclear Information System (INIS)

    Gries, W.H.

    1976-06-01

    This is a report of the study of the implantation of heavy ions at medium keV-energies into electrically conducting mono-elemental solids, at ion doses too small to cause significant loss of the implanted ions by resputtering. The study has been undertaken to investigate the possibility of accurate portioning of matter in submicrogram quantities, with some specific applications in mind. The problem is extensively investigated both on a theoretical level and in practice. A mathematical model is developed for calculating the loss of implanted ions by resputtering as a function of the implanted ion dose and the sputtering yield. Numerical data are produced therefrom which permit a good order-of-magnitude estimate of the loss for any ion/solid combination in which the ions are heavier than the solid atoms, and for any ion energy from 10 to 300 keV. The implanted ion dose is measured by integration of the ion beam current, and equipment and techniques are described which make possible the accurate integration of an ion current in an electromagnetic isotope separator. The methods are applied to two sample cases, one being a stable isotope, the other a radioisotope. In both cases independent methods are used to show that the implantation is indeed quantitative, as predicted. At the same time the sample cases are used to demonstrate two possible applications for quantitative ion implantation, viz. firstly for the manufacture of calibration standards for instrumental micromethods of elemental trace analysis in metals, and secondly for the determination of the half-lives of long-lived radioisotopes by a specific activity method. It is concluded that the present study has advanced quantitative ion implantation to the state where it can be successfully applied to the solution of problems in other fields

  6. Ion implantation - an introduction

    International Nuclear Information System (INIS)

    Townsend, P.D.

    1986-01-01

    Ion implantation is a widely used technique with a literature that covers semiconductor production, surface treatments of steels, corrosion resistance, catalysis and integrated optics. This brief introduction outlines advantages of the technique, some aspects of the underlying physics and examples of current applications. Ion implantation is already an essential part of semiconductor technology while in many other areas it is still in an early stage of development. The future scope of the subject is discussed. (author)

  7. Comparison of registration accuracy of skin- and bone-implanted fiducials for frameless stereotaxis of the brain: a prospective study.

    Science.gov (United States)

    Ammirati, Mario; Gross, Jeffrey D; Ammirati, Giuseppe; Dugan, Sharon

    2002-08-01

    The registration accuracy of skin- and bone-implanted fiducials using a frameless stereotactic system were analyzed prospectively.Twenty-eight patients underwent resection of intra-axial neoplasmas after both skin- and bone-implantable fiducial markers were placed. Both sets of fiducials were independently co-registered to a magnetic resonance imaging data set acquired preoperatively using the ISG Viewing Wandtrade mark. Root mean square errors were recorded as an objective measure of registration accuracy of the two types of fiducials.Root mean square errors of bone-implanted fiducials registration were lower than those of skin fiducials; however, this difference was not statistically significant (p = 0.206).The registration accuracy of skin- and bone-implanted fiducials appears to be similar. Still, bone-implanted fiducials may be advantageous compared to skin fiducials when re-registration of the patient-image space is desired intraoperatively such as during major drift in the patient's position or after surgical repositioning.

  8. Simple Implant Augmentation Rhinoplasty.

    Science.gov (United States)

    Nguyen, Anh H; Bartlett, Erica L; Kania, Katarzyna; Bae, Sang Mo

    2015-11-01

    Augmentation rhinoplasty among Asian patients is often performed to improve the height of the nasal dorsum. As the use of autogenous tissues poses certain limitations, alloplastic materials are a viable alternative with a long history of use in Asia. The superiority of one implant prosthesis over another for augmentation rhinoplasty is a matter of debate, with each material representing varying strengths and weaknesses, indications for use, and precautions to consider in nasal implant placement. An implant prosthesis should be used on a case-by-case basis. Augmentation rhinoplasty requires the consideration of specific anatomical preoperative factors, including the external nose, nasal length, nasofrontal angle, humps, and facial proportions. It is equally important to consider several operative guidelines to appropriately shape implants to minimize the occurrence of adverse effects and postoperative complications. The most common postoperative complications include infection, nasal height change, movement of implant prosthesis, and silicone implant protrusion. In addition, the surgeon should consider the current standards of Asian beauty aesthetics to better understand the patient's desired outcome.

  9. Biomaterials in cochlear implants

    Science.gov (United States)

    Stöver, Timo; Lenarz, Thomas

    2011-01-01

    The cochlear implant (CI) represents, for almost 25 years now, the gold standard in the treatment of children born deaf and for postlingually deafened adults. These devices thus constitute the greatest success story in the field of ‘neurobionic’ prostheses. Their (now routine) fitting in adults, and especially in young children and even babies, places exacting demands on these implants, particularly with regard to the biocompatibility of a CI’s surface components. Furthermore, certain parts of the implant face considerable mechanical challenges, such as the need for the electrode array to be flexible and resistant to breakage, and for the implant casing to be able to withstand external forces. As these implants are in the immediate vicinity of the middle-ear mucosa and of the junction to the perilymph of the cochlea, the risk exists – at least in principle – that bacteria may spread along the electrode array into the cochlea. The wide-ranging requirements made of the CI in terms of biocompatibility and the electrode mechanism mean that there is still further scope – despite the fact that CIs are already technically highly sophisticated – for ongoing improvements to the properties of these implants and their constituent materials, thus enhancing the effectiveness of these devices. This paper will therefore discuss fundamental material aspects of CIs as well as the potential for their future development. PMID:22073103

  10. Plasma source ion implantation

    International Nuclear Information System (INIS)

    Conrad, J.R.; Forest, C.

    1986-01-01

    The authors' technique allows the ion implantation to be performed directly within the ion source at higher currents without ion beam extraction and transport. The potential benefits include greatly increased production rates (factors of 10-1000) and the ability to implant non-planar targets without rastering or shadowing. The technique eliminates the ion extractor grid set, beam raster equipment, drift space and target manipulator equipment. The target to be implanted is placed directly within the plasma source and is biased to a large negative potential so that plasma ions gain energy as they accelerate through the potential drop across the sheath that forms at the plasma boundary. Because the sheath surrounds the target on all sides, all surfaces of the target are implanted without the necessity to raster the beam or to rotate the target. The authors have succeeded in implanting nitrogen ions in a silicon target to the depths and concentrations required for surface treatment of materials like stainless steel and titanium alloys. They have performed ESCA measurements of the penetration depth profile of a silicon target that was biased to 30 kV in a nitrogen discharge plasma. Nitrogen ions were implanted to a depth of 700A at a peak concentration of 30% atomic. The measured profile is quite similar to a previously obtained profile in titanium targets with conventional techniques

  11. Contraceptive implants: current perspectives

    Directory of Open Access Journals (Sweden)

    Rowlands S

    2014-09-01

    Full Text Available Sam Rowlands,1,2 Stephen Searle3 1Centre of Postgraduate Medical Research and Education, School of Health and Social Care, Bournemouth University, Bournemouth, United Kingdom; 2Dorset HealthCare, Bournemouth, United Kingdom; 3Sexual Health Services, Chesterfield, United KingdomAbstract: Progestin-only contraceptive implants are a highly cost-effective form of long-acting reversible contraception. They are the most effective reversible contraceptives and are of a similar effectiveness to sterilization. Pregnancies are rare in women using this method of contraception, and those that do occur must be fully investigated, with an ultrasound scan of the arm and serum etonogestrel level if the implant cannot be located. There are very few contraindications to use of implants, and they have an excellent safety profile. Both acceptability and continuation with the method are high. Noncontraceptive benefits include improvements in dysmenorrhea, ovulatory pain, and endometriosis. Problematic bleeding is a relatively common adverse effect that must be covered in preinsertion information-giving and supported adequately if it occurs. Recognized training for both insertion and removal should be undertaken. Care needs to be taken at both insertion and removal to avoid neurovascular injury. Implants should always be palpable; if they are not, noninsertion should be assumed until disproven. Etonogestrel implants are now radiopaque, which aids localization. Anticipated difficult removals should be performed by specially trained experts. Keywords: contraceptive, subdermal implant, etonogestrel, levonorgestrel, progestin-only, long-acting reversible contraception

  12. Anodized dental implant surface

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Mishra

    2017-01-01

    Full Text Available Purpose: Anodized implants with moderately rough surface were introduced around 2000. Whether these implants enhanced biologic effect to improve the environment for better osseointegration was unclear. The purpose of this article was to review the literature available on anodized surface in terms of their clinical success rate and bone response in patients till now. Materials and Methods: A broad electronic search of MEDLINE and PubMed databases was performed. A focus was made on peer-reviewed dental journals. Only articles related to anodized implants were included. Both animal and human studies were included. Results: The initial search of articles resulted in 581 articles on anodized implants. The initial screening of titles and abstracts resulted in 112 full-text papers; 40 animal studies, 16 studies on cell adhesion and bacterial adhesion onto anodized surfaced implants, and 47 human studies were included. Nine studies, which do not fulfill the inclusion criteria, were excluded. Conclusions: The long-term studies on anodized surface implants do favor the surface, but in most of the studies, anodized surface is compared with that of machined surface, but not with other surfaces commercially available. Anodized surface in terms of clinical success rate in cases of compromised bone and immediately extracted sockets has shown favorable success.

  13. Short dental implants: an emerging concept in implant treatment.

    Science.gov (United States)

    Al-Hashedi, Ashwaq Ali; Taiyeb Ali, Tara Bai; Yunus, Norsiah

    2014-06-01

    Short implants have been advocated as a treatment option in many clinical situations where the use of conventional implants is limited. This review outlines the effectiveness and clinical outcomes of using short implants as a valid treatment option in the rehabilitation of edentulous atrophic alveolar ridges. Initially, an electronic search was performed on the following databases: Medline, PubMed, Embase, Cochrane Database of Systematic Reviews, and DARE using key words from January 1990 until May 2012. An additional hand search was included for the relevant articles in the following journals: International Journal of Oral and Maxillofacial Implants, Clinical Oral Implants Research, Journal of Clinical Periodontology, International Journal of Periodontics, Journal of Periodontology, and Clinical Implant Dentistry and Related Research. Any relevant papers from the journals' references were hand searched. Articles were included if they provided detailed data on implant length, reported survival rates, mentioned measures for implant failure, were in the English language, involved human subjects, and researched implants inserted in healed atrophic ridges with a follow-up period of at least 1 year after implant-prosthesis loading. Short implants demonstrated a high rate of success in the replacement of missing teeth in especially atrophic alveolar ridges. The advanced technology and improvement of the implant surfaces have encouraged the success of short implants to a comparable level to that of standard implants. However, further randomized controlled clinical trials and prospective studies with longer follow-up periods are needed.

  14. Comparison of stereotactic radiosurgery and fractionated stereotactic radiotherapy of acoustic neurinomas according to 3-D tumor volume shrinkage and quality of life

    International Nuclear Information System (INIS)

    Henzel, Martin; Engenhart-Cabillic, Rita; Hamm, Klaus; Surber, Gunnar; Kleinert, Gabriele; Sitter, Helmut; Gross, Markus W.

    2009-01-01

    Background and purpose: stereotactic radiosurgery (SRS) and also fractionated stereotactic radiotherapy (SRT) offer high local control (LC) rates (> 90%). This study aimed to evaluate three-dimensional (3-D) tumor volume (TV) shrinkage and to assess quality of life (QoL) after SRS/SRT. Patients and methods: from 1999 to 2005, 35/74 patients were treated with SRS, and 39/74 with SRT. Median age was 60 years. Treatment was delivered by a linear accelerator. Median single dose was 13 Gy (SRS) or 54 Gy (SRT). Patients were followed up ≥ 12 months after SRS/SRT. LC and toxicity were evaluated by clinical examinations and magnetic resonance imaging. 3-D TV shrinkage was evaluated with the planning system. QoL was assessed using the questionnaire Short Form-36. Results: Median follow-up was 50/36 months (SRS/SRT). Actuarial 5-year freedom from progression/overall survival was 88.1%/100% (SRS), and 87.5%/87.2% (SRT). TV shrinkage was 15.1%/40.7% (SRS/SRT; p = 0.01). Single dose ( 0.05). Compared with the German normal population, patients had worse values for all domains except for mental health. Conclusion: TV shrinkage was significantly higher after SRT than after SRS. Main symptoms were not affected by SRS/SRT. Retrospectively, QoL was neither affected by SRS nor by SRT. (orig.)

  15. Stereotactic Radiosurgery for Benign (World Health Organization Grade I) Cavernous Sinus Meningiomas-International Stereotactic Radiosurgery Society (ISRS) Practice Guideline: A Systematic Review.

    Science.gov (United States)

    Lee, Cheng-Chia; Trifiletti, Daniel M; Sahgal, Arjun; DeSalles, Antonio; Fariselli, Laura; Hayashi, Motohiro; Levivier, Marc; Ma, Lijun; Álvarez, Roberto Martínez; Paddick, Ian; Regis, Jean; Ryu, Samuel; Slotman, Ben; Sheehan, Jason

    2018-03-15

    Stereotactic radiosurgery (SRS) has become popular as a standard treatment for cavernous sinus (CS) meningiomas. To summarize the published literature specific to the treatment of CS meningioma with SRS found through a systematic review, and to create recommendations on behalf of the International Stereotactic Radiosurgery Society. Articles published from January 1963 to December 2014 were systemically reviewed. Three electronic databases, PubMed, EMBASE, and The Cochrane Central Register of Controlled Trials, were searched. Publications in English with at least 10 patients (each arm) were included. Of 569 screened abstracts, a total of 49 full-text articles were included in the analysis. All studies were retrospective. Most of the reports had favorable outcomes with 5-yr progression-free survival (PFS) rates ranging from 86% to 99%, and 10-yr PFS rates ranging from 69% to 97%. The post-SRS neurological preservation rate ranged from 80% to 100%. Resection can be considered for the treatment of larger (>3 cm in diameter) and symptomatic CS meningioma in patients both receptive to and medically eligible for open surgery. Adjuvant or salvage SRS for residual or recurrent tumor can be utilized depending on factors such as tumor volume and proximity to adjacent critical organs at risk. The literature is limited to level III evidence with respect to outcomes of SRS in patients with CS meningioma. Based on the observed results, SRS offers a favorable benefit to risk profile for patients with CS meningioma.

  16. Stereotactic body radiotherapy for renal cell cancer and pancreatic cancer. Literature review and practice recommendations of the DEGRO Working Group on Stereotactic Radiotherapy

    International Nuclear Information System (INIS)

    Panje, Cedric; Andratschke, Nikolaus; Guckenberger, Matthias; Brunner, Thomas B.; Niyazi, Maximilian

    2016-01-01

    This report of the Working Group on Stereotactic Radiotherapy of the German Society of Radiation Oncology (DEGRO) aims to provide a literature review and practice recommendations for stereotactic body radiotherapy (SBRT) of primary renal cell cancer and primary pancreatic cancer. A literature search on SBRT for both renal cancer and pancreatic cancer was performed with focus on prospective trials and technical aspects for clinical implementation. Data on renal and pancreatic SBRT are limited, but show promising rates of local control for both treatment sites. For pancreatic cancer, fractionated SBRT should be preferred to single-dose treatment to reduce the risk of gastrointestinal toxicity. Motion-compensation strategies and image guidance are paramount for safe SBRT delivery in both tumor entities. SBRT for renal cancer and pancreatic cancer have been successfully evaluated in phase I and phase II trials. Pancreatic SBRT should be practiced carefully and only within prospective protocols due to the risk of severe gastrointestinal toxicity. SBRT for primary renal cell cancer appears a viable option for medically inoperable patients but future research needs to better define patient selection criteria and the detailed practice of SBRT. (orig.) [de

  17. BAHA implant: implantation technique and complications.

    Science.gov (United States)

    Fontaine, N; Hemar, P; Schultz, P; Charpiot, A; Debry, C

    2014-02-01

    BAHA implants have been shown to be effective in certain forms of conductive hearing loss, but the presence of the titanium abutment is responsible for sometimes severe skin reactions. The objective of this study was to compare two operative techniques: skin flap, and full-thickness skin graft. Between January 2004 and January 2011, 72 patients were treated by BAHA implant and 32 of these patients (total of 41 implants) were included in the study. Two surgical techniques were used: full-thickness skin graft (n=21) and skin flap (n=20). Four types of skin complications were observed: necrosis, inflammation/infection, hypertrophic scar, and fixture loss due to inadequate osseointegration. Complications requiring surgical revision were observed in 20% of cases with the skin flap method and 38% of cases with the skin graft technique, with no significant difference between the two groups (P=0.31). The skin graft technique appears to be associated with a higher rate of major complications. The most common complication is hypertrophic scar. The apparently high complication rate in this series can be explained by a selection bias (exclusion of a large number of complication-free patients). Copyright © 2013. Published by Elsevier Masson SAS.

  18. Stereotactic laser induced thermotherapy (LITT): a novel treatment for brain lesions regrowing after radiosurgery.

    Science.gov (United States)

    Torres-Reveron, Juan; Tomasiewicz, Hilarie C; Shetty, Anil; Amankulor, Nduka M; Chiang, Veronica L

    2013-07-01

    Since the inception of radiosurgery, the management of brain metastases has become a common problem for neurosurgeons. Although the use of stereotactic radiosurgery and/or whole brain radiation therapy serves to control the majority of disease burden, patients who survive longer than 6-8 months sometimes face the problem of symptomatic radiographically regrowing lesions with few treatment options. Here we investigate the feasibility of use of MRI-guided stereotactic laser induced thermotherapy (LITT) as a novel treatment option for these lesions. Six patients who had previously undergone gamma knife stereotactic radiosurgery for brain metastases were selected. All patients had an initial favorable response to radiosurgery but subsequently developed regrowth of at least one lesion associated with recurrent edema and progressive neurological symptoms requiring ongoing steroids for symptom control. All lesions were evaluated for craniotomy, but were deemed unresectable due to deep location or patient's comorbidities. Stereotactic biopsies were performed prior to the thermotherapy procedure in all cases. LITT was performed using the Visualase system and follow-up MRI imaging was used to determine treatment response. In all six patients biopsy results were negative for tumor and consistent with adverse radiation effects also known as radiation necrosis. Patients tolerated the procedure well and were discharged from the hospital within 48 h of the procedure. In 4/6 cases there was durable improvement of neurological symptoms until death. In all cases steroids were weaned off within 2 months. One patient died from systemic causes related to his cancer a month after the procedure. One patient had regrowth of the lesion 3 months after the procedure and required re-initiation of steroids and standard craniotomy for surgical resection. There were no complications directly related to the thermocoagulation procedure. Stereotactic laser induced thermotherapy is a feasible

  19. Dosimetric comparison between intra-cavitary breast brachytherapy techniques for accelerated partial breast irradiation and a novel stereotactic radiotherapy device for breast cancer: GammaPod™

    Science.gov (United States)

    Ödén, Jakob; Toma-Dasu, Iuliana; Yu, Cedric X.; Feigenberg, Steven J.; Regine, William F.; Mutaf, Yildirim D.

    2013-07-01

    The GammaPod™ device, manufactured by Xcision Medical Systems, is a novel stereotactic breast irradiation device. It consists of a hemispherical source carrier containing 36 Cobalt-60 sources, a tungsten collimator with two built-in collimation sizes, a dynamically controlled patient support table and a breast immobilization cup also functioning as the stereotactic frame for the patient. The dosimetric output of the GammaPod™ was modelled using a Monte Carlo based treatment planning system. For the comparison, three-dimensional (3D) models of commonly used intra-cavitary breast brachytherapy techniques utilizing single lumen and multi-lumen balloon as well as peripheral catheter multi-lumen implant devices were created and corresponding 3D dose calculations were performed using the American Association of Physicists in Medicine Task Group-43 formalism. Dose distributions for clinically relevant target volumes were optimized using dosimetric goals set forth in the National Surgical Adjuvant Breast and Bowel Project Protocol B-39. For clinical scenarios assuming similar target sizes and proximity to critical organs, dose coverage, dose fall-off profiles beyond the target and skin doses at given distances beyond the target were calculated for GammaPod™ and compared with the doses achievable by the brachytherapy techniques. The dosimetric goals within the protocol guidelines were fulfilled for all target sizes and irradiation techniques. For central targets, at small distances from the target edge (up to approximately 1 cm) the brachytherapy techniques generally have a steeper dose fall-off gradient compared to GammaPod™ and at longer distances (more than about 1 cm) the relation is generally observed to be opposite. For targets close to the skin, the relative skin doses were considerably lower for GammaPod™ than for any of the brachytherapy techniques. In conclusion, GammaPod™ allows adequate and more uniform dose coverage to centrally and peripherally

  20. Surgical Evacuation of Spontaneous Supratentorial Lobar Intracerebral Hemorrhage: Comparison of Safety and Efficacy of Stereotactic Aspiration, Endoscopic Surgery, and Craniotomy.

    Science.gov (United States)

    Li, Yuqian; Yang, Ruixin; Li, Zhihong; Yang, Yanping; Tian, Bo; Zhang, Xingye; Wang, Bao; Lu, Dan; Guo, Shaochun; Man, Minghao; Yang, Yang; Luo, Tao; Gao, Guodong; Li, Lihong

    2017-09-01

    The safety and efficacy of craniotomy, endoscopic surgery, and stereotactic aspiration for surgical evacuation of spontaneous supratentorial lobar intracerebral hemorrhage (ICH) is yet uncertain. The present study analyzed the clinical and radiographic data from 99 patients with spontaneous supratentorial lobar ICH, retrospectively, to address this issue. Patients who underwent craniotomy, endoscopy surgery, or stereotactic aspiration were assigned to the craniotomy group (n = 31), endoscopy surgery group (n = 32), or stereotactic aspiration group (n = 36), respectively. The characteristics of all the enrolled patients at the time of admission were assimilated. Also, the therapeutic effects of the three surgical procedures were evaluated based on short-term outcomes within 30 days and long-term outcomes at 6 months after the ictus. The results showed that stereotactic aspiration and endoscopic surgery were associated with a superior clinical therapeutic effect in both short-term and long-term outcomes than craniotomy for the treatment of spontaneous supratentorial lobar ICH. Notably, severely affected patients with hematoma volume > 60 mL or Glasgow Coma Scale score 4-8 may benefit more from endoscopic surgery than the two other surgical procedures. The current findings demonstrate that both stereotactic aspiration and endoscopic surgery possess an apparent advantage over craniotomy for the evacuation of spontaneous supratentorial lobar ICH. The endoscopic surgery might be more safe and effective with higher evacuation rate, better functional neurological outcomes, and lower complication and mortality rates. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Percutaneous computed tomography guided biopsy of spinal lesions

    International Nuclear Information System (INIS)

    Vakhnina-Vassila, O; Flokatoula, M.; Stamatakis, V.; Geroukis, I.; Vlachou, I.; Petinelli, A.; Stathopoulou, S.; Kokkinis, C.

    2012-01-01

    Full text: Introduction: The decision to undertake a spinal biopsy has to be based on a thorough risk benefit analysis. Objectives and tasks: The main purpose of this presentation is to review all the parameters and technical characteristics that must be taken under consideration for a proper planning and implementation of a percutaneous CT-guided biopsy of spinal lesions. Material and methods: The benefit of a CT-guided biopsy is determined by the assessment that the information received will affect the patient's clinical management and therapeutic decisions. Prerequisite in designing and conducting a CT-guided biopsy is the knowledge of : 1) The advantages and disadvantages against an open biopsy; 2) Its indications and counter-indications; 3)The complications that may occur; 4) Imaging tests that must be taken in before the procedure; 5)The exact position of the patient that must be chosen (prone, supine, lateral recumbent); 6)The needle's approach that is chosen (rear/front, through neck, costospinal, lateral); 7) Evaluation of the parameters for targeting the lesion (spin section, section of the vertebral, lesion section); 8)The advantages and limitations of each technique (thin needle biopsy and thick needle biopsy); 9)The limitations of the procedure. Results: CT-guided percutaneous biopsy, a technique of high diagnostic accuracy and low percentage of complications, is the method of choice for the pathoanatomical determination and accurate diagnosis of spinal lesions. Conclusion: Knowledge of the parameters that ensure its proper planning and execution settle the procedure as a valuable and secure tool that raise the diagnostic accuracy

  2. Computed-Tomography-Guided Punctures Using a New Guidance Device

    International Nuclear Information System (INIS)

    Magnusson, A.; Radecka, E.; Loennemark, M.; Raland, H.

    2005-01-01

    PURPOSE: To evaluate a new adjunctive guidance device, a puncture guide, constructed to simplify computed tomography (CT)-guided punctures and to make the procedure more accurate and safe. MATERIAL AND METHODS: 17 patients referred for CT-guided punctures were included in the study. There were 10 thoracic and 7 abdominal or pelvic lesions with a mean maximum diameter of 29 ± 18 mm. All punctures were performed using a laser guide combined with the new device. The needle guide created a streak artefact in the image, indicating the needle path. RESULTS: The puncture was successful at the first attempt in 15 of the 17 patients. The artefact was visible in all patients, and in the majority there was a distinct artefact reaching from the entry point to the lesion. The deviation between the angle of the streak artefact and the final angle of the needle was 1.1 degrees. CONCLUSION: The benefits of the puncture guide were the artefact pointing at the target, the needle support, and accuracy when performing CT-guided punctures

  3. Optical Coherence Tomography-Guided Decisions in Retinoblastoma Management.

    Science.gov (United States)

    Soliman, Sameh E; VandenHoven, Cynthia; MacKeen, Leslie D; Héon, Elise; Gallie, Brenda L

    2017-06-01

    Assess the role of handheld optical coherence tomography (OCT) in guiding management decisions during diagnosis, treatment, and follow-up of eyes affected by retinoblastoma. Retrospective, noncomparative, single-institution case series. All children newly diagnosed with retinoblastoma from January 2011 to December 2015 who had an OCT session during their active treatment at The Hospital for Sick Children (SickKids) in Toronto, Canada. The OCT sessions for fellow eyes of unilateral retinoblastoma without any suspicious lesion and those performed more than 6 months after the last treatment were excluded. Data collected included age at presentation, sex, family history, RB1 mutation status, 8th edition TNMH cancer staging and International Intraocular Retinoblastoma Classification (IIRC), and number of OCT sessions per eye. Details of each session were scored for indication-related details (informative or not) and assessed for guidance (directive or not), diagnosis (staging changed, new tumors found or excluded), treatment (modified, stopped, or modality shifted), or follow-up modified. Frequency of OCT-guided management decisions, stratified by indication and type of guidance (confirmatory vs. influential). Sixty-three eyes of 44 children had 339 OCT sessions over the course of clinical management (median number of OCT scans per eye, 5; range, 1-15). The age at presentation and presence of a heritable RB1 mutation significantly correlated with an increased number of OCT sessions. Indications included evaluation of post-treatment scar (55%) or fovea (16%), and posterior pole scanning for new tumors (11%). Of all sessions, 92% (312/339) were informative; 19 of 27 noninformative sessions had large, elevated lesions; of these, 14 of 19 were T2a or T2b (IIRC group C or D) eyes. In 94% (293/312) of the informative sessions, OCT directed treatment decisions (58%), diagnosis (16%), and follow-up (26%). Optical coherence tomography influenced and changed management from pre-OCT clinical plans in 15% of all OCT sessions and 17% of directive sessions. Optical coherence tomography improves the accuracy of clinical evaluation in retinoblastoma management. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  4. A gene therapy of experimental parkinsonism monkeys with intra-striatums implantation of AAV-TH with CT guiding

    International Nuclear Information System (INIS)

    Wang Wei; Mao Jun; Yu Xiaoping; Liu Sheng; Hu Weixin; Zeng Zhaojun; Cai Weijun; Wu Xiaobing

    2003-01-01

    Objective: To observe the transfection ability to neuron and the therapy effect of adeno-associated virus vector (AAV) mediated intracerebral expressing of human tyrosine hydroxylase (TH) in the Rhesus monkey of Parkinson disease with CT guiding. Methods: Six Rhesus monkeys were induced into hemi-parkinsonism models by infusion of MPTP into right internal carotid artery. Under the guidance of CT and stereotactic apparatus, the recombinant adeno-associated virus vectors-human tyrosine hydroxylase were injected into the right caudate nucleus of 5 PD monkeys. The motor ability of the PD model was evaluated for 6 months after implantation. The content of DA, DOPAC, and HVA in the caudate nucleus was assayed with HPLC, and the expression of the tyrosine hydroxylase gene was detected with immunohistochemistry and RT-PCR. Results: The method of stereotactic puncture guided with CT had the features of real-time operating, fine location, and mini-trauma. The motor ability of all five models was all ameliorated after stereotactical injection of AAV-hTH vectors from two weeks up to six months. One PD monkey did not show any twist in response to apomorphine test. The frequency of twirl in the other 4 PD monkeys in response to apomorphine test was decreased by 42%-70% compared with that preoperatively. The contents of DA and DA metabolites in the lesion caudate nucleus were increased. Many TH positive cells in the implantation sites of caudate nucleus were shown by immunohistochemistry, which was different from the contralateral caudate nucleus. TH-mRNA was found in the treated side of caudate nucleus with RT-PCR, but no positive detection in the untreated side of caudate nucleus or in other sites in the brain. The negative results of RT-PCR were also shown in samples of the heart, liver, kidney tissue, or right side caudate nucleus of the uninjected monkey. Conclusion: Under the guidance of CT and stereotactic apparatus, the AAV-hTH vector can be injected accurately into the

  5. New dental implant selection criterion based on implant design

    OpenAIRE

    El-Anwar, Mohamed I.; El-Zawahry, Mohamed M.; Ibraheem, Eman M.; Nassani, Mohammad Zakaria; ElGabry, Hisham

    2017-01-01

    Objective: A comparative study between threaded and plain dental implant designs was performed to find out a new criterion for dental implant selection. Materials and Methods: Several dental implant designs with a systematic increase in diameter and length were positioned in a cylindrical-shaped bone section and analyzed using finite element method. Four loading types were tested on different dental implant designs; tension of 50 N, compression of 100 N, bending of 20 N, and torque of 2 Nm, t...

  6. Implant isotopy (II).

    Science.gov (United States)

    Muratori, G

    1995-01-01

    Because nature has given humans from 14 to 16 teeth per arch, the author maintains that an implantologist ought to replace each missing tooth with an implant and calls this philosophical creed "implant isotopy". Three different prosthetic solutions are suggested for the cases of either complete or partially edentulous arches, where from 12 to 14 abutments are emerging from the gingiva. The first type consists of parallel protruding posts. The second type is a modification of the first method through the connection of all the posts (although they are not perfectly parallel) via a titanium wire-drawn bar to be welded via endoral welding. Finally, the third type consists of a laboratory cast titanium denture composed of different sections that can be connected to one another and to the implant abutments via endoral welding.

  7. Dental implants: A review.

    Science.gov (United States)

    Guillaume, B

    2016-12-01

    A high number of patients have one or more missing tooth and it is estimated that one in four American subjects over the age of 74 have lost all their natural teeth. Many options exist to replace missing teeth but dental implants have become one of the most used biomaterial to replace one (or more) missing tooth over the last decades. Contemporary dental implants made with titanium have been proven safe and effective in large series of patients. This review considers the main historical facts concerned with dental implants and present the different critical factors that will ensure a good osseo-integration that will ensure a stable prosthesis anchorage. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. Complications in implant dentistry.

    Science.gov (United States)

    Hanif, Ayesha; Qureshi, Saima; Sheikh, Zeeshan; Rashid, Haroon

    2017-01-01

    After tooth loss, an individual may seek tooth replacement so that his/her function and esthetics could be restored. Clinical prosthodontics, during the past decade, has significantly improved and developed according to the advancements in the science and patient's demands and needs. Conventional options in prosthodontics for substituting a missing single tooth include the removable partial denture, partial and full coverage bridgework, and resin-bonded bridgework. Dental implants have gained increasing popularity over the years as they are capable of restoring the function to near normal in both partial and completely edentulous arches. With substantial evidence available, fixed implant-supported prosthesis are fully acknowledged as a reliable treatment option for the replacement of single or multiple missing teeth nowadays. While dental implants are increasingly becoming the choice of replacement for missing teeth, the impediments associated with them are progressively emerging too.

  9. Intracranial depth electrodes implantation in the era of image-guided surgery

    Directory of Open Access Journals (Sweden)

    Ricardo Silva Centeno

    2011-08-01

    Full Text Available The advent of modern image-guided surgery has revolutionized depth electrode implantation techniques. Stereoelectroencephalography (SEEG, introduced by Talairach in the 1950s, is an invasive method for three-dimensional analysis on the epileptogenic zone based on the technique of intracranial implantation of depth electrodes. The aim of this article is to discuss the principles of SEEG and their evolution from the Talairach era to the image-guided surgery of today, along with future prospects. Although the general principles of SEEG have remained intact over the years, the implantation of depth electrodes, i.e. the surgical technique that enables this method, has undergone tremendous evolution over the last three decades, due the advent of modern imaging techniques, computer systems and new stereotactic techniques. The use of robotic systems, the constant evolution of imaging and computing techniques and the use of depth electrodes together with microdialysis probes will open up enormous prospects for applying depth electrodes and SEEG both for investigative use and for therapeutic use. Brain stimulation of deep targets and the construction of "smart" electrodes may, in the near future, increase the need to use this method.

  10. Intracranial depth electrodes implantation in the era of image-guided surgery.

    Science.gov (United States)

    Centeno, Ricardo Silva; Yacubian, Elza Márcia Targas; Caboclo, Luis Otávio Sales Ferreira; Júnior, Henrique Carrete; Cavalheiro, Sérgio

    2011-08-01

    The advent of modern image-guided surgery has revolutionized depth electrode implantation techniques. Stereoelectroencephalography (SEEG), introduced by Talairach in the 1950s, is an invasive method for three-dimensional analysis on the epileptogenic zone based on the technique of intracranial implantation of depth electrodes. The aim of this article is to discuss the principles of SEEG and their evolution from the Talairach era to the image-guided surgery of today, along with future prospects. Although the general principles of SEEG have remained intact over the years, the implantation of depth electrodes, i.e. the surgical technique that enables this method, has undergone tremendous evolution over the last three decades, due the advent of modern imaging techniques, computer systems and new stereotactic techniques. The use of robotic systems, the constant evolution of imaging and computing techniques and the use of depth electrodes together with microdialysis probes will open up enormous prospects for applying depth electrodes and SEEG both for investigative use and for therapeutic use. Brain stimulation of deep targets and the construction of "smart" electrodes may, in the near future, increase the need to use this method.

  11. Tungsten contamination in ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Polignano, M.L., E-mail: maria.polignano@st.com; Barbarossa, F.; Galbiati, A.; Magni, D.; Mica, I.

    2016-06-15

    In this paper the tungsten contamination in ion implantation processes is studied by DLTS analysis both in typical operating conditions and after contamination of the implanter by implantation of wafers with an exposed tungsten layer. Of course the contaminant concentration is orders of magnitude higher after contamination of the implanter, but in addition our data show that different mechanisms are active in a not contaminated and in a contaminated implanter. A moderate tungsten contamination is observed also in a not contaminated implanter, however in that case contamination is completely not energetic and can be effectively screened by a very thin oxide. On the contrary, the contamination due to an implantation in a previously contaminated implanter is reduced but not suppressed even by a relatively thick screen oxide. The comparison with SRIM calculations confirms that the observed deep penetration of the contaminant cannot be explained by a plain sputtering mechanism.

  12. [Tinnitus and implants].

    Science.gov (United States)

    Despreaux, G; Tison, P; Van Den Abbeele, T; Moine, A; Frachet, B

    1990-01-01

    The experience with cochlear implantation at Avicenne hospital prompted us to carry out a retrospective study on tinnitus in a population of operated patients. Improvement or disappearance of the symptoms was noted in all cases. These results, which partly match those found in the literature, are probably produced by rehabilitation inhibiting the "deafferentation" mechanisms in analogy with pain phenomena. In some precise cases, which are described, they led us to proposing implantation even though the main, if not sole, complaint of the patient was tinnitus.

  13. Osseointegration of Immediate Transalveolar Implants

    OpenAIRE

    Yoel González Beriau; Eduardo Enrique Castillo Betancourt; Bienvenido Mesa Reinaldo

    2016-01-01

    Background: osseointegration is critical to start prosthetic rehabilitation. Objective: to describe osseointegration of immediate transalveolar implants. Methods: a prospective case series study was conducted from January 2012 to December 2013. It included all patients (75 patients with 79 implants) who attended the Prosthodontics service. Age, sex, osseointegration, cause of tooth loss, region of the implant, specific tooth, bone level and keratinized gingiva around the implant, were the var...

  14. Recent advances in dental implants.

    Science.gov (United States)

    Hong, Do Gia Khang; Oh, Ji-Hyeon

    2017-12-01

    Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

  15. An Excellent Clinical Outcome with Stereotactic Radiosurgery in a Geriatric Patient with Multiple and Recurrent Brain Metastases.

    Science.gov (United States)

    Thapa, Bicky; Borghei-Razavi, Hamid; M Mohammadi, Alireza; Ahluwalia, Manmeet

    2017-12-22

    The incidence of brain metastases range from 10 to 20% of all adult patients with cancer and lung cancer is associated with one of the highest incidences of brain metastases. In geriatric patients, who already have limited cognitive function, whole brain radiation therapy (WBRT) can be a problem. Stereotactic radiosurgery (SRS) is a one day, outpatient treatment with minimal effect to normal brain and could particularly be useful in elderly patients. We report the case of a geriatric patient with metastatic lung adenocarcinoma who had multiple brain metastases and recurrences, who responded well to the stereotactic radiosurgery (six sessions) with acceptable tumor control.

  16. Stereotactic fractionated radiotherapy and LINAC radiosurgery in the treatment of vestibular schwannoma-report about both stereotactic methods from a single institution.

    Science.gov (United States)

    Kopp, Christine; Fauser, Claudius; Müller, Axel; Astner, Sabrina T; Jacob, Vesna; Lumenta, Christianto; Meyer, Bernhard; Tonn, Jörg-Christian; Molls, Michael; Grosu, Anca-Ligia

    2011-08-01

    To evaluate tumor control and side effects associated with radiosurgery (RS) and stereotactic fractionated radiotherapy (SFR) for vestibular schwannomas (VSs) in a group of patients treated at the same institution. Between May 1997 and June 2007, 115 consecutive cases of VS were treated in our department. The SFR group (47 patients), including larger tumors (maximum diameter >1.5 cm), received a total dose of 54 Gy at 1.8 Gy per fraction. The RS group (68 patients, maximum diameter new trigeminal neuropathy occurred in 9 of 68 patients (13%). A high tumor control rate and low number of side effects are registered after SFR and RS of VS. These results confirm that considering tumor diameter, both RS and SFR are good treatment modalities for VS. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. SU-E-T-642: Safety Procedures for Error Elimination in Cyberknife Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT)

    International Nuclear Information System (INIS)

    Hussain, A; Alkafi, A; Al-Najjar, W; Moftah, B

    2014-01-01

    Purpose: Cyberknife system is used for providing stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) hypofractionation scheme. The whole treatment delivery is based on live imaging of the patient. The minor error made at any stage may bring severe radiation injury to the patient or damage to the system itself. Several safety measures were taken to make the system safer. Methods: The radiation treatment provided thru a 6MV linac attached to Kuka robot (Cyberknife G4, Accuray Inc. Sunnyvale, CA, USA). Several possible errors were identified related to patient alignment, treatment planning, dose delivery and physics quality assurance. During dose delivery, manual and visual checks were introduced to confirm pre and intra-treatment imaging to reduce possible errors. One additional step was introduced to confirm that software tracking-tools had worked correctly with highest possible confidence level. Robotic head move in different orientations over and around the patient body, the rigidity of linac-head cover and other accessories was checked periodically. The vender was alerted when a tiny or bigger piece of equipment needed additional interlocked support. Results: As of our experience treating 525 patients on Cyberknife during the last four years, we saw on and off technical issues. During image acquisition, it was made essential to follow the site-specific imaging protocols. Adequate anatomy was contoured to document the respective doses. Followed by auto-segmentation, manual tweaking was performed on every structure. The calculation box was enclosing the whole image during the final calculation. Every plan was evaluated on slice-by slice basis. To review the whole process, a check list was maintained during the physics 2nd-check. Conclusion: The implementation of manual and visual additional checks introduced along with automated checks for confirmation was found promising in terms of reduction in systematic errors and making the system

  18. Stereotactic radiosurgery and fractionated stereotactic radiotherapy for the treatment of acoustic schwannomas: comparative observations of 125 patients treated at one institution

    International Nuclear Information System (INIS)

    Andrews, David W.; Suarez, Oscar; Goldman, H. Warren; Downes, M. Beverly; Bednarz, Greg; Corn, Benjamin W.; Werner-Wasik, Maria; Rosenstock, Jeffrey; Curran, Walter J.

    2001-01-01

    Background: Stereotactic radiosurgery (SRS) and, more recently, fractionated stereotactic radiotherapy (SRT) have been recognized as noninvasive alternatives to surgery for the treatment of acoustic schwannomas. We review our experience of acoustic tumor treatments at one institution using a gamma knife for SRS and the first commercial world installation of a dedicated linac for SRT. Methods: Patients were treated with SRS on the gamma knife or SRT on the linac from October 1994 through August 2000. Gamma knife technique involved a fixed-frame multiple shot/high conformality single treatment, whereas linac technique involved daily conventional fraction treatments involving a relocatable frame, fewer isocenters, and high conformality established by noncoplanar arc beam shaping and differential beam weighting. Results: Sixty-nine patients were treated on the gamma knife, and 56 patients were treated on the linac, with 1 NF-2 patient common to both units. Three patients were lost to follow-up, and in the remaining 122 patients, mean follow-up was 119±67 weeks for SRS patients and 115±96 weeks for SRT patients. Tumor control rates were high (≥97%) for sporadic tumors in both groups but lower for NF-2 tumors in the SRT group. Cranial nerve morbidities were comparably low in both groups, with the exception of functional hearing preservation, which was 2.5-fold higher in patients who received conventional fraction SRT. Conclusion: SRS and SRT represent comparable noninvasive treatments for acoustic schwannomas in both sporadic and NF-2 patient groups. At 1-year follow-up, a significantly higher rate of serviceable hearing preservation was achieved in SRT sporadic tumor patients and may therefore be preferable to alternatives including surgery, SRS, or possibly observation in patients with serviceable hearing

  19. Biological in situ Dose Painting for Image-Guided Radiation Therapy Using Drug-Loaded Implantable Devices

    International Nuclear Information System (INIS)

    Cormack, Robert A.; Sridhar, Srinivas; Suh, W. Warren; D'Amico, Anthony V.; Makrigiorgos, G. Mike

    2010-01-01

    Purpose: Implantable devices routinely used for increasing spatial accuracy in modern image-guided radiation treatments (IGRT), such as fiducials or brachytherapy spacers, encompass the potential for in situ release of biologically active drugs, providing an opportunity to enhance the therapeutic ratio. We model this new approach for two types of treatment. Methods and Materials: Radiopaque fiducials used in IGRT, or prostate brachytherapy spacers ('eluters'), were assumed to be loaded with radiosensitizer for in situ drug slow release. An analytic function describing the concentration of radiosensitizer versus distance from eluters, depending on diffusion-elimination properties of the drug in tissue, was developed. Tumor coverage by the drug was modeled for tumors typical of lung stereotactic body radiation therapy treatments for various eluter dimensions and drug properties. Six prostate 125 I brachytherapy cases were analyzed by assuming implantation of drug-loaded spacers. Radiosensitizer-induced subvolume boost was simulated from which biologically effective doses for typical radiosensitizers were calculated in one example. Results: Drug distributions from three-dimensional arrangements of drug eluters versus eluter size and drug properties were tabulated. Four radiosensitizer-loaded fiducials provide adequate radiosensitization for ∼4-cm-diameter lung tumors, thus potentially boosting biologically equivalent doses in centrally located stereotactic body treated lesions. Similarly, multiple drug-loaded spacers provide prostate brachytherapy with flexible shaping of 'biologically equivalent doses' to fit requirements difficult to meet by using radiation alone, e.g., boosting a high-risk region juxtaposed to the urethra while respecting normal tissue tolerance of both the urethra and the rectum. Conclusions: Drug loading of implantable devices routinely used in IGRT provides new opportunities for therapy modulation via biological in situ dose painting.

  20. Successful treatment of tumor-induced osteomalacia due to an intracranial tumor by fractionated stereotactic radiotherapy.

    Science.gov (United States)

    Tarasova, Valentina D; Trepp-Carrasco, Alejandro G; Thompson, Robert; Recker, Robert R; Chong, William H; Collins, Michael T; Armas, Laura A G

    2013-11-01

    Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, characterized by tumor secretion of fibroblast growth factor-23 (FGF23) causing hypophosphatemia due to renal phosphate wasting. TIO is usually caused by small, benign, difficult-to-localize, mesenchymal tumors. Although surgery with wide excision of tumor borders is considered the "gold standard" for definitive therapy, it can be associated with considerable morbidity depending on the location. To date, radiation therapy has not been considered as an effective treatment modality in TIO. A 67-year-old female presented with multiple nontraumatic fractures, progressive bone pain, and muscle weakness for 4 years. She was found to have biochemical evidence of urinary phosphate wasting with low serum phosphorus, low-normal serum calcium, normal 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and high serum FGF23 levels. TIO was diagnosed. Selective venous sampling for FGF23 confirmed that a 1.7-cm left frontal mass, radiographically similar to a meningioma, was the causative tumor. She declined surgery due to fear of complications and instead underwent fractionated stereotactic radiotherapy for 6 weeks. In less than 4 years after radiation therapy, she was successfully weaned off phosphorus and calcitriol, starting from 2 g of oral phosphorus daily and 1 μg of calcitriol daily. Her symptoms have resolved, and she has not had any new fractures. Stereotactic radiotherapy was an effective treatment modality for TIO in our patient. Fractionated stereotactic radiation therapy represents an alternative to surgery for patients with TIO who are not surgical candidates or who decline surgery.

  1. SU-D-16A-06: Modeling Biological Effects of Residual Uncertainties For Stereotactic Radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L; Larson, D; McDermott, M; Sneed, P [UCSF Comprehensive Cancer Center, San Francisco, CA (United States); Sahgal, A [University of Toronto, Toronto, ON (Canada)

    2014-06-01

    Purpose: Residual uncertainties on the order of 1-2 mm are frequently observed when delivering stereotactic radiosurgery via on-line imaging guidance with a relocatable frame. In this study, a predictive model was developed to evalute potentiral late radiation effects associated with such uncertainties. Methods: A mathematical model was first developed to correlate the peripherial isodose volume with the internal and/or setup margins for a radiosurgical target. Such a model was then integrated with a previoulsy published logistic regression normal tissue complication model for determining the symptomatic radiation necrosis rate at various target sizes and prescription dose levels. The model was tested on a cohort of 15 brain tumor and tumor resection cavity patient cases and model predicted results were compared with the clinical results reported in the literature. Results: A normalized target diameter (D{sub 0}) in term of D{sub 0} = 6V/S, where V is the volume of a radiosurgical target and S is the surface of the target, was found to correlate excellently with the peripheral isodose volume for a radiosurgical delivery (logarithmic regression R{sup 2} > 0.99). The peripheral isodose volumes were found increase rapidly with increasing uncertainties levels. In general, a 1-mm residual uncertainties as calculated to result in approximately 0.5%, 1%, and 3% increases in the symptomatic radiation necrosis rate for D{sub 0} = 1 cm, 2 cm, and 3 cm based on the prescription guideline of RTOG 9005, i.e., 21 Gy to a lesion of 1 cm in diameter, 18 Gy to a lesion 2 cm in diameter, and 15 Gy to a lesion 3 cm in diameter respectively. Conclusion: The results of study suggest more stringent criteria on residual uncertainties are needed when treating a large target such as D{sub 0}≤ 3 cm with stereotactic radiosurgery. Dr. Ma and Dr. Sahgal are currently serving on the board of international society of stereotactic radiosurgery (ISRS)

  2. The lazaroid U74389G protects normal brain from stereotactic radiosurgery-induced radiation injury

    International Nuclear Information System (INIS)

    Buatti, John M.; Friedman, William A.; Theele, Daniel P.; Bova, Francis J.; Mendenhall, William M.

    1996-01-01

    Purpose: To test an established model of stereotactic radiosurgery-induced radiation injury with pretreatments of either methylprednisolone or the lazaroid U74389G. Methods and Materials: Nine cats received stereotactic radiosurgery with a linear accelerator using an animal radiosurgery device. Each received a dose of 125.0 Gy prescribed to the 84% isodose shell to the anterior limb of the right internal capsule. One animal received no pretreatment, two received citrate vehicle, three received 30 mg/kg of methylprednisolone, and three received 5 mg/kg of U74389G. After irradiation, the animals had frequent neurologic examinations, and neurologic deficits developed in all of them. Six months after the radiation treatment, the animals were anesthetized, and had gadolinium-enhanced magnetic resonance (MR) scans, followed by Evans blue dye perfusion, euthanasia, and brain fixation. Results: Magnetic resonance scans revealed a decrease in the size of the lesions from a mean volume of 0.45 ± 0.06 cm 3 in the control, vehicle-treated, and methylprednisolone-treated animals to 0.22 ± 0.14 cm 3 in the U74389G-treated group. The scans also suggested the absence of necrosis and ventricular dilatation in the lazaroid-treated group. Gross pathology revealed that lesions produced in the untreated, vehicle-treated, and methylprednisolone-treated cats were similar and were characterized by a peripheral zone of Evans blue dye staining with a central zone of a mature coagulative necrosis and focal hemorrhage. However, in the U74389G-treated animals, the lesions were found to have an area of Evans blue dye staining, but lacked discrete areas of necrosis and hemorrhage. Conclusion: These results suggest that the lazaroid U74389G protects the normal brain from radiation injury produced by stereotactic radiosurgery

  3. Compass model-based quality assurance for stereotactic VMAT treatment plans.

    Science.gov (United States)

    Valve, Assi; Keyriläinen, Jani; Kulmala, Jarmo

    2017-12-01

    To use Compass as a model-based quality assurance (QA) tool for stereotactic body radiation therapy (SBRT) and stereotactic radiation therapy (SRT) volumetric modulated arc therapy (VMAT) treatment plans calculated with Eclipse treatment planning system (TPS). Twenty clinical stereotactic VMAT SBRT and SRT treatment plans were blindly selected for evaluation. Those plans included four different treatment sites: prostate, brain, lung and body. The plans were evaluated against dose-volume histogram (DVH) parameters and 2D and 3D gamma analysis. The dose calculated with Eclipse treatment planning system (TPS) was compared to Compass calculated dose (CCD) and Compass reconstructed dose (CRD). The maximum differences in mean dose of planning target volume (PTV) were 2.7 ± 1.0% between AAA and Acuros XB calculation algorithm TPS dose, -7.6 ± 3.5% between Eclipse TPS dose and CCD dose and -5.9 ± 3.7% between Eclipse TPS dose and CRD dose for both Eclipse calculation algorithms, respectively. 2D gamma analysis was not able to identify all the cases that 3D gamma analysis specified for further verification. Compass is suitable for QA of SBRT and SRT treatment plans. However, the QA process should include wide set of DVH-based dose parameters and 3D gamma analysis should be the preferred method when performing clinical patient QA. The results suggest that the Compass should not be used for smaller field sizes than 3 × 3 cm 2 or the beam model should be adjusted separately for both small (FS ≤ 3 cm) and large (FS > 3 cm) field sizes. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  4. Application of Raman spectroscopy to identify microcalcifications and underlying breast lesions at stereotactic core needle biopsy

    Science.gov (United States)

    Barman, Ishan; Dingari, Narahara Chari; Saha, Anushree; McGee, Sasha; Galindo, Luis H.; Liu, Wendy; Plecha, Donna; Klein, Nina; Dasari, Ramachandra Rao; Fitzmaurice, Maryann

    2013-01-01

    Microcalcifications are a feature of diagnostic significance on a mammogram and a target for stereotactic breast needle biopsy. Here, we report development of a Raman spectroscopy technique to simultaneously identify microcalcification status and diagnose the underlying breast lesion, in real-time, during stereotactic core needle biopsy procedures. Raman spectra were obtained ex vivo from 146 tissue sites from fresh stereotactic breast needle biopsy tissue cores from 33 patients, including 50 normal tissue sites, 77 lesions with microcalcifications, and 19 lesions without microcalcifications, using a compact clinical system. The Raman spectra were modeled based on the breast tissue components and a support vector machine framework was used to develop a single-step diagnostic algorithm to distinguish normal tissue, fibrocystic change (FCC), fibroadenoma (FA) and breast cancer, in the absence and presence of microcalcifications. This algorithm was subjected to leave-one-site-out cross-validation, yielding a positive predictive value, negative predictive value, sensitivity and specificity of 100%, 95.6%, 62.5% and 100% for diagnosis of breast cancer (with or without microcalcifications) and an overall accuracy of 82.2% for classification into specific categories of normal tissue, FCC, FA or breast cancer (with and without microcalcifications). Notably, the majority of breast cancers diagnosed are ductal carcinoma in situ (DCIS), the most common lesion associated with microcalcifications, which could not be diagnosed using previous Raman algorithm(s). Our study demonstrates the potential of Raman spectroscopy to concomitantly detect microcalcifications and diagnose associated lesions, including DCIS, and thus provide real-time feedback to radiologists during such biopsy procedures, reducing non-diagnostic and false negative biopsies. PMID:23729641

  5. Stereotactic Fractionated Radiotherapy in the Treatment of Juxtapapillary Choroidal Melanoma: The McGill University Experience

    Energy Technology Data Exchange (ETDEWEB)

    Al-Wassia, Rolina; Dal Pra, Alan; Shun, Kitty; Shaban, Ahmed [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); Corriveau, Christine [Department of Ophthalmology, Notre Dame Hospital, Centre Hospitalier de l' Universite de Montreal, Montreal, Quebec (Canada); Edelstein, Chaim; Deschenes, Jean [Department of Ophthalmology, McGill University Health Centre, Montreal, Quebec (Canada); Ruo, Russel; Patrocinio, Horacio [Department of Medical Physics, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); Cury, Fabio L.B. [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); DeBlois, Francois [Department of Medical Physics, Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Shenouda, George, E-mail: george.shenouda@muhc.mcgill.ca [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada)

    2011-11-15

    Purpose: To report our experience with linear accelerator-based stereotactic fractionated radiotherapy in the treatment of juxtapapillary choroidal melanoma. Methods and Materials: We performed a retrospective review of 50 consecutive patients diagnosed with juxtapapillary choroidal melanoma and treated with linear accelerator-based stereotactic fractionated radiotherapy between April 2003 and December 2009. Patients with small to medium sized lesions (Collaborative Ocular Melanoma Study classification) located within 2 mm of the optic disc were included. The prescribed radiation dose was 60 Gy in 10 fractions. The primary endpoints included local control, enucleation-free survival, and complication rates. Results: The median follow-up was 29 months (range, 1-77 months). There were 31 males and 29 females, with a median age of 69 years (range, 30-92 years). Eighty-four percent of the patients had medium sized lesions, and 16% of patients had small sized lesions. There were four cases of local progression (8%) and three enucleations (6%). Actuarial local control rates at 2 and 5 years were 93% and 86%, respectively. Actuarial enucleation-free survival rates at 2 and 5 years were 94% and 84%, respectively. Actuarial complication rates at 2 and 5 years were 33% and 88%, respectively, for radiation-induced retinopathy; 9.3% and 46.9%, respectively, for dry eye; 12% and 53%, respectively, for cataract; 30% and 90%, respectively, for visual loss [Snellen acuity (decimal equivalent), <0.1]; 11% and 54%, respectively, for optic neuropathy; and 18% and 38%, respectively, for neovascular glaucoma. Conclusions: Linear accelerator-based stereotactic fractionated radiotherapy using 60 Gy in 10 fractions is safe and has an acceptable toxicity profile. It has been shown to be an effective noninvasive treatment for juxtapapillary choroidal melanomas.

  6. Geometric accuracy of field alignment in fractionated stereotactic conformal radiotherapy of brain tumors

    International Nuclear Information System (INIS)

    Kortmann, Rolf D.; Becker, Gerd; Perelmouter, Jury; Buchgeister, Markus; Meisner, Christoph; Bamberg, Michael

    1999-01-01

    Purpose: To assess the accuracy of field alignment in patients undergoing three-dimensional (3D) conformal radiotherapy of brain tumors, and to evaluate the impact on the definition of planning target volume and control procedures. Methods and Materials: Geometric accuracy was analyzed in 20 patients undergoing fractionated stereotactic conformal radiotherapy for brain tumors. Rigid head fixation was achieved by using cast material. Transfer of stereotactic coordinates was performed by an external positioning device. The accuracy during treatment planning was quantitatively assessed by using repeated computed tomography (CT) examinations in treatment position (reproducibility of isocenter). Linear discrepancies were measured between treatment plan and CT examination. In addition, for each patient, a series of 20 verifications were taken in orthogonal projections. Linear discrepancies were measured between first and all subsequent verifications (accuracy during treatment delivery). Results: For the total group of patients, the distribution of deviations during treatment setup showed mean values between -0.3-1.2 mm, with standard deviations (SD) of 1.3-2.0 mm. During treatment delivery, the distribution of deviations revealed mean values between 0.7-0.8 mm, with SDs of 0.5-0.6 mm, respectively. For all patients, deviations for the transition to the treatment machine were similar to deviations during subsequent treatment delivery, with 95% of all absolute deviations between less than 2.8 and 4.6 mm. Conclusion: Random fluctuations of field displacements during treatment planning and delivery prevail. Therefore, our quantitative data should be considered when prescribing the safety margins of the planning target volume. Repeated CT examination are useful to detect operator errors and large random or systematic deviations before start of treatment. Control procedures during treatment delivery appear to be of limited importance. In addition, our findings should help to

  7. Stereotactic radiation therapy for malignant choroidal tumors: preliminary, short-term results.

    Science.gov (United States)

    Bellmann, C; Fuss, M; Holz, F G; Debus, J; Rohrschneider, K; Völcker, H E; Wannenmacher, M

    2000-02-01

    To evaluate the role of stereotactic radiation therapy (SRT) in the treatment of malignant choroidal tumors. Prospective, noncomparative case series. Ten patients with unifocal choroidal metastasis (three lung carcinoma, three breast carcinoma, three colon carcinoma, one cutaneous melanoma) and five patients with primary choroidal melanoma underwent single-dose or fractionated SRT. Before treatment, computed tomography (CT) scans of the orbit were obtained with the patient wearing an individualized immobilization mask. An integrated macro-CCD-camera system viewed the eye for detection of movements. Three-dimensional computer-based treatment planning was carried out. Dose distribution was calculated and displayed in isodose lines on the CT data set. For SRT, a dedicated stereotactic linear accelerator (6 MV) was used. Total doses for choroidal metastases were 12 to 20 Gy in a single dose or 30 Gy over 10 days (3 Gy each session), and total doses for choroidal melanoma were 50 Gy over 5 or 10 days (10 or 5 Gy each session). Best corrected visual acuity (ETDRS-chart), biomicroscopy, ultrasound examination, fluorescein angiography, and magnetic resonance imaging (MRI) were performed before treatment and at regular intervals after completion of SRT. During a follow-up period from 1 to 34 months (median, 6.5 months), local tumor control was achieved in all eyes. A decrease in tumor size on ultrasonography or MRI was noted in eight patients. No persistent side effects were observed during follow-up. Stereotactic radiation therapy allows steep dose gradients outside the target volume by minimizing the field of exposure. Thus only low radiation doses affect surrounding radiosensitive ocular structures. Our initial findings suggest that this technique may be effective in controlling tumor growth. Further studies are needed to compare treatment efficacy and safety with conventional treatment methods.

  8. Quality of Life After Stereotactic Radiotherapy for Stage I Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Voort van Zyp, Noelle C. van der; Prevost, Jean-Briac; Holt, Bronno van der; Braat, Cora; Klaveren, Robertus J. van; Pattynama, Peter M.; Levendag, Peter C.; Nuyttens, Joost J.

    2010-01-01

    Purpose: To determine the impact of stereotactic radiotherapy on the quality of life of patients with inoperable early-stage non-small-cell lung cancer (NSCLC). Overall survival, local tumor control, and toxicity were also evaluated in this prospective study. Methods and Materials: From January 2006 to February 2008, quality of life, overall survival, and local tumor control were assessed in 39 patients with pathologically confirmed T1 to 2N0M0 NSCLC. These patients were treated with stereotactic radiotherapy. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) C30 and the QLQ LC13 lung cancer-specific questionnaire were used to investigate changes in quality of life. Assessments were done before treatment, at 3 weeks, and at 2, 4, 6, 9, and 12 months after treatment, until death or progressive disease. Toxicity was evaluated using common terminology criteria for adverse events version 3.0. Results: Emotional functioning improved significantly after treatment. Other function scores and QLQ C30 and QLQ LC13 lung symptoms (such as dyspnea and coughing) showed no significant changes. The overall 2-year survival rate was 62%. After a median follow-up of 17 months, 1 patient had a local recurrence (3%). No grade 4 or 5 treatment-related toxicity occurred. Grade 3 toxicity consisted of thoracic pain, which occurred in 1 patient within 4 months of treatment, while it occurred thereafter in 2 patients. Conclusions: Quality of life was maintained, and emotional functioning improved significantly after stereotactic radiotherapy for stage I NSCLC, while survival was acceptable, local tumor control was high, and toxicity was low.

  9. Conformity of LINAC-Based Stereotactic Radiosurgery Using Dynamic Conformal Arcs and Micro-Multileaf Collimator

    International Nuclear Information System (INIS)

    Hazard, Lisa J.; Wang, Brian; Skidmore, Thomas B.; Chern, Shyh-Shi; Salter, Bill J.; Jensen, Randy L.; Shrieve, Dennis C.

    2009-01-01

    Purpose: To assess the conformity of dynamic conformal arc linear accelerator-based stereotactic radiosurgery and to describe a standardized method of isodose surface (IDS) selection. Methods and Materials: In 174 targets, the conformity index (CI) at the prescription IDS used for treatment was calculated as CI = (PIV/PVTV)/(PVTV/TV), where TV is the target volume, PIV (prescription isodose volume) is the total volume encompassed by the prescription IDS, and PVTV is the TV encompassed by the IDS. In addition, a 'standardized' prescription IDS (sIDS) was chosen according to the following criteria: 95% of the TV was encompassed by the PIV and 99% of TV was covered by 95% of the prescription dose. The CIs at the sIDS were also calculated. Results: The median CI at the prescription IDS and sIDS was 1.63 and 1.47, respectively (p < 0.001). In 132 of 174 cases, the volume of normal tissue in the PIV was reduced by the prescription to the sIDS compared with the prescription IDS, in 20 cases it remained unchanged, and in 22 cases it was increased. Conclusion: The CIs obtained with linear accelerator-based stereotactic radiosurgery are comparable to those previously reported for gamma knife stereotactic radiosurgery. Using a uniform method to select the sIDS, adequate target coverage was usually achievable with prescription to an IDS greater than that chosen by the treating physician (prescription IDS), providing sparing of normal tissue. Thus, the sIDS might aid physicians in identifying a prescription IDS that balances coverage and conformity

  10. Stereotactic external beam irradiation in previously untreated brain tumors in children and adolescents.

    Science.gov (United States)

    Freeman, C R; Souhami, L; Caron, J L; Villemure, J G; Olivier, A; Montes, J; Farmer, J P; Podgorsak, E B

    1994-01-01

    Stereotactically guided external beam irradiation may be a useful form of treatment for small, well-circumscribed, but surgically inaccessible, primary brain tumors that are either benign or of low malignant potential. Between March 1988 and December 1991, 10 children and adolescents with previously untreated primary brain tumors were treated with stereotactic external beam irradiation (SEBI) using a linac-based dynamic technique. Eleven lesions were treated in the 10 patients. Treatment was given using a collimator diameter of 1.5-4 cm (median 2 cm). Single fractions of 18, 20, and 25 Gy were used for 3 lesions in 2 patients. A fractionated schedule delivering a median dose of 42 Gy in 6 fractions over 2 weeks was used in the remaining 8 patients. Morbidity related to treatment was minimal. Three patients suffered a temporary worsening of preexisting neurological symptoms and/or signs at 2, 5, and 5 months posttreatment, with subsequent recovery in all. With a median follow up post-SEBI of 17.5 months (range 5-47 months), improvement in neurological findings related to the lesion was noted for 5 treated lesions; 6 remained clinically stable. Seven of the 11 treated lesions improved radiologically, and only 2 showed evidence of progressive disease. Stereotactic external beam irradiation represents a potentially valuable therapeutic option for selected primary brain tumors in the pediatric and adolescent age group. Morbidity related to the treatment appears acceptable in frequency and type, and preliminary data with regard to response are encouraging. However, in order to assess the impact of such treatment on long-term tumor control and survival, further experience with a larger cohort of patients followed for a longer period of time will be necessary.

  11. Implantable Impedance Plethysmography

    Directory of Open Access Journals (Sweden)

    Michael Theodor

    2014-08-01

    Full Text Available We demonstrate by theory, as well as by ex vivo and in vivo measurements that impedance plethysmography, applied extravascularly directly on large arteries, is a viable method for monitoring various cardiovascular parameters, such as blood pressure, with high accuracy. The sensor is designed as an implant to monitor cardiac events and arteriosclerotic progression over the long term.

  12. Implant-abutment interface

    African Journals Online (AJOL)

    healing collars, abutments, transfer copings and analogs, which increases inventory costs and complexity. Limitations of external hex became more evident ..... 0.75mm or bone platform switching which involves an inward bone ring in the coronal part of the implant. 34 that is in continuity with the alveolar bone crest .

  13. Corrosion of bio implants

    Indian Academy of Sciences (India)

    Chemical stability, mechanical behaviour and biocompatibility in body fluids and tissues are the basic requirements for successful application of implant materials in bone fractures and replacements. Corrosion is one of the major processes affecting the life and service of orthopaedic devices made of metals and alloys used ...

  14. Remote actuated valve implant

    Energy Technology Data Exchange (ETDEWEB)

    McKnight, Timothy E.; Johnson, Anthony; Moise, Kenneth J.; Ericson, Milton Nance; Baba, Justin S.; Wilgen, John B.; Evans, Boyd Mccutchen

    2016-05-10

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  15. Ion Implantation of Polymers

    DEFF Research Database (Denmark)

    Popok, Vladimir

    2012-01-01

    is put on the low-energy implantation of metal ions causing the nucleation and growth of nanoparticles in the shallow polymer layers. Electrical, optical and magnetic properties of metal/polymer composites are under the discussion and the approaches towards practical applications are overviewed....

  16. Implantable Drug Dispenser

    Science.gov (United States)

    Collins, E. R. J.

    1983-01-01

    Drugs such as insulin are injected as needed directly into bloodstream by compact implantable dispensing unit. Two vapor cavities produce opposing forces on drug-chamber diaphragm. Heaters in cavities allow control of direction and rate of motion of bellows. Dispensing capsule fitted with coil so batteries can be recharged by induction.

  17. Allergy to Surgical Implants.

    Science.gov (United States)

    Pacheco, Karin A

    2015-01-01

    Surgical implants have a wide array of therapeutic uses, most commonly in joint replacements, but also in repair of pes excavatum and spinal disorders, in cardiac devices (stents, patches, pacers, valves), in gynecological implants, and in dentistry. Many of the metals used are immunologically active, as are the methacrylates and epoxies used in conjunction with several of these devices. Allergic responses to surgical components can present atypically as failure of the device, with nonspecific symptoms of localized pain, swelling, warmth, loosening, instability, itching, or burning; localized rash is infrequent. Identification of the specific metal and cement components used in a particular implant can be difficult, but is crucial to guide testing and interpretation of results. Nickel, cobalt, and chromium remain the most common metals implicated in implant failure due to metal sensitization; methacrylate-based cements are also important contributors. This review will provide a guide on how to assess and interpret the clinical history, identify the components used in surgery, test for sensitization, and provide advice on possible solutions. Data on the pathways of metal-induced immune stimulation are included. In this setting, the allergist, the dermatologist, or both have the potential to significantly improve surgical outcomes and patient care. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  18. Implantable enzyme amperometric biosensors.

    Science.gov (United States)

    Kotanen, Christian N; Moussy, Francis Gabriel; Carrara, Sandro; Guiseppi-Elie, Anthony

    2012-05-15

    The implantable enzyme amperometric biosensor continues as the dominant in vivo format for the detection, monitoring and reporting of biochemical analytes related to a wide range of pathologies. Widely used in animal studies, there is increasing emphasis on their use in diabetes care and management, the management of trauma-associated hemorrhage and in critical care monitoring by intensivists in the ICU. These frontier opportunities demand continuous indwelling performance for up to several years, well in excess of the currently approved seven days. This review outlines the many challenges to successful deployment of chronically implantable amperometric enzyme biosensors and emphasizes the emerging technological approaches in their continued development. The foreign body response plays a prominent role in implantable biotransducer failure. Topics considering the approaches to mitigate the inflammatory response, use of biomimetic chemistries, nanostructured topographies, drug eluting constructs, and tissue-to-device interface modulus matching are reviewed. Similarly, factors that influence biotransducer performance such as enzyme stability, substrate interference, mediator selection and calibration are reviewed. For the biosensor system, the opportunities and challenges of integration, guided by footprint requirements, the limitations of mixed signal electronics, and power requirements, has produced three systems approaches. The potential is great. However, integration along the multiple length scales needed to address fundamental issues and integration across the diverse disciplines needed to achieve success of these highly integrated systems, continues to be a challenge in the development and deployment of implantable amperometric enzyme biosensor systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Corrosion of bio implants

    Indian Academy of Sciences (India)

    Chemical stability, mechanical behaviour and biocompatibility in body fluids and tissues are the basic requirements for successful application of implant materials in ... and surface modification of stainless steel with bioceramic coatings are considered potential methods for improving the performance of orthopaedic devices.

  20. Remote actuated valve implant

    Science.gov (United States)

    McKnight, Timothy E; Johnson, Anthony; Moise, Jr., Kenneth J; Ericson, Milton Nance; Baba, Justin S; Wilgen, John B; Evans, III, Boyd McCutchen

    2014-02-25

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  1. Middle ear implants

    Directory of Open Access Journals (Sweden)

    K S Gangadhara Somayaji

    2013-01-01

    Full Text Available Hearing loss is becoming more common in the society living in cities with lot of background noise around, and frequent use of gadgets like mobile phones, MP3s, and IPods are adding to the problem. The loss may involve the conductive or perceptive pathway. Majority of the patients with conductive hearing loss will revert back to normal hearing levels with medical and/or surgical treatment. However, in sensorineural hearing loss, many factors are involved in the management. Though traditionally hearing aids in various forms are the most commonly used modality in managing these patients, there are some drawbacks associated with them. Implantable middle ear amplifiers represent the most recent breakthrough in the management of hearing loss. Middle ear implants are surgically implanted electronic devices that aim to correct hearing loss by stimulating the ossicular chain or middle ear. Of late, they are also being used in the management of congenital conductive hearing loss and certain cases of chronic otitis media with residual hearing loss. The article aims to provide general information about the technology, indications and contraindications, selection of candidates, available systems, and advantages of middle ear implants. (MEI

  2. Target migration from re-inflation of adjacent atelectasis during lung stereotactic body radiotherapy.

    Science.gov (United States)

    Mao, Bijing; Verma, Vivek; Zheng, Dandan; Zhu, Xiaofeng; Bennion, Nathan R; Bhirud, Abhijeet R; Poole, Maria A; Zhen, Weining

    2017-06-10

    Stereotactic body radiotherapy (SBRT) is a widely accepted option for the treatment of medically inoperable early-stage non-small cell lung cancer (NSCLC). Herein, we highlight the importance of interfraction image guidance during SBRT. We describe a case of early-stage NSCLC associated with segmental atelectasis that translocated 15 mm anteroinferiorly due to re-expansion of the adjacent segmental atelectasis following the first fraction. The case exemplifies the importance of cross-sectional image-guided radiotherapy that shows the intended target, as opposed to aligning based on rigid anatomy alone, especially in cases associated with potentially "volatile" anatomic areas.

  3. A Prospective Cohort Study of Gated Stereotactic Liver Radiation Therapy Using Continuous Internal Electromagnetic Motion Monitoring

    DEFF Research Database (Denmark)

    Worm, Esben S; Høyer, Morten; Hansen, Rune

    2018-01-01

    PURPOSE: Intrafraction motion can compromise the treatment accuracy in liver stereotactic body radiation therapy (SBRT). Respiratory gating can improve treatment delivery; however, gating based on external motion surrogates is inaccurate. The present study reports the use of Calypso-based internal.......0 percentage points (range 0.7-22.0) without gating and 0.8 percentage point (range 0.2-2.0) with gating. CONCLUSIONS: Gating using internal motion monitoring was successfully applied for liver SBRT. It markedly improved the geometric and dosimetric accuracy compared with nongated standard treatment....

  4. Frame-Based Immobilization and Targeting for Stereotactic Body Radiation Therapy

    International Nuclear Information System (INIS)

    Murray, Bryan C.; Forster, Kenneth; Timmerman, Robert

    2007-01-01

    Frame-based stereotactic body radiation therapy (SBRT), such as that conducted with Elekta's Stereotactic Body Frame, can provide an extra measure of precision in the delivery of radiation to extracranial targets, and facilitates secure patient immobilization. In this paper, we review the steps involved in optimal use of an extra-cranial immobilization device for SBRT treatments. Our approach to using frame-based SBRT consists of 4 steps: patient immobilization, tumor and organ motion control, treatment/planning correlation, and daily targeting with pretreatment quality assurance. Patient immobilization was achieved with the Vac-Loc bag, which uses styrofoam beads to conform to the patient's shape comfortably within the body frame. Organ and motion control was assessed under fluoroscopy and controlled via a frame-mounted abdominal pressure plate. The compression screw was tightened until the diaphragmatic excursion range was < 1 cm. Treatment planning was performed using the Philips Pinnacle 6.2b system. In this treatment process, a 20 to 30 noncoplanar beam arrangement was initially selected and an inverse beam weight optimization algorithm was applied. Those beams with low beam weights were removed, leaving a manageable number of beams for treatment delivery. After planning, daily targeting using computed tomography (CT) to verify x-, y-, and z-coordinates of the treatment isocenter were used as a measure of quality assurance. We found our daily setup variation typically averaged < 5 mm in all directions, which is comparable to other published studies on Stereotactic Body Frame. Treatment time ranged from 30 to 45 minutes. Results demonstrate that patients have experienced high rates of local control with acceptable rates of severe side effects-by virtue of the tightly constrained treatment fields. The body frame facilitated comfortable patient positioning and quality assurance checks of the tumor, in relation to another set of independent set of coordinates

  5. The university of Florida frameless high-precision stereotactic radiotherapy system

    International Nuclear Information System (INIS)

    Bova, Francis J.; Buatti, John M.; Friedman, William A.; Mendenhall, William M.; Yang, Ching-Chong; Liu, Chihray

    1997-01-01

    Purpose: To develop and test a system for high precision fractionated stereotactic radiotherapy that separates immobilization and localization devices. Methods and Materials: Patient localization is achieved through detection and digital registration of an independent bite plate system. The bite plate is made and linked to a set of six infrared light emitting diodes (IRLEDs). These IRLEDs are detected by an infrared camera system that identifies the position of each IRLED within 0.1 to 0.15 mm. Calibration of the camera system defines isocenter and translational X, Y, and Z axes of the stereotactic radiosurgery subsystem and thereby digitally defines the virtual treatment room space in a computer linked to the camera system. Positions of the bite plate's IRLEDs are processed digitally using a computer algorithm so that positional differences between an actual bite plate position and a desired position can be resolved within 0.1 mm of translation (X, Y, and Z distance) and 0.1 degree of rotation. Furthermore, bite plate misalignment can be displayed digitally in real time with translational (x, y, and z) and rotational (roll, pitch, and yaw) parameters for an actual bite plate position. Immobilization is achieved by a custom head mold and thermal plastic mask linked by hook-and-loop fastener tape. The head holder system permits rotational and translational movements for daily treatment positioning based on the bite plate localization system. Initial testing of the localization system was performed on 20 patients treated with radiosurgery. The system was used to treat 11 patients with fractionated stereotactic radiotherapy. Results: Assessment of bite plate localization in radiosurgery patients revealed that the patient's bite plate could be positioned and repositioned within 0.5 ± 0.3 mm (standard deviation). After adjustments, the first 11 patients were treated with the bite plate repositioning error reduced to 0.2 ± 0.1 mm. Conclusions: High precision

  6. Localization Accuracy and Immobilization Effectiveness of a Stereotactic Body Frame for a Variety of Treatment Sites

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Ryan, E-mail: Ryan.Foster@utsouthwestern.edu [Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas (United States); Meyer, Jeffrey; Iyengar, Puneeth; Pistenmaa, David; Timmerman, Robert; Choy, Hak [Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas (United States); Solberg, Timothy [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2013-12-01

    Purpose: The purpose of this study was to analyze the pretreatment setup errors and intrafraction motion using cone beam computed tomography (CBCT) for stereotactic body radiation therapy patients immobilized and localized with a stereotactic body frame for a variety of treatment sites. Methods and Materials: Localization errors were recorded for patients receiving SBRT for 141 lung, 29 liver, 48 prostate, and 45 spine tumors representing 1005 total localization sessions. All patients were treated in a stereotactic body frame with a large custom-molded vacuum pillow. Patients were first localized to the frame using tattoos placed during simulation. Subsequently, the frame was aligned to the room lasers according to the stereotactic coordinates determined from the treatment plan. Every patient received a pretreatment and an intrafraction CBCT. Abdominal compression was used for all liver patients and for approximately 40% of the lung patients to reduce tumor motion due to respiration. Results: The mean ± standard deviation pretreatment setup errors from all localizations were −2.44 ± 3.85, 1.31 ± 5.84, and 0.11 ± 3.76 mm in the anteroposterior, superoinferior, and lateral directions, respectively. The mean pretreatment localization results among all treatment sites were not significantly different (F test, P<.05). For all treatment sites, the mean ± standard deviation intrafraction shifts were 0.33 ± 1.34, 0.15 ± 1.45, and −0.02 ± 1.17 mm in the anteroposterior, superoinferior, and lateral directions, respectively. The mean unidimensional intrafraction shifts were statistically different for several of the comparisons (P<.05) as assessed by the Tukey-Kramer test. Conclusions: Despite the varied tumor locations, the pretreatment mean localization errors for all sites were found to be consistent among the treatment sites and not significantly different, indicating that the body frame is a suitable immobilization and localization device for a variety of

  7. Localization Accuracy and Immobilization Effectiveness of a Stereotactic Body Frame for a Variety of Treatment Sites

    International Nuclear Information System (INIS)

    Foster, Ryan; Meyer, Jeffrey; Iyengar, Puneeth; Pistenmaa, David; Timmerman, Robert; Choy, Hak; Solberg, Timothy

    2013-01-01

    Purpose: The purpose of this study was to analyze the pretreatment setup errors and intrafraction motion using cone beam computed tomography (CBCT) for stereotactic body radiation therapy patients immobilized and localized with a stereotactic body frame for a variety of treatment sites. Methods and Materials: Localization errors were recorded for patients receiving SBRT for 141 lung, 29 liver, 48 prostate, and 45 spine tumors representing 1005 total localization sessions. All patients were treated in a stereotactic body frame with a large custom-molded vacuum pillow. Patients were first localized to the frame using tattoos placed during simulation. Subsequently, the frame was aligned to the room lasers according to the stereotactic coordinates determined from the treatment plan. Every patient received a pretreatment and an intrafraction CBCT. Abdominal compression was used for all liver patients and for approximately 40% of the lung patients to reduce tumor motion due to respiration. Results: The mean ± standard deviation pretreatment setup errors from all localizations were −2.44 ± 3.85, 1.31 ± 5.84, and 0.11 ± 3.76 mm in the anteroposterior, superoinferior, and lateral directions, respectively. The mean pretreatment localization results among all treatment sites were not significantly different (F test, P<.05). For all treatment sites, the mean ± standard deviation intrafraction shifts were 0.33 ± 1.34, 0.15 ± 1.45, and −0.02 ± 1.17 mm in the anteroposterior, superoinferior, and lateral directions, respectively. The mean unidimensional intrafraction shifts were statistically different for several of the comparisons (P<.05) as assessed by the Tukey-Kramer test. Conclusions: Despite the varied tumor locations, the pretreatment mean localization errors for all sites were found to be consistent among the treatment sites and not significantly different, indicating that the body frame is a suitable immobilization and localization device for a variety of

  8. Alignment verification in stereotactic radiosurgery with use of graphic arts film

    International Nuclear Information System (INIS)

    Sweet, J.; Lamba, M.

    1990-01-01

    This paper evaluates the use of graphic arts film for field alignment verification of linear accelerator-based stereotactic radiosurgery. The characteristic curve was generated for Fuji RO-100 graphic arts film in a standard leaded radiation therapy cassette at 6 MV. The linear portion of the curve and the film contrast are presented and their clinical advantages discussed. The high contrast of this graphic arts film improves visualization of the 5-mm ball bearing (simulated target) in small, circular treatment fields. Comparison with standard port film demonstrates the large linear range of the graphic arts film, which proved useful in visualization of the simulated target within the small, circular treatment field

  9. Fractionated stereotactic radiosurgery with concurrent temozolomide chemotherapy for locally recurrent glioblastoma multiforme: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Greenspoon JN

    2014-03-01

    Full Text Available Jeffrey Noah Greenspoon,1 Waseem Sharieff,1 Holger Hirte,1 Andrew Overholt,1 Rocco Devillers,2 Thorsteinn Gunnarsson,2 Anthony Whitton11Department of Oncology, McMaster University, ON, Canada; 2Department of Surgery, McMaster University, ON, CanadaAbstract: Local recurrence represents a significant challenge in the management of patients with glioblastoma multiforme. Salvage treatment options are limited by lack of clinical efficacy. Recent studies have demonstrated a significant response rate and acceptable toxicity with the use of fractionated stereotactic radiosurgery in this patient population. Our primary objective was to determine the efficacy and toxicity of fractionated stereotactic radiosurgery combined with concurrent temozolomide chemotherapy as a salvage treatment for recurrent glioblastoma multiforme. We prospectively collected treatment and outcome data for patients having fractionated stereotactic radiosurgery for locally recurrent glioblastoma multiforme after radical radiotherapy. Eligible patients had a maximum recurrence diameter of 60 mm without causing significant mass effect. The gross tumor volume was defined as the enhancing lesion on an enhanced fine-slice T1 (spin–lattice magnetic resonance imaging, and a circumferential setup margin of 1 mm was used to define the planning target volume. All patients were treated using robotic radiosurgery with three dose/fractionation schedules ranging from 25 to 35 Gy in five fractions, depending on the maximum tumor diameter. Concurrent temozolomide 75 mg/m2 was prescribed to all patients. Tumor response was judged using the Macdonald criteria, and toxicity was assessed using the CTCAE (Common Terminology Criteria for Adverse Events. A total of 31 patients were enrolled in this study. The median overall survival was 9 months, and progression-free survival was 7 months. The 6-month progression-free survival was 60% with a 95% confidence interval of 43%–77%. The a priori

  10. Analysis of Electronic Densities and Integrated Doses in Multiform Glioblastomas Stereotactic Radiotherapy

    International Nuclear Information System (INIS)

    Baron-Aznar, C.; Moreno-Jimenez, S.; Celis, M. A.; Ballesteros-Zebadua, P.; Larraga-Gutierrez, J. M.

    2008-01-01

    Integrated dose is the total energy delivered in a radiotherapy target. This physical parameter could be a predictor for complications such as brain edema and radionecrosis after stereotactic radiotherapy treatments for brain tumors. Integrated Dose depends on the tissue density and volume. Using CT patients images from the National Institute of Neurology and Neurosurgery and BrainScan(c) software, this work presents the mean density of 21 multiform glioblastomas, comparative results for normal tissue and estimated integrated dose for each case. The relationship between integrated dose and the probability of complications is discussed

  11. Stereotactic biopsy aided by a computer graphics workstation: experience with 200 consecutive cases.

    Science.gov (United States)

    Ulm, A J; Bova, F J; Friedman, W A

    2001-12-01

    The advent of modern computer technology has made it possible to examine not just the target point, but the entire trajectory in planning for stereotactic biopsies. Two hundred consecutive biopsies were performed by one surgeon, utilizing a computer graphics workstation. The target point, entry point, and complete trajectory were carefully scrutinized and adjusted to minimize potential complications. Pathologically abnormal tissue was obtained in 197 cases (98.5%). There was no mortality in this series. Symptomatic hemorrhages occurred in 4 cases (2%). Computer graphics workstations facilitate safe and effective biopsies in virtually any brain area.

  12. In vivo monitoring of glial scar proliferation on chronically implanted neural electrodes by fiber optical coherence tomography

    Science.gov (United States)

    Xie, Yijing; Martini, Nadja; Hassler, Christina; Kirch, Robert D.; Stieglitz, Thomas; Seifert, Andreas; Hofmann, Ulrich G.

    2014-01-01

    In neural prosthetics and stereotactic neurosurgery, intracortical electrodes are often utilized for delivering therapeutic electrical pulses, and recording neural electrophysiological signals. Unfortunately, neuroinflammation impairs the neuron-electrode-interface by developing a compact glial encapsulation around the implants in long term. At present, analyzing this immune reaction is only feasible with post-mortem histology; currently no means for specific in vivo monitoring exist and most applicable imaging modalities can not provide information in deep brain regions. Optical coherence tomography (OCT) is a well established imaging modality for in vivo studies, providing cellular resolution and up to 1.2 mm imaging depth in brain tissue. A fiber based spectral domain OCT was shown to be capable of minimally invasive brain imaging. In the present study, we propose to use a fiber based spectral domain OCT to monitor the progression of the tissue's immune response through scar encapsulation progress in a rat animal model. A fine fiber catheter was implanted in rat brain together with a flexible polyimide microelectrode in sight both of which acts as a foreign body and induces the brain tissue immune reaction. OCT signals were collected from animals up to 12 weeks after implantation and thus gliotic scarring in vivo monitored for that time. Preliminary data showed a significant enhancement of the OCT backscattering signal during the first 3 weeks after implantation, and increased attenuation factor of the sampled tissue due to the glial scar formation. PMID:25191264

  13. Effect of cochlear implant technology in sequentially bilaterally implanted adults.

    Science.gov (United States)

    Budenz, Cameron L; Roland, J Thomas; Babb, James; Baxter, Peter; Waltzman, Susan B

    2009-09-01

    Bilateral sequential cochlear implantation outcomes are dependent on many different factors. Newer technology in the second implanted ear may also contribute to outcome. This study examines the effect of cochlear implant technology on speech recognition outcomes in a population of adult patients who have undergone bilateral sequential implantation using different technologies in each ear. Retrospective chart review. Tertiary referral center. Twenty adults who underwent bilateral sequential cochlear implantation with different technologies and processing strategies in each ear were patients for this study. Control Group A included patients (n = 8) who were simultaneously implanted, and Control Group B (n = 3) were patients who were sequentially implanted with the same technology. Bilateral sequential cochlear implantation. The outcome measure was the Consonant-Nucleus-Consonant monosyllabic word test administered in each implanted ear and in the binaural condition before and 1 year after operation. A multivariate analysis was performed to account for factors including duration of deafness, length of device usage, and severity of deafness. There was significant improvement from before to 1 year after the operation in word scores for the individual ears and in the binaural condition for all groups. All patients were consistent users of both devices, and the use of different technology in the second implanted ear did not affect the patients' ability to benefit from bilateral implantation despite the use of different devices and processing strategies. Bilateral sequential implantation with newer and/or differing technology in the second implanted ear did not reduce the benefits of bilateral stimulation and should not be considered a deterrent to second-sided implantation.

  14. Prosthodontic management of implant therapy.

    Science.gov (United States)

    Thalji, Ghadeer; Bryington, Matthew; De Kok, Ingeborg J; Cooper, Lyndon F

    2014-01-01

    Implant-supported dental restorations can be screw-retained, cement-retained, or a combination of both, whereby a metal superstructure is screwed to the implants and crowns are individually cemented to the metal frame. Each treatment modality has advantages and disadvantages. The use of computer-aided design/computer-assisted manufacture technologies for the manufacture of implant superstructures has proved to be advantageous in the quality of materials, precision of the milled superstructures, and passive fit. Maintenance and recall evaluations are an essential component of implant therapy. The longevity of implant restorations is limited by their biological and prosthetic maintenance requirements. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Case report of a near medical event in stereotactic radiotherapy due to improper units of measure from a treatment planning system.

    Science.gov (United States)

    Gladstone, D J; Li, S; Jarvis, L A; Hartford, A C

    2011-07-01

    The authors hereby notify the Radiation Oncology community of a potentially lethal error due to improper implementation of linear units of measure in a treatment planning system. The authors report an incident in which a patient was nearly mistreated during a stereotactic radiotherapy procedure due to inappropriate reporting of stereotactic coordinates by the radiation therapy treatment planning system in units of centimeter rather than in millimeter. The authors suggest a method to detect such errors during treatment planning so they are caught and corrected prior to the patient positioning for treatment on the treatment machine. Using pretreatment imaging, the authors found that stereotactic coordinates are reported with improper linear units by a treatment planning system. The authors have implemented a redundant, independent method of stereotactic coordinate calculation. Implementation of a double check of stereotactic coordinates via redundant, independent calculation is simple and accurate. Use of this technique will avoid any future error in stereotactic treatment coordinates due to improper linear units, transcription, or other similar errors. The authors recommend an independent double check of stereotactic treatment coordinates during the treatment planning process in order to avoid potential mistreatment of patients.

  16. Case report of a near medical event in stereotactic radiotherapy due to improper units of measure from a treatment planning system

    International Nuclear Information System (INIS)

    Gladstone, D. J.; Li, S.; Jarvis, L. A.; Hartford, A. C.

    2011-01-01

    Purpose: The authors hereby notify the Radiation Oncology community of a potentially lethal error due to improper implementation of linear units of measure in a treatment planning system. The authors report an incident in which a patient was nearly mistreated during a stereotactic radiotherapy procedure due to inappropriate reporting of stereotactic coordinates by the radiation therapy treatment planning system in units of centimeter rather than in millimeter. The authors suggest a method to detect such errors during treatment planning so they are caught and corrected prior to the patient positioning for treatment on the treatment machine. Methods: Using pretreatment imaging, the authors found that stereotactic coordinates are reported with improper linear units by a treatment planning system. The authors have implemented a redundant, independent method of stereotactic coordinate calculation. Results: Implementation of a double check of stereotactic coordinates via redundant, independent calculation is simple and accurate. Use of this technique will avoid any future error in stereotactic treatment coordinates due to improper linear units, transcription, or other similar errors. Conclusions: The authors recommend an independent double check of stereotactic treatment coordinates during the treatment planning process in order to avoid potential mistreatment of patients.

  17. Comparing conVEntional RadioTherapy with stereotactIC body radiotherapy in patients with spinAL metastases: study protocol for an randomized controlled trial following the cohort multiple randomized controlled trial design

    International Nuclear Information System (INIS)

    Velden, Joanne M. van der; Verkooijen, Helena M.; Seravalli, Enrica; Hes, Jochem; Gerlich, A. Sophie; Kasperts, Nicolien; Eppinga, Wietse S. C.; Verlaan, Jorrit-Jan; Vulpen, Marco van

    2016-01-01

    Standard radiotherapy is the treatment of first choice in patients with symptomatic spinal metastases, but is only moderately effective. Stereotactic body radiation therapy is increasingly used to treat spinal metastases, without randomized evidence of superiority over standard radiotherapy. The VERTICAL study aims to quantify the effect of stereotactic radiation therapy in patients with metastatic spinal disease. This study follows the ‘cohort multiple Randomized Controlled Trial’ design. The VERTICAL study is conducted within the PRESENT cohort. In PRESENT, all patients with bone metastases referred for radiation therapy are enrolled. For each patient, clinical and patient-reported outcomes are captured at baseline and at regular intervals during follow-up. In addition, patients give informed consent to be offered experimental interventions. Within PRESENT, 110 patients are identified as a sub cohort of eligible patients (i.e. patients with unirradiated painful, mechanically stable spinal metastases who are able to undergo stereotactic radiation therapy). After a protocol amendment, also patients with non-spinal bony metastases are eligible. From the sub cohort, a random selection of patients is offered stereotactic radiation therapy (n = 55), which patients may accept or refuse. Only patients accepting stereotactic radiation therapy sign informed consent for the VERTICAL trial. Non-selected patients (n = 55) receive standard radiotherapy, and are not aware of them serving as controls. Primary endpoint is pain response after three months. Data will be analyzed by intention to treat, complemented by instrumental variable analysis in case of substantial refusal of the stereotactic radiation therapy in the intervention arm. This study is designed to quantify the treatment response after (stereotactic) radiation therapy in patients with symptomatic spinal metastases. This is the first randomized study in palliative care following the cohort multiple Randomized

  18. Analyses of fractured implant fixture after prolonged implantation

    Science.gov (United States)

    Choe, Han-Cheol; Lee, June-Kyu; Chung, Chae-Heon

    2004-07-01

    Although fortunately rare, fracture of implants causes significant problems for both clinicians and patients. The major cause of a fractured implant may be corrosion fatigue fracture. To investigate how to increase the fatigue life and corrosion resistance of dental implants, the surface morphology of six Steri-Oss fractured implants was analyzed. The period of implantation after loading in patient jaws varied between 23 months and 37 months. The topography and surface chemical composition were studied with electron probe micro-analysis (point mapping, energy dispersive x-ray spectroscopy) and field emission scanning electron microscopy. All samples were fractured at the screw root and the crest formed a keen-edged shape. The five samples were fractured at the first thread of the fixture and one sample at the third thread of fixture. The fatigue cracks were mainly nucleated and grown at scratches occurring for the screw root and crest formation and the cervix portion of the implant having a small curvature. The pits were nucleated in the vicinity of inclusions such as SiO2 and corrosion fatigue cracking was predominantly propagated. Corrosion products were found on the opposite side of the starting point of corrosion fatigue crack. From observations of fatigue striations, it is possible to predict the life time of fractured implants and estimate the cleavage fracture and dimple fracture of implants. In this study, analysis of fractured surfaces revealed the characteristics of the implant materials, problems of design, fatigue life, and manufacturing process. In order to protect against corrosion fatigue fractures and prolong the fatigue life of dental implants, we must consider the implant design, implant manufacturing, and surface treatment of the implant materials.

  19. Impact of stereotactic large-core needle biopsy on diagnosis and surgical treatment of nonpalpable breast cancer

    NARCIS (Netherlands)

    Verkooijen, H. M.; Borel Rinkes, I. H.; Peeters, P. H.; Landheer, M. L.; van Es, N. J.; Mali, W. P.; Klinkenbijl, J. H.; van Vroonhoven, T. J.

    2001-01-01

    Stereotactic large-core needle biopsy is increasingly replacing needle-localized breast biopsy for the diagnosis of nonpalpable breast disease. In this prospective study, the impact of the introduction of this technique on diagnosis and surgical treatment of nonpalpable breast cancer was assessed in

  20. MRI-guided vacuum-assisted breast biopsy: comparison with stereotactically guided and ultrasound-guided techniques

    Energy Technology Data Exchange (ETDEWEB)

    Imschweiler, Thomas; Freiwald, Bianka; Kubik-Huch, Rahel A. [Kantonspital Baden AG, Institute for Radiology, Baden (Switzerland); Haueisen, Harald [Kantonspital Aarau AG, Institute for Radiology, Aarau (Switzerland); Kampmann, Gert [Clinica Sant' Anna, Lugano, Sorengo (Switzerland); Rageth, Luzi [Adjumed Services AG, Zurich (Switzerland); Seifert, Burkhardt [Institute for Social and Preventive Medicine, University of Zurich, Division of Biostatistics, Zuerich (Switzerland); Rageth, Christoph [Breast Centre, Zurich (Switzerland)

    2014-01-15

    To analyse the development of MRI-guided vacuum-assisted biopsy (VAB) in Switzerland and to compare the procedure with stereotactically guided and ultrasound-guided VAB. We performed a retrospective analysis of VABs between 2009 and 2011. A total of 9,113 VABs were performed. Of these, 557 were MRI guided. MRI-guided VAB showed the highest growth rate (97 %) of all three procedures. The technical success rates for MRI-guided, stereotactically guided and ultrasound-guided VAB were 98.4 % (548/557), 99.1 % (5,904/5,960) and 99.6 % (2,585/2,596), respectively. There were no significant differences (P = 0.12) between the MRI-guided and the stereotactically guided procedures. The technical success rate for ultrasound-guided VAB was significantly higher than that for MRI-guided VAB (P < 0.001). There were no complications using MRI-guided VAB requiring open surgery. The malignancy diagnosis rate for MRI-guided VAB was similar to that for stereotactically guided VAB (P = 0.35). MRI-guided VAB is a safe and accurate procedure that provides insight into clinical breast findings. (orig.)

  1. 10 CFR 35.690 - Training for use of remote afterloader units, teletherapy units, and gamma stereotactic...

    Science.gov (United States)

    2010-01-01

    ... residency training in a radiation therapy program approved by the Residency Review Committee of the... radiation safety, radionuclide handling, treatment planning, quality assurance, and clinical use of stereotactic radiosurgery, remote afterloaders and external beam therapy; or (b)(1) Has completed a structured...

  2. Significant Risk Factors for Postoperative Enlargement of Basal Ganglia Hematoma after Frameless Stereotactic Aspiration: Antiplatelet Medication and Concomitant IVH.

    Science.gov (United States)

    Son, Wonsoo; Park, Jaechan

    2017-09-01

    Frameless stereotactic aspiration of a hematoma can be the one of the treatment options for spontaneous intracerebral hemorrhage in the basal ganglia. Postoperative hematoma enlargement, however, can be a serious complication of intracranial surgery that frequently results in severe neurological deficit and even death. Therefore, it is important to identify the risk factors of postoperative hematoma growth. During a 13-year period, 101 patients underwent minimally invasive frameless stereotactic aspiration for basal ganglia hematoma. Patients were classified into two groups according to whether or not they had postoperative hematoma enlargement in a computed tomography scan. Baseline demographic data and several risk factors, such as hypertension, preoperative hematoma growth, antiplatelet medication, presence of concomitant intraventricular hemorrhage (IVH), were analysed via a univariate statistical study. Nine of 101 patients (8.9%) showed hematoma enlargement after frameless stereotactic aspiration. Among the various risk factors, concomitant IVH and antiplatelet medication were found to be significantly associated with postoperative enlargement of hematomas. In conclusion, our study revealed that aspirin use and concomitant IVH are factors associated with hematoma enlargement subsequent to frameless stereotactic aspiration for basal ganglia hematoma.

  3. Optimization of MOSFET-type sensor calibration for the implementation of in vivo dosimetry in stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Sors, A.; Cassol, E.; Duthil, P.; Cassol, E.; Lotterie, J.A.; Berry, I.; Franceries, X.; Hallil, A.; Sors, A.; Latorzeff, I.; Lotterie, J.A.; Redon, A.; Berry, I.; Latorzeff, I.; Redon, A.; Berry, I.; Sors, A.; Cassol, E.; Hallil, A.; Latorzeff, I.; Duthil, P.; Lotterie, J.A.; Redon, A.; Berry, I.; Franceries, X.

    2010-01-01

    Within the frame of a project of assessment of in vivo dosimetry methods in stereotactic radiosurgery delivering an irradiation by a conformational dynamic arc therapy technique, the authors more precisely report the assessment and optimization of the calibration of MOSFET and micro MOSFET sensors. Measurements are performed on a Navel's system equipped with a multi-blade collimator. Short communication

  4. Radiosurgery for epilepsy: Systematic review and International Stereotactic Radiosurgery Society (ISRS) practice guideline.

    Science.gov (United States)

    McGonigal, Aileen; Sahgal, Arjun; De Salles, Antonio; Hayashi, Motohiro; Levivier, Marc; Ma, Lijun; Martinez, Roberto; Paddick, Ian; Ryu, Samuel; Slotman, Ben J; Régis, Jean

    2017-11-01

    While there are many reports of radiosurgery for treatment of drug-resistant epilepsy, a literature review is lacking. The aim of this systematic review is to summarize current literature on the use of stereotactic radiosurgery (RS) for treatment of epilepsy. Literature search was performed using various combinations of the search terms "radiosurgery", "stereotactic radiosurgery", "Gamma Knife", "epilepsy" and "seizure", from 1990 until October 2015. Level of evidence was assessed according to the PRISMA guidelines. Fifty-five articles fulfilled inclusion criteria. Level 2 evidence (prospective studies) was available for the clinical indications of mesial temporal lobe epilepsy (MTLE) and hypothalamic hamartoma (HH) treated by Gamma Knife (GK) RS. For remaining indications including corpus callosotomy as palliative treatment, epilepsy related to cavernous malformation and extra-temporal epilepsy, only Level 4 data was available (case report, prospective observational study, or retrospective case series). No Level 1 evidence was available. Based on level 2 evidence, RS is an efficacious treatment to control seizures in MTLE, possibly resulting in superior neuropsychological outcomes and quality of life metrics in selected subjects compared to microsurgery. RS has a better risk-benefit ratio for small hypothalamic hamartomas compared to surgical methods Delayed therapeutic effect resulting in ongoing seizures is associated with morbidity and mortality risk. Lack of level 1 evidence precludes the formation of guidelines at present. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Excellent local tumor response after fractionated stereotactic radiation therapy for locally recurrent nasopharynx cancer

    International Nuclear Information System (INIS)

    Ahn, Y. C.; Lim, D. H.; Choi, D. R.; Kim, D. K.; Kim, D. Y.; Huh, S. J.; Baek, C. H.; Chu, K. C.; Yoon, S. S.; Park, K. C.

    1997-01-01

    This study is to report experience with Fractionated Stereotactic Radiation Therapy (FSRT) for locally recurrent nasopharynx cancer after curative conventional radiation therapy. Three patients with locally recurrent and symptomatic nasopharynx cancer were given FSRT as reirradiation method between the period of September of 1995 and August of 1996. For two patients, application of FSRT is their third radiation therapy directed to the nasopharynx. Two patients were given low dose chemotherapy as radiation sensitizer concurrently with FSRT. Authors used 3-dimensional coordinate system by individually made, relocatable Gill-Thomas-Cosman (GTC) stereotactic frame and multiple non-coplanar arc therapy dose planning was done using XKnife-3. Total of 45 Gy/18 fractions or 50 Gy/20 fractions were given. Authors observed satisfactory symptomatic improvement and remarkable objective tumor size decrease by follow-up MR images taken 1 month post-FSRT in all three patients, while no neurologic side effect attributable to reirradiation was noticed. Two died at 7 and 9 months with loco-regional and distant seeding outside FSRT field, while one patient is living for 4 month. Authors experienced satisfactory therapeutic effectiveness and safety of FSRT as reirradiation method for locally recurrent nasopharynx cancer. Development of more effective systemic chemotherapeutic regimen is desired for distant metastasis. (author)

  6. Dosimetry for synchrotron stereotactic radiotherapy: from a macroscopic approach to microscopic energy deposits consideration

    International Nuclear Information System (INIS)

    Edouard, M.

    2010-01-01

    Numerous therapeutic strategies are currently being evaluated to find a curative treatment for high grade glioma. Among them, radiation therapy is partially effective but limited by the insufficient differential effect that can be reached between the dose delivered to the tumor compared to the one received by the healthy tissues. Synchrotron stereotactic radiotherapy aims at increasing this differential effect with a localized dose boost obtained by low energy x-rays stereotactic irradiations (≤ 100 keV) in presence of heavy elements restricted to the target area. This PhD work takes place in the general context of the future clinical trials foreseen at the European Synchrotron Radiation Facility. The first objective was to optimize the dose delivery to the target, at a macroscopic scale. We have demonstrated in particular that an even number of weighted beams was required to homogenize the tumor dose distribution. Microdosimetry studies were then performed to evaluate the dose delivered at the cellular level, taking into account the fine high-Z element distribution. These theoretical results have been compared to in vitro studies. Cell survival studies were performed using either a 3D glioma model (spheroids) or cells irradiated in suspension in an iodinated medium. (author) [fr

  7. Failure Mode and Effect Analysis for Delivery of Lung Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Perks, Julian R., E-mail: julian.perks@ucdmc.ucdavis.edu [University of California Davis Medical Center, Sacramento, CA (United States); Stanic, Sinisa; Stern, Robin L.; Henk, Barbara; Nelson, Marsha S.; Harse, Rick D.; Mathai, Mathew; Purdy, James A.; Valicenti, Richard K.; Siefkin, Allan D.; Chen, Allen M. [University of California Davis Medical Center, Sacramento, CA (United States)

    2012-07-15

    Purpose: To improve the quality and safety of our practice of stereotactic body radiation therapy (SBRT), we analyzed the process following the failure mode and effects analysis (FMEA) method. Methods: The FMEA was performed by a multidisciplinary team. For each step in the SBRT delivery process, a potential failure occurrence was derived and three factors were assessed: the probability of each occurrence, the severity if the event occurs, and the probability of detection by the treatment team. A rank of 1 to 10 was assigned to each factor, and then the multiplied ranks yielded the relative risks (risk priority numbers). The failure modes with the highest risk priority numbers were then considered to implement process improvement measures. Results: A total of 28 occurrences were derived, of which nine events scored with significantly high risk priority numbers. The risk priority numbers of the highest ranked events ranged from 20 to 80. These included transcription errors of the stereotactic coordinates and machine failures. Conclusion: Several areas of our SBRT delivery were reconsidered in terms of process improvement, and safety measures, including treatment checklists and a surgical time-out, were added for our practice of gantry-based image-guided SBRT. This study serves as a guide for other users of SBRT to perform FMEA of their own practice.

  8. [MRI guided stereotactic thalamotomy for the treatment of the neurogenic pain].

    Science.gov (United States)

    Balás, I; Llumiguano, C; Horvath, Z; Kovér, F; Dóczi, T P

    Medial thalamotomy is one of the first stereotactic operations to have been used for neurogenic pain, has a low complication rate and no risk of the development of iatrogenic neurogenic pain. It represents selective local relief for all types of pain, without causing somatosensorial deficit. We did 39 posteromedial thalamotomies in patients with persistent intractable pain due to various disorders. The pain was assessed pre- and postoperatively on the VAS (Visual Analogic Scale). Half of the patients operated on had relief of pain after thalamotomy. In 84% (n = 39) of our cases this relief occurred on the second day, in 70% (n = 35) after three months, in 63% (n = 27) after six months, in 64% (n = 25) after nine months, in 62% (n = 23) of the patients after 12 months, and in 62% (n = 22) after 24 months. Three patients had temporary complications and one a permanent complication, but this did not make him an invalid. Posteromedial stereotactic thalamotomy under MR guidance can provide safe, effective treatment for persistent, intractable pain.

  9. Functional MRI for immediate monitoring stereotactic thalamotomy in a patient with essential tremor

    Energy Technology Data Exchange (ETDEWEB)

    Hesselmann, Volker; Schaaf, Maike; Krug, Barbara; Lackner, Klaus [University of Cologne, Department of Radiology, Cologne (Germany); Maarouf, Mohammed; Hunsche, Stefan; Sturm, Volker [University of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); Lasek, Kathrin [Universitaetsklinikum Schleswig Holstein, Klinik fuer Neurologie, Luebeck (Germany); Wedekind, Christoph [Akademisches Lehrkrankenhaus der Universitaet Erlangen-Nuernberg, Belegabteilung fuer Neurochirurgie, Klinikum Bamberg, Bamberg (Germany)

    2006-10-15

    The effect of stereotactic thalamotomy was assessed with pre- and postoperative functional magnetic resonance imaging (fMRI) under motor stimulation. A patient with unilateral essential tremor (ET) of the left arm underwent stereotactically guided thalamotomy of the right ventral intermediate thalamic nucleus (VIM). FMRI was done directly before and after surgery on a 1.5-Tesla scanner. The stimulation paradigm was maintainance of the affected arm in an extended position and hand clenching being performed in a block design manner. Statistical analysis was done with Brain Voyager 2000. After thalamotomy the tremor diminished completely. As a difference between the pre- and postoperative fMRI, a significant activation was found in the VIM contralateral to the activation site, adjacent to the inferior olivary nucleus contralateral to the activation site and in the dorsal cingulum. In conclusion, fMRI can detect the functional effect of thalamotomy for tremor treatment. Direct postoperative fMRI provides a sufficient method for estimating the effect of thalamotomy immediately after intervention. The importance of the intermediate thalamic nucleus and the olivary nucleus in tremor generation is supported by our findings. (orig.)

  10. Optimization of dose distribution for the system of linear accelerator-based stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Suh Taesuk.

    1990-01-01

    This work addresses a method for obtaining an optimal dose distribution of stereotactic radiosurgery. Since stereotactic radiosurgery utilizes multiple noncoplanar arcs and a three-dimensional dose evaluation technique, many beam parameters and complex optimization criteria are included in the dose optimization. Consequently, a lengthy computation time is required to optimize even the simplest case by a trial and error method. The basic approach presented here is to use both an analytical and an experimental optimization to minimize the dose to critical organs while maintaining a dose shaped to the target. The experimental approach is based on shaping the target volumes using multiple isocenters from dose experience, or on field shaping using a beam's eye view technique. The analytical approach is to adapt computer-aided design optimization to find optimum parameters automatically. Three-dimensional approximate dose models are developed to simulate the exact dose model using a spherical or cylindrical coordinate system. Optimum parameters are found much faster with the use of computer-aided design optimization techniques. The implementation of computer-aided design algorithms with the approximate dose model and the application of the algorithms to several cases are discussed. It is shown that the approximate dose model gives dose distributions similar to those of the exact dose model, which makes the approximate dose model an attractive alternative to the exact dose model, and much more efficient in terms of computer-aided design and visual optimization

  11. Stereotactic Laser Ablation for Medically Intractable Epilepsy: The Next Generation of Minimally Invasive Epilepsy Surgery

    Directory of Open Access Journals (Sweden)

    Michael Joseph LaRiviere

    2016-12-01

    Full Text Available Epilepsy is a common, disabling illness that is refractory to medical treatment in approximately one third of patients, particularly among those with mesial temporal lobe epilepsy. While standard open mesial temporal resection is effective, achieving seizure freedom in most patients, efforts to develop safer, minimally invasive techniques have been underway for over half a century. Stereotactic ablative techniques, in particular radiofrequency ablation, were first developed in the 1960s, with refinements in the 1990s with the advent of modern computed tomography and magnetic resonance-based imaging. In the past 5 years, the most recent techniques have used MRI-guided laser interstitial thermotherapy (LITT, whose development began in the 1980s, saw refinements in MRI thermal imaging through the 1990s, and was initially used primarily for the treatment of intracranial and extracranial tumors. The present review describes the original stereotactic ablation trials, followed by modern imaging-guided radiofrequency ablation series for mesial temporal lobe epilepsy. The development of LITT and MRI thermometry are then discussed. Finally, the two currently available MRI-guided laser interstitial thermotherapy systems are reviewed for their role in the treatment of mesial temporal lobe and other medically refractory epilepsies.

  12. Long-term results of stereotactic radiosurgery to the pituitary gland in Cushing's disease

    International Nuclear Information System (INIS)

    Degerblad, M.; Raehn, T.; Bergstrand, G.; Thoren, M.

    1986-01-01

    Gamma radiation from 60 Co delivered with stereotactic technique was given to the pituitary gland in 35 patients, aged 18-65 years, with Cushing's disease. The doses were 70-100 Gy in each single irradiation. The size of the sella turcica was normal in the majority of the patients. The observation time was 3-9 years in 29 patiens. Out of them, 14 (48%) obtained clinical remission and normal urinary cortisol after one irradiation. Eight achieved remission after two to four irradiations. In total, 22 out of 29 patients (76%) obtained remission. In 12 of them remission was obtained in 1 year and in another 10 within 3 years. No recurrences were observed. Improvement was seen in 2 patients after one and three irradiations. Bilateral adrenalectomy was performed in 5 patients owing to unsatisfactory effect of irradiation. Pituitary insufficiency with gonadotropin, thyrotropin or cortocotropin failure was demonstrated in 12 of 22 patients in remission. This occurred 4 months to 7 years after the first irradiation. Another 6 patients were followed less than 3 years after the first irradiation. Two obtained remission after the first treatment, whereas the other 4 improved. Stereotactic pituitary irradiation is suggested as a non-invasive therapeutic alternative in Cushing's disease for example in patients with considerable surgical risk or as a supplement to pituitary microsurgery. (author)

  13. Quality assurance program for prototype stereotactic system developed for neptun 10 Pc linac

    International Nuclear Information System (INIS)

    Khoshbin Khoshnazar, A.R.; Bahreyni Toossi, M.T.; Hashemiyan, A.R.; Bahreyni Toossi, M.T.; Salek, R.

    2005-01-01

    A prototype stereotactic radiosurgery set was designed and constructed for a Neptun 10 Pc linac that is currently being used at Imam Reza hospital in Mashad. Materials and Methods: A complete quality assurance program was designed and performed for the constructed system including isocentric accuracy test, localization accuracy test, dose delivery accuracy test and leakage radiation test. Target simulator, control alignment device and plexiglass phantom which were parts of the developed hardware were used to fulfill quality assurance program. Results: The average isocentric shift resulted from the gantry rotation and couch turning were respectively obtained to be 1.4 and 2 mm. The average localization error in the three coordinates was found to be 2.2 mm. The total treatment uncertainty due to all of the probable errors in the system was equal to 4.32 mm. The dose delivery accuracy test was carried out, the result indicated a 3.7% difference between the given and measured dose. Conclusion: The quality assurance tests showed consistent performance of the constructed system within the accepted limits; however, some inconsistency might exist in certain cases. The safety of stereotactic radiosurgery system method is increased when the overall uncertainty is minimized nd the treatment of the lesions adjacent to critical organs is avoided

  14. Quality assurance procedure for a gamma guided stereotactic breast biopsy system.

    Science.gov (United States)

    Welch, Benjamin L; Brem, Rachel; Black, Rachel; Majewski, Stan

    2006-01-01

    A quality assurance procedure has been developed for a prototype gamma-ray guided stereotactic biopsy system. The system consists of a compact small-field-of-view gamma-ray camera mounted to the rotational arm of a Lorad stereotactic biopsy system. The small-field-of-view gamma-ray camera has been developed for clinical applications where mammographic X-ray localization is not possible. Marker sources that can be imaged with the gamma-camera have been designed and built for quality assurance testing and to provide a fiducial reference mark. An algorithm for determining the three dimensional location of a region of interest, such as a lesion, relative to the fiducial mark has been implemented into the software control of the camera. This system can be used to determine the three-dimensional location of a region of interest from a stereo pair of images and that information can be used to guide a biopsy needle to that site. Point source phantom tests performed with the system have demonstrated that the camera can be used to localize a point of interest to within 1 mm, which is satisfactory for its use in needle localization.

  15. Design and development of new collimator cones for fractionated stereotactic radiation therapy in Samsung Medical Center.

    Science.gov (United States)

    Ahn, Y C; Ju, S G; Kim, D Y; Choi, D R; Huh, S J; Park, Y H; Lim, D H; Kim, M K

    1999-05-01

    In stereotactic radiotherapy using X-Knife system, the commercially supplied collimator cone system had a few mechanical limitations. The authors have developed new collimator cones to overcome these limitations and named them "SMC type" collimator cones. We made use of cadmium-free cerrobend alloy within the stainless steel cylinder housing. We made nine cones of relatively larger sizes (3.0 cm to 7.0 cm in diameter) and of shorter length with bigger clearance from the isocenter than the commercial cones. The cone housing and the collimator cones were designed to insert into the wedge mount of the gantry head to enable double-exposure linac-gram taking. The mechanical accuracy of pointing to the isocenter was tested by ball test and cone rotation test, and the dosimetric measurements were performed, all of which were with satisfactory results. A new innovative quality assurance procedure using linac-grams on the patients at the actual treatment setup was attempted after taking 10 sets of AP and lateral linac-grams and the overall mechanical isocenter accuracy was excellent (average error = 0.4 +/- 0.2 mm). We have developed the SMC type collimator cone system mainly for fractionated stereotactic radiation therapy use with our innovative ideas. The new cones' mechanical accuracy and physical properties were satisfactory for clinical use, and the verification of the isocenter accuracy on the actual treatment setup has become possible.

  16. Stereotactic radiosurgery of angiographically occult vascular malformations: Indications and preliminary experience

    International Nuclear Information System (INIS)

    Kondziolka, D.; Lunsford, L.D.; Coffey, R.J.; Bissonette, D.J.; Flickinger, J.C.

    1990-01-01

    Stereotactic radiosurgery has been shown to treat successfully angiographically demonstrated arteriovenous malformations of the brain. Angiographic obliteration has represented cure and eliminated the risk of future hemorrhage. The role of radiosurgery in the treatment of angiographically occult vascular malformations (AOVMs) has been less well defined. In the initial 32 months of operation of the 201-source cobalt-60 gamma knife at the University of Pittsburgh, 24 patients meeting strict criteria for high-risk AOVMs were treated. Radiosurgery was used conservatively; each patient had sustained two or more hemorrhages and had a magnetic resonance imaging-defined AOVM located in a region of the brain where microsurgical removal was judged to pose an excessive risk. Venous angiomas were excluded by performance of high-resolution subtraction angiography in each patient. Fifteen malformations were in the medulla, pons, and/or mesencephalon, and 5 were located in the thalamus or basal ganglia. Follow-up ranged from 4 to 24 months. Nineteen patients either improved or remained clinically stable and did not hemorrhage again during the follow-up interval. One patient suffered another hemorrhage 7 months after radiosurgery. Five patients experienced temporary worsening of pre-existing neurological deficits that suggested delayed radiation injury. Magnetic resonance imaging demonstrated signal changes and edema surrounding the radiosurgical target. Dose-volume guidelines for avoiding complications were constructed. Our initial experience indicates that stereotactic radiosurgery can be performed safely in patients with small, well-circumscribed AOVMs located in deep, critical, or relatively inaccessible cerebral locations

  17. The role of stereotactic radiation therapy in the management of children with brain tumors.

    Science.gov (United States)

    Lew, C M; LaVally, B

    1995-10-01

    Conventional radiation therapy plays an important role in the management of intracranial tumors in children. For certain tumors radiation therapy serves as the primary mode of treatment, and for others it plays an adjuvant role with surgery and/or chemotherapy. Improvements in long-term survival rates have focused attention on the long-term sequelae of brain tumors and their treatment, and the sequelae, in turn, have become important targets for clinical investigation. Long-term side effects of particular concern in children include cranial nerve damage, memory and intellectual deficits, pituitary-hypothalamic dysfunction, demyelinization of brain tissue, and secondary malignancies. A new form of radiation therapy, stereotactic radiotherapy (SRT), merges the technologies of stereotactic surgery and conventional fractionated radiotherapy. The intent is to deliver maximum tumoricidal doses to the target while limiting the dose to normal surrounding brain tissue. The key feature of SRT is a noninvasive, relocatable immobilization system to assure accurate and reproducible positioning during planning and treatment. The headframes used for children have been modified to address their specific needs. The complexities of this process require careful preparation of patients and their families and the participation of many disciplines. Long-term follow-up will be essential to evaluate the effectiveness of this innovative treatment.

  18. Exclusive irradiation of cyst adenoid carcinomas: contribution of a dose complement in stereotactic mode

    International Nuclear Information System (INIS)

    Coche-Dequeant, B.; Lefebvre, J.L.; Lacornerie, T.; Lartigau, E.; Attar, M.

    2009-01-01

    The cyst adenoid carcinoma is a rare malignant tumor that reaches principally the salivary glands; It is characterized by a clinical aggressiveness, the presence of peri neural invasions, frequent local recurrences and a high rate of metastases dissemination at delayed distance. The treatment is surgery with a postoperative adjuvant radiotherapy. for the patients suffering of inoperable tumors, the exclusive radiotherapy gives bad results with tests of use of heavy particles. The place of a hypo fractionated treatment on a stereotactic mode has not been evaluated, especially in dose complement after three dimensional irradiation. The purpose was to answer the following question if the Cyberknife was useful to deliver a complement of hypo fractionated stereotactic dose for the inoperable head and neck tumors. The limited number of patients does not allow a definitive conclusion. however, this therapy option seems interesting for the inoperable tumors subject to the management of the toxicity induced by the treatment. The evaluation of the irradiation volumes remains the critical element for the feasibility of this kind of protocol. (N.C.)

  19. Re-irradiation of recurrent anaplastic ependymoma using radiosurgery or fractionated stereotactic radiotherapy.

    Science.gov (United States)

    Murai, Taro; Sato, Kengo; Iwabuchi, Michio; Manabe, Yoshihiko; Ogino, Hiroyuki; Iwata, Hiromitsu; Tatewaki, Koshi; Yokota, Naoki; Ohta, Seiji; Shibamoto, Yuta

    2016-03-01

    Recurrent ependymomas were retreated with stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT). The efficacy, toxicities, and differences between SRS and FSRT were analyzed. Eight patients with recurrent ependymomas fulfilling the criteria described below were evaluated. Inclusion criteria were: (1) the patient had previously undergone surgery and conventional radiotherapy as first-line treatment; (2) targets were located in or adjacent to the eloquent area or were deep-seated; and (3) the previously irradiated volume overlapped the target lesion. FSRT was delivered to 18 lesions, SRS to 20 lesions. A median follow-up period was 23 months. The local control rate was 76 % at 3 years. No significant differences in local control were observed due to tumor size or fractionation schedule. Lesions receiving >25 Gy/5 fr or 21 Gy/3 fr did not recur within 1 year, whereas no dose-response relationship was observed in those treated with SRS. No grade ≥2 toxicity was observed. Our treatment protocol provided an acceptable LC rate and minimal toxicities. Because local recurrence of tumors may result in patient death, a minimum dose of 21 Gy/3 fr or 25 Gy/5 fr or higher may be most suitable for treatment of these cases.

  20. Physical properties of a linear accelerator-based stereotactic installed at national cancer institute

    International Nuclear Information System (INIS)

    Attala, E.M.; Deiab, N.A.; Elawady, R.A.

    2005-01-01

    The purpose of this paper is to present the dosimetry and mechanical accuracy of the first dedicated Siemens PRIMUS M6/6ST linear accelerator-based Stereotactic installed in National Cancer Institute for stereotactic radiosurgery and radiotherapy (SRS/SRT). The data were obtained during the installation, acceptance test procedure, and commissioning of the unit. The Primus M6/6ST has a single 6-MV beam with the same beam characteristics as that of the mother unit, the Siemens. The dosimetric data were taken using pin point ion chamber. The cone sizes vary from 12.5 to 40.0 mm diameter. The mechanical stability of the entire system was verified. The variations in isocenter position with table, gantry, and collimator rotation were found to be < 0.5 mm with a compounded accuracy of < or = 1.0 mm. The beam profiles of all cones in the x and y directions were within +/- 0.5 mm and match with the physical size of the cone. The basic dosimetry parameters such as tissue maximum ratio (TMR), off-axis ratio (OAR) and cone factor needed for patient treatment were evaluated. The mechanical and dosimetric characteristics including dose linearity of this unit are presented and found to be suitable for SRS/SRT. The difficulty in absolute dose measurement for small cone is discussed

  1. Phantom dosimetry for conformal stereotactic radiotherapy with a Head and Neck Localizer frame

    Energy Technology Data Exchange (ETDEWEB)

    Ravindran, B. Paul [Department of Radiation Oncology, Christian Medical College Hospital, Vellore (India)]. E-mail: paul@cmcvellore.ac.in; Fairclough, Lee [Department of Radiation Therapy, Princess Margaret Hospital, Toronto (Canada); Jaywant, Satish M. [Department of Clinical Physics, Princess Margaret Hospital, Toronto (Canada)

    2001-07-01

    Linear accelerator based stereotactic radiotherapy (SRT) with the Gill-Thomas-Cosman (GTC) re-locatable frame has been in use for several years. The use of the frame is limited to treating lesions above the hard palate. For treating tumours in the head and neck region, the Head and Neck Localizer (HNL) frame has been designed by Radionics Inc. for use with their XPlan treatment planning software. In this study we have used a spherical acrylic phantom commercially known as the 'Lucy' phantom (Sandstrom Sandstrom Trade and Technology Inc.) to perform thermoluminiscent as well as film dosimetry for the HNL frame. A radio-opaque marker was placed in the phantom and a film test carried out to verify the accuracy in isocentre positioning. The results of the dosimetry with TLD were within 2% for points near the isocentre and 5% (or 2 mm in steep gradients) in the planning target volume (PTV). In regions of low dose, larger percentage differences in local dose were observed, but all differences were within 5% of isocentre dose. The film dosimetry provided dose distributions that matched well with those generated by the XPlan stereotactic treatment planning software. (author)

  2. Optimal MRI methods for direct stereotactic targeting of the subthalamic nucleus and globus pallidus

    International Nuclear Information System (INIS)

    O'Gorman, Ruth L.; Shmueli, Karin; Ashkan, Keyoumars; Selway, Richard P.; Samuel, Michael; Lythgoe, David J.; Shahidiani, Asal; Wastling, Stephen J.; Footman, Michelle; Jarosz, Jozef

    2011-01-01

    Reliable identification of the subthalamic nucleus (STN) and globus pallidus interna (GPi) is critical for deep brain stimulation (DBS) of these structures. The purpose of this study was to compare the visibility of the STN and GPi with various MRI techniques and to assess the suitability of each technique for direct stereotactic targeting. MR images were acquired from nine volunteers with T2- and proton density-weighted (PD-W) fast spin echo, susceptibility-weighted imaging (SWI), phase-sensitive inversion recovery and quantitative T1, T2 and T2 * mapping sequences. Contrast-to-noise ratios (CNR) for the STN and GPi were calculated for all sequences. Targeting errors on SWI were evaluated on magnetic susceptibility maps. The sequences demonstrating the best conspicuity of DBS target structures (SWI and T2*) were then applied to ten patients with movement disorders, and the CNRs for these techniques were assessed. SWI offers the highest CNR for the STN, but standard PD-W images provide the best CNR for the pallidum. Susceptibility maps indicated that the GPi margins may be shifted slightly on SWI, although no shifts were seen for the STN. SWI may improve the visibility of the STN on pre-operative MRI, potentially improving the accuracy of direct stereotactic targeting. (orig.)

  3. Optimal MRI methods for direct stereotactic targeting of the subthalamic nucleus and globus pallidus

    Energy Technology Data Exchange (ETDEWEB)

    O' Gorman, Ruth L. [King' s College Hospital, Department of Neuroradiology, London (United Kingdom); University Children' s Hospital (Kinderspital), MR Zentrum, Zurich (Switzerland); Shmueli, Karin [National Institutes of Health, Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, Bethesda, MD (United States); Ashkan, Keyoumars; Selway, Richard P. [King' s College Hospital, Department of Neurosurgery, London (United Kingdom); Samuel, Michael [King' s College Hospital, Department of Neurology, London (United Kingdom); Lythgoe, David J.; Shahidiani, Asal [Institute of Psychiatry, Department of Clinical Neuroscience, London (United Kingdom); Wastling, Stephen J. [Institute of Psychiatry, Department of Clinical Neuroscience, London (United Kingdom); King' s College Hospital, Department of Medical Engineering and Physics, London (United Kingdom); Footman, Michelle [King' s College Hospital, Department of Medical Engineering and Physics, London (United Kingdom); Jarosz, Jozef [King' s College Hospital, Department of Neuroradiology, London (United Kingdom)

    2011-01-15

    Reliable identification of the subthalamic nucleus (STN) and globus pallidus interna (GPi) is critical for deep brain stimulation (DBS) of these structures. The purpose of this study was to compare the visibility of the STN and GPi with various MRI techniques and to assess the suitability of each technique for direct stereotactic targeting. MR images were acquired from nine volunteers with T2- and proton density-weighted (PD-W) fast spin echo, susceptibility-weighted imaging (SWI), phase-sensitive inversion recovery and quantitative T1, T2 and T2{sup *} mapping sequences. Contrast-to-noise ratios (CNR) for the STN and GPi were calculated for all sequences. Targeting errors on SWI were evaluated on magnetic susceptibility maps. The sequences demonstrating the best conspicuity of DBS target structures (SWI and T2*) were then applied to ten patients with movement disorders, and the CNRs for these techniques were assessed. SWI offers the highest CNR for the STN, but standard PD-W images provide the best CNR for the pallidum. Susceptibility maps indicated that the GPi margins may be shifted slightly on SWI, although no shifts were seen for the STN. SWI may improve the visibility of the STN on pre-operative MRI, potentially improving the accuracy of direct stereotactic targeting. (orig.)

  4. Measurement of the absorbed dose in the very small size photon beams used in stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Derreumaux, S.; Huet, C.; Robbes, I.; Trompier, F.; Boisserie, G.; Brunet, G.; Buchheit, I.; Sarrazin, T.; Chea, M.

    2008-01-01

    After the radiotherapy accident in Toulouse, the French authority of nuclear safety and the French agency of health products safety have asked the IR.S.N. to establish, together with experts from the French society of medical physics and the French society of radiotherapy and oncology, a national protocol on dose calibration for the very small beams used in stereotactic radiotherapy. The research and reflexions of the working group 'GT minifaisceaux ' set up by the I.R.S.N. are presented in this final report. A review of the international literature has been performed. A national survey has been done to know the present practices in the dosimetry of small fields. A campaign of measurements of the data needed to characterize the small beams for the different stereotactic systems has started, using different types of detectors acquired by the I.R.S.N.. In this report are presented a deep synthesis on the problems related to the dosimetry of small fields, the results of the national survey, the first results of the campaign of measurements and the recommendations of the GT. (authors)

  5. Optimization of Stereotactic Radiotherapy Treatment Delivery Technique for Base-Of-Skull Meningiomas

    International Nuclear Information System (INIS)

    Clark, Brenda G.; Candish, Charles; Vollans, Emily; Gete, Ermias; Lee, Richard; Martin, Monty; Ma, Roy; McKenzie, Michael

    2008-01-01

    This study compares static conformal field (CF), intensity modulated radiotherapy (IMRT), and dynamic arcs (DA) for the stereotactic radiotherapy of base-of-skull meningiomas. Twenty-one cases of base-of-skull meningioma (median planning target volume [PTV] = 21.3 cm 3 ) previously treated with stereotactic radiotherapy were replanned with each technique. The plans were compared for Radiation Therapy Oncology Group conformity index (CI) and homogeneity index (HI), and doses to normal structures at 6 dose values from 50.4 Gy to 5.6 Gy. The mean CI was 1.75 (CF), 1.75 (DA), and 1.66 (IMRT) (p 3 , the CI (IMRT) was always superior to CI (DA) and CI (CF). At PTV sizes below 25 cm 3 , there was no significant difference in CI between each technique. There was no significant difference in HI between plans. The total volume of normal tissue receiving 50.4, 44.8, and 5.6 Gy was significantly lower when comparing IMRT to CF and DA plans (p 3 , due to improved conformity and normal tissue sparing, in particular for the brain stem and ipsilateral temporal lobe

  6. The use of stereotactic radiosurgical boost in the treatment of medulloblastomas

    International Nuclear Information System (INIS)

    Woo, Charles; Stea, Baldassarre; Lulu, Bruce; Hamilton, Allan; Cassady, J. Robert

    1997-01-01

    Purpose: Starting in 1992, we began using a stereotactic radiosurgical (SRS) boost for the treatment of medulloblastomas. Four patients ranging in age from 7 to 42 years old have since been treated and are the subject of this retrospective study. Methods and Materials: All patients were initially treated with a maximally debulking surgery and external beam radiotherapy, which were then followed by a stereotactic radiosurgical boost using a modified 6 MeV linear accelerator. Radiosurgical boost doses ranged from 4.50 to 10.0 Gy. Target volumes ranged from 1.1 to 8.1 cc. The procedure was well tolerated with minimal acute toxicities. Results: All four patients are alive without evidence of recurrence (at 8 to 35 months). Acute nausea and vomiting was elicited during the radiosurgical procedure in the first patient treated. We have since begun premedicating patients with antiemetics or treating under general anesthesia. Late complications consisted of panhypopituitarism in one patient, which was thought to be attributable to the previous course of whole-brain radiotherapy. We have not observed any incidence of radionecrosis in this small cohort of patients. Conclusions: Our preliminary results with the use of radiosurgery for medulloblastomas are optimistic, and we would like to suggest the inclusion of a radiosurgery boost in future clinical trials for treatment of this disease

  7. Optimization of the primary collimator settings for fractionated IMRT stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Tobler, Matt; Leavitt, Dennis D.; Watson, Gordon

    2004-01-01

    Advances in field-shaping techniques for stereotactic radiosurgery/radiotherapy have allowed dynamic adjustment of field shape with gantry rotation (dynamic conformal arc) in an effort to minimize dose to critical structures. Recent work evaluated the potential for increased sparing of dose to normal tissues when the primary collimator setting is optimized to only the size necessary to cover the largest shape of the dynamic micro multi leaf field. Intensity-modulated radiotherapy (IMRT) is now a treatment option for patients receiving stereotactic radiotherapy treatments. This multisegmentation of the dose delivered through multiple fixed treatment fields provides for delivery of uniform dose to the tumor volume while allowing sparing of critical structures, particularly for patients whose tumor volumes are less suited for rotational treatment. For these segmented fields, the total number of monitor units (MUs) delivered may be much greater than the number of MUs required if dose delivery occurred through an unmodulated treatment field. As a result, undesired dose delivered, as leakage through the leaves to tissues outside the area of interest, will be proportionally increased. This work will evaluate the role of optimization of the primary collimator setting for these IMRT treatment fields, and compare these results to treatment fields where the primary collimator settings have not been optimized

  8. Combined stereotactic biopsy and stepping-source interstitial irradiation of glioblastoma multiforme.

    Science.gov (United States)

    Brehmer, Stefanie; Guthier, Christian V; Clausen, Sven; Schneider, Frank; Schulte, Dirk-Michael; Benker, Matthias; Bludau, Frederic; Glatting, Gerhard; Marx, Alexander; Schmiedek, Peter; Hesser, Jürgen; Wenz, Frederik; Giordano, Frank A

    2018-04-01

    Patients diagnosed with glioblastoma multiforme receiving stereotactic biopsy only either due to tumor localization or impaired clinical status face a devastating prognosis with very short survival times. One strategy to provide an initial cytoreductive and palliative therapy at the time of the stereotactic biopsy is interstitial irradiation through the pre-defined trajectory of the biopsy channel. We designed a novel treatment planning system and evaluated the treatment potential of a fixed-source and a stepping-source algorithm for interstitial radiosurgery on non-spherical glioblastoma in direct adjacency to risk structures. Using both setups, we show that radiation doses delivered to 100% of the gross tumor volume shifts from sub-therapeutic (10-12 Gy) to sterilizing single doses (25-30 Gy) when using the stepping source algorithm due to improved sparing of organs-at-risk. Specifically, the maximum doses at the brain stem were 100% of the PTV dose when a fixed central source and 38% when a stepping-source algorithm was used. We also demonstrated precision of intracranial target points and stability of superficial and deep trajectories using both a phantom and a body donor study. Our setup now for the first time provides a basis for a clinical proof-of-concept trial and may widen palliation options for patients with limited life expectancy that should not undergo time-consuming therapies.

  9. Use of stereotactic radiosurgery in the treatment of gynecologic malignancies: A review

    Science.gov (United States)

    Long, Beverly; Eskander, Ramez N; Tewari, Krishnansu S

    2014-01-01

    Recent retrospective studies have reported the use of stereotactic radiosurgery (SRS) in the treatment of gynecologic cancers. SRS uses real-time imaging and high dose radiation beams attached to precise robotic arms to target malignant lesions while sparing normal tissue. The purpose of this review is to examine the indications for SRS in gynecologic oncology, review the current literature regarding the use of SRS in gynecologic cancers, and identify future directions for research in this area. Literature on stereotactic radiosurgery was reviewed using the PubMed search engine. Articles written in English from 1993-2013 were reviewed, and 20 case series and clinical trials were included. The safety and efficacy SRS has been demonstrated in all gynecologic disease sites including cervical, endometrial, vulvar, vaginal, and ovarian cancers. Indications for its use include non-central pelvic recurrences in previously irradiated patients, complex or non-resectable disease recurrence, and solitary brain metastases. Toxicities are usually mild, though grade 3-4 toxicities have been reported. SRS is a promising second line treatment modality for patients with primary or recurrent disease who cannot undergo standard surgical or radiation therapy. Further research is required to determine optimal dosing and fractionation schedules, delineate appropriate patient populations, and assess longterm morbidity and survival. PMID:24976937

  10. EORTC 22972-26991/MRC BR10 trial: Fractionated stereotactic boost following conventional radiotherapy of high grade gliomas

    International Nuclear Information System (INIS)

    Baumert, Brigitta G.; Brada, Michael; Bernier, Jacques; Kortmann, Rolf D.; Dehing-Oberije, Cary; Collette, Laurence; Davis, J. Bernard

    2008-01-01

    Background and purpose: The EORTC trial No. 22972 investigated the role of an additional fractionated stereotactic boost (fSRT) to conventional radiotherapy for patients with high grade gliomas. A quality-assurance (QA) programme was run in conjunction with the study and was the first within the EORTC addressing the quality of a supposedly highly accurate treatment technique such as stereotactic radiotherapy. A second aim was to investigate a possible relation between the clinical results of the stereotactic boost arm and the results of the QA. Materials and methods: The trial was closed in 2001 due to low accrual. In total, 25 patients were randomized: 14 into the experimental arm and 11 into the control arm. Six centres randomized patients, 8 centres had completed the dummy run (DR) for the stereotactic boost part. All participating centres (9) were asked to complete a quality-assurance questionnaire. The DR consisted of treatment planning according to the guidelines of the protocol on 3 different tumour volumes drawn on CT images of a humanized phantom. The SRT technique to be used was evaluated by the questionnaire. Clinical data from patients recruited to the boost arm from 6 participating centres were analysed. Results: There was a full compliance to the protocol requirements for 5 centres. Major and minor deviations in conformality were observed for 2 and 3 centres, respectively. Of the 8 centres which completed the DR, one centre did not comply with the requirements of stereotactic radiotherapy concerning accuracy, dosimetry and planning. Median follow-up and median overall survival were 39.2 and 21.4 months, respectively. Acute and late toxicities of the stereotactic boost were low. One radiation necrosis was seen for a patient who has not received the SRT boost. Three reported serious adverse events were all seizures and probably therapy-related. Conclusions: Overall compliance was good but not ideal from the point of view of this highly precise radiation

  11. Dosimetric performance and array assessment of plastic scintillation detectors for stereotactic radiosurgery quality assurance

    International Nuclear Information System (INIS)

    Gagnon, Jean-Christophe; Theriault, Dany; Guillot, Mathieu; Archambault, Louis; Beddar, Sam; Gingras, Luc; Beaulieu, Luc

    2012-01-01

    Purpose: To compare the performance of plastic scintillation detectors (PSD) for quality assurance (QA) in stereotactic radiosurgery conditions to a microion-chamber (IC), Gafchromic EBT2 films, 60 008 shielded photon diode (SD) and unshielded diodes (UD), and assess a new 2D crosshair array prototype adapted to small field dosimetry. Methods: The PSD consists of a 1 mm diameter by 1 mm long scintillating fiber (BCF-60, Saint-Gobain, Inc.) coupled to a polymethyl-methacrylate optical fiber (Eska premier, Mitsubishi Rayon Co., Ltd., Tokyo, Japan). Output factors (S c,p ) for apertures used in radiosurgery ranging from 4 to 40 mm in diameter have been measured. The PSD crosshair array (PSDCA) is a water equivalent device made up of 49 PSDs contained in a 1.63 cm radius area. Dose profiles measurements were taken for radiosurgery fields using the PSDCA and were compared to other dosimeters. Moreover, a typical stereotactic radiosurgery treatment using four noncoplanar arcs was delivered on a spherical phantom in which UD, IC, or PSD was placed. Using the Xknife planning system (Integra Radionics Burlington, MA), 15 Gy was prescribed at the isocenter, where each detector was positioned. Results: Output Factors measured by the PSD have a mean difference of 1.3% with Gafchromic EBT2 when normalized to a 10 x 10 cm 2 field, and 1.0% when compared with UD measurements normalized to the 35 mm diameter cone. Dose profiles taken with the PSD crosshair array agreed with other single detectors dose profiles in spite of the presence of the 49 PSDs. Gamma values comparing 1D dose profiles obtained with PSD crosshair array with Gafchromic EBT2 and UD measured profiles shows 98.3% and 100.0%, respectively, of detector passing the gamma acceptance criteria of 0.3 mm and 2%. The dose measured by the PSD for a complete stereotactic radiosurgery treatment is comparable to the planned dose corrected for its SD-based S c,p within 1.4% and 0.7% for 5 and 35 mm diameter cone, respectively

  12. Dosimetric performance and array assessment of plastic scintillation detectors for stereotactic radiosurgery quality assurance.

    Science.gov (United States)

    Gagnon, Jean-Christophe; Thériault, Dany; Guillot, Mathieu; Archambault, Louis; Beddar, Sam; Gingras, Luc; Beaulieu, Luc

    2012-01-01

    To compare the performance of plastic scintillation detectors (PSD) for quality assurance (QA) in stereotactic radiosurgery conditions to a microion-chamber (IC), Gafchromic EBT2 films, 60 008 shielded photon diode (SD) and unshielded diodes (UD), and assess a new 2D crosshair array prototype adapted to small field dosimetry. The PSD consists of a 1 mm diameter by 1 mm long scintillating fiber (BCF-60, Saint-Gobain, Inc.) coupled to a polymethyl-methacrylate optical fiber (Eska premier, Mitsubishi Rayon Co., Ltd., Tokyo, Japan). Output factors (S(c,p)) for apertures used in radiosurgery ranging from 4 to 40 mm in diameter have been measured. The PSD crosshair array (PSDCA) is a water equivalent device made up of 49 PSDs contained in a 1.63 cm radius area. Dose profiles measurements were taken for radiosurgery fields using the PSDCA and were compared to other dosimeters. Moreover, a typical stereotactic radiosurgery treatment using four noncoplanar arcs was delivered on a spherical phantom in which UD, IC, or PSD was placed. Using the Xknife planning system (Integra Radionics Burlington, MA), 15 Gy was prescribed at the isocenter, where each detector was positioned. Output Factors measured by the PSD have a mean difference of 1.3% with Gafchromic EBT2 when normalized to a 10 × 10 cm(2) field, and 1.0% when compared with UD measurements normalized to the 35 mm diameter cone. Dose profiles taken with the PSD crosshair array agreed with other single detectors dose profiles in spite of the presence of the 49 PSDs. Gamma values comparing 1D dose profiles obtained with PSD crosshair array with Gafchromic EBT2 and UD measured profiles shows 98.3% and 100.0%, respectively, of detector passing the gamma acceptance criteria of 0.3 mm and 2%. The dose measured by the PSD for a complete stereotactic radiosurgery treatment is comparable to the planned dose corrected for its SD-based S(c,p) within 1.4% and 0.7% for 5 and 35 mm diameter cone, respectively. Furthermore

  13. Dosimetric performance and array assessment of plastic scintillation detectors for stereotactic radiosurgery quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Jean-Christophe; Theriault, Dany; Guillot, Mathieu; Archambault, Louis; Beddar, Sam; Gingras, Luc; Beaulieu, Luc [Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec G1R 2J6 (Canada); Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec G1R 2J6 (Canada); Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec G1R 2J6 (Canada); Department of Radiation Physics, Unit 94, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec G1R 2J6 (Canada)

    2012-01-15

    Purpose: To compare the performance of plastic scintillation detectors (PSD) for quality assurance (QA) in stereotactic radiosurgery conditions to a microion-chamber (IC), Gafchromic EBT2 films, 60 008 shielded photon diode (SD) and unshielded diodes (UD), and assess a new 2D crosshair array prototype adapted to small field dosimetry. Methods: The PSD consists of a 1 mm diameter by 1 mm long scintillating fiber (BCF-60, Saint-Gobain, Inc.) coupled to a polymethyl-methacrylate optical fiber (Eska premier, Mitsubishi Rayon Co., Ltd., Tokyo, Japan). Output factors (S{sub c,p}) for apertures used in radiosurgery ranging from 4 to 40 mm in diameter have been measured. The PSD crosshair array (PSDCA) is a water equivalent device made up of 49 PSDs contained in a 1.63 cm radius area. Dose profiles measurements were taken for radiosurgery fields using the PSDCA and were compared to other dosimeters. Moreover, a typical stereotactic radiosurgery treatment using four noncoplanar arcs was delivered on a spherical phantom in which UD, IC, or PSD was placed. Using the Xknife planning system (Integra Radionics Burlington, MA), 15 Gy was prescribed at the isocenter, where each detector was positioned. Results: Output Factors measured by the PSD have a mean difference of 1.3% with Gafchromic EBT2 when normalized to a 10 x 10 cm{sup 2} field, and 1.0% when compared with UD measurements normalized to the 35 mm diameter cone. Dose profiles taken with the PSD crosshair array agreed with other single detectors dose profiles in spite of the presence of the 49 PSDs. Gamma values comparing 1D dose profiles obtained with PSD crosshair array with Gafchromic EBT2 and UD measured profiles shows 98.3% and 100.0%, respectively, of detector passing the gamma acceptance criteria of 0.3 mm and 2%. The dose measured by the PSD for a complete stereotactic radiosurgery treatment is comparable to the planned dose corrected for its SD-based S{sub c,p} within 1.4% and 0.7% for 5 and 35 mm diameter cone

  14. [Implantable middle ear hearing aids].

    Science.gov (United States)

    à Wengen, D F

    2004-01-01

    Conventional acoustic hearing aids are limited in their performance. Due to physical laws their amplification of sound is limited to within 5 kHz. However, the frequencies between 5 and 10 kHz are essential for understanding consonants. Words can only be understood correctly if their consonants can be understood. Furthermore noise amplification remains a problem with hearing aids. Other problems consist of recurrent infections of the external auditory canal, intolerance for occlusion of the ear canal, feedback noise, and resonances in speech or singing. Implantable middle ear hearing aids like the Soundbridge of Symphonix-Siemens and the MET of Otologics offer improved amplification and a more natural sound. Since the first implantation of a Soundbridge in Switzerland in 1996 almost one thousand patients have been implanted worldwide. The currents systems are semi-implantable. The external audio processor containing the microphone, computer chip, battery and radio system is worn in the hair bearing area behind the ear. Implantation is only considered after unsuccessful fitting of conventional hearing aids. In Switzerland the cost for these implantable hearing aids is covered by social insurances. Initially the cost for an implant is higher than for hearing aids. However, hearing aids need replacement every 5 or 6 years whereas implants will last 20 to 30 years. Due to the superior sound quality and the improved understanding of speech in noise, the number of patients with implantable hearing aids will certainly increase in the next years. Other middle ear implants are in clinical testing.

  15. Efter cochlear implant

    DEFF Research Database (Denmark)

    Højen, Anders

    2007-01-01

      Dit barn har netop fået et cochlear implant. Hvad nu? Skal barnet fokusere udelukkende på at lære talt sprog, eller skal det også lære/fortsætte med tegnsprog eller støttetegn? Det er et vanskeligt spørgsmål, og før valget foretages, er det vigtigt at vurdere hvilke konsekvenser valget har, dels...... for den sproglige udvikling isoleret set, og dels for barnets udvikling ud fra en helhedsbetragtning. Dette indlæg fokuserer på, hvilke forventninger man kan have til cochlear implant-brugeres sproglige udvikling med talt sprog alene, hhv. med to sprog (tale og tegn). Disse forventninger er baseret på...

  16. Efter cochlear implant

    DEFF Research Database (Denmark)

    Højen, Anders

    Dit barn har netop fået et cochlear implant. Hvad nu? Skal barnet fokusere udelukkende på at lære talt sprog, eller skal det også lære/fortsætte med tegnsprog eller støttetegn? Det er et vanskeligt spørgsmål, og før valget foretages, er det vigtigt at vurdere hvilke konsekvenser valget har, dels...... for den sproglige udvikling isoleret set, og dels for barnets udvikling ud fra en helhedsbetragtning. Dette indlæg fokuserer på, hvilke forventninger man kan have til cochlear implant-brugeres sproglige udvikling med talt sprog alene, hhv. med to sprog (tale og tegn). Disse forventninger er baseret på...

  17. Piezosurgery in implant dentistry.

    Science.gov (United States)

    Stübinger, Stefan; Stricker, Andres; Berg, Britt-Isabelle

    2015-01-01

    Piezosurgery, or the use of piezoelectric devices, is being applied increasingly in oral and maxillofacial surgery. The main advantages of this technique are precise and selective cuttings, the avoidance of thermal damage, and the preservation of soft-tissue structures. Through the application of piezoelectric surgery, implant-site preparation, bone grafting, sinus-floor elevation, edentulous ridge splitting or the lateralization of the inferior alveolar nerve are very technically feasible. This clinical overview gives a short summary of the current literature and outlines the advantages and disadvantages of piezoelectric bone surgery in implant dentistry. Overall, piezoelectric surgery is superior to other methods that utilize mechanical instruments. Handling of delicate or compromised hard- and soft-tissue conditions can be performed with less risk for the patient. With respect to current and future innovative surgical concepts, piezoelectric surgery offers a wide range of new possibilities to perform customized and minimally invasive osteotomies.

  18. Bone Substitutes for Peri-Implant Defects of Postextraction Implants

    Directory of Open Access Journals (Sweden)

    Pâmela Letícia Santos

    2013-01-01

    Full Text Available Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immediately after tooth extraction, this study aimed to present a literature review about biomaterials surrounding immediate dental implants. The search included 56 articles published from 1969 to 2012. The results were based on data analysis and discussion. It was observed that implant fixation immediately after extraction is a reliable alternative to reduce the treatment length of prosthetic restoration. In general, the biomaterial should be used to increase bone/implant contact and enhance osseointegration.

  19. Ion implantation in metals

    International Nuclear Information System (INIS)

    Vook, F.L.

    1977-02-01

    The application of ion beams to metals is rapidly emerging as a promising area of research and technology. This report briefly describes some of the recent advances in the modification and study of the basic properties of metals by ion implantation techniques. Most of the research discussed illustrates some of the new and exciting applications of ion beams to metals which are under active investigation at Sandia Laboratories, Albuquerque

  20. Modelling of Hand Implants

    Czech Academy of Sciences Publication Activity Database

    Jírová, Jitka

    1999-01-01

    Roč. 1, č. 2 (1999), s. 67-78 ISSN 1509-409X. [Polish Scientific Conference Biomechanics 99 /4./. Polanica Zdrój, 08.09.1999-11.09.1999] R&D Projects: GA ČR GA103/96/0268; GA ČR GA103/97/0729 Keywords : wrist and finger joints implants biomechanics * numerical modelling * experimental research Subject RIV: FI - Traumatology, Orthopedics

  1. Pleural implants of thymoma

    International Nuclear Information System (INIS)

    Patan, D.; Danza, F.M.; Di Gregorio, F.

    1986-01-01

    Six observations of peculiar pleural implants completely separated from invasive thymomas (examined by conventional chest-x-ray and CT) were revoewed. CT was more effective than chest-x-ray; number, size and extent of plain film studies. Moreover CT provides a densitometric evaluation of the pleural pathology being useful in differential diagnosis. CT can also be helpful as a guide to needle biopsy

  2. Ion implantation in ices

    International Nuclear Information System (INIS)

    Strazzulla, G.; Baratta, G.A.; Palumbo, M.E.; Satorre, M.A.

    2000-01-01

    We have studied, by in situ infrared spectroscopy, some effects due to ion implantation in frozen ices. In particular mixtures containing C, N and O atoms (e.g., N 2 :H 2 O:CH 4 ) have been irradiated with unreactive (noble gases) ions: the resulting alteration of the frozen sample induces the formation of other molecules (e.g., CO 2 , R- - -OCN, CO and HCN) and of a refractory organic residue. Similar products are formed when mixtures containing only C and O atoms (e.g., H 2 O:CH 4 ) are irradiated with N ions, i.e. molecular species that include the projectile are formed. These results are important, in particular for their applications to planetary physics. In planetary environments ice thickness is usually much larger than the penetration depth of the relevant ion populations (solar wind ions, magnetospheric particles, etc.) and ion implantation phenomena are expected. Our results indicate that some molecular species observed on icy planetary surfaces could not be native of that object but formed by ion irradiation and/or by implantation of reactive ions

  3. [Osseointegration and dental implants].

    Science.gov (United States)

    Goto, Tetsuya

    2014-02-01

    The concept of osseointegration was developed and the term was coined Dr. Brånemark. Osseointegration is initially defined as the direct structural and functional connection between living bone and surface living bone and the surface of a loadbearing artificial implant, typically made of titanium. Osseointegration required new bone formation around fixture, the healing of implant system is similar to primary bone healing. Bone formation on the titanium surface needs the formation of oxide film, deposition of calcium phosphate, and deposition of the protein. However, osseointegration is not the direct bonding between bone and the titanium surface, there exists an amorphous layer including osteopontin or osteocalcin that osteoblasts use them as a scaffold. In clinical the ratio of bone and implant contacts is called as BIC, and BIC was from 40% to 60% if the osseointegration was obtained. Numerous studies were performed for the surface modification to increase the score of BIC. Recently, surface treatments such as glow discharge, acid-etch, or UV irradiation have been found to be effective for osseointegration. Further modification would be needed to maintain the osseointegration as well as to obtain the osseointegration.

  4. New dental implant selection criterion based on implant design.

    Science.gov (United States)

    El-Anwar, Mohamed I; El-Zawahry, Mohamed M; Ibraheem, Eman M; Nassani, Mohammad Zakaria; ElGabry, Hisham

    2017-01-01

    A comparative study between threaded and plain dental implant designs was performed to find out a new criterion for dental implant selection. Several dental implant designs with a systematic increase in diameter and length were positioned in a cylindrical-shaped bone section and analyzed using finite element method. Four loading types were tested on different dental implant designs; tension of 50 N, compression of 100 N, bending of 20 N, and torque of 2 Nm, to derive design curves. Better stress distribution on both spongy and cortical bone was noted with an increase in dental implant diameter and length. With the increase in dental implant side area, a stress reduction in the surrounding bones was observed, where threaded dental implants showed better behavior over the plain ones. Increasing value of ratio between dental implant side area and its cross-sectional area reduces stresses transferred to cortical and spongy bones. The use of implants with higher ratio of side area to cross-section area, especially with weak jaw bone, is recommended.

  5. Adaptive fractionated stereotactic Gamma Knife radiotherapy of meningioma using integrated stereotactic cone-beam-CT and adaptive re-planning (a-gkFSRT)

    Energy Technology Data Exchange (ETDEWEB)

    Stieler, F.; Wenz, F.; Abo-Madyan, Y.; Schweizer, B.; Polednik, M.; Herskind, C.; Giordano, F.A.; Mai, S. [University of Heidelberg, Department of Radiation Oncology, University Medical Center Mannheim, Mannheim (Germany)

    2016-11-15

    The Gamma Knife Icon (Elekta AB, Stockholm, Sweden) allows frameless stereotactic treatment using a combination of cone beam computer tomography (CBCT), a thermoplastic mask system, and an infrared-based high-definition motion management (HDMM) camera system for patient tracking during treatment. We report on the first patient with meningioma at the left petrous bone treated with adaptive fractionated stereotactic radiotherapy (a-gkFSRT). The first patient treated with Gamma Knife Icon at our institute received MR imaging for preplanning before treatment. For each treatment fraction, a daily CBCT was performed to verify the actual scull/tumor position. The system automatically adapted the planned shot positions to the daily position and recalculated the dose distribution (online adaptive planning). During treatment, the HDMM system recorded the intrafractional patient motion. Furthermore, the required times were recorded to define a clinical treatment slot. Total treatment time was around 20 min. Patient positioning needed 0.8 min, CBCT positioning plus acquisition 1.65 min, CT data processing and adaptive planning 2.66 min, and treatment 15.6 min. The differences for the five daily CBCTs compared to the reference are for rotation: -0.59 ± 0.49 /0.18 ± 0.20 /0.05 ± 0.36 and for translation: 0.94 ± 0.52 mm/-0.08 ± 0.08 mm/-1.13 ± 0.89 mm. Over all fractions, an intrafractional movement of 0.13 ± 0.04 mm was observed. The Gamma Knife Icon allows combining the accuracy of the stereotactic Gamma Knife system with the flexibility of fractionated treatment with the mask system and CBCT. Furthermore, the Icon system introduces a new online patient tracking system to the clinical routine. The interfractional accuracy of patient positioning was controlled with a thermoplastic mask and CBCT. (orig.) [German] Das Gamma Knife Icon (Elekta AB, Stockholm, Schweden) ermoeglicht die stereotaktische Behandlung von Patienten mittels Cone-beam-Computertomographie (CBCT

  6. Production of high thickness implanted layer

    International Nuclear Information System (INIS)

    Abdrashitov, V.G.; Ryzhov, V.V.; Turchanovskij, I.Yu.

    1987-01-01

    The possibilities of consecutive implantation and spray-coating method (CISC) for obtaining materials with implanted addition given profile were investigated. Taking nitrogen ions implantation as example, it is shown, that it is possible to control nitrogen distribution profile configuration by spray-coating of titanium layers with different thickness and by implantation dose change. Implanted layer thickness is determined by CISC cycle number

  7. Improving osseointegration of dental implants.

    Science.gov (United States)

    Elias, Carlos Nelson; Meirelles, Luiz

    2010-03-01

    In the beginning of implantology, the procedures adopted for treating patients were performed in two surgical phases with an interval of 3-6 months. Nowadays, it is possible to insert and load a dental implant in the same surgical procedure. This change is due to several factors, such as improvement of surgical technique, modifications of the implant design, increased quality of implant manufacturing, development of the surgical instruments' quality, careful patient screening and adequate treatment of the implant surface. The clinical results sh