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Sample records for imaging-guided high intensity

  1. High-Intensity Focused Ultrasound: Current Status for Image-Guided Therapy.

    PubMed

    Copelan, Alexander; Hartman, Jason; Chehab, Monzer; Venkatesan, Aradhana M

    2015-12-01

    Image-guided high-intensity focused ultrasound (HIFU) is an innovative therapeutic technology, permitting extracorporeal or endocavitary delivery of targeted thermal ablation while minimizing injury to the surrounding structures. While ultrasound-guided HIFU was the original image-guided system, MR-guided HIFU has many inherent advantages, including superior depiction of anatomic detail and superb real-time thermometry during thermoablation sessions, and it has recently demonstrated promising results in the treatment of both benign and malignant tumors. HIFU has been employed in the management of prostate cancer, hepatocellular carcinoma, uterine leiomyomas, and breast tumors, and has been associated with success in limited studies for palliative pain management in pancreatic cancer and bone tumors. Nonthermal HIFU bioeffects, including immune system modulation and targeted drug/gene therapy, are currently being explored in the preclinical realm, with an emphasis on leveraging these therapeutic effects in the care of the oncology patient. Although still in its early stages, the wide spectrum of therapeutic capabilities of HIFU offers great potential in the field of image-guided oncologic therapy. PMID:26622104

  2. Advances in MR image-guided high-intensity focused ultrasound therapy.

    PubMed

    Kim, Young-sun

    2015-05-01

    The clinical role of magnetic resonance image-guided high-intensity focused ultrasound (MR-HIFU) is rapidly expanding due to its merit of non-invasiveness. MR thermometry based on a proton resonance frequency shift technique is able to accurately measure HIFU-induced temperature changes, which provides considerable advantages over ultrasonography-guided HIFU in terms of safety and therapeutic efficacy. Recent studies and the resulting technological advances in MR-HIFU such as MR thermometry for moving organs, MR-acoustic radiation force imaging, and a volumetric mild hyperthermia technique further will expand its clinical roles from mere ablation therapy to targeted drug delivery and chemo- or radio-sensitisation for cancer treatment. In this article, MR-HIFU therapy is comprehensively reviewed with an emphasis on the roles of MR imaging in HIFU therapy, techniques of MR monitoring, recent advances in clinical MR-HIFU systems, and potential future applications of MR-HIFU therapy. In addition, the pros and cons of MR-HIFU when compared with ultrasonography-guided HIFU are discussed. PMID:25373687

  3. Transvaginal 3D Image-Guided High Intensity Focused Ultrasound Array

    NASA Astrophysics Data System (ADS)

    Held, Robert; Nguyen, Thuc Nghi; Vaezy, Shahram

    2005-03-01

    The goal of this project is to develop a transvaginal image-guided High Intensity Focused Ultrasound (HIFU) device using piezocomposite HIFU array technology, and commercially-available ultrasound imaging. Potential applications include treatment of uterine fibroids and abnormal uterine bleeding. The HIFU transducer was an annular phased array, with a focal length range of 30-60 mm, an elliptically-shaped aperture of 35×60 mm, and an operating frequency of 3 MHz. A pillow-shaped bag with water circulation will be used for coupling the HIFU energy into the tissue. An intra-cavity imaging probe (C9-5, Philips) was integrated with the HIFU array such that the focal axis of the HIFU transducer was within the image plane. The entire device will be covered by a gel-filled condom when inserted in the vaginal cavity. To control it, software packages were developed in the LabView programming environment. An imaging algorithm processed the ultrasound image to remove noise patterns due to the HIFU signal. The device will be equipped with a three-dimensional tracking system, using a six-degrees-of-freedom articulating arm. Necrotic lesions were produced in a tissue-mimicking phantom and a turkey breast sample for all focal lengths. Various HIFU doses allow various necrotic lesion shapes, including thin ellipsoidal, spherical, wide cylindrical, and teardrop-shaped. Software control of the device allows multiple foci to be activated sequentially for desired lesion patterns. Ultrasound imaging synchronization can be achieved using hardware signals obtained from the imaging system, or software signals determined empirically for various imaging probes. The image-guided HIFU device will provide a valuable tool in visualization of uterine fibroid tumors for the purposes of planning and subsequent HIFU treatment of the tumor, all in a 3D environment. The control system allows for various lesions of different shapes to be optimally positioned in the tumor to cover the entire tumor

  4. Investigation of therapy improvement using real-time photoacoustic imaging guided high intensity focused ultrasound

    NASA Astrophysics Data System (ADS)

    Cui, Huizhong

    There are a lot of risks in cancer treatment by invasive surgery, such as bleeding, wound infection, and long recovery time, etc. Therefore, there is great need for minimally- or non-invasive treatment. High intensity focused ultrasound (HIFU) is a rapidly growing and truly non-invasive technology. It has been widely used in therapeutic applications, such as rapid tissue heating and tissue ablation. With proper imaging guidance, HIFU treatment can be performed totally noninvasively. Currently, ultrasound imaging-guided HIFU has been extensively studied. However, ultrasound imaging guidance is less precise because of the relatively low imaging contrast, sensitivity, and specificity for noninvasive detection. In this study, we employed photoacoustic imaging (PAI) technique, which has been developed a novel promising imaging technique for early cancer detection, to guide HIFU treatment. The goal of this study is to investigate the feasibility of PAI to guide, monitor in real time and enhance the HIFU therapy. In this dissertation, as the first step, the integrated PAI and HIFU system had been shown to have the feasibility to guide HIFU both ex vivo and in vivo. Then, the system was improved and developed to a real-time PAI-guided HIFU system. It is demonstrated that the sensitivity of PA detection for HIFU lesion is very high and the saturation of PA signals can be used as the indicator for tissue coagulation. During the temperature measurement using this system, laser-enhanced HIFU heating was found. Thus, we further investigated the laser enhanced technique in both HIFU heating and pulsed HIFU thrombolysis. In the HIFU therapy, laser light was employed to illuminate the sample concurrently with HIFU radiation. The resulting cavitation was detected with a passive cavitation detector. We demonstrated that concurrent light illumination during HIFU has the potential to significantly enhance HIFU by reducing cavitation threshold.

  5. Magnetic resonance image-guided versus ultrasound-guided high-intensity focused ultrasound in the treatment of breast cancer

    PubMed Central

    Li, Sheng; Wu, Pei-Hong

    2013-01-01

    Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is a common cancer in women. HIFU therapy, in combination with other therapies, has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Currently, HIFU therapy is not commonly used in breast cancer treatment, and efforts to promote the application of HIFU is expected. In this article, we compare different image-guided models for HIFU and reviewed the status, drawbacks, and potential of HIFU therapy for breast cancer. PMID:23237221

  6. Magnetic resonance image-guided versus ultrasound-guided high-intensity focused ultrasound in the treatment of breast cancer.

    PubMed

    Li, Sheng; Wu, Pei-Hong

    2013-08-01

    Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is a common cancer in women. HIFU therapy, in combination with other therapies, has the potential to improve both oncologic and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Currently, HIFU therapy is not commonly used in breast cancer treatment, and efforts to promote the application of HIFU is expected. In this article, we compare different image-guided models for HIFU and reviewed the status, drawbacks, and potential of HIFU therapy for breast cancer. PMID:23237221

  7. High-Dose, Single-Fraction Image-Guided Intensity-Modulated Radiotherapy for Metastatic Spinal Lesions

    SciTech Connect

    Yamada, Yoshiya Bilsky, Mark H.; Lovelock, D. Michael; Venkatraman, Ennapadam S.; Toner, Sean; Johnson, Jared; Zatcky, Joan N.P.; Zelefsky, Michael J.; Fuks, Zvi

    2008-06-01

    Purpose: To report tumor control and toxicity for patients treated with image-guided intensity-modulated radiotherapy (RT) for spinal metastases with high-dose single-fraction RT. Methods and Materials: A total of 103 consecutive spinal metastases in 93 patients without high-grade epidural spinal cord compression were treated with image-guided intensity-modulated RT to doses of 18-24 Gy (median, 24 Gy) in a single fraction between 2003 and 2006. The spinal cord dose was limited to a 14-Gy maximal dose. The patients were prospectively examined every 3-4 months with clinical assessment and cross-sectional imaging. Results: The overall actuarial local control rate was 90% (local failure developed in 7 patients) at a median follow-up of 15 months (range, 2-45 months). The median time to local failure was 9 months (range, 2-15 months) from the time of treatment. Of the 93 patients, 37 died. The median overall survival was 15 months. In all cases, death was from progression of systemic disease and not local failure. The histologic type was not a statistically significant predictor of survival or local control. The radiation dose was a significant predictor of local control (p = 0.03). All patients without local failure also reported durable symptom palliation. Acute toxicity was mild (Grade 1-2). No case of radiculopathy or myelopathy has developed. Conclusion: High-dose, single-fraction image-guided intensity-modulated RT is a noninvasive intervention that appears to be safe and very effective palliation for patients with spinal metastases, with minimal negative effects on quality of life and a high probability of tumor control.

  8. Clinical Application of High-Dose, Image-Guided Intensity-Modulated Radiotherapy in High-Risk Prostate Cancer

    SciTech Connect

    Bayley, Andrew; Rosewall, Tara; Craig, Tim; Bristow, Rob; Chung, Peter; Gospodarowicz, Mary; Menard, Cynthia; Milosevic, Michael; Warde, Padraig; Catton, Charles

    2010-06-01

    Purpose: To report the feasibility and early toxicity of dose-escalated image-guided IMRT to the pelvic lymph nodes (LN), prostate (P), and seminal vesicles (SV). Methods and Materials: A total of 103 high-risk prostate cancer patients received two-phase, dose-escalated, image-guided IMRT with 3 years of androgen deprivation therapy. Clinical target volumes (CTVs) were delineated using computed tomography/magnetic resonance co-registration and included the prostate, portions of the SV, and the LN. Planning target volume margins (PTV) used were as follows: P (10 mm, 7 mm posteriorly), SV (10 mm), and LN (5 mm). Organs at risk (OaR) were the rectal and bladder walls, femoral heads, and large and small bowel. The IMRT was planned with an intended dose of 55.1 Gy in 29 fractions to all CTVs (Phase 1), with P+SV consecutive boost of 24.7 Gy in 13 fractions. Daily online image guidance was performed using bony landmarks and intraprostatic markers. Feasibility criteria included delivery of intended doses in 80% of patients, 95% of CTV displacements incorporated within PTV during Phase 1, and acute toxicity rate comparable to that of lower-dose pelvic techniques. Results: A total of 91 patients (88%) received the total prescription dose. All patients received at least 72 Gy. In Phase 1, 63 patients (61%) received the intended 55.1 Gy, whereas 87% of patients received at least 50 Gy. Dose reductions were caused by small bowel and rectal wall constraints. All CTVs received the planned dose in >95% of treatment fractions. There were no Radiation Therapy Oncology Group acute toxicities greater than Grade 3, although there were five incidences equivalent to Grade 3 within a median follow-up of 23 months. Conclusion: These results suggest that dose escalation to the PLN+P+SV using IMRT is feasible, with acceptable rates of acute toxicity.

  9. Improvement in toxicity in high risk prostate cancer patients treated with image-guided intensity-modulated radiotherapy compared to 3D conformal radiotherapy without daily image guidance

    PubMed Central

    2014-01-01

    Background Image-guided radiotherapy (IGRT) facilitates the delivery of a very precise radiation dose. In this study we compare the toxicity and biochemical progression-free survival between patients treated with daily image-guided intensity-modulated radiotherapy (IG-IMRT) and 3D conformal radiotherapy (3DCRT) without daily image guidance for high risk prostate cancer (PCa). Methods A total of 503 high risk PCa patients treated with radiotherapy (RT) and endocrine treatment between 2000 and 2010 were retrospectively reviewed. 115 patients were treated with 3DCRT, and 388 patients were treated with IG-IMRT. 3DCRT patients were treated to 76 Gy and without daily image guidance and with 1–2 cm PTV margins. IG-IMRT patients were treated to 78 Gy based on daily image guidance of fiducial markers, and the PTV margins were 5–7 mm. Furthermore, the dose-volume constraints to both the rectum and bladder were changed with the introduction of IG-IMRT. Results The 2-year actuarial likelihood of developing grade > = 2 GI toxicity following RT was 57.3% in 3DCRT patients and 5.8% in IG-IMRT patients (p < 0.001). For GU toxicity the numbers were 41.8% and 29.7%, respectively (p = 0.011). On multivariate analysis, 3DCRT was associated with a significantly increased risk of developing grade > = 2 GI toxicity compared to IG-IMRT (p < 0.001, HR = 11.59 [CI: 6.67-20.14]). 3DCRT was also associated with an increased risk of developing GU toxicity compared to IG-IMRT. The 3-year actuarial biochemical progression-free survival probability was 86.0% for 3DCRT and 90.3% for IG-IMRT (p = 0.386). On multivariate analysis there was no difference in biochemical progression-free survival between 3DCRT and IG-IMRT. Conclusion The difference in toxicity can be attributed to the combination of the IMRT technique with reduced dose to organs-at-risk, daily image guidance and margin reduction. PMID:24495815

  10. Development of an endoluminal high-intensity ultrasound applicator for image-guided thermal therapy of pancreatic tumors

    NASA Astrophysics Data System (ADS)

    Adams, Matthew S.; Scott, Serena J.; Salgaonkar, Vasant A.; Jones, Peter D.; Plata-Camargo, Juan C.; Sommer, Graham; Diederich, Chris J.

    2015-03-01

    An ultrasound applicator for endoluminal thermal therapy of pancreatic tumors has been introduced and evaluated through acoustic/biothermal simulations and ex vivo experimental investigations. Endoluminal therapeutic ultrasound constitutes a minimally invasive conformal therapy and is compatible with ultrasound or MR-based image guidance. The applicator would be placed in the stomach or duodenal lumen, and sonication would be performed through the luminal wall into the tumor, with concurrent water cooling of the wall tissue to prevent its thermal injury. A finite-element (FEM) 3D acoustic and biothermal model was implemented for theoretical analysis of the approach. Parametric studies over transducer geometries and frequencies revealed that operating frequencies within 1-3 MHz maximize penetration depth and lesion volume while sparing damage to the luminal wall. Patient-specific FEM models of pancreatic head tumors were generated and used to assess the feasibility of performing endoluminal ultrasound thermal ablation and hyperthermia of pancreatic tumors. Results indicated over 80% of the volume of small tumors (~2 cm diameter) within 35 mm of the duodenum could be safely ablated in under 30 minutes or elevated to hyperthermic temperatures at steady-state. Approximately 60% of a large tumor (~5 cm diameter) model could be safely ablated by considering multiple positions of the applicator along the length of the duodenum to increase coverage. Prototype applicators containing two 3.2 MHz planar transducers were fabricated and evaluated in ex vivo porcine carcass heating experiments under MR temperature imaging (MRTI) guidance. The applicator was positioned in the stomach adjacent to the pancreas, and sonications were performed for 10 min at 5 W/cm2 applied intensity. MRTI indicated over 400C temperature rise in pancreatic tissue with heating penetration extending 3 cm from the luminal wall.

  11. Development of an endoluminal high-intensity ultrasound applicator for image-guided thermal therapy of pancreatic tumors

    PubMed Central

    Scott, Serena J.; Salgaonkar, Vasant A.; Jones, Peter D.; Plata-Camargo, Juan C.; Sommer, Graham; Diederich, Chris J.

    2015-01-01

    An ultrasound applicator for endoluminal thermal therapy of pancreatic tumors has been introduced and evaluated through acoustic/biothermal simulations and ex vivo experimental investigations. Endoluminal therapeutic ultrasound constitutes a minimally invinvasive conformal therapy and is compatible with ultrasound or MR-based image guidance. The applicator would be placed in the stomach or duodenal lumen, and sonication would be performed through the luminal wall into the tumor, with concurrent water cooling of the wall tissue to prevent its thermal injury. A finite-element (FEM) 3D acoustic and biothermal model was implemented for theoretical analysis of the approach. Parametric studies over transducer geometries and frequencies revealed that operating frequencies within 1-3 MHz maximize penetration depth and lesion volume while sparing damage to the luminal wall. Patient-specific FEM models of pancreatic head tumors were generated and used to assess the feasibility of performing endoluminal ultrasound thermal ablation and hyperthermia of pancreatic tumors. Results indicated over 80% of the volume of small tumors (~2 cm diameter) within 35 mm of the duodenum could be safely ablated in under 30 minutes or elevated to hyperthermic temperatures at steady-state. Approximately 60% of a large tumor (~5 cm diameter) model could be safely ablated by considering multiple positions of the applicator along the length of the duodenum to increase coverage. Prototype applicators containing two 3.2 MHz planar transducers were fabricated and evaluated in ex vivo porcine carcass heating experiments under MR temperature imaging (MRTI) guidance. The applicator was positioned in the stomach adjacent to the pancreas, and sonications were performed for 10 min at 5 W/cm2 applied intensity. MRTI indicated over 40°C temperature rise in pancreatic tissue with heating penetration extending 3 cm from the luminal wall. PMID:26677314

  12. HematoPorphyrin Monomethyl Ether polymer contrast agent for ultrasound/photoacoustic dual-modality imaging-guided synergistic high intensity focused ultrasound (HIFU) therapy

    PubMed Central

    Yan, Sijing; LU, Min; Ding, Xiaoya; Chen, Fei; He, Xuemei; Xu, Chunyan; Zhou, Hang; Wang, Qi; Hao, Lan; Zou, Jianzhong

    2016-01-01

    This study is to prepare a hematoporphyrin monomethyl ether (HMME)-loaded poly(lactic-co-glycolic acid) (PLGA) microcapsules (HMME/PLGA), which could not only function as efficient contrast agent for ultrasound (US)/photoacoustic (PA) imaging, but also as a synergistic agent for high intensity focused ultrasound (HIFU) ablation. Sonosensitizer HMME nanoparticles were integrated into PLGA microcapsules with the double emulsion evaporation method. After characterization, the cell-killing and cell proliferation-inhibiting effects of HMME/PLGA microcapsules on ovarian cancer SKOV3 cells were assessed. The US/PA imaging-enhancing effects and synergistic effects on HIFU were evaluated both in vitro and in vivo. HMME/PLGA microcapsules were highly dispersed with well-defined spherical morphology (357 ± 0.72 nm in diameter, PDI = 0.932). Encapsulation efficiency and drug-loading efficiency were 58.33 ± 0.95% and 4.73 ± 0.15%, respectively. The HMME/PLGA microcapsules remarkably killed the SKOV3 cells and inhibited the cell proliferation, significantly enhanced the US/PA imaging results and greatly enhanced the HIFU ablation effects on ovarian cancer in nude mice by the HMME-mediated sono-dynamic chemistry therapy (SDT). HMME/PLGA microcapsules represent a potential multifunctional contrast agent for HIFU diagnosis and treatment, which might provide a novel strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy for cancers by SDT in clinic. PMID:27535093

  13. HematoPorphyrin Monomethyl Ether polymer contrast agent for ultrasound/photoacoustic dual-modality imaging-guided synergistic high intensity focused ultrasound (HIFU) therapy.

    PubMed

    Yan, Sijing; Lu, Min; Ding, Xiaoya; Chen, Fei; He, Xuemei; Xu, Chunyan; Zhou, Hang; Wang, Qi; Hao, Lan; Zou, Jianzhong

    2016-01-01

    This study is to prepare a hematoporphyrin monomethyl ether (HMME)-loaded poly(lactic-co-glycolic acid) (PLGA) microcapsules (HMME/PLGA), which could not only function as efficient contrast agent for ultrasound (US)/photoacoustic (PA) imaging, but also as a synergistic agent for high intensity focused ultrasound (HIFU) ablation. Sonosensitizer HMME nanoparticles were integrated into PLGA microcapsules with the double emulsion evaporation method. After characterization, the cell-killing and cell proliferation-inhibiting effects of HMME/PLGA microcapsules on ovarian cancer SKOV3 cells were assessed. The US/PA imaging-enhancing effects and synergistic effects on HIFU were evaluated both in vitro and in vivo. HMME/PLGA microcapsules were highly dispersed with well-defined spherical morphology (357 ± 0.72 nm in diameter, PDI = 0.932). Encapsulation efficiency and drug-loading efficiency were 58.33 ± 0.95% and 4.73 ± 0.15%, respectively. The HMME/PLGA microcapsules remarkably killed the SKOV3 cells and inhibited the cell proliferation, significantly enhanced the US/PA imaging results and greatly enhanced the HIFU ablation effects on ovarian cancer in nude mice by the HMME-mediated sono-dynamic chemistry therapy (SDT). HMME/PLGA microcapsules represent a potential multifunctional contrast agent for HIFU diagnosis and treatment, which might provide a novel strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy for cancers by SDT in clinic. PMID:27535093

  14. Magnetic Resonance Imaging-Guided High-Intensity Focused Ultrasound Ablation of Uterine Fibroids: Effect of Bowel Interposition on Procedure Feasibility and a Unique Bowel Displacement Technique

    PubMed Central

    Kim, Young-sun; Lim, Hyo Keun; Rhim, Hyunchul

    2016-01-01

    Purpose To evaluate the effect of bowel interposition on assessing procedure feasibility, and the usefulness and limiting conditions of bowel displacement techniques in magnetic resonance imaging-guided high-intensity focused ultrasound (MR-HIFU) ablation of uterine fibroids. Materials and Methods Institutional review board approved this study. A total of 375 screening MR exams and 206 MR-HIFU ablations for symptomatic uterine fibroids performed between August 2010 and March 2015 were retrospectively analyzed. The effect of bowel interposition on procedure feasibility was assessed by comparing pass rates in periods before and after adopting a unique bowel displacement technique (bladder filling, rectal filling and subsequent bladder emptying; BRB maneuver). Risk factors for BRB failure were evaluated using logistic regression analysis. Results Overall pass rates of pre- and post-BRB periods were 59.0% (98/166) and 71.7% (150/209), and in bowel-interposed cases they were 14.6% (7/48) and 76.4% (55/72), respectively. BRB maneuver was technically successful in 81.7% (49/60). Through-the-bladder sonication was effective in eight of eleven BRB failure cases, thus MR-HIFU could be initiated in 95.0% (57/60). A small uterus on treatment day was the only significant risk factor for BRB failure (B = 0.111, P = 0.017). Conclusion The BRB maneuver greatly reduces the fraction of patients deemed ineligible for MR-HIFU ablation of uterine fibroids due to interposed bowels, although care is needed when the uterus is small. PMID:27186881

  15. Long-term outcomes from dose-escalated image-guided intensity-modulated radiotherapy with androgen deprivation: encouraging results for intermediate- and high-risk prostate cancer

    PubMed Central

    Wilcox, Shea W; Aherne, Noel J; Benjamin, Linus C; Wu, Bosco; de Campos Silva, Thomaz; McLachlan, Craig S; McKay, Michael J; Last, Andrew J; Shakespeare, Thomas P

    2014-01-01

    Purpose Dose-escalated (DE) radiotherapy in the setting of localized prostate cancer has been shown to improve biochemical disease-free survival (bDFS) in several studies. In the same group of patients, androgen deprivation therapy (ADT) has been shown to confer a survival benefit when combined with radiotherapy doses of up to 70 Gy; however, there is currently little long-term data on patients who have received high-dose intensity-modulated radiotherapy (IMRT) with ADT. We report the long-term outcomes in a large cohort of patients treated with the combination of DE image-guided IMRT (IG-IMRT) and ADT. Methods and materials Patients with localized prostate cancer were identified from a centralized database across an integrated cancer center. All patients received DE IG-IMRT, combined with ADT, and had a minimum follow up of 12 months post-radiotherapy. All relapse and toxicity data were collected prospectively. Actuarial bDFS, metastasis-free survival, prostate cancer-specific survival, and multivariate analyses were calculated using the SPSS v20.0 statistical package. Results Seven hundred and eighty-two eligible patients were identified with a median follow up of 46 months. Overall, 4.3% of patients relapsed, 2.0% developed distant metastases, and 0.6% died from metastatic prostate cancer. At 5-years, bDFS was 88%, metastasis-free survival was 95%, and prostate cancer-specific survival was 98%. Five-year grade 2 genitourinary and gastrointestinal toxicity was 2.1% and 3.4%, respectively. No grade 3 or 4 late toxicities were reported. Pretreatment prostate specific antigen (P=0.001) and Gleason score (P=0.03) were significant in predicting biochemical failure on multivariate analysis. Conclusion There is a high probability of tumor control with DE IG-IMRT combined with androgen deprivation, and this is a technique with a low probability of significant late toxicity. Our long term results corroborate the safety and efficacy of treating with IG-IMRT to high doses

  16. Clinical Consideration of Treatment to Ablate Uterine Fibroids with Magnetic Resonance Imaging-guided High Intensity Focused Ultrasound (MRgFUS): Sonalleve

    PubMed Central

    Jeong, Jae-Hyeok; Hong, Gil Pyo; Kim, Yu-Ri; Ha, Jae-Eun

    2016-01-01

    Objectives Magnetic resonance imaging (MRI)-guided high intensity focused ultrasound surgery (MRgFUS) is a newly emerging non-invasive technique for the treatment of uterine fibroids. The purpose of this study is to review the clinical impact of MRgFUS. Methods This study examined 157 patients. The high intensity focused ultrasound (HIFU) utilized in this study was Philips Achieva 1.5 Tesla MR (Philips Healthcare, Best, the Netherlands) and Sonalleve HIFU system. The patients were followed in post-operative Month 1, Month 3, and Month 6 to investigate any change. Then, these were further classified according to the use of uterine stimulant (oxytocin) in parallel, Funaki Type of uterine fibroid, HIFU intensity, and non-perfused volume (NPV) ratio. Results When the uterine stimulant was utilized, the HIFU intensity was measured at significantly lower levels, compared with the group not using uterine stimulant, and treatment duration was significantly. The NPV ratio was found significantly higher in the group using uterine stimulant. Concerning the correlation between Funaki Type of uterine fibroid and average sonication power, it was found that the closer to Type I, the lower the sonication power, the shorter the treatment duration, and the higher the NPV ratio significantly. Conclusions In this study, it was found that the lower the Funaki Types of uterine fibroids, and the higher the NPV ratio immediately after the operation, the larger the uterine fibroid volume decrease and SSS change were. Also, if uterine stimulant was used in parallel in treatment, treatment duration and HIFU intensity could become shorter and lower. PMID:27617244

  17. Characterizing an agar/gelatin phantom for image guided dosing and feedback control of high-intensity focused ultrasound.

    PubMed

    Dunmire, Barbrina; Kucewicz, John C; Mitchell, Stuart B; Crum, Lawrence A; Sekins, K Michael

    2013-02-01

    The temperature dependence of an agar/gelatin phantom was evaluated. The purpose was to predict the material property response to high-intensity focused ultrasound (HIFU) for developing ultrasound guided dosing and targeting feedback. Changes in attenuation, sound speed, shear modulus and thermal properties with temperature were examined from 20°C to 70°C for 3 weeks post-manufacture. The attenuation decreased with temperature by a power factor of 0.15. Thermal conductivity, diffusivity and specific heat all increased linearly with temperature for a total change of approximately 16%, 10% and 6%, respectively. Sound speed had a parabolic dependence on temperature similar to that of water. Initially, the shear modulus irreversibly declined with even a slight increase in temperature. Over time, the gel maintained its room temperature shear modulus with moderate heating. A stable phantom was achieved within 2 weeks post-manufacture that possessed quasi-reversible material properties up to nearly 55°C. PMID:23245823

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

    SciTech Connect

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

    2008-07-01

    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.

  19. Image-Guided Intensity-Modulated Photon Radiotherapy Using Multifractionated Regimen to Paraspinal Chordomas and Rare Sarcomas

    SciTech Connect

    Terezakis, Stephanie A. Lovelock, D. Michael; Bilsky, Mark H.; Hunt, Margaret A.; Zatcky, Joan N.P.; Yamada, Yoshiya

    2007-12-01

    Purpose: Image-guided intensity-modulated radiotherapy enables delivery of high-dose radiation to tumors close to the spinal cord. We report our experience with multifractionated regimens using image-guided intensity-modulated radiotherapy to treat gross paraspinal disease to doses beyond cord tolerance. Methods and Materials: We performed a retrospective review of 27 consecutive patients with partially resected or unresectable paraspinal tumors irradiated to >5,300 cGy in standard fractionation. Results: The median follow-up was 17.4 months (range, 2.1-47.3). Eighteen sarcomas, seven chordomas, and two ependymomas were treated. The median dose to the planning target volume was 6,600 cGy (range, 5,396-7,080) in 180- or 200-cGy fractions. The median planning target volume was 164 cm{sup 3} (range, 29-1,116). Seven patients developed recurrence at the treatment site (26%), and 6 of these patients had high-grade tumors. Three patients with recurrence had metastatic disease at the time of radiotherapy. The 2-year local control rate was 65%, and the 2-year overall survival rate was 79%. Of the 5 patients who died, 4 had metastatic disease at death. Twenty-three patients (84%) reported either no pain or improved pain at the last follow-up visit. Sixteen patients discontinued narcotic use after treatment (62.5%). Twenty-three patients (89%) had a stable or improved American Spine Injury Association score at the last follow-up visit. No patient experienced radiation-induced myelopathy. Conclusions: The dose to paraspinal tumors has traditionally been limited to respect cord tolerance. With image-guided intensity-modulated radiotherapy, greater doses of radiation delivered in multiple fractions can be prescribed with excellent target coverage, effective palliation, and acceptable toxicity and local control.

  20. Feasibility of intensity-modulated and image-guided radiotherapy for locally advanced esophageal cancer

    PubMed Central

    2014-01-01

    Background In this study the feasibility of intensity-modulated radiotherapy (IMRT) and tomotherapy-based image-guided radiotherapy (IGRT) for locally advanced esophageal cancer was assessed. Methods A retrospective study of ten patients with locally advanced esophageal cancer who underwent concurrent chemotherapy with IMRT (1) and IGRT (9) was conducted. The gross tumor volume was treated to a median dose of 70 Gy (62.4-75 Gy). Results At a median follow-up of 14 months (1-39 months), three patients developed local failures, six patients developed distant metastases, and complications occurred in two patients (1 tracheoesophageal fistula, 1 esophageal stricture requiring repeated dilatations). No patients developed grade 3-4 pneumonitis or cardiac complications. Conclusions IMRT and IGRT may be effective for the treatment of locally advanced esophageal cancer with acceptable complications. PMID:24742268

  1. Temporary organ displacement coupled with image-guided, intensity-modulated radiotherapy for paraspinal tumors

    PubMed Central

    2013-01-01

    Background To investigate the feasibility and dosimetric improvements of a novel technique to temporarily displace critical structures in the pelvis and abdomen from tumor during high-dose radiotherapy. Methods Between 2010 and 2012, 11 patients received high-dose image-guided intensity-modulated radiotherapy with temporary organ displacement (TOD) at our institution. In all cases, imaging revealed tumor abutting critical structures. An all-purpose drainage catheter was introduced between the gross tumor volume (GTV) and critical organs at risk (OAR) and infused with normal saline (NS) containing 5-10% iohexol. Radiation planning was performed with the displaced OARs and positional reproducibility was confirmed with cone-beam CT (CBCT). Patients were treated within 36 hours of catheter placement. Radiation plans were re-optimized using pre-TOD OARs to the same prescription and dosimetrically compared with post-TOD plans. A two-tailed permutation test was performed on each dosimetric measure. Results The bowel/rectum was displaced in six patients and kidney in four patients. One patient was excluded due to poor visualization of the OAR; thus 10 patients were analyzed. A mean of 229 ml (range, 80–1000) of NS 5-10% iohexol infusion resulted in OAR mean displacement of 17.5 mm (range, 7–32). The median dose prescribed was 2400 cGy in one fraction (range, 2100–3000 in 3 fractions). The mean GTV Dmin and PTV Dmin pre- and post-bowel TOD IG-IMRT dosimetry significantly increased from 1473 cGy to 2086 cGy (p=0.015) and 714 cGy to 1214 cGy (p=0.021), respectively. TOD increased mean PTV D95 by 27.14% of prescription (p=0.014) while the PTV D05 decreased by 9.2% (p=0.011). TOD of the bowel resulted in a 39% decrease in mean bowel Dmax (p=0.008) confirmed by CBCT. TOD of the kidney significantly decreased mean kidney dose and Dmax by 25% (0.022). Conclusions TOD was well tolerated, reproducible, and facilitated dose escalation to previously radioresistant tumors

  2. Rationale and development of image-guided intensity-modulated radiotherapy post-prostatectomy: the present standard of care?

    PubMed Central

    Murray, Julia R; McNair, Helen A; Dearnaley, David P

    2015-01-01

    The indications for post-prostatectomy radiotherapy have evolved over the last decade, although the optimal timing, dose, and target volume remain to be well defined. The target volume is susceptible to anatomical variations with its borders interfacing with the rectum and bladder. Image-guided intensity-modulated radiotherapy has become the gold standard for radical prostate radiotherapy. Here we review the current evidence for image-guided techniques with intensity-modulated radiotherapy to the prostate bed and describe current strategies to reduce or account for interfraction and intrafraction motion. PMID:26635484

  3. Integral test phantom for dosimetric quality assurance of image guided and intensity modulated stereotactic radiotherapy

    SciTech Connect

    Letourneau, Daniel; Keller, Harald; Sharpe, Michael B.; Jaffray, David A.

    2007-05-15

    The objective of this work is to develop a dosimetric phantom quality assurance (QA) of linear accelerators capable of cone-beam CT (CBCT) image guided and intensity-modulated radiotherapy (IG-IMRT). This phantom is to be used in an integral test to quantify in real-time both the performance of the image guidance and the dose delivery systems in terms of dose localization. The prototype IG-IMRT QA phantom consisted of a cylindrical imaging phantom (CatPhan) combined with an array of 11 radiation diodes mounted on a 10 cm diameter disk, oriented perpendicular to the phantom axis. Basic diode response characterization was performed for 6 and 18 MV photons. The diode response was compared to planning system calculations in the open and penumbrae regions of simple and complex beam arrangements. The clinical use of the QA phantom was illustrated in an integral test of an IG-IMRT treatment designed for a clinical spinal radiosurgery case. The sensitivity of the phantom to multileaf collimator (MLC) calibration and setup errors in the clinical setting was assessed by introducing errors in the IMRT plan or by displacing the phantom. The diodes offered good response linearity and long-term reproducibility for both 6 and 18 MV. Axial dosimetry of coplanar beams (in a plane containing the beam axes) was made possible with the nearly isoplanatic response of the diodes over 360 deg. of gantry (usually within {+-}1%). For single beam geometry, errors in phantom placement as small as 0.5 mm could be accurately detected (in gradient {>=}1%/mm). In clinical setting, MLC systematic errors of 1 mm on a single MLC bank introduced in the IMRT plan were easily detectable with the QA phantom. The QA phantom demonstrated also sufficient sensitivity for the detection of setup errors as small as 1 mm for the IMRT delivery. These results demonstrated that the prototype can accurately and efficiently verify the entire IG-IMRT process. This tool, in conjunction with image guidance capabilities

  4. Tumor Control Outcomes After Hypofractionated and Single-Dose Stereotactic Image-Guided Intensity-Modulated Radiotherapy for Extracranial Metastases From Renal Cell Carcinoma

    SciTech Connect

    Zelefsky, Michael J.; Greco, Carlo; Motzer, Robert; Magsanoc, Juan Martin; Pei Xin; Lovelock, Michael; Mechalakos, Jim; Zatcky, Joan; Fuks, Zvi; Yamada, Yoshiya

    2012-04-01

    Purpose: To report tumor local progression-free outcomes after treatment with single-dose, image-guided, intensity-modulated radiotherapy and hypofractionated regimens for extracranial metastases from renal cell primary tumors. Patients and Methods: Between 2004 and 2010, 105 lesions from renal cell carcinoma were treated with either single-dose, image-guided, intensity-modulated radiotherapy to a prescription dose of 18-24 Gy (median, 24) or hypofractionation (three or five fractions) with a prescription dose of 20-30 Gy. The median follow-up was 12 months (range, 1-48). Results: The overall 3-year actuarial local progression-free survival for all lesions was 44%. The 3-year local progression-free survival for those who received a high single-dose (24 Gy; n = 45), a low single-dose (<24 Gy; n = 14), or hypofractionation regimens (n = 46) was 88%, 21%, and 17%, respectively (high single dose vs. low single dose, p = .001; high single dose vs. hypofractionation, p < .001). Multivariate analysis revealed the following variables were significant predictors of improved local progression-free survival: 24 Gy dose compared with a lower dose (p = .009) and a single dose vs. hypofractionation (p = .008). Conclusion: High single-dose, image-guided, intensity-modulated radiotherapy is a noninvasive procedure resulting in high probability of local tumor control for metastatic renal cell cancer generally considered radioresistant according to the classic radiobiologic ranking.

  5. Predictors of Local Control After Single-Dose Stereotactic Image-Guided Intensity-Modulated Radiotherapy for Extracranial Metastases

    SciTech Connect

    Greco, Carlo; Zelefsky, Michael J.; Lovelock, Michael; Fuks, Zvi; Hunt, Margie; Rosenzweig, Kenneth; Zatcky, Joan; Kim, Balem; Yamada, Yoshiya

    2011-03-15

    Purpose: To report tumor local control after treatment with single-dose image-guided intensity-modulated radiotherapy (SD-IGRT) to extracranial metastatic sites. Methods and Materials: A total of 126 metastases in 103 patients were treated with SD-IGRT to prescription doses of 18-24 Gy (median, 24 Gy) between 2004 and 2007. Results: The overall actuarial local relapse-free survival (LRFS) rate was 64% at a median follow-up of 18 months (range, 2-45 months). The median time to failure was 9.6 months (range, 1-23 months). On univariate analysis, LRFS was significantly correlated with prescription dose (p = 0.029). Stratification by dose into high (23 to 24 Gy), intermediate (21 to 22 Gy), and low (18 to 20 Gy) dose levels revealed highly significant differences in LRFS between high (82%) and low doses (25%) (p < 0.0001). Overall, histology had no significant effect on LRFS (p = 0.16). Renal cell histology displayed a profound dose-response effect, with 80% LRFS at the high dose level (23 to 24 Gy) vs. 37% with low doses ({<=}22 Gy) (p = 0.04). However, for patients who received the high dose level, histology was not a statistically significant predictor of LRFS (p = 0.90). Target organ (bone vs. lymph node vs. soft tissues) (p = 0.5) and planning target volume size (p = 0.55) were not found to be associated with long-term LRFS probability. Multivariate Cox regression analysis confirmed prescription dose to be a significant predictor of LRFS (p = 0.003). Conclusion: High-dose SD-IGRT is a noninvasive procedure resulting in high probability of local tumor control. Single-dose IGRT may be effectively used to locally control metastatic deposits regardless of histology and target organ, provided sufficiently high doses (> 22 Gy) of radiation are delivered.

  6. Clinical applications of image guided-intensity modulated radiation therapy (IG-IMRT) for conformal avoidance of normal tissue

    NASA Astrophysics Data System (ADS)

    Gutierrez, Alonso Navar

    2007-12-01

    Recent improvements in imaging technology and radiation delivery have led to the development of advanced treatment techniques in radiotherapy which have opened the door for novel therapeutic approaches to improve the efficacy of radiation cancer treatments. Among these advances is image-guided, intensity modulated radiation therapy (IG-IMRT), in which imaging is incorporated to aid in inter-/intra-fractional target localization and to ensure accurate delivery of precise and highly conformal dose distributions. In principle, clinical implementation of IG-IMRT should improve normal tissue sparing and permit effective biological dose escalation thus widening the radiation therapeutic window and lead to increases in survival through improved local control of primary neoplastic diseases. Details of the development of three clinical applications made possible solely with IG-IMRT radiation delivery techniques are presented: (1) Laparoscopically implanted tissue expander radiotherapy (LITE-RT) has been developed to enhance conformal avoidance of normal tissue during the treatment of intra-abdominopelvic cancers. LITE-RT functions by geometrically displacing surrounding normal tissue and isolating the target volume through the interfractional inflation of a custom-shaped tissue expander throughout the course of treatment. (2) The unique delivery geometry of helical tomotherapy, a novel form of IG-IMRT, enables the delivery of composite treatment plan m which whole brain radiotherapy (WBRT) with hippocampal avoidance, hypothesized to reduce the risk of memory function decline and improve the patient's quality of life, and simultaneously integrated boost to multiple brain metastases to improve intracranial tumor control is achieved. (3) Escalation of biological dose to targets through integrated, selective subvolume boosts have been shown to efficiently increase tumor dose without significantly increasing normal tissue dose. Helical tomotherapy was used to investigate the

  7. Construction of a high-tech operating room for image-guided surgery using VR.

    PubMed

    Suzuki, Naoki; Hattori, Asaki; Suzuki, Shigeyuki; Otake, Yoshito; Hayashibe, Mitsuhiro; Kobayashi, Susumu; Nezu, Takehiko; Sakai, Haruo; Umezawa, Yuji

    2005-01-01

    This project aimed to construct an operating room to implement high dimensional (3D, 4D) medical imaging and medical virtual reality techniques that would enable clinical tests for new surgical procedures. We designed and constructed such an operating room at Dai-san Hospital, the Jikei Univ. School of Medicine, Tokyo, Japan. The room was equipped with various facilities for image-guided, robot and tele- surgery. In this report, we describe an outline of our "high-tech operating room" and future plans. PMID:15718793

  8. Image-guided high-dose-rate brachytherapy in inoperable endometrial cancer

    PubMed Central

    Petsuksiri, J; Chansilpa, Y; Hoskin, P J

    2014-01-01

    Inoperable endometrial cancer may be treated with curative aim using radical radiotherapy alone. The radiation techniques are external beam radiotherapy (EBRT) alone, EBRT plus brachytherapy and brachytherapy alone. Recently, high-dose-rate brachytherapy has been used instead of low-dose-rate brachytherapy. Image-guided brachytherapy enables sufficient coverage of tumour and reduction of dose to the organs at risk, thus increasing the therapeutic ratio of treatment. Local control rates with three-dimensional brachytherapy appear better than with conventional techniques (about 90–100% and 70–90%, respectively). PMID:24807067

  9. Involved-Site Image-Guided Intensity Modulated Versus 3D Conformal Radiation Therapy in Early Stage Supradiaphragmatic Hodgkin Lymphoma

    SciTech Connect

    Filippi, Andrea Riccardo; Ciammella, Patrizia; Piva, Cristina; Ragona, Riccardo; Botto, Barbara; Gavarotti, Paolo; Merli, Francesco; Vitolo, Umberto; Iotti, Cinzia; Ricardi, Umberto

    2014-06-01

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows for margin reduction and highly conformal dose distribution, with consistent advantages in sparing of normal tissues. The purpose of this retrospective study was to compare involved-site IG-IMRT with involved-site 3D conformal RT (3D-CRT) in the treatment of early stage Hodgkin lymphoma (HL) involving the mediastinum, with efficacy and toxicity as primary clinical endpoints. Methods and Materials: We analyzed 90 stage IIA HL patients treated with either involved-site 3D-CRT or IG-IMRT between 2005 and 2012 in 2 different institutions. Inclusion criteria were favorable or unfavorable disease (according to European Organization for Research and Treatment of Cancer criteria), complete response after 3 to 4 cycles of an adriamycin- bleomycin-vinblastine-dacarbazine (ABVD) regimen plus 30 Gy as total radiation dose. Exclusion criteria were chemotherapy other than ABVD, partial response after ABVD, total radiation dose other than 30 Gy. Clinical endpoints were relapse-free survival (RFS) and acute toxicity. Results: Forty-nine patients were treated with 3D-CRT (54.4%) and 41 with IG-IMRT (45.6%). Median follow-up time was 54.2 months for 3D-CRT and 24.1 months for IG-IMRT. No differences in RFS were observed between the 2 groups, with 1 relapse each. Three-year RFS was 98.7% for 3D-CRT and 100% for IG-IMRT. Grade 2 toxicity events, mainly mucositis, were recorded in 32.7% of 3D-CRT patients (16 of 49) and in 9.8% of IG-IMRT patients (4 of 41). IG-IMRT was significantly associated with a lower incidence of grade 2 acute toxicity (P=.043). Conclusions: RFS rates at 3 years were extremely high in both groups, albeit the median follow-up time is different. Acute tolerance profiles were better for IG-IMRT than for 3D-CRT. Our preliminary results support the clinical safety and efficacy of advanced RT planning and delivery techniques in patients affected with early stage HL, achieving complete

  10. Image-Guided Radio-Frequency Gain Calibration for High-Field MRI

    PubMed Central

    Breton, Elodie; McGorty, KellyAnne; Wiggins, Graham C.; Axel, Leon; Kim, Daniel

    2010-01-01

    High-field (≥ 3T) MRI provides a means to increase the signal-to-noise ratio, due to its higher tissue magnetization compared with 1.5T. However, both the static magnetic field (B0) and the transmit radio-frequency (RF) field (B1+) inhomogeneities are comparatively higher than those at 1.5T. These challenging factors at high-field strengths make it more difficult to accurately calibrate the transmit RF gain using standard RF calibration procedures. An image-based RF calibration procedure was therefore developed, in order to accurately calibrate the transmit RF gain within a specific region-of-interest (ROI). Using a single-shot ultra-fast gradient echo pulse sequence with centric k-space reordering, a series of “saturation-no-recovery” images was acquired by varying the flip angle of the preconditioning pulse. In the resulting images, the signal null occurs in regions where the flip angle of the preconditioning pulse is 90°. For a given ROI, the mean signal can be plotted as a function of the nominal flip angle, and the resulting curve can be used to quantitatively identify the signal null. This image-guided RF calibration procedure was evaluated through phantom and volunteer imaging experiments at 3T and 7T. The image-guided RF calibration results in vitro were consistent with standard B0 and B1+ maps. The standard automated RF calibration procedure produced approximately 20% and 15–30% relative error in the transmit RF gain in the left kidney at 3T and brain at 7T, respectively. For initial application, a T2 mapping pulse sequence was applied at 7T. The T2 measurements in the thalamus at 7T were 60.6 ms and 48.2 ms using the standard and image-guided RF calibration procedures, respectively. This rapid, image-guided RF calibration procedure can be used to optimally calibrate the flip angle for a given ROI and thus minimize measurement errors for quantitative MRI and MR spectroscopy. PMID:20014333

  11. Ultrasmall Cu2-x S Nanodots for Highly Efficient Photoacoustic Imaging-Guided Photothermal Therapy.

    PubMed

    Mou, Juan; Li, Pei; Liu, Chengbo; Xu, Huixiong; Song, Liang; Wang, Jin; Zhang, Kun; Chen, Yu; Shi, Jianlin; Chen, Hangrong

    2015-05-20

    Monodisperse, ultrasmall (<5 nm) Cu(2-x)S nanodots (u-Cu(2-x)S NDs) with significantly strong near-infrared absorption and conversion are successfully demonstrated for effective deep-tissue photoacoustic imaging-guided photothermal therapy both in vitro and in vivo. Owing to ultrasmall nanoparticle size and high water dispersibility as well as long stability, such nanodots possess a prolonged circulation in blood and good passive accumulation within tumors through the enhanced permeability and retention effect. These u-Cu(2-x)S NDs have negligible side effects to both blood and normal tissues according to in vivo toxicity evaluations for up to 3 months, showing excellent hemo/histocompatibility. Furthermore, these u-Cu(2-x)S NDs can be thoroughly cleared through feces and urine within 5 days, showing high biosafety for further potential clinical translation. This novel photoacoustic imaging-guided photothermal therapy based on u-Cu(2-x)S NDs composed of a single component shows great prospects as a multifunctional nanoplatform with integration and multifunction for cancer diagnosis and therapy. PMID:25641784

  12. Clinical Experience With Image-Guided Radiotherapy in an Accelerated Partial Breast Intensity-Modulated Radiotherapy Protocol

    SciTech Connect

    Leonard, Charles E.; Tallhamer, Michael M.S.; Johnson, Tim; Hunter, Kari C.M.D.; Howell, Kathryn; Kercher, Jane; Widener, Jodi; Kaske, Terese; Paul, Devchand; Sedlacek, Scot; Carter, Dennis L.

    2010-02-01

    Purpose: To explore the feasibility of fiducial markers for the use of image-guided radiotherapy (IGRT) in an accelerated partial breast intensity modulated radiotherapy protocol. Methods and Materials: Nineteen patients consented to an institutional review board approved protocol of accelerated partial breast intensity-modulated radiotherapy with fiducial marker placement and treatment with IGRT. Patients (1 patient with bilateral breast cancer; 20 total breasts) underwent ultrasound guided implantation of three 1.2- x 3-mm gold markers placed around the surgical cavity. For each patient, table shifts (inferior/superior, right/left lateral, and anterior/posterior) and minimum, maximum, mean error with standard deviation were recorded for each of the 10 BID treatments. The dose contribution of daily orthogonal films was also examined. Results: All IGRT patients underwent successful marker placement. In all, 200 IGRT treatment sessions were performed. The average vector displacement was 4 mm (range, 2-7 mm). The average superior/inferior shift was 2 mm (range, 0-5 mm), the average lateral shift was 2 mm (range, 1-4 mm), and the average anterior/posterior shift was 3 mm (range, 1 5 mm). Conclusions: This study shows that the use of IGRT can be successfully used in an accelerated partial breast intensity-modulated radiotherapy protocol. The authors believe that this technique has increased daily treatment accuracy and permitted reduction in the margin added to the clinical target volume to form the planning target volume.

  13. Phase II Trial of Hypofractionated Image-Guided Intensity-Modulated Radiotherapy for Localized Prostate Adenocarcinoma

    SciTech Connect

    Martin, Jarad M.; Rosewall, Tara; Bayley, Andrew; Bristow, Robert; Chung, Peter; Crook, Juanita; Gospodarowicz, Mary; McLean, Michael; Menard, Cynthia; Milosevic, Michael; Warde, Padraig; Catton, Charles

    2007-11-15

    Purpose: To assess in a prospective trial the feasibility and late toxicity of hypofractionated radiotherapy (RT) for prostate cancer. Methods and Materials: Eligible patients had clinical stage T1c-2cNXM0 disease. They received 60 Gy in 20 fractions over 4 weeks with intensity-modulated radiotherapy including daily on-line image guidance with intraprostatic fiducial markers. Results: Between June 2001 and March 2004, 92 patients were treated with hypofractionated RT. The cohort had a median prostate-specific antigen value of 7.06 ng/mL. The majority had Gleason grade 5-6 (38%) or 7 (59%) disease, and 82 patients had T1c-T2a clinical staging. Overall, 29 patients had low-risk, 56 intermediate-risk, and 7 high-risk disease. Severe acute toxicity (Grade 3-4) was rare, occurring in only 1 patient. Median follow-up was 38 months. According to the Phoenix definition for biochemical failure, the rate of biochemical control at 14 months was 97%. According to the previous American Society for Therapeutic Radiology and Oncology definition, biochemical control at 3 years was 76%. The incidence of late toxicity was low, with no severe (Grade {>=}3) toxicity at the most recent assessment. Conclusions: Hypofractionated RT using 60 Gy in 20 fractions over 4 weeks with image guidance is feasible and is associated with low rates of late bladder and rectal toxicity. At early follow-up, biochemical outcome is comparable to that reported for conventionally fractionated controls. The findings are being tested in an ongoing, multicenter, Phase III trial.

  14. High definition cross-well electrical resistivity imaging using seismoelectric focusing and image-guided inversion

    NASA Astrophysics Data System (ADS)

    Sava, P.; Revil, A.; Karaoulis, M.

    2014-08-01

    We propose a new, simple and efficient method to image electrical resistivity between a set of wells. Our procedure consists of two steps: first, we map the interfaces between various subsurface formations using seismoelectric conversions; second, we derive the formation resistivity using image-guided cross-well electric tomography. In the first step, we focus seismic energy at a set of points located on a regular grid between wells, which enables us to map the geological formations in terms of heterogeneities in electrical, hydraulic and/or seismic properties. The density of the scanning points (i.e. the seismoelectric image resolution) is related to the wavelength of the seismic impulse used to scan the formations. Each time the seismic energy is focused at a point, the resulting electrical potential burst (equivalent to the one generated by a volumetric seismic source) is recorded remotely at a set of electrodes positioned in wells (the reference electrode can be located on the ground surface or far enough to be considered at infinity). We construct a high-resolution `seismoelectric' image by assigning the electrical potential simulated at these fixed electrodes to the location of the seismic focus. In a follow-up step, the structure of this image is used in image-guided inversion to improve electrical resistivity tomography between the two wells. The structural information from the seismoelectric image is used to impose constraints on the model covariance matrix used in the inversion of the electrical resistivity data. This approach offers new perspectives in recovering fine structure of resistivity (high definition resistivity tomography) between the wells, which cannot be resolved through conventional cross-well resistivity or from seismic tomography alone.

  15. A Study of Image-Guided Intensity-Modulated Radiotherapy With Fiducials for Localized Prostate Cancer Including Pelvic Lymph Nodes

    SciTech Connect

    Hsu, Annie; Pawlicki, Todd; Luxton, Gary; Hara, Wendy; King, Christopher R. . E-mail: crking@stanford.edu

    2007-07-01

    Purpose: To study the impact on nodal coverage and dose to fixed organs at risk when using daily fiducial localization of the prostate to deliver intensity-modulated radiotherapy (IMRT). Methods and Materials: Five patients with prostate cancer in whom prostate and pelvic nodes were irradiated with IMRT were studied. Dose was prescribed such that 95% of the prostate planning target volume (PTV) and 90% of the nodal PTV were covered. Random and systematic prostate displacements in the anterior-posterior, superior-inferior, and left-right directions were simulated to shift the original isocenter of the IMRT plan. The composite dose during the course of treatment was calculated. Results: Compared with a static setup, simulating random shifts reduced dose by less than 1.5% for nodal hotspot (i.e., dose to 1 cm{sup 3}), by less than 1% for the 90% nodal PTV coverage, and by less than 0.5% for the nodal mean dose. Bowel and femoral head hotspots were reduced by less than 1.5% and 2%, respectively. A 10-mm systematic offset reduced nodal coverage by up to 10%. Conclusion: The use of prostate fiducials for daily localization during IMRT treatment results in negligible changes in dose coverage of pelvic nodes or normal tissue sparing in the absence of a significant systematic offset. This offers a simple and practical solution to the problem of image-guided radiotherapy for prostate cancer when including pelvic nodes.

  16. Single fraction multimodal image guided focal salvage high-dose-rate brachytherapy for recurrent prostate cancer

    PubMed Central

    Rischke, Hans-Christian; Meyer, Philipp Tobias; Knobe, Sven; Volgeova-Neher, Natalja; Kollefrath, Michael; Jilg, Cordula Annette; Grosu, Anca Ligia; Baltas, Dimos; Kroenig, Malte

    2016-01-01

    Purpose We present a novel method for treatment of locally recurrent prostate cancer (PCa) following radiation therapy: focal, multimodal image guided high-dose-rate (HDR) brachytherapy. Material and methods We treated two patients with recurrent PCa after primary (#1) or adjuvant (#2) external beam radiation therapy. Multiparametric magnetic resonance imaging (mpMRI), choline, positron emission tomography combined with computed tomography (PET/CT), or prostate-specific membrane antigen (PSMA)-PET combined with CT identified a single intraprostatic lesion. Positron emission tomography or magnetic resonance imaging – transrectal ultrasound (MRI-TRUS) fusion guided transperineal biopsy confirmed PCa within each target lesion. We defined a PET and mpMRI based gross tumor volume (GTV). A 5 mm isotropic margin was applied additionally to each lesion to generate a planning target volume (PTV), which accounts for technical fusion inaccuracies. A D90 of 18 Gy was intended in one fraction to each PTV using ultrasound guided HDR brachytherapy. Results Six month follow-up showed adequate prostate specific antygen (PSA) decline in both patients (ΔPSA 83% in patient 1 and ΔPSA 59.3% in patient 2). Follow-up 3-tesla MRI revealed regressive disease in both patients and PSMA-PET/CT showed no evidence of active disease in patient #1. No acute or late toxicities occurred. Conclusions Single fraction, focal, multimodal image guided salvage HDR brachytherapy for recurrent prostate cancer is a feasible therapy for selected patients with single lesions. This approach has to be evaluated in larger clinical trials. PMID:27504134

  17. Image-guided high-dose-rate brachytherapy of malignancies in various inner organs - technique, indications, and perspectives.

    PubMed

    Bretschneider, Tina; Ricke, Jens; Gebauer, Bernhard; Streitparth, Florian

    2016-06-01

    In the last few years, minimally invasive tumor ablation performed by interventional radiologists has gained increasing relevance in oncologic patient care. Limitations of thermal ablation techniques such as radiofrequency ablation (RFA), microwave ablation (MWA), and laser-induced thermotherapy (LITT), including large tumor size, cooling effects of adjacent vessels, and tumor location near thermosensitive structures, have led to the development of image-guided high-dose-rate (HDR) brachytherapy, especially for the treatment of liver malignancies. This article reviews technical properties of image-guided brachytherapy, indications and its current clinical role in multimodal cancer treatment. Furthermore, perspectives of this novel therapy option will be discussed. PMID:27504135

  18. Image-guided high-dose-rate brachytherapy of malignancies in various inner organs – technique, indications, and perspectives

    PubMed Central

    Bretschneider, Tina; Ricke, Jens; Gebauer, Bernhard

    2016-01-01

    In the last few years, minimally invasive tumor ablation performed by interventional radiologists has gained increasing relevance in oncologic patient care. Limitations of thermal ablation techniques such as radiofrequency ablation (RFA), microwave ablation (MWA), and laser-induced thermotherapy (LITT), including large tumor size, cooling effects of adjacent vessels, and tumor location near thermosensitive structures, have led to the development of image-guided high-dose-rate (HDR) brachytherapy, especially for the treatment of liver malignancies. This article reviews technical properties of image-guided brachytherapy, indications and its current clinical role in multimodal cancer treatment. Furthermore, perspectives of this novel therapy option will be discussed. PMID:27504135

  19. Salvage image-guided intensity modulated or stereotactic body reirradiation of local recurrence of prostate cancer

    PubMed Central

    Jereczek-Fossa, B A; Fodor, C; Bazzani, F; Maucieri, A; Ronchi, S; Ferrario, S; Colangione, S P; Gerardi, M A; Caputo, M; Cecconi, A; Gherardi, F; Vavassori, A; Comi, S; Cambria, R; Garibaldi, C; Cattani, F; De Cobelli, O; Orecchia, R

    2015-01-01

    Objective: To retrospectively evaluate external beam reirradiation (re-EBRT) delivered to the prostate/prostatic bed for local recurrence, after radical or adjuvant/salvage radiotherapy (RT). Methods: 32 patients received re-EBRT between February 2008 and October 2013. All patients had clinical/radiological local relapse in the prostate or prostatic bed and no distant metastasis. re-EBRT was delivered with selective RT technologies [stereotactic RT including CyberKnifeTM (Accuray, Sunnyvale, CA); image-guidance and intensity-modulated RT etc.]. Toxicity was evaluated using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria. Biochemical control was assessed according to the Phoenix definition (NADIR + 2 ng ml−1). Results: Acute urinary toxicity: G0, 24 patients; G1, 6 patients; G2, 2 patients. Acute rectal toxicity: G0, 28 patients; G1, 2 patients; and G2, 1 patient. Late urinary toxicity (evaluated in 30 cases): G0, 23 patients; G1, 6 patients; G2, 1 patient. Late renal toxicity: G0, 25 patients; G1, 5 patients. A mean follow-up of 21.3 months after re-EBRT showed that 13 patients were free of cancer, 3 were alive with biochemical relapse and 12 patients were alive with clinically evident disease. Four patients had died: two of disease progression and two of other causes. Conclusion: re-EBRT using modern technology is a feasible approach for local prostate cancer recurrence offering 2-year tumour control in about half of the patients. Toxicity of re-EBRT is low. Future studies are needed to identify the patients who would benefit most from this treatment. Advances in knowledge: Our series, based on experience in one hospital alone, shows that re-EBRT for local relapse of prostate cancer is feasible and offers a 2-year cure in about half of the patients. PMID:26055506

  20. Dosimetric evaluation of planning target volume margin reduction for prostate cancer via image-guided intensity-modulated radiation therapy

    NASA Astrophysics Data System (ADS)

    Hwang, Taejin; Kang, Sei-Kwon; Cheong, Kwang-Ho; Park, Soah; Yoon, Jai-Woong; Han, Taejin; Kim, Haeyoung; Lee, Meyeon; Kim, Kyoung-Joo; Bae, Hoonsik; Suh, Tae-Suk

    2015-07-01

    The aim of this study was to quantitatively estimate the dosimetric benefits of the image-guided radiation therapy (IGRT) system for the prostate intensity-modulated radiation therapy (IMRT) delivery. The cases of eleven patients who underwent IMRT for prostate cancer without a prostatectomy at our institution between October 2012 and April 2014 were retrospectively analyzed. For every patient, clinical target volume (CTV) to planning target volume (PTV) margins were uniformly used: 3 mm, 5 mm, 7 mm, 10 mm, 12 mm, and 15 mm. For each margin size, the IMRT plans were independently optimized by one medical physicist using Pinnalce3 (ver. 8.0.d, Philips Medical System, Madison, WI) in order to maintain the plan quality. The maximum geometrical margin (MGM) for every CT image set, defined as the smallest margin encompassing the rectum at least at one slice, was between 13 mm and 26 mm. The percentage rectum overlapping PTV (%V ROV ), the rectal normal tissue complication probability (NTCP) and the mean rectal dose (%RD mean ) increased in proportion to the increase of PTV margin. However the bladder NTCP remained around zero to some extent regardless of the increase of PTV margin while the percentage bladder overlapping PTV (%V BOV ) and the mean bladder dose (%BD mean ) increased in proportion to the increase of PTV margin. Without relatively large rectum or small bladder, the increase observed for rectal NTCP, %RDmean and %BD mean per 1-mm PTV margin size were 1.84%, 2.44% and 2.90%, respectively. Unlike the behavior of the rectum or the bladder, the maximum dose on each femoral head had little effect on PTV margin. This quantitative study of the PTV margin reduction supported that IG-IMRT has enhanced the clinical effects over prostate cancer with the reduction of normal organ complications under the similar level of PTV control.

  1. Image-Guided Radiotherapy in Near Real Time With Intensity-Modulated Radiotherapy Megavoltage Treatment Beam Imaging

    SciTech Connect

    Mao Weihua Hsu, Annie; Riaz, Nadeem; Lee, Louis; Wiersma, Rodney; Luxton, Gary; King, Christopher; Xing Lei; Solberg, Timothy

    2009-10-01

    Purpose: To utilize image-guided radiotherapy (IGRT) in near real time by obtaining and evaluating the online positions of implanted fiducials from continuous electronic portal imaging device (EPID) imaging of prostate intensity-modulated radiotherapy (IMRT) delivery. Methods and Materials: Upon initial setup using two orthogonal images, the three-dimensional (3D) positions of all implanted fiducial markers are obtained, and their expected two-dimensional (2D) locations in the beam's-eye-view (BEV) projection are calculated for each treatment field. During IMRT beam delivery, EPID images of the megavoltage treatment beam are acquired in cine mode and subsequently analyzed to locate 2D locations of fiducials in the BEV. Simultaneously, 3D positions are estimated according to the current EPID image, information from the setup portal images, and images acquired at other gantry angles (the completed treatment fields). The measured 2D and 3D positions of each fiducial are compared with their expected 2D and 3D setup positions, respectively. Any displacements larger than a predefined tolerance may cause the treatment system to suspend the beam delivery and direct the therapists to reposition the patient. Results: Phantom studies indicate that the accuracy of 2D BEV and 3D tracking are better than 1 mm and 1.4 mm, respectively. A total of 7330 images from prostate treatments were acquired and analyzed, showing a maximum 2D displacement of 6.7 mm and a maximum 3D displacement of 6.9 mm over 34 fractions. Conclusions: This EPID-based, real-time IGRT method can be implemented on any external beam machine with portal imaging capabilities without purchasing any additional equipment, and there is no extra dose delivered to the patient.

  2. Predictors of Toxicity After Image-guided High-dose-rate Interstitial Brachytherapy for Gynecologic Cancer

    SciTech Connect

    Lee, Larissa J.; Viswanathan, Akila N.

    2012-12-01

    Purpose: To identify predictors of grade 3-4 complications and grade 2-4 rectal toxicity after three-dimensional image-guided high-dose-rate (HDR) interstitial brachytherapy for gynecologic cancer. Methods and Materials: Records were reviewed for 51 women (22 with primary disease and 29 with recurrence) treated with HDR interstitial brachytherapy. A single interstitial insertion was performed with image guidance by computed tomography (n = 43) or magnetic resonance imaging (n = 8). The median delivered dose in equivalent 2-Gy fractions was 72.0 Gy (45 Gy for external-beam radiation therapy and 24 Gy for brachytherapy). Toxicity was reported according to the Common Toxicity Criteria for Adverse Events. Actuarial toxicity estimates were calculated by the Kaplan-Meier method. Results: At diagnosis, the median patient age was 62 years and the median tumor size was 3.8 cm. The median D90 and V100 were 71.4 Gy and 89.5%; the median D2cc for the bladder, rectum, and sigmoid were 64.6 Gy, 61.0 Gy, and 52.7 Gy, respectively. The actuarial rates of all grade 3-4 complications at 2 years were 20% gastrointestinal, 9% vaginal, 6% skin, 3% musculoskeletal, and 2% lymphatic. There were no grade 3-4 genitourinary complications and no grade 5 toxicities. Grade 2-4 rectal toxicity was observed in 10 patients, and grade 3-4 complications in 4; all cases were proctitis with the exception of 1 rectal fistula. D2cc for rectum was higher for patients with grade 2-4 (68 Gy vs 57 Gy for grade 0-1, P=.03) and grade 3-4 (73 Gy vs 58 Gy for grade 0-2, P=.02) rectal toxicity. The estimated dose that resulted in a 10% risk of grade 2-4 rectal toxicity was 61.8 Gy (95% confidence interval, 51.5-72.2 Gy). Discussion: Image-guided HDR interstitial brachytherapy results in acceptable toxicity for women with primary or recurrent gynecologic cancer. D2cc for the rectum is a reliable predictor of late rectal complications. Three-dimensional-based treatment planning should be performed to ensure

  3. High volume image guided injections and structured rehabilitation in shoulder impingement syndrome: a retrospective study

    PubMed Central

    Morton, Sarah; Chan, Otto; Ghozlan, Asser; Price, Jessica; Perry, John; Morrissey, Dylan

    2015-01-01

    Summary Background the aim was to establish the effect of a high volume-image guided injection and structured rehabilitation (HVIGI&SR) on both pain and function in shoulder impingement syndrome (SIS). Methods 44 participants treated between January 2008 and January 2012 with a >3 month history of recalcitrant ultrasound-confirmed SIS were sent a retrospective questionnaire. All participants had received a HVIGI under ultrasound-guidance consisting of 20 mls of Marcaine with 50 mg of hydrocortisone, followed by a period of physiotherapist-led rehabilitation. The validated Shoulder Pain and Disability Index (SPADI) score was used to establish the change in the score between 1 week pre-injection and 3 weeks post-injection, along with an 11-point pain scale. Results 59% of participants responded. There was a clinically and statistically significant decrease in the SPADI score of 58.7 ± 29.9 (p<0.01). 76% of participants had an improvement in their score of over 50% from their initial score. There was a clinically and statistically significant improvement in pain of 5.19 ± 2.62 (p<0.01) on the numerical rating scale of pain. Conclusion HVIGI&SR should be considered for short-term treatment of SIS as it showed a significant improvement in both pain and function. A prolonged period of physiotherapist-led rehabilitation can then be undertaken for long term benefits. PMID:26605194

  4. Image-guided intensity-modulated radiotherapy for prostate cancer: Dose constraints for the anterior rectal wall to minimize rectal toxicity

    SciTech Connect

    Peterson, Jennifer L.; Buskirk, Steven J.; Heckman, Michael G.; Diehl, Nancy N.; Bernard, Johnny R.; Tzou, Katherine S.; Casale, Henry E.; Bellefontaine, Louis P.; Serago, Christopher; Kim, Siyong; Vallow, Laura A.; Daugherty, Larry C.; Ko, Stephen J.

    2014-04-01

    Rectal adverse events (AEs) are a major concern with definitive radiotherapy (RT) treatment for prostate cancer. The anterior rectal wall is at the greatest risk of injury as it lies closest to the target volume and receives the highest dose of RT. This study evaluated the absolute volume of anterior rectal wall receiving a high dose to identify potential ideal dose constraints that can minimize rectal AEs. A total of 111 consecutive patients with Stage T1c to T3a N0 M0 prostate cancer who underwent image-guided intensity-modulated RT at our institution were included. AEs were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. The volume of anterior rectal wall receiving 5 to 80 Gy in 2.5-Gy increments was determined. Multivariable Cox regression models were used to identify cut points in these volumes that led to an increased risk of early and late rectal AEs. Early AEs occurred in most patients (88%); however, relatively few of them (13%) were grade ≥2. At 5 years, the cumulative incidence of late rectal AEs was 37%, with only 5% being grade ≥2. For almost all RT doses, we identified a threshold of irradiated absolute volume of anterior rectal wall above which there was at least a trend toward a significantly higher rate of AEs. Most strikingly, patients with more than 1.29, 0.73, or 0.45 cm{sup 3} of anterior rectal wall exposed to radiation doses of 67.5, 70, or 72.5 Gy, respectively, had a significantly increased risk of late AEs (relative risks [RR]: 2.18 to 2.72; p ≤ 0.041) and of grade ≥ 2 early AEs (RR: 6.36 to 6.48; p = 0.004). Our study provides evidence that definitive image-guided intensity-modulated radiotherapy (IG-IMRT) for prostate cancer is well tolerated and also identifies dose thresholds for the absolute volume of anterior rectal wall above which patients are at greater risk of early and late complications.

  5. Optimization and quality assurance of an image-guided radiation therapy system for intensity-modulated radiation therapy radiotherapy

    SciTech Connect

    Tsai, Jen-San; Micaily, Bizhan; Miyamoto, Curtis

    2012-10-01

    To develop a quality assurance (QA) of XVI cone beam system (XVIcbs) for its optimal imaging-guided radiotherapy (IGRT) implementation, and to construe prostate tumor margin required for intensity-modulated radiation therapy (IMRT) if IGRT is unavailable. XVIcbs spatial accuracy was explored with a humanoid phantom; isodose conformity to lesion target with a rice phantom housing a soap as target; image resolution with a diagnostic phantom; and exposure validation with a Radcal ion chamber. To optimize XVIcbs, rotation flexmap on coincidency between gantry rotational axis and that of XVI cone beam scan was investigated. Theoretic correlation to image quality of XVIcbs rotational axis stability was elaborately studied. Comprehensive QA of IGRT using XVIcbs has initially been explored and then implemented on our general IMRT treatments, and on special IMRT radiotherapies such as head and neck (H and N), stereotactic radiation therapy (SRT), stereotactic radiosurgery (SRS), and stereotactic body radiotherapy (SBRT). Fifteen examples of prostate setup accounted for 350 IGRT cone beam system were analyzed. IGRT accuracy results were in agreement {+-} 1 mm. Flexmap 0.25 mm met the manufacturer's specification. Films confirmed isodose coincidence with target (soap) via XVIcbs, otherwise not. Superficial doses were measured from 7.2-2.5 cGy for anatomic diameters 15-33 cm, respectively. Image quality was susceptible to rotational stability or patient movement. IGRT using XVIcbs on general IMRT treatments such as prostate, SRT, SRS, and SBRT for setup accuracy were verified; and subsequently coordinate shifts corrections were recorded. The 350 prostate IGRT coordinate shifts modeled to Gaussian distributions show central peaks deviated off the isocenter by 0.6 {+-} 3.0 mm, 0.5 {+-} 4.5 mm in the X(RL)- and Z(SI)-coordinates, respectively; and 2.0 {+-} 3.0 mm in the Y(AP)-coordinate as a result of belly and bladder capacity variations. Sixty-eight percent of confidence was

  6. A cost effective and high fidelity fluoroscopy simulator using the Image-Guided Surgery Toolkit (IGSTK)

    NASA Astrophysics Data System (ADS)

    Gong, Ren Hui; Jenkins, Brad; Sze, Raymond W.; Yaniv, Ziv

    2014-03-01

    The skills required for obtaining informative x-ray fluoroscopy images are currently acquired while trainees provide clinical care. As a consequence, trainees and patients are exposed to higher doses of radiation. Use of simulation has the potential to reduce this radiation exposure by enabling trainees to improve their skills in a safe environment prior to treating patients. We describe a low cost, high fidelity, fluoroscopy simulation system. Our system enables operators to practice their skills using the clinical device and simulated x-rays of a virtual patient. The patient is represented using a set of temporal Computed Tomography (CT) images, corresponding to the underlying dynamic processes. Simulated x-ray images, digitally reconstructed radiographs (DRRs), are generated from the CTs using ray-casting with customizable machine specific imaging parameters. To establish the spatial relationship between the CT and the fluoroscopy device, the CT is virtually attached to a patient phantom and a web camera is used to track the phantom's pose. The camera is mounted on the fluoroscope's intensifier and the relationship between it and the x-ray source is obtained via calibration. To control image acquisition the operator moves the fluoroscope as in normal operation mode. Control of zoom, collimation and image save is done using a keypad mounted alongside the device's control panel. Implementation is based on the Image-Guided Surgery Toolkit (IGSTK), and the use of the graphics processing unit (GPU) for accelerated image generation. Our system was evaluated by 11 clinicians and was found to be sufficiently realistic for training purposes.

  7. Image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiotherapy (WP-IMRT) for locally advanced cervical cancer: a prospective study from Chiang Mai University Hospital, Thailand

    PubMed Central

    Wanwilairat, Somsak; Chakrabandhu, Somvilai; Klunklin, Pitchayaponne; Onchan, Wimrak; Tippanya, Damrongsak; Nopnop, Wannapa; Galalae, Razvan; Chitapanarux, Imjai

    2013-01-01

    Purpose A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiation therapy (WP-IMRT) for locally advanced cervical cancer. Material and methods Fifteen patients with locally advanced cervical cancer were enrolled into the study. WP-IMRT was used to treat the Clinical Target Volume (CTV) with a dose of 45 Gy in 25 fractions. Concurrent cisplatin (40 mg/m2) was prescribed during radiotherapy (RT) on weekly basis. IGBT using computed tomography was performed at the dose of 7 Gy × 4 fractions to the High-Risk Clinical Target Volume (HR-CTV). Results The mean cumulative doses – in terms of equivalent dose of 2 Gy (EQD2) – of IGBT plus WP-IMRT to HR-CTV, bladder, rectum, and sigmoid colon were 88.3, 85.0, 68.2 and 73.6 Gy, respectively. In comparison with standard (point A prescription) dose-volume histograms, volume-based image-guided brachytherapy improved the cumulative doses for bladder of 67%, rectum of 47% and sigmoid of 46%. At the median follow-up time of 14 months, the local control, metastasis-free survival and overall survival rates were 93%, 100% and 93%, respectively. No grade 3-4 acute and late toxicities were observed. Conclusion The combination of image-guided brachytherapy and intensity-modulated radiotherapy improved the dose distribution to tumor volumes and avoided overdose in OARs which could be converted in excellent local control and toxicity profiles. PMID:23634150

  8. High contrast optical imaging methods for image guided laser ablation of dental caries lesions

    PubMed Central

    LaMantia, Nicole R.; Tom, Henry; Chan, Kenneth H.; Simon, Jacob C.; Darling, Cynthia L.; Fried, Daniel

    2014-01-01

    Laser based methods are well suited for automation and can be used to selectively remove dental caries to minimize the loss of healthy tissues and render the underlying enamel more resistant to acid dissolution. The purpose of this study was to determine which imaging methods are best suited for image-guided ablation of natural non-cavitated carious lesions on occlusal surfaces. Multiple caries imaging methods were compared including near-IR and visible reflectance and quantitative light fluorescence (QLF). In order for image-guided laser ablation to be feasible, chemical and physical modification of tooth surfaces due to laser irradiation cannot greatly reduce the contrast between sound and demineralized dental hard tissues. Sound and demineralized surfaces of 48 extracted human molar teeth with non-cavitated lesions were examined. Images were acquired before and after laser irradiation using visible and near-IR reflectance and QLF at several wavelengths. Polarization sensitive-optical coherence tomography was used to confirm that lesions were present. The highest contrast was attained at 1460-nm and 1500–1700-nm, wavelengths coincident with higher water absorption. The reflectance did not decrease significantly after laser irradiation for those wavelengths. PMID:24791129

  9. High contrast optical imaging methods for image guided laser ablation of dental caries lesions

    NASA Astrophysics Data System (ADS)

    LaMantia, Nicole R.; Tom, Henry; Chan, Kenneth H.; Simon, Jacob C.; Darling, Cynthia L.; Fried, Daniel

    2014-02-01

    Laser based methods are well suited for automation and can be used to selectively remove dental caries to minimize the loss of healthy tissues and render the underlying enamel more resistant to acid dissolution. The purpose of this study was to determine which imaging methods are best suited for image-guided ablation of natural non-cavitated carious lesions on occlusal surfaces. Multiple caries imaging methods were compared including near-IR and visible reflectance and quantitative light fluorescence (QLF). In order for image-guided laser ablation to be feasible, chemical and physical modification of tooth surfaces due to laser irradiation cannot greatly reduce the contrast between sound and demineralized dental hard tissues. Sound and demineralized surfaces of 48 extracted human molar teeth with non-cavitated lesions were examined. Images were acquired before and after laser irradiation using visible and near-IR reflectance and QLF at several wavelengths. Polarization sensitive-optical coherence tomography was used to confirm that lesions were present. The highest contrast was attained at 1460-nm and 1500-1700-nm, wavelengths coincident with higher water absorption. The reflectance did not decrease significantly after laser irradiation for those wavelengths.

  10. High quantum efficiency megavoltage imaging with thick scintillator detectors for image guided radiation therapy

    NASA Astrophysics Data System (ADS)

    Gopal, Arun

    In image guided radiation therapy (IGRT), imaging devices serve as guidance systems to aid patient set-up and tumor volume localization. Traditionally, 2-D megavoltage x-ray imagers, referred to as electronic portal imaging devices (EPIDs), have been used for planar target localization, and have recently been extended to perform 3-D volumetric reconstruction via cone-beam computed tomography (CBCT). However, current EPIDs utilize thin and inefficient phosphor screen detectors and are subsequently limited by poor soft tissue visualization, which limits their use for CBCT. Therefore, the use of thick scintillation media as megavoltage x-ray detectors for greater x-ray sensitivity and enhanced image quality has recently been of significant interest. In this research, two candidates for thick scintillators: CsI(Tl) and terbium doped scintillation glass were investigated in separate imaging configurations. In the first configuration, a thick scintillation crystal (TSC) consisting of a thick, monolithic slab of CsI(Tl) was coupled to a mirror-lens-camera system. The second configuration is based on a fiber-optic scintillation glass array (FOSGA), wherein the scintillation glass is drawn into long fiber-optic conduits, inserted into a grid-type housing constructed out of polymer-tungsten alloy, and coupled to an array of photodiodes for digital read-out. The imaging prototypes were characterized using theoretical studies and imaging measurements to obtain fundamental metrics of imaging performance. Spatial resolution was measured based on a modulation transfer function (MTF), noise was evaluated in terms of a noise power spectrum (NPS), and overall contrast was characterized in the form of detective quantum efficiency (DQE). The imaging studies were used to optimize the TSC and FOSGA imagers and propose prototype configurations for order-of-magnitude improvements in overall image quality. In addition, a fast and simple technique was developed to measure the MTF, NPS, and

  11. Re-irradiation of unresectable recurrent head and neck cancer: using Helical Tomotherapy as image-guided intensity-modulated radiotherapy

    PubMed Central

    Jeong, Songmi; Yoo, Eun Jung; Kim, Ji Yoon; Han, Chi Wha; Kim, Ki Jun

    2013-01-01

    Purpose Re-irradiation (re-RT) is considered a treatment option for inoperable locoregionally recurrent head and neck cancer (HNC) after prior radiotherapy. We evaluated the efficacy and safety of re-RT using Helical Tomotherapy as image-guided intensity-modulated radiotherapy in recurrent HNC. Materials and Methods Patients diagnosed with recurrent HNC and received re-RT were retrospectively reviewed. Primary endpoint was overall survival (OS) and secondary endpoints were locoregional control and toxicities. Results The median follow-up period of total 9 patients was 18.7 months (range, 4.1 to 76 months) and that of 3 alive patients was 49 months (range, 47 to 76 months). Median dose of first radiotherapy and re-RT was 64.8 and 47.5 Gy10. Median cumulative dose of the two courses of radiotherapy was 116.3 Gy10 (range, 91.8 to 128.9 Gy10) while the median interval between the two courses of radiation was 25 months (range, 4 to 137 months). The response rate after re-RT of the evaluated 8 patients was 75% (complete response, 4; partial response, 2). Median locoregional relapse-free survival after re-RT was 11.9 months (range, 3.4 to 75.1 months) and 5 patients eventually presented with treatment failure (in-field failure, 2; in- and out-field failure, 2; out-field failure, 1). Median OS of the 8 patients was 20.3 months (range, 4.1 to 75.1 months). One- and two-year OS rates were 62.5% and 50%, respectively. Grade 3 leucopenia developed in one patient as acute toxicity, and grade 2 osteonecrosis and trismus as chronic toxicity in another patient. Conclusion Re-RT using Helical Tomotherapy for previously irradiated patients with unresectable locoregionally recurrent HNC may be a feasible treatment option with long-term survival and acceptable toxicities. PMID:24501708

  12. High-performance iron oxide nanoparticles for magnetic particle imaging - guided hyperthermia (hMPI).

    PubMed

    Bauer, Lisa M; Situ, Shu F; Griswold, Mark A; Samia, Anna Cristina S

    2016-06-16

    Magnetic particle imaging (MPI) is an emerging imaging modality that allows the direct and quantitative mapping of iron oxide nanoparticles. In MPI, the development of tailored iron oxide nanoparticle tracers is paramount to achieving high sensitivity and good spatial resolution. To date, most MPI tracers being developed for potential clinical applications are based on spherical undoped magnetite nanoparticles. For the first time, we report on the systematic investigation of the effects of changes in chemical composition and shape anisotropy on the MPI performance of iron oxide nanoparticle tracers. We observed a 2-fold enhancement in MPI signal through selective doping of magnetite nanoparticles with zinc. Moreover, we demonstrated focused magnetic hyperthermia heating by adapting the field gradient used in MPI. By saturating the iron oxide nanoparticles outside of a field free region (FFR) with an external static field, we can selectively heat a target region in our test sample. By comparing zinc-doped magnetite cubic nanoparticles with undoped spherical nanoparticles, we could show a 5-fold improvement in the specific absorption rate (SAR) in magnetic hyperthermia while providing good MPI signal, thereby demonstrating the potential for high-performance focused hyperthermia therapy through an MPI-guided approach (hMPI). PMID:27210742

  13. Comparative evaluation of two dose optimization methods for image-guided, highly-conformal, tandem and ovoids cervix brachytherapy planning.

    PubMed

    Ren, Jiyun; Menon, Geetha; Sloboda, Ron

    2013-04-01

    Although the Manchester system is still extensively used to prescribe dose in brachytherapy (BT) for locally advanced cervix cancer, many radiation oncology centers are transitioning to 3D image-guided BT, owing to the excellent anatomy definition offered by modern imaging modalities. As automatic dose optimization is highly desirable for 3D image-based BT, this study comparatively evaluates the performance of two optimization methods used in BT treatment planning--Nelder-Mead simplex (NMS) and simulated annealing (SA)--for a cervix BT computer simulation model incorporating a Manchester-style applicator. Eight model cases were constructed based on anatomical structure data (for high risk-clinical target volume (HR-CTV), bladder, rectum and sigmoid) obtained from measurements on fused MR-CT images for BT patients. D90 and V100 for HR-CTV, D2cc for organs at risk (OARs), dose to point A, conformation index and the sum of dwell times within the tandem and ovoids were calculated for optimized treatment plans designed to treat the HR-CTV in a highly conformal manner. Compared to the NMS algorithm, SA was found to be superior as it could perform optimization starting from a range of initial dwell times, while the performance of NMS was strongly dependent on their initial choice. SA-optimized plans also exhibited lower D2cc to OARs, especially the bladder and sigmoid, and reduced tandem dwell times. For cases with smaller HR-CTV having good separation from adjoining OARs, multiple SA-optimized solutions were found which differed markedly from each other and were associated with different choices for initial dwell times. Finally and importantly, the SA method yielded plans with lower dwell time variability compared with the NMS method. PMID:23459004

  14. Comparative evaluation of two dose optimization methods for image-guided, highly-conformal, tandem and ovoids cervix brachytherapy planning

    NASA Astrophysics Data System (ADS)

    Ren, Jiyun; Menon, Geetha; Sloboda, Ron

    2013-04-01

    Although the Manchester system is still extensively used to prescribe dose in brachytherapy (BT) for locally advanced cervix cancer, many radiation oncology centers are transitioning to 3D image-guided BT, owing to the excellent anatomy definition offered by modern imaging modalities. As automatic dose optimization is highly desirable for 3D image-based BT, this study comparatively evaluates the performance of two optimization methods used in BT treatment planning—Nelder-Mead simplex (NMS) and simulated annealing (SA)—for a cervix BT computer simulation model incorporating a Manchester-style applicator. Eight model cases were constructed based on anatomical structure data (for high risk-clinical target volume (HR-CTV), bladder, rectum and sigmoid) obtained from measurements on fused MR-CT images for BT patients. D90 and V100 for HR-CTV, D2cc for organs at risk (OARs), dose to point A, conformation index and the sum of dwell times within the tandem and ovoids were calculated for optimized treatment plans designed to treat the HR-CTV in a highly conformal manner. Compared to the NMS algorithm, SA was found to be superior as it could perform optimization starting from a range of initial dwell times, while the performance of NMS was strongly dependent on their initial choice. SA-optimized plans also exhibited lower D2cc to OARs, especially the bladder and sigmoid, and reduced tandem dwell times. For cases with smaller HR-CTV having good separation from adjoining OARs, multiple SA-optimized solutions were found which differed markedly from each other and were associated with different choices for initial dwell times. Finally and importantly, the SA method yielded plans with lower dwell time variability compared with the NMS method.

  15. High-performance iron oxide nanoparticles for magnetic particle imaging - guided hyperthermia (hMPI)

    NASA Astrophysics Data System (ADS)

    Bauer, Lisa M.; Situ, Shu F.; Griswold, Mark A.; Samia, Anna Cristina S.

    2016-06-01

    Magnetic particle imaging (MPI) is an emerging imaging modality that allows the direct and quantitative mapping of iron oxide nanoparticles. In MPI, the development of tailored iron oxide nanoparticle tracers is paramount to achieving high sensitivity and good spatial resolution. To date, most MPI tracers being developed for potential clinical applications are based on spherical undoped magnetite nanoparticles. For the first time, we report on the systematic investigation of the effects of changes in chemical composition and shape anisotropy on the MPI performance of iron oxide nanoparticle tracers. We observed a 2-fold enhancement in MPI signal through selective doping of magnetite nanoparticles with zinc. Moreover, we demonstrated focused magnetic hyperthermia heating by adapting the field gradient used in MPI. By saturating the iron oxide nanoparticles outside of a field free region (FFR) with an external static field, we can selectively heat a target region in our test sample. By comparing zinc-doped magnetite cubic nanoparticles with undoped spherical nanoparticles, we could show a 5-fold improvement in the specific absorption rate (SAR) in magnetic hyperthermia while providing good MPI signal, thereby demonstrating the potential for high-performance focused hyperthermia therapy through an MPI-guided approach (hMPI).Magnetic particle imaging (MPI) is an emerging imaging modality that allows the direct and quantitative mapping of iron oxide nanoparticles. In MPI, the development of tailored iron oxide nanoparticle tracers is paramount to achieving high sensitivity and good spatial resolution. To date, most MPI tracers being developed for potential clinical applications are based on spherical undoped magnetite nanoparticles. For the first time, we report on the systematic investigation of the effects of changes in chemical composition and shape anisotropy on the MPI performance of iron oxide nanoparticle tracers. We observed a 2-fold enhancement in MPI signal

  16. Interfractional change of high-risk CTV D90 during image-guided brachytherapy for uterine cervical cancer

    PubMed Central

    Ohkubo, Yu; Ohno, Tatsuya; Noda, Shin-ei; Kubo, Nobuteru; Nakagawa, Akiko; Kawahara, Masahiro; Abe, Takanori; Kiyohara, Hiroki; Wakatsuki, Masaru; Nakano, Takashi

    2013-01-01

    The purpose of this study was to evaluate interfractional changes of the minimum dose delivered to 90% of the high-risk clinical target volume (HR-CTV D90) and D2cc of the bladder and rectum during brachytherapy for uterine cervical cancer patients. A total of 52 patients received external beam radiotherapy and high-dose-rate intracavitary brachytherapy (ICBT). For each of four ICBT applications, a pelvic CT scan was performed and the HR-CTV was delineated. Retrospectively, these patients were divided into two groups: (i) the standard dose group with 6 Gy to point A in each ICBT, and (ii) the adaptive dose group with a modified dose to point A to cover the HR-CTV with the 6-Gy isodose line as much as possible. The HR-CTV D90 was assessed in every session, and analyzed as interfractional changes. In the standard dose group, the interfractional changes of the HR-CTV D90 showed a linear increase from the first to the third of the four ICBT (average 6.1, 6.6, 7.0 and 7.1 Gy, respectively). In contrast, those of the adaptive dose group remained almost constant (average 7.2, 7.2, 7.3 and 7.4 Gy, respectively). Especially, in the case of a large HR-CTV volume (≥35 cm3) at first ICBT, the total HR-CTV D90 of the adaptive dose group with brachytherapy was significantly higher than that of the standard dose group. There were no significant differences in total D2cc in bladder and rectum between the two groups. Image-guided adaptive brachytherapy based on interfractional tumor volume change improves the dose to the HR-CTV while keeping rectal and bladder doses within acceptable levels. PMID:23732770

  17. Interfractional change of high-risk CTV D90 during image-guided brachytherapy for uterine cervical cancer.

    PubMed

    Ohkubo, Yu; Ohno, Tatsuya; Noda, Shin-ei; Kubo, Nobuteru; Nakagawa, Akiko; Kawahara, Masahiro; Abe, Takanori; Kiyohara, Hiroki; Wakatsuki, Masaru; Nakano, Takashi

    2013-11-01

    The purpose of this study was to evaluate interfractional changes of the minimum dose delivered to 90% of the high-risk clinical target volume (HR-CTV D90) and D2cc of the bladder and rectum during brachytherapy for uterine cervical cancer patients. A total of 52 patients received external beam radiotherapy and high-dose-rate intracavitary brachytherapy (ICBT). For each of four ICBT applications, a pelvic CT scan was performed and the HR-CTV was delineated. Retrospectively, these patients were divided into two groups: (i) the standard dose group with 6 Gy to point A in each ICBT, and (ii) the adaptive dose group with a modified dose to point A to cover the HR-CTV with the 6-Gy isodose line as much as possible. The HR-CTV D90 was assessed in every session, and analyzed as interfractional changes. In the standard dose group, the interfractional changes of the HR-CTV D90 showed a linear increase from the first to the third of the four ICBT (average 6.1, 6.6, 7.0 and 7.1 Gy, respectively). In contrast, those of the adaptive dose group remained almost constant (average 7.2, 7.2, 7.3 and 7.4 Gy, respectively). Especially, in the case of a large HR-CTV volume (≥35 cm(3)) at first ICBT, the total HR-CTV D90 of the adaptive dose group with brachytherapy was significantly higher than that of the standard dose group. There were no significant differences in total D2cc in bladder and rectum between the two groups. Image-guided adaptive brachytherapy based on interfractional tumor volume change improves the dose to the HR-CTV while keeping rectal and bladder doses within acceptable levels. PMID:23732770

  18. Vaginal tolerance of CT based image-guided high-dose rate interstitial brachytherapy for gynecological malignancies

    PubMed Central

    2014-01-01

    Background Purpose of this study was to identify predictors of vaginal ulcer after CT based three-dimensional image-guided high-dose-rate interstitial brachytherapy (HDR-ISBT) for gynecologic malignancies. Methods Records were reviewed for 44 female (14 with primary disease and 30 with recurrence) with gynecological malignancies treated with HDR-ISBT with or without external beam radiation therapy. The HDR-ISBT applicator insertion was performed with image guidance by trans-rectal ultrasound and CT. Results The median clinical target volume was 35.5 ml (2.4-142.1 ml) and the median delivered dose in equivalent dose in 2 Gy fractions (EQD2) for target volume D90 was 67.7 Gy (48.8-94.2 Gy, doses of external-beam radiation therapy and brachytherapy were combined). For re-irradiation patients, median EQD2 of D2cc for rectum and bladder, D0.5cc, D1cc, D2cc, D4cc, D6cc and D8cc for vaginal wall was 91.1 Gy, 100.9 Gy, 260.3 Gy, 212.3 Gy, 170.1 Gy, 117.1 Gy, 105.2 Gy, and 94.7 Gy, respectively. For those without prior radiation therapy, median EQD2 of D2cc for rectum and bladder, D0.5cc, D1cc, D2cc, D4cc, D6cc and D8cc for vaginal wall was 56.3 Gy, 54.3 Gy, 147.4 Gy, 126.2 Gy, 108.0 Gy, 103.5 Gy, 94.7 Gy, and 80.7 Gy, respectively. Among five patients with vaginal ulcer, three had prior pelvic radiation therapy in their initial treatment and three consequently suffered from fistula formation. On univariate analysis, re-irradiation and vaginal wall D2cc in EQD2 was the clinical predictors of vaginal ulcer (p = 0.035 and p = 0.025, respectively). The ROC analysis revealed that vaginal wall D2cc is the best predictor of vaginal ulcer. The 2-year incidence rates of vaginal ulcer in the patients with vaginal wall D2cc in EQD2 equal to or less than 145 Gy and over 145 Gy were 3.7% and 23.5%, respectively, with a statistically significant difference (p = 0.026). Conclusions Re-irradiation and vaginal D2cc is a significant predictor of vaginal ulcer after HDR-ISBT for

  19. Whole brain radiotherapy plus simultaneous in-field boost with image guided intensity-modulated radiotherapy for brain metastases of non-small cell lung cancer

    PubMed Central

    2014-01-01

    Background Whole brain radiotherapy (WBRT) plus sequential focal radiation boost is a commonly used therapeutic strategy for patients with brain metastases. However, recent reports on WBRT plus simultaneous in-field boost (SIB) also showed promising outcomes. The objective of present study is to retrospectively evaluate the efficacy and toxicities of WBRT plus SIB with image guided intensity-modulated radiotherapy (IG-IMRT) for inoperable brain metastases of NSCLC. Methods Twenty-nine NSCLC patients with 87 inoperable brain metastases were included in this retrospective study. All patients received WBRT at a dose of 40 Gy/20 f, and SIB boost with IG-IMRT at a dose of 20 Gy/5 f concurrent with WBRT in the fourth week. Prior to each fraction of IG-IMRT boost, on-line positioning verification and correction were used to ensure that the set-up errors were within 2 mm by cone beam computed tomography in all patients. Results The one-year intracranial control rate, local brain failure rate, and distant brain failure rate were 62.9%, 13.8%, and 19.2%, respectively. The two-year intracranial control rate, local brain failure rate, and distant brain failure rate were 42.5%, 30.9%, and 36.4%, respectively. Both median intracranial progression-free survival and median survival were 10 months. Six-month, one-year, and two-year survival rates were 65.5%, 41.4%, and 13.8%, corresponding to 62.1%, 41.4%, and 10.3% of intracranial progression-free survival rates. Patients with Score Index for Radiosurgery in Brain Metastases (SIR) >5, number of intracranial lesions <3, and history of EGFR-TKI treatment had better survival. Three lesions (3.45%) demonstrated radiation necrosis after radiotherapy. Grades 2 and 3 cognitive impairment with grade 2 radiation leukoencephalopathy were observed in 4 (13.8%) and 4 (13.8%) patients. No dosimetric parameters were found to be associated with these late toxicities. Patients received EGFR-TKI treatment had higher incidence of grades 2–3

  20. Acute Toxicity After Image-Guided Intensity Modulated Radiation Therapy Compared to 3D Conformal Radiation Therapy in Prostate Cancer Patients

    SciTech Connect

    Wortel, Ruud C.; Incrocci, Luca; Pos, Floris J.; Lebesque, Joos V.; Witte, Marnix G.; Heide, Uulke A. van der; Herk, Marcel van; Heemsbergen, Wilma D.

    2015-03-15

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows significant dose reductions to organs at risk in prostate cancer patients. However, clinical data identifying the benefits of IG-IMRT in daily practice are scarce. The purpose of this study was to compare dose distributions to organs at risk and acute gastrointestinal (GI) and genitourinary (GU) toxicity levels of patients treated to 78 Gy with either IG-IMRT or 3D-CRT. Methods and Materials: Patients treated with 3D-CRT (n=215) and IG-IMRT (n=260) receiving 78 Gy in 39 fractions within 2 randomized trials were selected. Dose surface histograms of anorectum, anal canal, and bladder were calculated. Identical toxicity questionnaires were distributed at baseline, prior to fraction 20 and 30 and at 90 days after treatment. Radiation Therapy Oncology Group (RTOG) grade ≥1, ≥2, and ≥3 endpoints were derived directly from questionnaires. Univariate and multivariate binary logistic regression analyses were applied. Results: The median volumes receiving 5 to 75 Gy were significantly lower (all P<.001) with IG-IMRT for anorectum, anal canal, and bladder. The mean dose to the anorectum was 34.4 Gy versus 47.3 Gy (P<.001), 23.6 Gy versus 44.6 Gy for the anal canal (P<.001), and 33.1 Gy versus 43.2 Gy for the bladder (P<.001). Significantly lower grade ≥2 toxicity was observed for proctitis, stool frequency ≥6/day, and urinary frequency ≥12/day. IG-IMRT resulted in significantly lower overall RTOG grade ≥2 GI toxicity (29% vs 49%, respectively, P=.002) and overall GU grade ≥2 toxicity (38% vs 48%, respectively, P=.009). Conclusions: A clinically meaningful reduction in dose to organs at risk and acute toxicity levels was observed in IG-IMRT patients, as a result of improved technique and tighter margins. Therefore reduced late toxicity levels can be expected as well; additional research is needed to quantify such reductions.

  1. Image-guided high-dose-rate interstitial brachytherapy – a valuable salvage treatment approach for loco-regional recurrence of papillary thyroid cancer

    PubMed Central

    Wu, Ning; Zhao, Hongfu; Han, Dongmei; Zhao, Zhipeng; Ge, Yuxin

    2016-01-01

    Purpose To report the treatment effect of image-guided high-dose-rate (HDR) interstitial brachytherapy for refractory recurrence of papillary thyroid cancer (PTC). Case report This 66-year-old female presented with recurrence 5 years after thyroidectomy for PTC. Despite external irradiation and radioactive 131I, the lesion expanded as 3.7 × 3.0 × 2.3 cm3 and 2.0 × 1.5 × 1.5 cm3. The locoregional recurrent tumor was treated with image-guided HDR interstitial brachytherapy. The total dose of 30 Gy in 6 fractions were delivered on the whole recurrent tumor. Results Removal of the recurrent tumor was securely achieved by HDR interstitial brachytherapy guided with ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) scanning. The refractory tumor in the patients healed uneventfully after HDR interstitial brachytherapy without recurrence during the 14 months of follow-up. Conclusions The image-guided HDR interstitial brachytherapy may be a valuable salvage treatment approach for refractory recurrence of PTC. PMID:27257420

  2. Image guided radiation therapy boost in combination with high-dose-rate intracavitary brachytherapy for the treatment of cervical cancer

    PubMed Central

    Wang, Xianliang; Li, Jie; Yuan, Ke; Yin, Gang; Wan, Bin

    2016-01-01

    Purpose The purpose of this study was to demonstrate the dosimetric and clinical feasibility of image guided radiation therapy (IGRT) combined with high-dose-rate (HDR) intracavitary brachytherapy (ICBT) to improve dose distribution in cervical cancer treatment. Material and methods For 42 cervical cancer patients, magnetic resonance imaging (MRI) scans were acquired after completion of whole pelvic irradiation 45-46 Gy and 5 fractions of B + I (ICBT + IGRT) treatment were subsequently received. The high risk clinical target volume (HRCTV), intermediate risk clinical target volume (IRCTV), bladder, rectum, and sigmoid were contoured on the computed tomography (CT) scans. The total planning aim doses for HRCTV was D90% > 85 Gy, whilst constraints for rectum and sigmoid were D2cc < 75 Gy and D2cc < 90 Gy for bladder in terms of an equivalent dose in 2 Gy (EQD2) for external beam radiotherapy (EBRT) and brachytherapy boost. The IGRT plan was optimized on top of the ICBT dose distribution. A dosimetric comparison was made between B + I and optimized ICBT (O-ICBT) only. Results The mean D90% of HRCTV was comparable for B + I and O-ICBT (p = 0.82). For B + I plan, HRCTV D100%, IRCTV D100%, and IRCTV D90% were significantly increased by a mean of 10.52 Gy, 5.61 Gy, and 2.70 Gy, respectively (p < 0.01). The D2cc for bladder, rectum, and sigmoid were lower by a mean of 21.36, 6.78, and 10.65 Gy, respectively (p < 0.01). The mean rectum V60 Gy value over 42 patients was almost the same for both techniques but for bladder and sigmoid B + I had higher V60 Gy mean values as compared with the O-ICBT. Conclusions B + I can improve dose distribution in cervical cancer treatment; it could be useful for tumors extended beyond the reach of intracavitary/interstitial brachytherapy (IC/ISBT) or for centers that are inexperienced or ill-equipped with IC/ISBT techniques. Additional confirmatory prospective studies with larger numbers of patients and longer follow-up are required to

  3. Does Image-Guided Radiotherapy Improve Toxicity Profile in Whole Pelvic-Treated High-Risk Prostate Cancer? Comparison Between IG-IMRT and IMRT

    SciTech Connect

    Chung, Hans T. Xia Ping; Chan, Linda W.; Park-Somers, Eileen; Roach, Mack

    2009-01-01

    Purpose: To evaluate the impact of adding image-guided (IG) technique to intensity-modulated radiotherapy (IMRT) on dosimetric avoidance of organs at risk (OAR) and acute toxicities. Methods and Materials: A total of 25 consecutively treated patients (10 from National University Hospital and 15 from University of California San Francisco) with high-risk prostate cancer formed the study cohort. All received definitive IMRT with prophylactic nodal RT. Similar IMRT contouring and planning techniques were used at both centers. At University of California, San Francisco, intraprostatic fiducial markers were used for daily pretreatment on-line corrections (IG-IMRT). In contrast, at the National University Hospital, no fiducial markers were used (IMRT). At University of California, San Francisco, the planning target volume margins to the prostate were 2-3 mm. At the National University Hospital, they were 1 cm circumferentially, except for 0.5 cm posteriorly. The acute rectal and bladder toxicities and dosimetric endpoints to the planning target volume and organs at risk were compared. Results: The planning target volume dose coverage was not significantly different between IMRT and IG-IMRT for the prostate, seminal vesicles, and lymph nodes. The volume of rectum and bladder receiving {>=}40, {>=}60, and {>=}70 Gy were all significantly less using IG-IMRT (p <0.001). IG-IMRT yielded lower acute Radiation Therapy Oncology Group Grade 2 rectal (80% vs. 13%, p = 0.004) and bladder (60% vs. 13%, p = 0.014) toxicities. Conclusions: IG-IMRT, using daily target localization with fiducial markers, permits the use of smaller margins and correspondingly lower doses to the organs at risk, such as the rectum and bladder. These tangible gains appear to translate into lower clinically significant toxicities.

  4. An image-intensive ePR for image-guided minimally invasive spine surgery applications including real-time intra-operative image acquisition, archival, and display

    NASA Astrophysics Data System (ADS)

    Documet, Jorge R.; Le, Anh; Liu, Brent; Huang, H. K.; Chiu, John

    2009-02-01

    Recent developments in medical imaging informatics have improved clinical workflow in Radiology enterprise but gaps remain in the clinical workflow from diagnosis to surgical treatment through post-operative follow-up. One solution to bridge this gap is the development of an electronic patient record (ePR) that integrates key imaging and informatics data during the pre, intra, and post-operative phases of clinical workflow. We present an ePR system based on standards and tailored to the clinical application for image-guided minimally invasive spinal surgery (MISS). The ePR system has been implemented in a clinical environment for a half-year.

  5. Improved Clinical Outcomes With High-Dose Image Guided Radiotherapy Compared With Non-IGRT for the Treatment of Clinically Localized Prostate Cancer

    SciTech Connect

    Zelefsky, Michael J.; Kollmeier, Marisa; Cox, Brett; Fidaleo, Anthony; Sperling, Dahlia; Pei, Xin; Carver, Brett; Coleman, Jonathan; Lovelock, Michael; Hunt, Margie

    2012-09-01

    Purpose: To compare toxicity profiles and biochemical tumor control outcomes between patients treated with high-dose image-guided radiotherapy (IGRT) and high-dose intensity-modulated radiotherapy (IMRT) for clinically localized prostate cancer. Materials and Methods: Between 2008 and 2009, 186 patients with prostate cancer were treated with IGRT to a dose of 86.4 Gy with daily correction of the target position based on kilovoltage imaging of implanted prostatic fiducial markers. This group of patients was retrospectively compared with a similar cohort of 190 patients who were treated between 2006 and 2007 with IMRT to the same prescription dose without, however, implanted fiducial markers in place (non-IGRT). The median follow-up time was 2.8 years (range, 2-6 years). Results: A significant reduction in late urinary toxicity was observed for IGRT patients compared with the non-IGRT patients. The 3-year likelihood of grade 2 and higher urinary toxicity for the IGRT and non-IGRT cohorts were 10.4% and 20.0%, respectively (p = 0.02). Multivariate analysis identifying predictors for grade 2 or higher late urinary toxicity demonstrated that, in addition to the baseline Internatinoal Prostate Symptom Score, IGRT was associated with significantly less late urinary toxicity compared with non-IGRT. The incidence of grade 2 and higher rectal toxicity was low for both treatment groups (1.0% and 1.6%, respectively; p = 0.81). No differences in prostate-specific antigen relapse-free survival outcomes were observed for low- and intermediate-risk patients when treated with IGRT and non-IGRT. For high-risk patients, a significant improvement was observed at 3 years for patients treated with IGRT compared with non-IGRT. Conclusions: IGRT is associated with an improvement in biochemical tumor control among high-risk patients and a lower rate of late urinary toxicity compared with high-dose IMRT. These data suggest that, for definitive radiotherapy, the placement of fiducial markers

  6. Imaging Guided Breast Interventions.

    PubMed

    Masroor, Imrana; Afzal, Shaista; Sufian, Saira Naz

    2016-06-01

    Breast imaging is a developing field, with new and upcoming innovations, decreasing the morbidity and mortality related to breast pathologies with main emphasis on breast cancer. Breast imaging has an essential role in the detection and management of breast disease. It includes a multimodality approach, i.e. mammography, ultrasound, magnetic resonance imaging, nuclear medicine techniques and interventional procedures, done for the diagnosis and definitive management of breast abnormalities. The range of methods to perform biopsy of a suspicious breast lesion found on imaging has also increased markedly from the 1990s with hi-technological progress in surgical as well as percutaneous breast biopsy methods. The image guided percutaneous breast biopsy procedures cause minimal breast scarring, save time, and relieve the patient of the anxiety of going to the operation theatre. The aim of this review was to describe and discuss the different image guided breast biopsy techniques presently employed along with the indications, contraindication, merits and demerits of each method. PMID:27353993

  7. Image-guided radiation therapy: Physician's perspectives

    PubMed Central

    Gupta, T.; Narayan, C. Anand

    2012-01-01

    The evolution of radiotherapy has been ontogenetically linked to medical imaging. Over the years, major technological innovations have resulted in substantial improvements in radiotherapy planning, delivery, and verification. The increasing use of computed tomography imaging for target volume delineation coupled with availability of computer-controlled treatment planning and delivery systems have progressively led to conformation of radiation dose to the target tissues while sparing surrounding normal tissues. Recent advances in imaging technology coupled with improved treatment delivery allow near-simultaneous soft-tissue localization of tumor and repositioning of patient. The integration of various imaging modalities within the treatment room for guiding radiation delivery has vastly improved the management of geometric uncertainties in contemporary radiotherapy practice ushering in the paradigm of image-guided radiation therapy (IGRT). Image-guidance should be considered a necessary and natural corollary to high-precision radiotherapy that was long overdue. Image-guided radiation therapy not only provides accurate information on patient and tumor position on a quantitative scale, it also gives an opportunity to verify consistency of planned and actual treatment geometry including adaptation to daily variations resulting in improved dose delivery. The two main concerns with IGRT are resource-intensive nature of delivery and increasing dose from additional imaging. However, increasing the precision and accuracy of radiation delivery through IGRT is likely to reduce toxicity with potential for dose escalation and improved tumor control resulting in favourable therapeutic index. The radiation oncology community needs to leverage this technology to generate high-quality evidence to support widespread adoption of IGRT in contemporary radiotherapy practice. PMID:23293448

  8. Image-guided tissue engineering

    PubMed Central

    Ballyns, Jeffrey J; Bonassar, Lawrence J

    2009-01-01

    Replication of anatomic shape is a significant challenge in developing implants for regenerative medicine. This has lead to significant interest in using medical imaging techniques such as magnetic resonance imaging and computed tomography to design tissue engineered constructs. Implementation of medical imaging and computer aided design in combination with technologies for rapid prototyping of living implants enables the generation of highly reproducible constructs with spatial resolution up to 25 μm. In this paper, we review the medical imaging modalities available and a paradigm for choosing a particular imaging technique. We also present fabrication techniques and methodologies for producing cellular engineered constructs. Finally, we comment on future challenges involved with image guided tissue engineering and efforts to generate engineered constructs ready for implantation. PMID:19583811

  9. High intensity hadron accelerators

    SciTech Connect

    Teng, L.C.

    1989-05-01

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics.

  10. Overview of image-guided radiation therapy

    SciTech Connect

    Xing Lei . E-mail: lei@reyes.stanford.edu; Thorndyke, Brian; Schreibmann, Eduard; Yang Yong; Li, T.-F.; Kim, Gwe-Ya; Luxton, Gary; Koong, Albert

    2006-07-01

    Radiation therapy has gone through a series of revolutions in the last few decades and it is now possible to produce highly conformal radiation dose distribution by using techniques such as intensity-modulated radiation therapy (IMRT). The improved dose conformity and steep dose gradients have necessitated enhanced patient localization and beam targeting techniques for radiotherapy treatments. Components affecting the reproducibility of target position during and between subsequent fractions of radiation therapy include the displacement of internal organs between fractions and internal organ motion within a fraction. Image-guided radiation therapy (IGRT) uses advanced imaging technology to better define the tumor target and is the key to reducing and ultimately eliminating the uncertainties. The purpose of this article is to summarize recent advancements in IGRT and discussed various practical issues related to the implementation of the new imaging techniques available to radiation oncology community. We introduce various new IGRT concepts and approaches, and hope to provide the reader with a comprehensive understanding of the emerging clinical IGRT technologies. Some important research topics will also be addressed.

  11. An EW technology research of jamming IR imaging guided missiles

    NASA Astrophysics Data System (ADS)

    Wu, Xiu-qin; Rong, Hua; Liang, Jing-ping; Chen, Qi; Chen, Min-rong

    2009-07-01

    The IR-Imaging-Guided Weapons have been playing an important role in the modern warfare by means of select attacking the vital parts of targets with the features of highly secret attacking, high precision, and excellent anti-jamming capability ,therefore, they are viewed to be one of the promising precisely guided weapons ,receiving great concern through out the world. This paper discusses the characteristics of IR-Imaging guidance systems at the highlight of making a study of correlated technologies of jamming IR-Imaging-Guided Weapons on the basis of elaborating the operational principles of IR-Imaging-guided Weapons.

  12. Image-guided high-dose-rate brachytherapy: preliminary outcomes and toxicity of a joint interventional radiology and radiation oncology technique for achieving local control in challenging cases

    PubMed Central

    Kishan, Amar U.; Lee, Edward W.; McWilliams, Justin; Lu, David; Genshaft, Scott; Motamedi, Kambiz; Demanes, D. Jeffrey; Park, Sang June; Hagio, Mary Ann; Wang, Pin-Chieh

    2015-01-01

    Purpose To determine the ability of image-guided high-dose-rate brachytherapy (IG-HDR) to provide local control (LC) of lesions in non-traditional locations for patients with heavily pre-treated malignancies. Material and methods This retrospective series included 18 patients treated between 2012 and 2014 with IG-HDR, either in combination with external beam radiotherapy (EBRT; n = 9) or as monotherapy (n = 9). Lesions were located in the pelvis (n = 5), extremity (n = 2), abdomen/retroperitoneum (n = 9), and head/neck (n = 2). All cases were performed in conjunction between interventional radiology and radiation oncology. Toxicity was graded based on CTCAE v4.0 and local failure was determined by RECIST criteria. Kaplan-Meier analysis was performed for LC and overall survival. Results The median follow-up was 11.9 months. Two patients had localized disease at presentation; the remainder had recurrent and/or metastatic disease. Seven patients had prior EBRT, with a median equivalent dose in 2 Gy fractions (EQD2) of 47.0 Gy. The median total EQD2s were 34 Gy and 60.9 Gy for patients treated with monotherapy or combination therapy, respectively. Image-guided high-dose rate brachytherapy was delivered in one to six fractions. Six patients had local failures at a median interval of 5.27 months with a one-year LC rate of 59.3% and a one-year overall survival of 40.7%. Six patients died from their disease at a median interval of 6.85 months from the end of treatment. There were no grade ≥ 3 acute toxicities but two patients had serious long term toxicities. Conclusions We demonstrate a good one year LC rate of nearly 60%, and a favorable toxicity profile when utilizing IG-HDR to deliver high doses of radiation with high precision into targets not readily accessible by other forms of local therapy. These preliminary results suggest that further studies utilizing this approach may be considered for patients with difficult to access lesions that require LC. PMID:26622237

  13. Endovascular image-guided interventions (EIGIs)

    PubMed Central

    Rudin, Stephen; Bednarek, Daniel R.; Hoffmann, Kenneth R.

    2009-01-01

    Minimally invasive interventions are rapidly replacing invasive surgical procedures for the most prevalent human disease conditions. X-ray image-guided interventions carried out using the insertion and navigation of catheters through the vasculature are increasing in number and sophistication. In this article, we offer our vision for the future of this dynamic field of endovascular image-guided interventions in the form of predictions about (1) improvements in high-resolution detectors for more accurate guidance, (2) the implementation of high-resolution region of interest computed tomography for evaluation and planning, (3) the implementation of dose tracking systems to control patient radiation risk, (4) the development of increasingly sophisticated interventional devices, (5) the use of quantitative treatment planning with patient-specific computer fluid dynamic simulations, and (6) the new expanding role of the medical physicist. We discuss how we envision our predictions will come to fruition and result in the universal goal of improved patient care. PMID:18293585

  14. High intensity proton synchrotrons

    NASA Astrophysics Data System (ADS)

    Craddock, M. K.

    1986-10-01

    Strong initiatives are being pursued in a number of countries for the construction of ``kaon factory'' synchrotrons capable of producing 100 times more intense proton beams than those available now from machines such as the Brookhaven AGS and CERN PS. Such machines would yield equivalent increases in the fluxes of secondary particles (kaons, pions, muons, antiprotons, hyperons and neutrinos of all varieties)—or cleaner beams for a smaller increase in flux—opening new avenues to various fundamental questions in both particle and nuclear physics. Major areas of investigation would be rare decay modes, CP violation, meson and hadron spectroscopy, antinucleon interactions, neutrino scattering and oscillations, and hypernuclear properties. Experience with the pion factories has already shown how high beam intensities make it possible to explore the ``precision frontier'' with results complementary to those achievable at the ``energy frontier''. This paper will describe proposals for upgrading and AGS and for building kaon factories in Canada, Europe, Japan and the United States, emphasizing the novel aspects of accelerator design required to achieve the desired performance (typically 100 μA at 30 GeV).

  15. Folic Acid-Targeted and Cell Penetrating Peptide-Mediated Theranostic Nanoplatform for High-Efficiency Tri-Modal Imaging-Guided Synergistic Anticancer Phototherapy.

    PubMed

    Li, Na; Li, Tingting; Liu, Chen; Ye, Shiyi; Liang, Jiangong; Han, Heyou

    2016-05-01

    A novel nanomaterial with precisely-defined size and shape, biocompatible composition, and excellent stability, which can integrate multi modal targeted imaging and therapy into a single system for visualized therapeutics, has recently attracted significant research interest. Here, we developed a multifunctional nanoplatform based on silica-coated 4-mercaptobenzoic acid-modified gold nanorods (Au NRs) decorated with gold nanoclusters rich in the photosensitizer Ce6 (Au-Ce6 NCs). The nanoparticles also comprised folic acid and cell penetrating peptide molecules anchored on the surface, obtaining the Au@SiO2@Au-cell penetrating peptide nanocomposite. The Au-Ce6 NCs enhanced the photophysical stability, provided numerous bonding sites and offered a large surface-area and interior space to achieve a high drug loading efficiency (up to 55%). The anchored folic acid and cell penetrating peptide synergistically enhanced the efficiency of uptake of nanocomposites by HeLa cells (up to 70.7%) and improved therapeutic efficacy. The nanocomposite also has good water-solubility, excellent biocompatibility, and long-term stability against illumination and exposure to pH 3-12, thus facilitating their bioapplications in cancer theranostics. Here, the nanocomposite was established for high-resolution and noninvasive tri-modal surface-enhanced Raman spectrum/dark-field/fluorescence imaging-guided high-efficiency synergistic photodynamic/photothermal therapy of cancer. Our studies demonstrate that the multifunctional nanocomposite has the potential as a novel and sensitive contrast agent for complementary and synergistic theranostics in the clinic. PMID:27305812

  16. Functional Image-Guided Radiotherapy Planning in Respiratory-Gated Intensity-Modulated Radiotherapy for Lung Cancer Patients With Chronic Obstructive Pulmonary Disease

    SciTech Connect

    Kimura, Tomoki; Nishibuchi, Ikuno; Murakami, Yuji; Kenjo, Masahiro; Kaneyasu, Yuko; Nagata, Yasushi

    2012-03-15

    Purpose: To investigate the incorporation of functional lung image-derived low attenuation area (LAA) based on four-dimensional computed tomography (4D-CT) into respiratory-gated intensity-modulated radiotherapy (IMRT) or volumetric modulated arc therapy (VMAT) in treatment planning for lung cancer patients with chronic obstructive pulmonary disease (COPD). Methods and Materials: Eight lung cancer patients with COPD were the subjects of this study. LAA was generated from 4D-CT data sets according to CT values of less than than -860 Hounsfield units (HU) as a threshold. The functional lung image was defined as the area where LAA was excluded from the image of the total lung. Two respiratory-gated radiotherapy plans (70 Gy/35 fractions) were designed and compared in each patient as follows: Plan A was an anatomical IMRT or VMAT plan based on the total lung; Plan F was a functional IMRT or VMAT plan based on the functional lung. Dosimetric parameters (percentage of total lung volume irradiated with {>=}20 Gy [V20], and mean dose of total lung [MLD]) of the two plans were compared. Results: V20 was lower in Plan F than in Plan A (mean 1.5%, p = 0.025 in IMRT, mean 1.6%, p = 0.044 in VMAT) achieved by a reduction in MLD (mean 0.23 Gy, p = 0.083 in IMRT, mean 0.5 Gy, p = 0.042 in VMAT). No differences were noted in target volume coverage and organ-at-risk doses. Conclusions: Functional IGRT planning based on LAA in respiratory-guided IMRT or VMAT appears to be effective in preserving a functional lung in lung cancer patients with COPD.

  17. Prospective Clinical Trial of Positron Emission Tomography/Computed Tomography Image-Guided Intensity-Modulated Radiation Therapy for Cervical Carcinoma With Positive Para-Aortic Lymph Nodes

    SciTech Connect

    Esthappan, Jacqueline Chaudhari, Summer; Santanam, Lakshmi; Mutic, Sasa; Olsen, Jeffrey; MacDonald, Dusten M.; Low, Daniel A.; Singh, Anurag K.; Grigsby, Perry W.

    2008-11-15

    Purpose: To describe a more aggressive treatment technique allowing dose escalation to positive para-aortic lymph nodes (PALN) in patients with cervical cancer, by means of positron emission tomography (PET)/computed tomography (CT)-guided intensity-modulated radiation therapy (IMRT). Here, we describe methods for simulation and planning of these treatments and provide objectives for target coverage as well as normal tissue sparing to guide treatment plan evaluation. Methods and Materials: Patients underwent simulation on a PET/CT scanner. Treatment plans were generated to deliver 60.0 Gy to the PET-positive PALN and 50.0 Gy to the PALN and pelvic lymph node beds. Treatment plans were optimized to deliver at least 95% of the prescribed doses to at least 95% of each target volume. Dose-volume histograms were calculated for normal structures. Results: The plans of 10 patients were reviewed. Target coverage goals were satisfied in all plans. Analysis of dose-volume histograms indicated that treatment plans involved irradiation of approximately 50% of the bowel volume to at least 25.0 Gy, with less than 10% receiving at least 50.0 Gy and less than 1% receiving at least 60.0. With regard to kidney sparing, approximately 50% of the kidney volume received at least 16.0 Gy, less than 5% received at least 50.0 Gy, and less than 1% received at least 60.0 Gy. Conclusions: We have provided treatment simulation and planning methods as well as guidelines for the evaluation of target coverage and normal tissue sparing that should facilitate the more aggressive treatment of cervical cancer.

  18. Single Vocal Cord Irradiation: Image Guided Intensity Modulated Hypofractionated Radiation Therapy for T1a Glottic Cancer: Early Clinical Results

    SciTech Connect

    Al-Mamgani, Abrahim; Kwa, Stefan L.S.; Tans, Lisa; Moring, Michael; Fransen, Dennie; Mehilal, Robert; Verduijn, Gerda M.; Baatenburg de Jong, Rob J.; Heijmen, Ben J.M.; Levendag, Peter C.

    2015-10-01

    Purpose: To report, from a retrospective analysis of prospectively collected data, on the feasibility, outcome, toxicity, and voice-handicap index (VHI) of patients with T1a glottic cancer treated by a novel intensity modulated radiation therapy technique developed at our institution to treat only the involved vocal cord: single vocal cord irradiation (SVCI). Methods and Materials: Thirty patients with T1a glottic cancer were treated by means of SVCI. Dose prescription was set to 16 × 3.63 Gy (total dose 58.08 Gy). The clinical target volume was the entire vocal cord. Setup verification was done by means of an online correction protocol using cone beam computed tomography. Data for voice quality assessment were collected prospectively at baseline, end of treatment, and 4, 6, and 12 weeks and 6, 12, and 18 months after treatment using VHI questionnaires. Results: After a median follow-up of 30 months (range, 7-50 months), the 2-year local control and overall survival rates were 100% and 90% because no single local recurrence was reported and 3 patients died because of comorbidity. All patients have completed the intended treatment schedule; no treatment interruptions and no grade 3 acute toxicity were reported. Grade 2 acute dermatitis or dysphagia was reported in only 5 patients (17%). No serious late toxicity was reported; only 1 patient developed temporary grade 2 laryngeal edema, and responded to a short-course of corticosteroid. The VHI improved significantly, from 33.5 at baseline to 9.5 and 10 at 6 weeks and 18 months, respectively (P<.001). The control group, treated to the whole larynx, had comparable local control rates (92.2% vs 100%, P=.24) but more acute toxicity (66% vs 17%, P<.0001) and higher VHI scores (23.8 and 16.7 at 6 weeks and 18 months, respectively, P<.0001). Conclusion: Single vocal cord irradiation is feasible and resulted in maximal local control rate at 2 years. The deterioration in VHI scores was slight and temporary and

  19. An Image-Guided Study of Setup Reproducibility of Postmastectomy Breast Cancer Patients Treated With Inverse-Planned Intensity Modulated Radiation Therapy

    SciTech Connect

    Feng, Christine H.; Gerry, Emily; Chmura, Steven J.; Hasan, Yasmin; Al-Hallaq, Hania A.

    2015-01-01

    Purpose: To calculate planning target volume (PTV) margins for chest wall and regional nodal targets using daily orthogonal kilovolt (kV) imaging and to study residual setup error after kV alignment using volumetric cone-beam computed tomography (CBCT). Methods and Materials: Twenty-one postmastectomy patients were treated with intensity modulated radiation therapy with 7-mm PTV margins. Population-based PTV margins were calculated from translational shifts after daily kV positioning and/or weekly CBCT data for each of 8 patients, whose surgical clips were used as surrogates for target volumes. Errors from kV and CBCT data were mathematically combined to generate PTV margins for 3 simulated alignment workflows: (1) skin marks alone; (2) weekly kV imaging; and (3) daily kV imaging. Results: The kV data from 613 treatment fractions indicated that a 7-mm uniform margin would account for 95% of daily shifts if patients were positioned using only skin marks. Total setup errors incorporating both kV and CBCT data were larger than those from kV alone, yielding PTV expansions of 7 mm anterior–posterior, 9 mm left–right, and 9 mm superior–inferior. Required PTV margins after weekly kV imaging were similar in magnitude as alignment to skin marks, but rotational adjustments of patients were required in 32% ± 17% of treatments. These rotations would have remained uncorrected without the use of daily kV imaging. Despite the use of daily kV imaging, CBCT data taken at the treatment position indicate that an anisotropic PTV margin of 6 mm anterior–posterior, 4 mm left–right, and 8 mm superior–inferior must be retained to account for residual errors. Conclusions: Cone-beam CT provides additional information on 3-dimensional reproducibility of treatment setup for chest wall targets. Three-dimensional data indicate that a uniform 7-mm PTV margin is insufficient in the absence of daily IGRT. Interfraction movement is greater than suggested by 2-dimensional

  20. Efficacy and safety of image-guided interstitial single fraction high-dose-rate brachytherapy in the management of metastatic malignant melanoma

    PubMed Central

    Bretschneider, Tina; Mohnike, Konrad; Hass, Peter; Seidensticker, Ricarda; Göppner, Daniela; Dudeck, Oliver; Streitparth, Florian

    2015-01-01

    Purpose Computed tomography (CT) or magnetic resonance imaging (MRI) guided brachytherapy provides high tumor control rates in hepatocellular carcinoma (HCC) and colorectal liver metastases. In contrast to thermal ablation methods such as radiofrequency ablation (RFA), much less restrictions apply with respect to tumor location or size. In this study, we determined the efficacy and safety of CT- or MRI-guided brachytherapy in metastatic melanoma. Material and methods Fifty-two metastases of malignant melanoma in 14 patients were included in this retrospective study. Local tumor control and safety were evaluated as primary and secondary endpoints. Furthermore, we evaluated overall survival and progression free survival. Tumor locations were liver (n = 31), lung (n = 15), adrenal (n = 3), lymph nodes (n = 2), and kidney (n = 1). Treatment planning was performed using three-dimensional CT or MRI data acquired after percutaneous applicator positioning under CT or open MRI guidance. Subsequently, single fraction high-dose-rate (HDR) brachytherapy was applied using a 192Iridium source. Clinical and cross-sectional follow-up were performed every 3 months post intervention. Results The median diameter of treated lesions was 1.5 cm (range: 0.7-10 cm). Doses between 15 and 20 Gy were applied (median dose: 19.9 Gy). The mean irradiation time ranged between 7-45 minutes. After treatment, there was one patient with a cholangitis. After a median follow up of five months, the median local tumor control was 90%. The median overall survival of the patients was 8 months. The median progression free survival of the patients was 6 months. Conclusions Image-guided HDR brachytherapy is a safe and effective treatment procedure in metastatic malignant melanoma. PMID:26034497

  1. A Comparison of Two Different High-Volume Image-Guided Injection Procedures for Patients With Chronic Noninsertional Achilles Tendinopathy: A Pragmatic Retrospective Cohort Study.

    PubMed

    Wheeler, Patrick C; Mahadevan, Dev; Bhatt, Raj; Bhatia, Maneesh

    2016-01-01

    We undertook a comparison evaluation of outcomes after 2 different high-volume image-guided injection (HVIGI) procedures performed under direct ultrasound guidance in patients with chronic noninsertional Achilles tendinopathy. In group A, the HVIGI involved high-volume (10 mL of 1% lidocaine combined with 40 mL of saline) and no dry needling. In group B, the HVIGI involved a smaller volume (10 mL of 1% lidocaine combined with 20 mL of saline) and dry needling of the Achilles tendon. A total of 34 patients were identified from the clinical records, with a mean overall age of 50.6 (range 26 to 83) years and an overall mean follow-up duration of 277 (range 49 to 596) days. The change between the preinjection and postinjection Victorian Institute of Sports Assessment-Achilles scores of 33.4 ± 22.5 points in group A and 6.94 ± 22.2 points in group B, was statistically significant (p = .002). In group A, 3 patients (16.7%) required surgical treatment compared with 6 patients (37.5%) in group B requiring surgical treatment (p = .180). Our results indicated that a higher volume without dry needling compared with a lower volume with dry needling resulted in greater improvement in noninsertional Achilles tendinopathy. However, confounding factors mean it is not possible to categorically state that this difference was solely due to different injection techniques. PMID:27286927

  2. High volume image-guided injections and structured rehabilitation improve greater trochanter pain syndrome in the short and medium term: a combined retrospective and prospective case series

    PubMed Central

    Morton, Sarah; Chan, Otto; Price, Jessica; Pritchard, Melanie; Crisp, Tom; Perry, John D.; Morrissey, Dylan

    2015-01-01

    Summary Background the aim of this study was to measure the effects of high volume image-guided injections and structured rehabilitation (HVIGI&SR) for greater trochanter pain syndrome (GTPS). Methods 31 consecutive subjects were recruited (23 retrospectively; 8 prospectively) over 5 months. GTPS was diagnosed based on history and examination findings, alongside radiological examination. The HVI-GI used a 22-gauge spinal needle to administer 10ml of 0.5% Marcaine and 50 mg hydrocortisone just deep to the periosteum underlying the gluteal tendon insertion under ultrasound guidance, followed by structured rehabilitation. A visual analogue scale (VAS) for pain was used as the main outcome measure. Results the mean VAS improved from 81.7 mm (±17.6) to 42.3 mm (±28.3), (p<0.05) in the prospective subjects at a mean of 6 weeks, considered clinically significant. In the retrospective subjects the mean VAS had improved from 74.6 (±10.9) mm to 38.2(±31.2) mm at two weeks (p<0.01) and 31.3 (±27.6) mm at the final time point, a mean of 60 weeks (p<0.01). The Hip and Groin Outcome Score in the prospective group showed a non-significant increase from 173.2 to 296.1 (p=0.12). Conclusion HVIGI&SR should be considered when short- and medium-term pain-relieving treatment for GTPS is required. Controlled studies are warranted to fully establish effectiveness, and assess long term effects. Level of evidence case series. PMID:26261785

  3. Image-guided focal therapy for prostate cancer.

    PubMed

    Sankineni, Sandeep; Wood, Bradford J; Rais-Bahrami, Soroush; Walton Diaz, Annerleim; Hoang, Anthony N; Pinto, Peter A; Choyke, Peter L; Türkbey, Barış

    2014-11-01

    The adoption of routine prostate specific antigen screening has led to the discovery of many small and low-grade prostate cancers which have a low probability of causing mortality. These cancers, however, are often treated with radical therapies resulting in long-term side effects. There has been increasing interest in minimally invasive focal therapies to treat these tumors. While imaging modalities have improved rapidly over the past decade, similar advances in image-guided therapy are now starting to emerge--potentially achieving equivalent oncologic efficacy while avoiding the side effects of conventional radical surgery. The purpose of this article is to review the existing literature regarding the basis of various focal therapy techniques such as cryotherapy, microwave, laser, and high intensity focused ultrasound, and to discuss the results of recent clinical trials that demonstrate early outcomes in patients with prostate cancer. PMID:25205025

  4. Image-guided focal therapy for prostate cancer

    PubMed Central

    Sankineni, Sandeep; Wood, Bradford J.; Rais-Bahrami, Soroush; Diaz, Annerleim Walton; Hoang, Anthony N.; Pinto, Peter A.; Choyke, Peter L.; Türkbey, Barış

    2014-01-01

    The adoption of routine prostate specific antigen screening has led to the discovery of many small and low-grade prostate cancers which have a low probability of causing mortality. These cancers, however, are often treated with radical therapies resulting in long-term side effects. There has been increasing interest in minimally invasive focal therapies to treat these tumors. While imaging modalities have improved rapidly over the past decade, similar advances in image-guided therapy are now starting to emerge—potentially achieving equivalent oncologic efficacy while avoiding the side effects of conventional radical surgery. The purpose of this article is to review the existing literature regarding the basis of various focal therapy techniques such as cryotherapy, microwave, laser, and high intensity focused ultrasound, and to discuss the results of recent clinical trials that demonstrate early outcomes in patients with prostate cancer. PMID:25205025

  5. Encouraging Early Clinical Outcomes With Helical Tomotherapy-Based Image-Guided Intensity-Modulated Radiation Therapy for Residual, Recurrent, and/or Progressive Benign/Low-Grade Intracranial Tumors: A Comprehensive Evaluation

    SciTech Connect

    Gupta, Tejpal

    2012-02-01

    Purpose: To report early clinical outcomes of helical tomotherapy (HT)-based image-guided intensity-modulated radiation therapy (IMRT) in brain tumors of varying shape, size, and location. Materials and Methods: Patients with residual, recurrent, and/or progressive low-grade intracranial and skull-base tumors were treated on a prospective protocol of HT-based IMRT and followed clinicoradiologically. Standardized metrics were used for plan evaluation and outcome analysis. Results: Twenty-seven patients with 30 lesions were treated to a median radiotherapy dose of 54 Gy in 30 fractions. All HT plans resulted in excellent target volume coverage with steep dose-gradients. The mean (standard deviation) dose homogeneity index and conformity index was 0.07 (0.05) and 0.71 (0.08) respectively. At first response assessment, 20 of 30 lesions were stable, whereas 9 showed partial regression. One patient with a recurrent clival chordoma though neurologically stable showed imaging-defined progression, whereas another patient with stable disease on serial imaging had sustained neurologic worsening. With a median follow-up of 19 months (interquartile range, 11-26 months), the 2-year clinicoradiological progression-free survival and overall survival was 93.3% and 100% respectively. Conclusions: Careful selection of radiotherapy technique is warranted for benign/low-grade brain tumors to achieve durable local control with minimum long-term morbidity. Large or complex-shaped tumors benefit most from IMRT. Our early clinical experience of HT-based IMRT for brain tumors has been encouraging.

  6. Online image-guided intensity-modulated radiotherapy for prostate cancer: How much improvement can we expect? A theoretical assessment of clinical benefits and potential dose escalation by improving precision and accuracy of radiation delivery

    SciTech Connect

    Ghilezan, Michel; Yan Di . E-mail: dyan@beaumont.edu; Liang Jian; Jaffray, David; Wong, John; Martinez, Alvaro

    2004-12-01

    Purpose: To quantify the theoretical benefit, in terms of improvement in precision and accuracy of treatment delivery and in dose increase, of using online image-guided intensity-modulated radiotherapy (IG-IMRT) performed with onboard cone-beam computed tomography (CT), in an ideal setting of no intrafraction motion/deformation, in the treatment of prostate cancer. Methods and materials: Twenty-two prostate cancer patients treated with conventional radiotherapy underwent multiple serial CT scans (median 18 scans per patient) during their treatment. We assumed that these data sets were equivalent to image sets obtainable by an onboard cone-beam CT. Each patient treatment was simulated with conventional IMRT and online IG-IMRT separately. The conventional IMRT plan was generated on the basis of pretreatment CT, with a clinical target volume to planning target volume (CTV-to-PTV) margin of 1 cm, and the online IG-IMRT plan was created before each treatment fraction on the basis of the CT scan of the day, without CTV-to-PTV margin. The inverse planning process was similar for both conventional IMRT and online IG-IMRT. Treatment dose for each organ of interest was quantified, including patient daily setup error and internal organ motion/deformation. We used generalized equivalent uniform dose (EUD) to compare the two approaches. The generalized EUD (percentage) of each organ of interest was scaled relative to the prescription dose at treatment isocenter for evaluation and comparison. On the basis of bladder wall and rectal wall EUD, a dose-escalation coefficient was calculated, representing the potential increment of the treatment dose achievable with online IG-IMRT as compared with conventional IMRT. Results: With respect to radiosensitive tumor, the average EUD for the target (prostate plus seminal vesicles) was 96.8% for conventional IMRT and 98.9% for online IG-IMRT, with standard deviations (SDs) of 5.6% and 0.7%, respectively (p < 0.0001). The average EUDs of

  7. First Clinical Release of an Online, Adaptive, Aperture-Based Image-Guided Radiotherapy Strategy in Intensity-Modulated Radiotherapy to Correct for Inter- and Intrafractional Rotations of the Prostate

    SciTech Connect

    Deutschmann, Heinz; Kametriser, Gerhard; Steininger, Philipp; Scherer, Philipp; Schoeller, Helmut; Gaisberger, Christoph; Mooslechner, Michaela; Mitterlechner, Bernhard; Weichenberger, Harald; Fastner, Gert; Wurstbauer, Karl; Jeschke, Stephan; Forstner, Rosemarie; Sedlmayer, Felix

    2012-08-01

    adaptive image-guided, intensity-modulated prostate protocol on a standard linear accelerator to correct 6 degrees of freedom of internal organ motion, allowing safe and straightforward implementation of margin reduction and dose escalation.

  8. High Intensity Lights

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Xenon arc lamps developed during the Apollo program by Streamlight, Inc. are the basis for commercial flashlights and emergency handlights. These are some of the brightest portable lights made. They throw a light some 50 times brighter than automobile high beams and are primarily used by police and military. The light penetrates fog and smoke and returns less back-scatter light. They are operated on portable power packs as boat and auto batteries. An infrared model produces totally invisible light for covert surveillance.

  9. Imaging informatics based on method of MR temperature measurement in high-intensity focused ultrasound

    NASA Astrophysics Data System (ADS)

    Chen, Xiangjiao; Zhang, Jianguo

    2014-03-01

    MR imaging has been used to perform imaging guided high-intensity focused ultrasound (HIFU) and meanwhile can also be used precisely to measure tissue temperature in theory. But in practice, the temperature environment and target are complex. Therefore, it is difficult to measure targeted temperature just by simply using the theory of numerical calculation based on MR image information. In this presentation, we presented new MR temperature measurement, based on imaging informatics, to measure the targeted tissue temperature in MR imaging guided HIFU therapeutic procedure. By heating up the water phantom experiments under HIFU, the new algorithm gives a satisfactory result compared with existing algorithm. Based on experimental data, we can see the accuracy increase 37.5% from 0.4048℃ up to 0.2530℃ when we choose new algorithms.

  10. Photosensitizer-Conjugated Silica-Coated Gold Nanoclusters for Fluorescence Imaging-Guided Photodynamic Therapy

    PubMed Central

    Huang, Peng; Lin, Jing; Wang, Shouju; Zhou, Zhijun; Li, Zhiming; Wang, Zhe; Zhang, Chunlei; Yue, Xuyi; Niu, Gang; Yang, Min; Cui, Daxiang; Chen, Xiaoyuan

    2013-01-01

    Multifunctional theranostics have recently been intensively explored to optimize the efficacy and safety of therapeutic regimens. In this work, a photo-theranostic agent based on chlorin e6 (Ce6) photosensitizer-conjugated silica-coated gold nanoclusters (AuNCs@SiO2-Ce6) is strategically designed and prepared for fluorescence imaging-guided photodynamic therapy (PDT). The AuNCs@SiO2-Ce6 shows the following features: i) high Ce6 photosensitizer loading; ii) no non-specific release of Ce6 during its circulation; iii) significantly enhanced cellular uptake efficiency of Ce6, offering a remarkably improved photodynamic therapeutic efficacy compared to free Ce6; iv) subcellular characterization of the nanoformula via both the fluorescence of Ce6 and plasmon luminescence of AuNCs; v) fluorescence imaging-guided photodynamic therapy (PDT). This photo-theranostics owns good stability, high water dispersibility and solubility, non-cytotoxicity, and good biocompatibility, thus facilitating its biomedical applications, particularly for multi-modal optical, CT and photoacoustic (PA) imaging guided PDT or sonodynamic therapy. PMID:23523428

  11. Dual-modality image guided high intensity focused ultrasound device design for prostate cancer: A numerical study

    NASA Astrophysics Data System (ADS)

    Hobson, Dexter; Curiel, Laura; Chapelon, Jean-Yves; Pichardo, Samuel

    2012-10-01

    In this study the feasibility of designing a multi-element prostate cancer treatment device using Magnetic Resonance Imaging and ultrasound imaging for guidance was determined. A parametric study was performed to determine the optimal focal length (L), operating frequency (f), element size (a) and central hole radius for lodging an imaging probe (r) of a device that would safely treat cancerous tissue within the prostate. Images from the Visible Human Project were used to determine simulated organ sizes and treatment locations. Elliptical tumors were placed throughout the simulated prostate and their lateral and axial limits were selected as test locations. Using Tesla C1060 (NVIDIA, Santa Clara, CA, USA) graphics processors, the Bio-Heat Transfer Equation was implemented to calculate the heating produced during the simulated treatment. L, f a and r were varied from 45 to 75mm, 2.25 to 3.00MHz, 1.5 to 8 times λ and 9 to 11mm, respectively. Results indicated that a device of 761 elements with a combination of L, f a and r of 68mm, 2.75MHz, 2.05λ and 9mm, respectively, could safely ablate tumors within the prostate and spare the surrounding organs.

  12. Hydrogel Spacer Prospective Multicenter Randomized Controlled Pivotal Trial: Dosimetric and Clinical Effects of Perirectal Spacer Application in Men Undergoing Prostate Image Guided Intensity Modulated Radiation Therapy

    SciTech Connect

    Mariados, Neil; Sylvester, John; Shah, Dhiren; Karsh, Lawrence; Hudes, Richard; Beyer, David; Kurtzman, Steven; Bogart, Jeffrey; Hsi, R. Alex; Kos, Michael; Ellis, Rodney; Logsdon, Mark; Zimberg, Shawn; Forsythe, Kevin; Zhang, Hong; Soffen, Edward; Francke, Patrick; Mantz, Constantine; Rossi, Peter; DeWeese, Theodore; and others

    2015-08-01

    Purpose: Perirectal spacing, whereby biomaterials are placed between the prostate and rectum, shows promise in reducing rectal dose during prostate cancer radiation therapy. A prospective multicenter randomized controlled pivotal trial was performed to assess outcomes following absorbable spacer (SpaceOAR system) implantation. Methods and Materials: Overall, 222 patients with clinical stage T1 or T2 prostate cancer underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans for treatment planning, followed with fiducial marker placement, and were randomized to receive spacer injection or no injection (control). Patients received postprocedure CT and MRI planning scans and underwent image guided intensity modulated radiation therapy (79.2 Gy in 1.8-Gy fractions). Spacer safety and impact on rectal irradiation, toxicity, and quality of life were assessed throughout 15 months. Results: Spacer application was rated as “easy” or “very easy” 98.7% of the time, with a 99% hydrogel placement success rate. Perirectal spaces were 12.6 ± 3.9 mm and 1.6 ± 2.0 mm in the spacer and control groups, respectively. There were no device-related adverse events, rectal perforations, serious bleeding, or infections within either group. Pre-to postspacer plans had a significant reduction in mean rectal V70 (12.4% to 3.3%, P<.0001). Overall acute rectal adverse event rates were similar between groups, with fewer spacer patients experiencing rectal pain (P=.02). A significant reduction in late (3-15 months) rectal toxicity severity in the spacer group was observed (P=.04), with a 2.0% and 7.0% late rectal toxicity incidence in the spacer and control groups, respectively. There was no late rectal toxicity greater than grade 1 in the spacer group. At 15 months 11.6% and 21.4% of spacer and control patients, respectively, experienced 10-point declines in bowel quality of life. MRI scans at 12 months verified spacer absorption. Conclusions: Spacer

  13. High Dose-Per-Fraction Irradiation of Limited Lung Volumes Using an Image-Guided, Highly Focused Irradiator: Simulating Stereotactic Body Radiotherapy Regimens in a Small-Animal Model

    SciTech Connect

    Cho, Jaeho; Kodym, Reinhard; Seliounine, Serguei

    2010-07-01

    Purpose: To investigate the underlying biology associated with stereotactic body radiotherapy (SBRT), both in vivo models and image-guided, highly focal irradiation systems are necessary. Here, we describe such an irradiation system and use it to examine normal tissue toxicity in a small-animal model at lung volumes similar to those associated with human therapy. Methods and Materials: High-dose radiation was delivered to a small volume of the left lung of C3H/HeJCr mice using a small-animal stereotactic irradiator. The irradiator has a collimation mechanism to produce focal radiation beams, an imaging subsystem consisting of a fluorescent screen coupled to a charge-coupled device camera, and a manual positioning stage. Histopathologic examination and micro-CT were used to evaluate the radiation response. Results: Focal obliteration of the alveoli by fibrous connective tissue, hyperplasia of the bronchiolar epithelium, and presence of a small number of inflammatory cells are the main reactions to low-volume/high-dose irradiation of the mouse lung. The tissue response suggested a radiation dose threshold for early phase fibrosis lying between 40 and 100 Gy. The irradiation system satisfied our requirements of high-dose-rate, small beam diameter, and precise localization and verification. Conclusions: We have established an experimental model and image-guided animal irradiation system for the study of high dose per fraction irradiations such as those used with SBRT at volumes analogous to those used in human beings. It will also allow the targeting of specific anatomical structures of the thorax or ultimately, orthotopic tumors of the lung.

  14. Harmonic generation at high intensities

    SciTech Connect

    Schafer, K.J.; Krause, J.L.; Kulander, K.C.

    1993-06-01

    Atomic electrons subject to intense laser fields can absorb many photons, leading either to multiphoton ionization or the emission of a single, energetic photon which can be a high multiple of the laser frequency. The latter process, high-order harmonic generation, has been observed experimentally using a range of laser wavelengths and intensities over the past several years. Harmonic generation spectra have a generic form: a steep decline for the low order harmonics, followed by a plateau extending to high harmonic order, and finally an abrupt cutoff beyond which no harmonics are discernible. During the plateau the harmonic production is a very weak function of the process order. Harmonic generation is a promising source of coherent, tunable radiation in the XUV to soft X-ray range which could have a variety of scientific and possibly technological applications. Its conversion from an interesting multiphoton phenomenon to a useful laboratory radiation source requires a complete understanding of both its microscopic and macroscopic aspects. We present some recent results on the response of single atoms at intensities relevant to the short pulse experiments. The calculations employ time-dependent methods, which we briefly review in the next section. Following that we discuss the behavior of the harmonics as a function of laser intensity. Two features are notable: the slow scaling of the harmonic intensities with laser intensity, and the rapid variation in the phase of the individual harmonics with respect to harmonic order. We then give a simple empirical formula that predicts the extent of the plateau for a given ionization potential, wavelength and intensity.

  15. Image-guided endobronchial ultrasound

    NASA Astrophysics Data System (ADS)

    Higgins, William E.; Zang, Xiaonan; Cheirsilp, Ronnarit; Byrnes, Patrick; Kuhlengel, Trevor; Bascom, Rebecca; Toth, Jennifer

    2016-03-01

    Endobronchial ultrasound (EBUS) is now recommended as a standard procedure for in vivo verification of extraluminal diagnostic sites during cancer-staging bronchoscopy. Yet, physicians vary considerably in their skills at using EBUS effectively. Regarding existing bronchoscopy guidance systems, studies have shown their effectiveness in the lung-cancer management process. With such a system, a patient's X-ray computed tomography (CT) scan is used to plan a procedure to regions of interest (ROIs). This plan is then used during follow-on guided bronchoscopy. Recent clinical guidelines for lung cancer, however, also dictate using positron emission tomography (PET) imaging for identifying suspicious ROIs and aiding in the cancer-staging process. While researchers have attempted to use guided bronchoscopy systems in tandem with PET imaging and EBUS, no true EBUS-centric guidance system exists. We now propose a full multimodal image-based methodology for guiding EBUS. The complete methodology involves two components: 1) a procedure planning protocol that gives bronchoscope movements appropriate for live EBUS positioning; and 2) a guidance strategy and associated system graphical user interface (GUI) designed for image-guided EBUS. We present results demonstrating the operation of the system.

  16. The utility of high-resolution intraoperative MRI in endoscopic transsphenoidal surgery for pituitary macroadenomas: early experience in the Advanced Multimodality Image Guided Operating suite

    PubMed Central

    Zaidi, Hasan A.; De Los Reyes, Kenneth; Barkhoudarian, Garni; Litvack, Zachary N.; Bi, Wenya Linda; Rincon-Torroella, Jordina; Mukundan, Srinivasan; Dunn, Ian F.; Laws, Edward R.

    2016-01-01

    Objective Endoscopic skull base surgery has become increasingly popular among the skull base surgery community, with improved illumination and angled visualization potentially improving tumor resection rates. Intraoperative MRI (iMRI) is used to detect residual disease during the course of the resection. This study is an investigation of the utility of 3-T iMRI in combination with transnasal endoscopy with regard to gross-total resection (GTR) of pituitary macroadenomas. Methods The authors retrospectively reviewed all endoscopic transsphenoidal operations performed in the Advanced Multimodality Image Guided Operating (AMIGO) suite from November 2011 to December 2014. Inclusion criteria were patients harboring presumed pituitary macroadenomas with optic nerve or chiasmal compression and visual loss, operated on by a single surgeon. Results Of the 27 patients who underwent transsphenoidal resection in the AMIGO suite, 20 patients met the inclusion criteria. The endoscope alone, without the use of iMRI, would have correctly predicted 13 (65%) of 20 cases. Gross-total resection was achieved in 12 patients (60%) prior to MRI. Intraoperative MRI helped convert 1 STR and 4 NTRs to GTRs, increasing the number of GTRs from 12 (60%) to 16 (80%). Conclusions Despite advances in visualization provided by the endoscope, the incidence of residual disease can potentially place the patient at risk for additional surgery. The authors found that iMRI can be useful in detecting unexpected residual tumor. The cost-effectiveness of this tool is yet to be determined. PMID:26926058

  17. Dynamic targeting image-guided radiotherapy

    SciTech Connect

    Huntzinger, Calvin; Munro, Peter; Johnson, Scott; Miettinen, Mika; Zankowski, Corey; Ahlstrom, Greg; Glettig, Reto; Filliberti, Reto; Kaissl, Wolfgang; Kamber, Martin; Amstutz, Martin; Bouchet, Lionel; Klebanov, Dan; Mostafavi, Hassan; Stark, Richard

    2006-07-01

    Volumetric imaging and planning for 3-dimensional (3D) conformal radiotherapy and intensity-modulated radiotherapy (IMRT) have highlighted the need to the oncology community to better understand the geometric uncertainties inherent in the radiotherapy delivery process, including setup error (interfraction) as well as organ motion during treatment (intrafraction). This has ushered in the development of emerging technologies and clinical processes, collectively referred to as image-guided radiotherapy (IGRT). The goal of IGRT is to provide the tools needed to manage both inter- and intrafraction motion to improve the accuracy of treatment delivery. Like IMRT, IGRT is a process involving all steps in the radiotherapy treatment process, including patient immobilization, computed tomogaphy (CT) simulation, treatment planning, plan verification, patient setup verification and correction, delivery, and quality assurance. The technology and capability of the Dynamic Targeting{sup TM} IGRT system developed by Varian Medical Systems is presented. The core of this system is a Clinac (registered) or Trilogy{sup TM} accelerator equipped with a gantry-mounted imaging system known as the On-Board Imager{sup TM} (OBI). This includes a kilovoltage (kV) x-ray source, an amorphous silicon kV digital image detector, and 2 robotic arms that independently position the kV source and imager orthogonal to the treatment beam. A similar robotic arm positions the PortalVision{sup TM} megavoltage (MV) portal digital image detector, allowing both to be used in concert. The system is designed to support a variety of imaging modalities. The following applications and how they fit in the overall clinical process are described: kV and MV planar radiographic imaging for patient repositioning, kV volumetric cone beam CT imaging for patient repositioning, and kV planar fluoroscopic imaging for gating verification. Achieving image-guided motion management throughout the radiation oncology process

  18. Image-guided navigation: a cost effective practical introduction using the Image-Guided Surgery Toolkit (IGSTK).

    PubMed

    Güler, Özgür; Yaniv, Ziv

    2012-01-01

    Teaching the key technical aspects of image-guided interventions using a hands-on approach is a challenging task. This is primarily due to the high cost and lack of accessibility to imaging and tracking systems. We provide a software and data infrastructure which addresses both challenges. Our infrastructure allows students, patients, and clinicians to develop an understanding of the key technologies by using them, and possibly by developing additional components and integrating them into a simple navigation system which we provide. Our approach requires minimal hardware, LEGO blocks to construct a phantom for which we provide CT scans, and a webcam which when combined with our software provides the functionality of a tracking system. A premise of this approach is that tracking accuracy is sufficient for our purpose. We evaluate the accuracy provided by a consumer grade webcam and show that it is sufficient for educational use. We provide an open source implementation of all the components required for a basic image-guided navigation as part of the Image-Guided Surgery Toolkit (IGSTK). It has long been known that in education there is no substitute for hands-on experience, to quote Sophocles, "One must learn by doing the thing; for though you think you know it, you have no certainty, until you try.". Our work provides this missing capability in the context of image-guided navigation. Enabling a wide audience to learn and experience the use of a navigation system. PMID:23367310

  19. SU-E-J-47: Development of a High-Precision, Image-Guided Radiotherapy, Multi- Purpose Radiation Isocenter Quality-Assurance Calibration and Checking System

    SciTech Connect

    Liu, C; Yan, G; Helmig, R; Lebron, S; Kahler, D

    2014-06-01

    Purpose: To develop a system that can define the radiation isocenter and correlate this information with couch coordinates, laser alignment, optical distance indicator (ODI) settings, optical tracking system (OTS) calibrations, and mechanical isocenter walkout. Methods: Our team developed a multi-adapter, multi-purpose quality assurance (QA) and calibration device that uses an electronic portal imaging device (EPID) and in-house image-processing software to define the radiation isocenter, thereby allowing linear accelerator (Linac) components to be verified and calibrated. Motivated by the concept that each Linac component related to patient setup for image-guided radiotherapy based on cone-beam CT should be calibrated with respect to the radiation isocenter, we designed multiple concentric adapters of various materials and shapes to meet the needs of MV and KV radiation isocenter definition, laser alignment, and OTS calibration. The phantom's ability to accurately define the radiation isocenter was validated on 4 Elekta Linacs using a commercial ball bearing (BB) phantom as a reference. Radiation isocenter walkout and the accuracy of couch coordinates, ODI, and OTS were then quantified with the device. Results: The device was able to define the radiation isocenter within 0.3 mm. Radiation isocenter walkout was within ±1 mm at 4 cardinal angles. By switching adapters, we identified that the accuracy of the couch position digital readout, ODI, OTS, and mechanical isocenter walkout was within sub-mm. Conclusion: This multi-adapter, multi-purpose isocenter phantom can be used to accurately define the radiation isocenter and represents a potential paradigm shift in Linac QA. Moreover, multiple concentric adapters allowed for sub-mm accuracy for the other relevant components. This intuitive and user-friendly design is currently patent pending.

  20. High Intensity Polarized Electron Gun

    SciTech Connect

    Redwine, Robert P.

    2012-07-31

    The goal of the project was to investigate the possibility of building a very high intensity polarized electron gun for the Electron-Ion Collider. This development is crucial for the eRHIC project. The gun implements a large area cathode, ring-shaped laser beam and active cathode cooling. A polarized electron gun chamber with a large area cathode and active cathode cooling has been built and tested. A preparation chamber for cathode activation has been built and initial tests have been performed. Major parts for a load-lock chamber, where cathodes are loaded into the vacuum system, have been manufactured.

  1. Optical clearing of the skin for near-infrared fluorescence image-guided surgery

    NASA Astrophysics Data System (ADS)

    Matsui, Aya; Lomnes, Stephen J.; Frangioni, John V.

    2009-03-01

    Near-infrared (NIR) light penetrates relatively deep into skin, but its usefulness for biomedical imaging is constrained by high scattering of living tissue. Previous studies have suggested that treatment with hyperosmotic ``clearing'' agents might change the optical properties of tissue, resulting in improved photon transport and reduced scatter. Since this would have a profound impact on image-guided surgery, we seek to quantify the magnitude of the optical clearing effect in living subjects. A custom NIR imaging system is used to perform sentinel lymph node mapping and superficial perforator angiography in vivo on 35-kg pigs in the presence or absence of glycerol or polypropylene glycol:polyethylene glycol (PPG:PEG) pretreatment of skin. Ex-vivo, NIR fluorescent standards are placed at a fixed distance beneath sections of excised porcine skin, either preserved in saline or stored dry, then treated or not treated with glycerol. Fluorescence intensity through the skin is quantified and analyzed statistically. Surprisingly, the expected increase in intensity is not measurable either in vivo or ex vivo, unless the skin is previously dried. Histological evaluation shows a morphological difference only in stratum corneum, with this difference being negligible in living tissue. In conclusion, topically applied hyperosmotic agents are ineffective for image-guided surgery of living subjects.

  2. Image-Guided Adrenal and Renal Biopsy

    PubMed Central

    Sharma, Karun V.; Venkatesan, Aradhana M.; Swerdlow, Daniel; DaSilva, Daniel; Beck, Avi; Jain, Nidhi; Wood, Bradford J.

    2010-01-01

    Image-guided biopsy is a safe and well-established technique that is familiar to most interventional radiologists (IRs). Improvements in image-guidance, biopsy tools and biopsy techniques now routinely allow for safe biopsy of renal and adrenal lesions which traditionally were considered difficult to reach or technically challenging. Image-guided biopsy is used to establish the definitive tissue diagnosis in adrenal mass lesions that can not be fully characterized with imaging or laboratory tests alone. It is also used to establish definitive diagnosis in some cases of renal parenchymal disease and has an expanding role in diagnosis and characterization of renal masses prior to treatment. Although basic principles and techniques for image-guided needle biopsy are similar regardless of organ, this paper will highlight some technical considerations, indications and complications which are unique to the adrenal gland and kidney because of their anatomic location and physiologic features. PMID:20540919

  3. Improving Performance During Image-Guided Procedures

    PubMed Central

    Duncan, James R.; Tabriz, David

    2015-01-01

    Objective Image-guided procedures have become a mainstay of modern health care. This article reviews how human operators process imaging data and use it to plan procedures and make intraprocedural decisions. Methods A series of models from human factors research, communication theory, and organizational learning were applied to the human-machine interface that occupies the center stage during image-guided procedures. Results Together, these models suggest several opportunities for improving performance as follows: 1. Performance will depend not only on the operator’s skill but also on the knowledge embedded in the imaging technology, available tools, and existing protocols. 2. Voluntary movements consist of planning and execution phases. Performance subscores should be developed that assess quality and efficiency during each phase. For procedures involving ionizing radiation (fluoroscopy and computed tomography), radiation metrics can be used to assess performance. 3. At a basic level, these procedures consist of advancing a tool to a specific location within a patient and using the tool. Paradigms from mapping and navigation should be applied to image-guided procedures. 4. Recording the content of the imaging system allows one to reconstruct the stimulus/response cycles that occur during image-guided procedures. Conclusions When compared with traditional “open” procedures, the technology used during image-guided procedures places an imaging system and long thin tools between the operator and the patient. Taking a step back and reexamining how information flows through an imaging system and how actions are conveyed through human-machine interfaces suggest that much can be learned from studying system failures. In the same way that flight data recorders revolutionized accident investigations in aviation, much could be learned from recording video data during image-guided procedures. PMID:24921628

  4. A multi-element high intensity focused ultrasound transducer: Design, fabrication, and testing

    NASA Astrophysics Data System (ADS)

    Vaezy, Shahram; Held, Robert; Miller, Blake; Fleury, Gerard

    2001-05-01

    The goal of this project is to develop an intra-cavity image-guided high intensity focused ultrasound (HIFU) device using piezocomposite technology and commercially available ultrasound imaging. The HIFU array, manufactured by Imasonic Corporation, is an 11-element annular phased array, with a focal length range of 30-60 mm, and operating frequency of 3 MHz (bandwidth of 1 MHz). The imaging probe (C9-5, Philips) is configured such that the focal axis of the HIFU beam was within the image plane. The array includes six complete central rings and five side-truncated peripheral rings, all with the natural radius of curvature of 50 mm. Impedance of all elements is approximately 50 ohms (10% accuracy for real and imaginary parts). Cross coupling between adjacent elements is less than, -40 dB. High power measurements showed more than 75% efficiency, at surface intensity of 2.66 W/cm2. Schlieren imaging showed effective focusing at all focal lengths (30-60 mm). The image-guided HIFU device requires water or hydrogel coupling, and possibly water cooling. The results of the full characterization for lesion formation in tissue-mimicking phantoms and biological tissues will be presented. Possible applications include uterine fibroids, abnormal uterine bleeding, and intraoperative hemostasis of occult hemorrhage.

  5. High intensity portable fluorescent light

    NASA Technical Reports Server (NTRS)

    Kendall, F. B.

    1972-01-01

    Eight high intensity portable fluorescent lights were produced. Three prototype lights were also produced, two of which were subsequently updated to the physical and operational configuration of the qualification and flight units. Positioning of lamp apertures and reflectors in these lights is such that the light is concentrated and intensified in a specific pattern rather than widely diffused. Indium amalgam control of mercury vapor pressure in the lamp gives high output at lamp ambient temperatures up to 105 C. A small amount of amalgam applied to each electrode stem helps to obtain fast warm-up. Shrinking a Teflon sleeve on the tube and potting metal caps on each end of the lamp minimizes dispersion of mercury vapor and glass particles in the event of accidental lamp breakage. Operation at 20 kHz allows the lamps to consume more power than at low frequency, thus increasing their light output and raising their efficiency. When used to expose color photographic film, light from the lamps produces results approximately equal to sunlight.

  6. Innovation in image-guided spine intervention.

    PubMed

    Murphy, Kieran J

    2011-04-01

    Image-guided spine intervention continues to evolve and is still an intellectually active field. But it is important not to confuse market and commercial success with intellectual, medical, or long-term success. What drives this evolution and innovation, and where is the activity currently? The history of vertebroplasty is a good case in point. PMID:21500137

  7. Hepatocellular carcinoma: modern image-guided therapies.

    PubMed

    Puppala, Sapna; Patel, Rafiuddin; Yap, Ki Sing; Patel, Jai; Wah, Tze; Snoddon, Andrew

    2016-03-01

    The most common primary malignancy of the liver and the third leading cause of cancer mortality worldwide is hepatocellular carcinoma (HCC), which presents a major global health problem due to its increasing incidence. Most cases of HCC are secondary to either infection (hepatitis B or C) or cirrhosis (alcohol being the most common cause). Clinical presentation is variable and the tumour can be an incidental finding. Treatment options for HCC and prognosis are dependent on many factors but most importantly tumour size and staging. The last two decades have revolutionised the treatment of HCC using image-guided techniques. The concepts of imaging and image-guided techniques are still young and not well described in standard textbooks and hence an up to date review article is essential. The clinical subspecialities may lack familiarity with image-guided techniques but are responsible for management of these patients before and after the treatment by interventional radiologists. This article reviews current image-guided techniques, evidence and outcomes and provides educational highlights and question and answers. The article provides an overview in a simple understandable manner to enable readers from various levels of practice and training to benefit from and apply in their practice. PMID:26787919

  8. High intensity protons in RHIC

    SciTech Connect

    Montag, C.; Ahrens, L.; Blaskiewicz, M.; Brennan, J. M.; Drees, K. A.; Fischer, W.; Huang, H.; Minty, M.; Robert-Demolaize, G.; Thieberger, P.; Yip, K.

    2012-01-05

    During the 2012 summer shutdown a pair of electron lenses will be installed in RHIC, allowing the beam-beam parameter to be increased by roughly 50 percent. To realize the corresponding luminosity increase bunch intensities have to be increased by 50 percent, to 2.5 {center_dot} 10{sup 11} protons per bunch. We list the various RHIC subsystems that are most affected by this increase, and propose beam studies to ensure their readiness. The proton luminosity in RHIC is presently limited by the beam-beam effect. To overcome this limitation, electron lenses will be installed in IR10. With the help of these devices, the headon beam-beam kick experienced during proton-proton collisions will be partially compensated, allowing for a larger beam-beam tuneshift at these collision points, and therefore increasing the luminosity. This will be accomplished by increasing the proton bunch intensity from the presently achieved 1.65 {center_dot} 10{sup 11} protons per bunch in 109 bunches per beam to 2.5 {center_dot} 10{sup 11}, thus roughly doubling the luminosity. In a further upgrade we aim for bunch intensities up to 3 {center_dot} 10{sup 11} protons per bunch. With RHIC originally being designed for a bunch intensity of 1 {center_dot} 10{sup 11} protons per bunch in 56 bunches, this six-fold increase in the total beam intensity by far exceeds the design parameters of the machine, and therefore potentially of its subsystems. In this note, we present a list of major subsystems that are of potential concern regarding this intensity upgrade, show their demonstrated performance at present intensities, and propose measures and beam experiments to study their readiness for the projected future intensities.

  9. Image-guided ablation for hepatocellular carcinoma.

    PubMed

    Lencioni, Riccardo; Crocetti, Laura

    2013-01-01

    Image-guided ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma (HCC) when surgical options-including resection and transplantation-are precluded. The term image-guided tumor ablation is defined as the direct application of chemical substances or sources of energy to a focal tumor in an attempt to achieve eradication or substantial tumor destruction. Over the past 25 years, several methods for local tumor destruction have been developed and clinically tested. Radiofrequency ablation (RFA) has shown superior anticancer effect and greater survival benefit with respect to the seminal percutaneous technique, ethanol injection, in meta-analyses of randomized controlled trials, and is currently established as the standard ablative modality. Nevertheless, novel thermal and nonthermal techniques for tumor ablation-including microwave ablation and irreversible electroporation-seem to have potential to improve the efficacy of RFA and are currently undergoing clinical investigation. PMID:22941021

  10. High-Resolution Optical Imaging of Benign and Malignant Mucosa in the Upper Aerodigestive Tract: An Atlas for Image-Guided Surgery

    PubMed Central

    Levy, Lauren L.; Vila, Peter M.; Park, Richard W.; Schwarz, Richard; Polydorides, Alexandros D.; Teng, Marita S.; Gurudutt, Vivek V.; Genden, Eric M.; Miles, Brett; Anandasabapathy, Sharmila; Gillenwater, Ann M.; Richards-Kortum, Rebecca; Sikora, Andrew G.

    2013-01-01

    Background High-resolution optical imaging provides real-time visualization of mucosa in the upper aerodigestive tract (UADT) which allows non-invasive discrimination of benign and neoplastic epithelium. The high-resolution microendoscope (HRME) utilizes a fiberoptic probe in conjunction with a tissue contrast agent to display nuclei and cellular architecture. This technology has broad potential applications to intraoperative margin detection and early cancer detection. Methods Our group has created an extensive image collection of both neoplastic and normal epithelium of the UADT. Here, we present and describe imaging characteristics of benign, dysplastic, and malignant mucosa in the oral cavity, oropharynx, larynx, and esophagus. Results There are differences in the nuclear organization and overall tissue architecture of benign and malignant mucosa which correlate with histopathologic diagnosis. Different anatomic subsites also display unique imaging characteristics. Conclusion HRME allows discrimination between benign and neoplastic mucosa, and familiarity with the characteristics of each subsite facilitates correct diagnosis. PMID:23641314

  11. Implementation of a high-sensitivity Micro-Angiographic Fluoroscope (HS-MAF) for in-vivo endovascular image guided interventions (EIGI) and region-of-interest computed tomography (ROI-CT)

    PubMed Central

    Ionita, C N; Keleshis, C.; Patel, V.; Yadava, G.; Hoffmann, K R; Bednarek, D R; Jain, A.; Rudin, S

    2008-01-01

    New advances in catheter technology and remote actuation for minimally invasive procedures are continuously increasing the demand for better x-ray imaging technology. The new x-ray high-sensitivity Micro-Angiographic Fluoroscope (HS-MAF) detector offers high resolution and real-time image-guided capabilities which are unique when compared with commercially available detectors. This detector consists of a 300 μm CsI input phosphor coupled to a dual stage GEN2 micro-channel plate light image intensifier (LII), followed by minifying fiber-optic taper coupled to a CCD chip. The HS-MAF detector image array is 1024×1024 pixels, with a 12 bit depth capable of imaging at 30 frames per second. The detector has a round field of view with 4 cm diameter and 35 microns pixels. The LII has a large variable gain which allows usage of the detector at very low exposures characteristic of fluoroscopic ranges while maintaining very good image quality. The custom acquisition program allows real-time image display and data storage. We designed a set of in-vivo experimental interventions in which placement of specially designed endovascular stents were evaluated with the new detector and with a standard x-ray image intensifier (XII). Capabilities such fluoroscopy, angiography and ROI-CT reconstruction using rotational angiography data were implemented and verified. The images obtained during interventions under radiographic control with the HS-MAF detector were superior to those with the XII. In general, the device feature markers, the device structures, and the vessel geometry were better identified with the new detector. High-resolution detectors such as HS-MAF can vastly improve the accuracy of localization and tracking of devices such stents or catheters. PMID:18958294

  12. Implementation of a high-sensitivity micro-angiographic fluoroscope (HS-MAF) for in-vivo endovascular image guided interventions (EIGI) and region-of-interest computed tomography (ROI-CT)

    NASA Astrophysics Data System (ADS)

    Ionita, C. N.; Keleshis, C.; Patel, V.; Yadava, G.; Hoffmann, K. R.; Bednarek, D. R.; Jain, A.; Rudin, S.

    2008-03-01

    New advances in catheter technology and remote actuation for minimally invasive procedures are continuously increasing the demand for better x-ray imaging technology. The new x-ray high-sensitivity Micro-Angiographic Fluoroscope (HS-MAF) detector offers high resolution and real-time image-guided capabilities which are unique when compared with commercially available detectors. This detector consists of a 300 μm CsI input phosphor coupled to a dual stage GEN2 micro-channel plate light image intensifier (LII), followed by minifying fiber-optic taper coupled to a CCD chip. The HS-MAF detector image array is 1024X1024 pixels, with a 12 bit depth capable of imaging at 30 frames per second. The detector has a round field of view with 4 cm diameter and 35 microns pixels. The LII has a large variable gain which allows usage of the detector at very low exposures characteristic of fluoroscopic ranges while maintaining very good image quality. The custom acquisition program allows real-time image display and data storage. We designed a set of in-vivo experimental interventions in which placement of specially designed endovascular stents were evaluated with the new detector and with a standard x-ray image intensifier (XII). Capabilities such fluoroscopy, angiography and ROI-CT reconstruction using rotational angiography data were implemented and verified. The images obtained during interventions under radiographic control with the HS-MAF detector were superior to those with the XII. In general, the device feature markers, the device structures, and the vessel geometry were better identified with the new detector. High-resolution detectors such as HS-MAF can vastly improve the accuracy of localization and tracking of devices such stents or catheters.

  13. High-accuracy 3D image-based registration of endoscopic video to C-arm cone-beam CT for image-guided skull base surgery

    NASA Astrophysics Data System (ADS)

    Mirota, Daniel J.; Uneri, Ali; Schafer, Sebastian; Nithiananthan, Sajendra; Reh, Douglas D.; Gallia, Gary L.; Taylor, Russell H.; Hager, Gregory D.; Siewerdsen, Jeffrey H.

    2011-03-01

    Registration of endoscopic video to preoperative CT facilitates high-precision surgery of the head, neck, and skull-base. Conventional video-CT registration is limited by the accuracy of the tracker and does not use the underlying video or CT image data. A new image-based video registration method has been developed to overcome the limitations of conventional tracker-based registration. This method adds to a navigation system based on intraoperative C-arm cone-beam CT (CBCT), in turn providing high-accuracy registration of video to the surgical scene. The resulting registration enables visualization of the CBCT and planning data within the endoscopic video. The system incorporates a mobile C-arm, integrated with an optical tracking system, video endoscopy, deformable registration of preoperative CT with intraoperative CBCT, and 3D visualization. Similarly to tracker-based approach, the image-based video-CBCT registration the endoscope is localized with optical tracking system followed by a direct 3D image-based registration of the video to the CBCT. In this way, the system achieves video-CBCT registration that is both fast and accurate. Application in skull-base surgery demonstrates overlay of critical structures (e.g., carotid arteries) and surgical targets with sub-mm accuracy. Phantom and cadaver experiments show consistent improvement of target registration error (TRE) in video overlay over conventional tracker-based registration-e.g., 0.92mm versus 1.82mm for image-based and tracker-based registration, respectively. The proposed method represents a two-fold advance-first, through registration of video to up-to-date intraoperative CBCT, and second, through direct 3D image-based video-CBCT registration, which together provide more confident visualization of target and normal tissues within up-to-date images.

  14. Compact instrument for fluorescence image-guided surgery

    NASA Astrophysics Data System (ADS)

    Wang, Xinghua; Bhaumik, Srabani; Li, Qing; Staudinger, V. Paul; Yazdanfar, Siavash

    2010-03-01

    Fluorescence image-guided surgery (FIGS) is an emerging technique in oncology, neurology, and cardiology. To adapt intraoperative imaging for various surgical applications, increasingly flexible and compact FIGS instruments are necessary. We present a compact, portable FIGS system and demonstrate its use in cardiovascular mapping in a preclinical model of myocardial ischemia. Our system uses fiber optic delivery of laser diode excitation, custom optics with high collection efficiency, and compact consumer-grade cameras as a low-cost and compact alternative to open surgical FIGS systems. Dramatic size and weight reduction increases flexibility and access, and allows for handheld use or unobtrusive positioning over the surgical field.

  15. [Image-guided stereotaxic biopsy of central nervous system lesions].

    PubMed

    Nasser, J A; Confort, C I; Ferraz, A; Esperança, J C; Duarte, F

    1998-06-01

    In a series of 44 image guided stereotactic biopsy from August 1995 until March 1997, findings were as follows (frequency order). Tumors, glioblastoma was the most frequent. Primary lymphoma and other conditions associated to AIDS. Metastasis, three cases, Vasculites, two cases, Arachnoid cyst, Creutzfeldt-Jakob, cortical degeneration, inespecific calcification (one case each). The age varied from 1 to 83 years. Forty one lesions were supratentorial, two infratentorial, and one was outside the brain (dura and skull) and we used stereotaxy to localize it. There was no mortality and morbidity was 2.3%. The literature is reviewed. We conclude that this procedure is safe and highly diagnostic. PMID:9698729

  16. Image-Guided Thromboembolectomy of Acute Arterial Occlusion in Children.

    PubMed

    Kim, Song-Yi; Han, Ahram; Choi, Chanjoong; Min, Sang-Il; Kim, Hyo-Cheol; Ha, Jongwon; Min, Seung-Kee

    2016-07-01

    Acute arterial thromboembolism (ATE) is rare in childhood, but this medical emergency requires immediate treatment. Described herein are separate instances of lower extremity ATE in 2 children, both of whom were successfully managed through image-guided thromboembolectomy (IGT). One patient, a 34-month-old female child with nephrotic syndrome, developed bilateral iliac and popliteal thromboembolic arterial occlusions after high-dose steroid therapy. Another 9-year-old girl suffered an embolism of left popliteal artery due to infectious endocarditis. Both patients underwent IGT using over-the-wire Fogarty catheters. During follow-up, presenting symptoms resolved without significant complications. PMID:27177711

  17. Comparison of Axxent-Xoft, 192Ir and 60Co high-dose-rate brachytherapy sources for image-guided brachytherapy treatment planning for cervical cancer

    PubMed Central

    Packianathan, S; He, R; Yang, C C

    2015-01-01

    Objective: To evaluate the dosimetric differences and similarities between treatment plans generated with Axxent-Xoft electronic brachytherapy source (Xoft-EBS), 192Ir and 60Co for tandem and ovoids (T&O) applicators. Methods: In this retrospective study, we replanned 10 patients previously treated with 192Ir high-dose-rate brachytherapy. Prescription was 7 Gy × 4 fractions to Point A. For each original plan, we created two additional plans with Xoft-EBS and 60Co. The dose to each organ at risk (OAR) was evaluated in terms of V35% and V50%, the percentage volume receiving 35% and 50% of the prescription dose, respectively, and D2cc, highest dose to a 2 cm3 volume of an OAR. Results: There was no difference between plans generated by 192Ir and 60Co, but the plans generated using Xoft-EBS showed a reduction of up to 50% in V35%, V50% and D2cc. The volumes of the 200% and 150% isodose lines, however, were 74% and 34% greater than the comparable volumes generated with the 192Ir source. Point B dose was on average only 16% of the Point A dose for plans generated with Xoft-EBS compared with 30% for plans generated with 192Ir or 60Co. Conclusion: The Xoft-EBS can potentially replace either 192Ir or 60Co in T&O treatments. Xoft-EBS offers either better sparing of the OARs compared with 192Ir or 60Co or at least similar sparing. Xoft-EBS-generated plans had higher doses within the target volume than 192Ir- or 60Co-generated ones. Advances in knowledge: This work presents newer knowledge in dosimetric comparison between Xoft-EBS, 192Ir or 60Co sources for T&O implants. PMID:25996576

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

    SciTech Connect

    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.

    2011-09-01

    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. Image-guided transorbital procedures with endoscopic video augmentation

    PubMed Central

    DeLisi, Michael P.; Mawn, Louise A.; Galloway, Robert L.

    2014-01-01

    Purpose: Surgical interventions to the orbital space behind the eyeball are limited to highly invasive procedures due to the confined nature of the region along with the presence of several intricate soft tissue structures. A minimally invasive approach to orbital surgery would enable several therapeutic options, particularly new treatment protocols for optic neuropathies such as glaucoma. The authors have developed an image-guided system for the purpose of navigating a thin flexible endoscope to a specified target region behind the eyeball. Navigation within the orbit is particularly challenging despite its small volume, as the presence of fat tissue occludes the endoscopic visual field while the surgeon must constantly be aware of optic nerve position. This research investigates the impact of endoscopic video augmentation to targeted image-guided navigation in a series of anthropomorphic phantom experiments. Methods: A group of 16 surgeons performed a target identification task within the orbits of four skull phantoms. The task consisted of identifying the correct target, indicated by the augmented video and the preoperative imaging frames, out of four possibilities. For each skull, one orbital intervention was performed with video augmentation, while the other was done with the standard image guidance technique, in random order. Results: The authors measured a target identification accuracy of 95.3% and 85.9% for the augmented and standard cases, respectively, with statistically significant improvement in procedure time (Z = −2.044, p = 0.041) and intraoperator mean procedure time (Z = 2.456, p = 0.014) when augmentation was used. Conclusions: Improvements in both target identification accuracy and interventional procedure time suggest that endoscopic video augmentation provides valuable additional orientation and trajectory information in an image-guided procedure. Utilization of video augmentation in transorbital interventions could further minimize

  20. Image-guided inversion of electrical resistivity data

    NASA Astrophysics Data System (ADS)

    Zhou, J.; Revil, A.; Karaoulis, M.; Hale, D.; Doetsch, J.; Cuttler, S.

    2014-04-01

    Electrical resistivity tomography (ERT) is based on solving a Poisson equation for the electrical potential and is characterized by a good sensitivity only in the vicinity of the electrodes used to gather the data. To provide more information to ERT, we propose an image-guided or structure-constrained inversion of the apparent resistivity data. This approach uses structural information obtained directly from a guiding image. This guiding image can be drawn from a high resolution geophysical method based on the propagation equation (e.g. migrated seismic or ground penetrating radar images) or possibly from a geological cross-section of the subsurface based on some prior geological expertise. The locations and orientations of the structural features can be extracted by image processing methods to determine the structure tensor and the semblances of the guiding image at a set of pixel. Then, we introduce these structural constraints into the inversion of the apparent resistivity data by weighting the four-direction smoothing matrix to smooth along, but not across, structural features. This approach allows preserving both discontinuities and coherences in the inversion of the resistivity data. The image-guided inversion is also combined with an image-guided interpolation approach used to focus a smooth resistivity image. This yields structurally-appealing resistivity tomograms, while the whole process remains computationally efficient. Such a procedure generates a more realistic resistivity distribution (closer to the true ones), which can be, in turn, used quantitatively using appropriate petrophysical transforms, to obtain parameters of interest such as porosity and saturation. We check the validity of this approach using two synthetic case studies as well as two real datasets. For the field data, the image used to guide the inversion of the electrical resistivity data is a GPR section in the first case and a combination of seismic and structural information in the

  1. Image-guided positioning and tracking.

    PubMed

    Ruan, Dan; Kupelian, Patrick; Low, Daniel A

    2011-01-01

    Radiation therapy aims at maximizing tumor control while minimizing normal tissue complication. The introduction of stereotactic treatment explores the volume effect and achieves dose escalation to tumor target with small margins. The use of ablative irradiation dose and sharp dose gradients requires accurate tumor definition and alignment between patient and treatment geometry. Patient geometry variation during treatment may significantly compromise the conformality of delivered dose and must be managed properly. Setup error and interfraction/intrafraction motion are incorporated in the target definition process by expanding the clinical target volume to planning target volume, whereas the alignment between patient and treatment geometry is obtained with an adaptive control process, by taking immediate actions in response to closely monitored patient geometry. This article focuses on the monitoring and adaptive response aspect of the problem. The term "image" in "image guidance" will be used in a most general sense, to be inclusive of some important point-based monitoring systems that can be considered as degenerate cases of imaging. Image-guided motion adaptive control, as a comprehensive system, involves a hierarchy of decisions, each of which balances simplicity versus flexibility and accuracy versus robustness. Patient specifics and machine specifics at the treatment facility also need to be incorporated into the decision-making process. Identifying operation bottlenecks from a system perspective and making informed compromises are crucial in the proper selection of image-guidance modality, the motion management mechanism, and the respective operation modes. Not intended as an exhaustive exposition, this article focuses on discussing the major issues and development principles for image-guided motion management systems. We hope these information and methodologies will facilitate conscientious practitioners to adopt image-guided motion management systems

  2. Stereofluoroscopic image-guided robotic biopsy system

    NASA Astrophysics Data System (ADS)

    Shi, Minyan; Liu, Hong; Tao, Gang; Fajardo, Laurie L.

    1999-07-01

    This paper presents the key techniques of a stereo- fluoroscopic image-guided robotic biopsy system: 3D position reconstruction, 3D path planning, path registration and robot trajectory control with safety considerations. This system automatically adjusts the needle inserting path according to a real-time 3D position error feedback. This system is particularly applicable to the soft tissue and organ biopsy, with advantages of increased accuracy, short completion time and minimum invasiveness to the patient. Simulation shows the safety and accuracy of this robotic biopsy system.

  3. Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation of liver tumours

    PubMed Central

    Bartels, L.W.; Deckers, R.; Ries, M.; Mali, W.P.Th.M.; Moonen, C.T.W.; van den Bosch, M.A.A.J.

    2012-01-01

    Abstract Recent decades have seen a paradigm shift in the treatment of liver tumours from invasive surgical procedures to minimally invasive image-guided ablation techniques. Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a novel, completely non-invasive ablation technique that has the potential to change the field of liver tumour ablation. The image guidance, using MR imaging and MR temperature mapping, provides excellent planning images and real-time temperature information during the ablation procedure. However, before clinical implementation of MR-HIFU for liver tumour ablation is feasible, several organ-specific challenges have to be addressed. In this review we discuss the MR-HIFU ablation technique, the liver-specific challenges for MR-HIFU tumour ablation, and the proposed solutions for clinical translation. PMID:23022541

  4. High Intensity Polarized Electron Sources

    NASA Astrophysics Data System (ADS)

    Poelker, M.; Adderley, P.; Brittian, J.; Clark, J.; Grames, J.; Hansknecht, J.; McCarter, J.; Stutzman, M. L.; Suleiman, R.; Surles-Law, K.

    2008-02-01

    During the 1990s, at numerous facilities world wide, extensive R&D devoted to constructing reliable GaAs photoguns helped ensure successful accelerator-based nuclear and high-energy physics programs using spin polarized electron beams. Today, polarized electron source technology is considered mature, with most GaAs photoguns meeting accelerator and experiment beam specifications in a relatively trouble-free manner. Proposals for new collider facilities however, require electron beams with parameters beyond today's state-of-the-art and serve to renew interest in conducting polarized electron source R&D. And at CEBAF/Jefferson Lab, there is an immediate pressing need to prepare for new experiments that require considerably more beam current than before. One experiment in particular—Q-weak, a parity violation experiment that will look for physics beyond the Standard Model—requires 180 uA average current at polarization >80% for a duration of one year, with run-averaged helicity correlated current asymmetry less than 0.1 ppm. Neighboring halls will continue taking beam during Q-weak, pushing the total average beam current from the gun beyond 300 uA. This workshop contribution describes R&D at Jefferson Lab, dedicated toward extending the operating current of polarized electron sources to meet the requirements of high current experiments at CEBAF and to better appreciate the technological challenges of new accelerators, particularly high average current machines like eRHIC that require at least 25 mA at high polarization.

  5. High-Intensity Proton Accelerator

    SciTech Connect

    Jay L. Hirshfield

    2011-12-27

    Analysis is presented for an eight-cavity proton cyclotron accelerator that could have advantages as compared with other accelerators because of its potentially high acceleration gradient. The high gradient is possible since protons orbit in a sequence of TE111 rotating mode cavities of equally diminishing frequencies with path lengths during acceleration that greatly exceed the cavity lengths. As the cavities operate at sequential harmonics of a basic repetition frequency, phase synchronism can be maintained over a relatively wide injection phase window without undue beam emittance growth. It is shown that use of radial vanes can allow cavity designs with significantly smaller radii, as compared with simple cylindrical cavities. Preliminary beam transport studies show that acceptable extraction and focusing of a proton beam after cyclic motion in this accelerator should be possible. Progress is also reported on design and tests of a four-cavity electron counterpart accelerator for experiments to study effects on beam quality arising from variations injection phase window width. This device is powered by four 500-MW pulsed amplifiers at 1500, 1800, 2100, and 2400 MHz that provide phase synchronous outputs, since they are driven from a with harmonics derived from a phase-locked 300 MHz source.

  6. Miniature image guided three-axis scanning and positioning system

    NASA Astrophysics Data System (ADS)

    Avirovik, Dragan; Dave, Digant; Priya, Shashank

    2012-04-01

    We have developed a high precision three axes scanning and positioning system for integration with Multifunctional Image Guided Surgical (MIGS) Platform. The stage integrates three main components: an optical coherence tomography (OCT) probe, laser scalpel and suction cup. The requirements for this stage were to provide scanning area of 400mm2, resolution of less than 10 microns and scanning velocity in the range of 10 - 40 mm/s. The stage was modeled using computer aided design software NX Unigraphics. In addition to the parameters mentioned above, additional boundary conditions for the stage were set as low volume and modularity. Optimized stage model was fabricated by using rapid prototyping technique that integrates low cost stepper motors, threaded rod drive train and a stepper motor controller. The EZ4axis stepper motor controller was able to provide 1/8th microstep resolution control over the motors, which met the criterion desired for the MIGS platform. Integration of computer controlled three-axis stage with MIGS platform provides the opportunity for conducting intricate surgical procedures using remote control or joystick. The device is image guided using the OCT probe and it is able to pin point any location requiring a laser scalpel incision. Due to the scanning capabilities, a high quality threedimensional image of the tissue topography is obtained which allows the surgeon to make a confident decision of where to apply the laser scalpel and make an incision.

  7. TU-D-BRD-01: Image Guided SBRT II: Challenges ' Pitfalls

    SciTech Connect

    Chang, Z; Yin, F; Cho, J

    2014-06-15

    Stereotactic body radiation therapy (SBRT) has been effective treatment for the management of various diseases, which often delivers high radiation dose in a single or a few fractions. SBRT therefore demands precise treatment delivery to the tumor while sparing adjacent healthy tissue. Recent developments in image guidance enable target localization with increased accuracy. With such improvements in localization, image-guided SBRT has been widely adopted into clinical practice. In SBRT, high radiation dose is generally delivered with small fields. Therefore, it is crucial to accurately measure dosimetric data for the small fields during commissioning. In addition, image-guided SBRT demands accurate image localization to ensure safety and quality of patient care. Lately, the reports of AAPM TG 142 and TG 104 have been published and added recommendations for imaging devices that are integrated with the linear accelerator for SBRT. Furthermore, various challenges and potential pitfalls lie in the clinical implementation of image-guided SBRT. In this lecture, these challenges and pitfalls of image-guided SBRT will be illustrated and discussed from dosimetric, technical and clinical perspectives.Being a promising technique, image-guided SBRT has shown great potentials, and will lead to more accurate and safer SBRT treatments. Learning Objectives: To understand dosimetric challenges and pitfalls for IGRT application in SBRT. To understand major clinical challenges and pitfalls for IGRT application in SBRT. To understand major technical challenges and pitfalls for IGRT application in SBRT.

  8. Hazards from High Intensity Lamps and Arcs

    NASA Technical Reports Server (NTRS)

    Sliney, D. H.

    1970-01-01

    The principal occupational health problem generally associated with high intensity arc lamps results from exposure of the eye and skin to ultraviolet radiation. Occasionally, the chorioretinal burns are of concern. The eye is generally more susceptible than the skin to injury from high intensity optical radiation sources whether ultraviolet, visible or infrared. Recent developments in technology have shown that some high intensity optical radiation sources which have output parameters greatly different from those encountered in the natural environment present a serious chorioretinal burn hazard.

  9. Technology and human errors in image-guided surgeries

    NASA Astrophysics Data System (ADS)

    Jiang, Zhaowei; Miao, Song; Zamorano, Lucia J.; Li, Qinghang; Gong, JianXing; Diaz, Fernando

    1998-06-01

    Using image guidance for stereotactic surgery has been widely adopted in neurosurgery, orthopedic surgery and other surgery operations. Careful, precise and robust implementation of image-guidance can offer surgeon accurate intra-operative information that traditional techniques can not reach. Weak design, careless utilization, and dilemma in quality assurance protocol may result in severe scenarios. It is because that introducing image guidance into the operating room involves high precise technologies, delicate instruments and sophisticated processes. These can offer precision as well as space for human errors. A method based on the 'failure modes and effects analysis' is introduced to systematically study human errors in the image-guided surgery field. The paper presented the fundamental steps and architectures of the method. For better understanding of the method, a simple example is also provided. Analyzing human errors with the 'failure mode and effects analysis' benefits the development life cycle of the image-guided surgery system. It also helps for designing the clinical quality assurance process and the training courses for surgeons.

  10. Image Guided Endoscopic Evacuation of Spontaneous Intracerebral Hemorrhage

    PubMed Central

    Miller, Chad M; Vespa, Paul; Saver, Jeffrey L; Kidwell, Chelsea S; Carmichael, Stanley T.; Alger, Jeffry; Frazee, John; Starkman, Sid; Liebeskind, David; Nenov, Valeriy; Elashoff, Robert; Martin, Neil

    2014-01-01

    Background Spontaneous intracerebral hemorrhage (ICH) is a devastating disease with high morbidity and mortality. ICH lacks an effective medical or surgical treatment despite the acknowledged pathophysiological benefits of achieved hemostasis and clot removal. Image guided stereotactic endoscopic hematoma evacuation is a promising minimally invasive approach designed to limit operative injury and maximize hematoma removal. Methods A single center randomized controlled trial was designed to assess the safety and efficacy of stereotactic hematoma evacuation compared to best medical management. Patients were randomized within 24 hours of hemorrhage in a 3:2 fashion to best medical management plus endoscopic hematoma evacuation or best medical management alone. Data was collected to assess efficacy and safety of hematoma evacuation and to identify procedural components requiring technical improvement. Results 10 patients have been enrolled and randomized to treatment. Six patients underwent endoscopic evacuation with a hematoma volume reduction of 80% +/−13 at 24 hours post procedure. The medical arm demonstrated a hematoma enlargement of 78% +/−142 during this same period. Rehemorrhage rates and deterioration rates were similar in the two groups. Mortality was 20% in the endoscopic group and 50% in the medical treatment cohort. The endoscopic technique was shown to be effective in identification and evacuation of hematomas while reduction in the number of endoscopic passes and maintenance of hemostasis require further study. Conclusion Image guided stereotactic endoscopic hematoma removal is a promising minimally invasive technique that is effective in immediate hematoma evacuation. This technique deserves further investigation to determine its role in ICH management. PMID:18424298

  11. An image guided small animal stereotactic radiotherapy system.

    PubMed

    Sha, Hao; Udayakumar, Thirupandiyur S; Johnson, Perry B; Dogan, Nesrin; Pollack, Alan; Yang, Yidong

    2016-04-01

    Small animal radiotherapy studies should be performed preferably on irradiators capable of focal tumor irradiation and healthy tissue sparing. In this study, an image guided small animal arc radiation treatment system (iSMAART) was developed which can achieve highly precise radiation targeting through the utilization of onboard cone beam computed tomography (CBCT) guidance. The iSMAART employs a unique imaging and radiation geometry where animals are positioned upright. It consists of a stationary x-ray tube, a stationary flat panel detector, and a rotatable and translational animal stage. System performance was evaluated in regards to imaging, image guidance, animal positioning, and radiation targeting using phantoms and tumor bearing animals. The onboard CBCT achieved good signal, contrast, and sub-millimeter spatial resolution. The iodine contrast CBCT accurately delineated orthotopic prostate tumors. Animal positioning was evaluated with ~0.3 mm vertical displacement along superior-inferior direction. The overall targeting precision was within 0.4 mm. Stereotactic radiation beams conformal to tumor targets can be precisely delivered from multiple angles surrounding the animal. The iSMAART allows radiobiology labs to utilize an image guided precision radiation technique that can focally irradiate tumors while sparing healthy tissues at an affordable cost. PMID:26958942

  12. An image guided small animal stereotactic radiotherapy system

    PubMed Central

    Sha, Hao; Udayakumar, Thirupandiyur S.; Johnson, Perry B.; Dogan, Nesrin; Pollack, Alan; Yang, Yidong

    2016-01-01

    Small animal radiotherapy studies should be performed preferably on irradiators capable of focal tumor irradiation and healthy tissue sparing. In this study, an image guided small animal arc radiation treatment system (iSMAART) was developed which can achieve highly precise radiation targeting through the utilization of onboard cone beam computed tomography (CBCT) guidance. The iSMAART employs a unique imaging and radiation geometry where animals are positioned upright. It consists of a stationary x-ray tube, a stationary flat panel detector, and a rotatable and translational animal stage. System performance was evaluated in regards to imaging, image guidance, animal positioning, and radiation targeting using phantoms and tumor bearing animals. The onboard CBCT achieved good signal, contrast, and sub-millimeter spatial resolution. The iodine contrast CBCT accurately delineated orthotopic prostate tumors. Animal positioning was evaluated with ∼0.3 mm vertical displacement along superior-inferior direction. The overall targeting precision was within 0.4 mm. Stereotactic radiation beams conformal to tumor targets can be precisely delivered from multiple angles surrounding the animal. The iSMAART allows radiobiology labs to utilize an image guided precision radiation technique that can focally irradiate tumors while sparing healthy tissues at an affordable cost. PMID:26958942

  13. Designing Tracking Software for Image-Guided Surgery Applications: IGSTK Experience

    PubMed Central

    Enquobahrie, Andinet; Gobbi, David; Turek, Matt; Cheng, Patrick; Yaniv, Ziv; Lindseth, Frank; Cleary, Kevin

    2009-01-01

    Objective Many image-guided surgery applications require tracking devices as part of their core functionality. The Image-Guided Surgery Toolkit (IGSTK) was designed and developed to interface tracking devices with software applications incorporating medical images. Methods IGSTK was designed as an open source C++ library that provides the basic components needed for fast prototyping and development of image-guided surgery applications. This library follows a component-based architecture with several components designed for specific sets of image-guided surgery functions. At the core of the toolkit is the tracker component that handles communication between a control computer and navigation device to gather pose measurements of surgical instruments present in the surgical scene. The representations of the tracked instruments are superimposed on anatomical images to provide visual feedback to the clinician during surgical procedures. Results The initial version of the IGSTK toolkit has been released in the public domain and several trackers are supported. The toolkit and related information are available at www.igstk.org. Conclusion With the increased popularity of minimally invasive procedures in health care, several tracking devices have been developed for medical applications. Designing and implementing high-quality and safe software to handle these different types of trackers in a common framework is a challenging task. It requires establishing key software design principles that emphasize abstraction, extensibility, reusability, fault-tolerance, and portability. IGSTK is an open source library that satisfies these needs for the image-guided surgery community. PMID:20037671

  14. High Intensity Radiated Fields (HIRF) project plan

    NASA Astrophysics Data System (ADS)

    Glynn, Michael S.; Blair, Jerry T.; Hintze, M. Marx

    1991-09-01

    Addressed here is the Federal Aviation Administration's approach to High Intensity Radiated Fields (HIRF) affecting the aviation community. Near- and far-term tasks are described. Deliverables, program management, scheduling, and cost issues are discussed.

  15. Protocol for a phase III randomised trial of image-guided intensity modulated radiotherapy (IG-IMRT) and conventional radiotherapy for late small bowel toxicity reduction after postoperative adjuvant radiation in Ca cervix

    PubMed Central

    Chopra, Supriya; Engineer, Reena; Mahantshetty, Umesh; Misra, Shagun; Phurailatpam, Reena; Paul, Siji N; Kannan, Sadhna; Kerkar, Rajendra; Maheshwari, Amita; Shylasree, TS; Ghosh, Jaya; Gupta, Sudeep; Thomas, Biji; Singh, Shalini; Sharma, Sanjiv; Chilikuri, Srinivas; Shrivastava, Shyam Kishore

    2012-01-01

    Introduction External beam radiation followed by vaginal brachytherapy (±chemotherapy) leads to reduction in the risk of local recurrence and improves progression-free survival in patients with adverse risk factors following Wertheim's hysterectomy albeit at the risk of late bowel toxicity. Intensity Modulated Radiotherapy (IMRT) results in reduction in bowel doses and has potential to reduce late morbidity, however, needs to be confirmed prospectively in a randomised trial. The present randomised trial tests reduction if any in late small bowel toxicity with the use of IMRT in postoperative setting. Methods and analysis Patients more than 18 years of age who need adjuvant (chemo) radiation will be eligible. Patients with residual pelvic or para-aortic nodal disease, history of multiple abdominal surgeries or any other medical bowel condition will be excluded. The trial will randomise patients into standard radiation or IMRT. The primary aim is to compare differences in late grades II–IV bowel toxicity between the two arms. The secondary aims of the study focus on evaluating correlation of dose–volume parameters and late toxicity and quality of life. The trial is planned as a multicentre randomised study. The trial is designed to detect a 13% difference in late grades II–IV bowel toxicity with an α of 0.05 and β of 0.80. A total of 240 patients will be required to demonstrate the aforesaid difference. Ethics and dissemination The trial is approved by institutional ethics review board and will be routinely monitored as per standard guidelines. The study results will be disseminated via peer reviewed scientific journals, conference presentations and submission to regulatory authorities. Registration The trial is registered with clinicaltrials.gov (NCT 01279135). PMID:23242243

  16. Image-Guided Spinal Ablation: A Review.

    PubMed

    Tsoumakidou, Georgia; Koch, Guillaume; Caudrelier, Jean; Garnon, Julien; Cazzato, Roberto Luigi; Edalat, Faramarz; Gangi, Afshin

    2016-09-01

    The image-guided thermal ablation procedures can be used to treat a variety of benign and malignant spinal tumours. Small size osteoid osteoma can be treated with laser or radiofrequency. Larger tumours (osteoblastoma, aneurysmal bone cyst and metastasis) can be addressed with radiofrequency or cryoablation. Results on the literature of spinal microwave ablation are scarce, and thus it should be used with caution. A distinct advantage of cryoablation is the ability to monitor the ice-ball by intermittent CT or MRI. The different thermal insulation, temperature and electrophysiological monitoring techniques should be applied. Cautious pre-procedural planning and intermittent intra-procedural monitoring of the ablation zone can help reduce neural complications. Tumour histology, patient clinical-functional status and life-expectancy should define the most efficient and least disabling treatment option. PMID:27329231

  17. Protein-based photothermal theranostics for imaging-guided cancer therapy

    NASA Astrophysics Data System (ADS)

    Rong, Pengfei; Huang, Peng; Liu, Zhiguo; Lin, Jing; Jin, Albert; Ma, Ying; Niu, Gang; Yu, Lun; Zeng, Wenbin; Wang, Wei; Chen, Xiaoyuan

    2015-10-01

    The development of imageable photothermal theranostics has attracted considerable attention for imaging guided photothermal therapy (PTT) with high tumor ablation accuracy. In this study, we strategically constructed a near-infrared (NIR) cyanine dye by introducing a rigid cyclohexenyl ring to the heptamethine chain to obtain a heptamethine dye CySCOOH with high fluorescence intensity and good stability. By covalent conjugation of CySCOOH onto human serum albumin (HSA), the as-prepared HSA@CySCOOH nanoplatform is highly efficient for NIR fluorescence/photoacoustic/thermal multimodality imaging and photothermal tumor ablation. The theranostic capability of HSA@CySCOOH was systematically evaluated both in vitro and in vivo. Most intriguingly, complete tumor elimination was achieved by intravenous injection of HSA@CySCOOH (CySCOOH, 1 mg kg-1 808 nm, 1.0 W cm-2 for 5 min) into 4T1 tumor-bearing mice, with no weight loss, noticeable toxicity, or tumor recurrence being observed. This as-prepared protein-based nanotheranostics exhibits high water dispersibility, no off target cytotoxicity, and good biodegradability and biocompatibility, thus facilitating its clinical translation to cancer photothermal theranostics.The development of imageable photothermal theranostics has attracted considerable attention for imaging guided photothermal therapy (PTT) with high tumor ablation accuracy. In this study, we strategically constructed a near-infrared (NIR) cyanine dye by introducing a rigid cyclohexenyl ring to the heptamethine chain to obtain a heptamethine dye CySCOOH with high fluorescence intensity and good stability. By covalent conjugation of CySCOOH onto human serum albumin (HSA), the as-prepared HSA@CySCOOH nanoplatform is highly efficient for NIR fluorescence/photoacoustic/thermal multimodality imaging and photothermal tumor ablation. The theranostic capability of HSA@CySCOOH was systematically evaluated both in vitro and in vivo. Most intriguingly, complete tumor

  18. Incidence of Secondary Cancer Development After High-Dose Intensity-Modulated Radiotherapy and Image-Guided Brachytherapy for the Treatment of Localized Prostate Cancer

    SciTech Connect

    Zelefsky, Michael J.; Housman, Douglas M.; Pei Xin; Alicikus, Zumre; Magsanoc, Juan Martin; Dauer, Lawrence T.; St Germain, Jean; Yamada, Yoshiya; Kollmeier, Marisa; Cox, Brett; Zhang Zhigang

    2012-07-01

    Purpose: To report the incidence and excess risk of second malignancy (SM) development compared with the general population after external beam radiotherapy (EBRT) and brachytherapy to treat prostate cancer. Methods and Materials: Between 1998 and 2001, 1,310 patients with localized prostate cancer were treated with EBRT (n = 897) or brachytherapy (n = 413). We compared the incidence of SMs in our patients with that of the general population extracted from the National Cancer Institute's Surveillance, Epidemiology, and End Results data set combined with the 2000 census data. Results: The 10-year likelihood of SM development was 25% after EBRT and 15% after brachytherapy (p = .02). The corresponding 10-year likelihood for in-field SM development in these groups was 4.9% and 1.6% (p = .24). Multivariate analysis showed that EBRT vs. brachytherapy and older age were the only significant predictors for the development of all SMs (p = .037 and p = .030), with a trend for older patients to develop a SM. The increased incidence of SM for EBRT patients was explained by the greater incidence of skin cancer outside the radiation field compared with that after brachytherapy (10.6% and 3.3%, respectively, p = .004). For the EBRT group, the 5- and 10-year mortality rate was 1.96% and 5.1% from out-of field cancer, respectively; for in-field SM, the corresponding mortality rates were 0.1% and 0.7%. Among the brachytherapy group, the 5- and 10-year mortality rate related to out-of field SM was 0.8% and 2.7%, respectively. Our observed SM rates after prostate RT were not significantly different from the cancer incidence rates in the general population. Conclusions: Using modern sophisticated treatment techniques, we report low rates of in-field bladder and rectal SM risks after prostate cancer RT. Furthermore, the likelihood of mortality secondary to a SM was unusual. The greater rate of SM observed with EBRT vs. brachytherapy was related to a small, but significantly increased, number of skin cancers in the EBRT patients compared with that of the general population.

  19. Advanced modeling of high intensity accelerators

    SciTech Connect

    Ryne, R.D.; Habib, S.; Wangler, T.P.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goals of this project were three-fold: (1) to develop a new capability, based on high performance (parallel) computers, to perform large scale simulations of high intensity accelerators; (2) to apply this capability to modeling high intensity accelerators under design at LANL; and (3) to use this new capability to improve the understanding of the physics of intense charge particle beams, especially in regard to the issue of beam halo formation. All of these goals were met. In particular, the authors introduced split-operator methods as a powerful and efficient means to simulate intense beams in the presence of rapidly varying accelerating and focusing fields. They then applied these methods to develop scaleable, parallel beam dynamics codes for modeling intense beams in linacs, and in the process they implemented a new three-dimensional space charge algorithm. They also used the codes to study a number of beam dynamics issues related to the Accelerator Production of Tritium (APT) project, and in the process performed the largest simulations to date for any accelerator design project. Finally, they used the new modeling capability to provide direction and validation to beam physics studies, helping to identify beam mismatch as a major source of halo formation in high intensity accelerators. This LDRD project ultimately benefited not only LANL but also the US accelerator community since, by promoting expertise in high performance computing and advancing the state-of-the-art in accelerator simulation, its accomplishments helped lead to approval of a new DOE Grand Challenge in Computational Accelerator Physics.

  20. Fundamental Physics Explored with High Intensity Laser

    NASA Astrophysics Data System (ADS)

    Tajima, T.; Homma, K.

    2012-10-01

    Over the last century the method of particle acceleration to high energies has become the prime approach to explore the fundamental nature of matter in laboratory. It appears that the latest search of the contemporary accelerator based on the colliders shows a sign of saturation (or at least a slow-down) in increasing its energy and other necessary parameters to extend this frontier. We suggest two pronged approach enabled by the recent progress in high intensity lasers. First we envision the laser-driven plasma accelerator may be able to extend the reach of the collider. For this approach to bear fruit, we need to develop the technology of high averaged power laser in addition to the high intensity. For this we mention that the latest research effort of ICAN is an encouraging sign. In addition to this, we now introduce the concept of the noncollider paradigm in exploring fundamental physics with high intensity (and large energy) lasers. One of the examples we mention is the laser wakefield acceleration (LWFA) far beyond TeV without large luminosity. If we relax or do not require the large luminosity necessary for colliders, but solely in ultrahigh energy frontier, we are still capable of exploring such a fundamental issue. Given such a high energetic particle source and high-intensity laser fields simultaneously, we expect to be able to access new aspects on the matter and the vacuum structure from fundamental physical point of views. LWFA naturally exploits the nonlinear optical effects in the plasma when it becomes of relativistic intensity. Normally nonlinear optical effects are discussed based upon polarization susceptibility of matter to external fields. We suggest application of this concept even to the vacuum structure as a new kind of order parameter to discuss vacuum-originating phenomena at semimacroscopic scales. This viewpoint unifies the following observables with the unprecedented experimental environment we envision; the dispersion relation of

  1. Optical imaging-guided cancer therapy with fluorescent nanoparticles

    PubMed Central

    Jiang, Shan; Gnanasammandhan, Muthu Kumara; Zhang, Yong

    2010-01-01

    The diagnosis and treatment of cancer have been greatly improved with the recent developments in nanotechnology. One of the promising nanoscale tools for cancer diagnosis is fluorescent nanoparticles (NPs), such as organic dye-doped NPs, quantum dots and upconversion NPs that enable highly sensitive optical imaging of cancer at cellular and animal level. Furthermore, the emerging development of novel multi-functional NPs, which can be conjugated with several functional molecules simultaneously including targeting moieties, therapeutic agents and imaging probes, provides new potentials for clinical therapies and diagnostics and undoubtedly will play a critical role in cancer therapy. In this article, we review the types and characteristics of fluorescent NPs, in vitro and in vivo imaging of cancer using fluorescent NPs and multi-functional NPs for imaging-guided cancer therapy. PMID:19759055

  2. Active constraint control for image-guided robotic surgery.

    PubMed

    Yen, P-L; Davies, B L

    2010-01-01

    The concept of active constraint control for image-guided robotic surgery is introduced, together with its benefits and a short outline of its history. The clinical use of active constraint control in orthopaedic surgery is discussed, together with the outcomes of a clinical trial for unicondylar knee replacement surgery. The evolution of the robotic design from large costly structures towards simpler, more cost-effective systems is also presented, leading to the design of the Acrobot 'Sculptor' system. A new approach to the achievement of robotic total knee replacement is also presented, in which a high-speed rotary cutter is used to slice through the bone to achieve a speedy resection. The control concept is presented, together with the results of trials on animal bones and a cadaver, showing that it is possible to remove large quantities of bone both quickly and accurately. PMID:20718267

  3. Image-guided diagnosis of prostate cancer can increase detection of tumors

    Cancer.gov

    In the largest prospective study to date of image-guided technology for identifying suspicious regions of the prostate to biopsy, researchers compared the ability of this technology to detect high-risk prostate cancer with that of the current standard of

  4. Rapidly pulsed, high intensity, incoherent light source

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.; Brandhorst, H. W., Jr. (Inventor)

    1974-01-01

    A rapid pulsing, high intensity, incoherent light is produced by selectively energizing a plurality of discharge lamps with a triggering circuit. Each lamp is connected to a capacitor, and a power supply is electrically connected to all but one of the capacitors. This last named capacitor is electrically connected to a discharge lamp which is connected to the triggering circuit.

  5. Motion compensated SLAM for image guided surgery.

    PubMed

    Mountney, Peter; Yang, Guang-Zhong

    2010-01-01

    The effectiveness and clinical benefits of image guided surgery are well established for procedures where there is manageable tissue motion. In minimally invasive cardiac, gastrointestinal, or abdominal surgery, large scale tissue deformation prohibits accurate registration and fusion of pre- and intraoperative data. Vision based techniques such as structure from motion and simultaneous localization and mapping are capable of recovering 3D structure and laparoscope motion. Current research in the area generally assumes the environment is static, which is difficult to satisfy in most surgical procedures. In this paper, a novel framework for simultaneous online estimation of laparoscopic camera motion and tissue deformation in a dynamic environment is proposed. The method only relies on images captured by the laparoscope to sequentially and incrementally generate a dynamic 3D map of tissue motion that can be co-registered with pre-operative data. The theoretical contribution of this paper is validated with both simulated and ex vivo data. The practical application of the technique is further demonstrated on in vivo procedures. PMID:20879352

  6. Interactive image-guided hepatic surgery

    NASA Astrophysics Data System (ADS)

    Stefansic, James D.; Herline, Alan J.; Bass, W. Andrew; Chapman, William C.; Galloway, Robert L., Jr.

    1999-05-01

    While laparoscopes are used for numerous minimally invasive procedures, minimally invasive liver resection and ablation occur infrequently. the paucity of cases is due to limited field of view and difficulty in determination of tumor location and margins under video guidance. By merging minimally invasive surgery with interactive, image-guided surgery, we hope to make laparoscopic liver procedures feasible. In previous work, we described methods for tracking an endoscope accurately in patient space and registration between endoscopic image space and physical space using the direct linear transformation (DLT). We have now developed a PC-based software system to display up to four 512 Χ 512 images indicating current surgical position using an active optical tracking system. We have used this system in several open liver cases and believe that a surface-based registration technique can be used to register physical space to tomographic space after liver mobilization. For preliminary phantom liver studies, our registration error is approximately 2.0mm. The surface-based registration technique will allow better localization of non-visible liver tumors, more accurate probe placement for ablation procedures, and more accurate margin determination for open surgical liver cases. The surface-based registration technique will allow better localization of non-visible liver tumors, more accurate probe placement for ablation procedures, and more accurate margin determination for open surgical liver cases. The surface-based/DLT registration methods, in combination with the video display and tracked endoscope, will hopefully make laparoscopic liver cryoablation and resection procedures feasible.

  7. The NASA High Intensity Radiated Fields Laboratory

    NASA Technical Reports Server (NTRS)

    Williams, Reuben A.

    1997-01-01

    High Intensity Radiated Fields (HIRF) are the result of a multitude of intentional and nonintentional electromagnetic sources that currently exists in the world. Many of today's digital systems are susceptible to electronic upset if subjected to certain electromagnetic environments (EME). Modern aerospace designers and manufacturers increasingly rely on sophisticated digital electronic systems to provide critical flight control in both military, commercial, and general aviation aircraft. In an effort to understand and emulate the undesired environment that high energy RF provides modern electronics, the Electromagnetics Research Branch (ERB) of the Flight Electronics and Technology Division (FETD) conducts research on RF and microwave measurement methods related to the understanding of HIRF. In the High Intensity Radiated Fields Laboratory, the effects of high energy radiating electromagnetic fields on avionics and electronic systems are tested and studied.

  8. AGS RESONANT EXTRACTION WITH HIGH INTENSITY BEAMS.

    SciTech Connect

    AHRENS,L.; BROWN,K.; GLENN,J.W.; ROSER,T.; TSOUPAS,N.; VANASSELT,W.

    1999-03-29

    The Brookhaven AGS third integer resonant extraction system allows the AGS to provide high quality, high intensity 25.5 GeV/c proton beams simultaneously to four target stations and as many as 8 experiments. With the increasing intensities (over 7 x 10{sup 13} protons/pulse) and associated longer spill periods (2.4 to 3 seconds long), we continue to run with low losses and high quality low modulation continuous current beams.[1] Learning to extract and transport these higher intensity beams has required a process of careful modeling and experimentation. We have had to learn how to correct for various instabilities and how to better match extraction and the transport lines to the higher emittance beams being accelerated in the AGS. Techniques employed include ''RF'' methods to smooth out momentum distributions and fine structure. We will present results of detailed multi-particle tracking modeling studies which enabled us to develop a clear understanding of beam loss mechanisms in the transport and extraction process. We will report on our status, experiences, and the present understanding of the intensity limitations imposed by resonant extraction and transport to fixed target stations.

  9. Beam diagnostics for high intensity hadron accelerators

    NASA Astrophysics Data System (ADS)

    Ausset, Patrick; Gardès, Daniel

    2007-07-01

    High intensity hadron beam accelerators have been recently proposed and developed either for the production of high intensity secondary beams for Nuclear and Particle Physics research (EURISOL, SPIRAL2, FAIR), or Applied Physics in the field of Accelerator Driven System and waste transmutation (EUROTRANS). For these applications, high power Linear Accelerator (LINAC) are planned to produce and accelerate hadron beams up to 1 GeV. Both commissioning and operation of these accelerators require dedicated beam instrumentation able to monitor and characterize on line as completely as possible the produced beams having a power in the range of 1 MW. Beam current, transverse beam centroı¨d position and profiles and beam energy are the most important characteristics that have to be measured. Due to the high average power of the beam, nondestructive or at least minimally intercepting beam sensors are required. Beam instrumentation for IPHI (CEA/DSM and CNRS/IN2P3 collaboration) which is a high intensity proton (3 MeV, 100 mA, CW operation) injector initially designed to be a possible front end for this kind of LINAC is under realization. Beam diagnostics already under operation, developments in progress will be described and will introduce a more general description of high power beam instrumentation.

  10. Ultrasound-guided high intensity focused ultrasound for the treatment of gynaecological diseases: A review of safety and efficacy.

    PubMed

    Zhang, Lian; Zhang, Wenyi; Orsi, Franco; Chen, Wenzhi; Wang, Zhibiao

    2015-05-01

    As a non-surgical treatment, high intensity focused ultrasound (HIFU) has received increasing interest for the treatment of gynaecological diseases over the last 10 years. Many studies have shown that HIFU is safe and effective in treating patients with uterine fibroids, adenomyosis, cervicitis or vulvar diseases. Both magnetic resonance imaging-guided HIFU (MRgHIFU) and ultrasound-guided HIFU (USgHIFU) can offer gynaecologists non-invasive techniques to treat patients with uterine benign diseases. Focused ultrasound therapy can also be used effectively to treat cervicitis and vulvar diseases. As gynaecologists gain more experience with this technology, the rate of severe adverse effects has been lowered with the development of this non-invasive technique. In this paper we review the literature available regarding the utilisation of magnetic resonance imaging-guided focused ultrasound/MRgHIFU or USgHIFU and new findings from our group in the treatment of gynaecological diseases: uterine fibroids, adenomyosis, cervicitis, vulvar diseases, caesarean scar pregnancies, and abdominal wall endometriosis. PMID:25609456

  11. Protein-Based Photothermal Theranostics for Imaging-Guided Cancer Therapy

    PubMed Central

    Rong, Pengfei; Huang, Peng; Liu, Zhiguo; Lin, Jing; Jin, Albert; Ma, Ying; Niu, Gang; Yu, Lun; Zeng, Wenbin; Wang, Wei; Chen, Xiaoyuan

    2015-01-01

    Development of imageable photothermal theranostics has attracted considerable attention for imaging guided photothermal therapy (PTT) with high tumor ablation accuracy. In this study, we strategically constructed a near-infrared (NIR) cyanine dye by introducing a rigid cyclohexenyl ring to the heptamethine chain to obtain a heptamethine dye CySCOOH with high fluorescence intensity and good stability. By covalent conjugation of CySCOOH onto human serum albumin (HSA), the as-prepared HSA@CySCOOH nanoplatform is highly efficient for NIR fluorescence/photoacoustic/thermal multimodality imaging and photothermal tumor ablation. The theranostic capability of HSA@CySCOOH was systematically evaluated both in vitro and in vivo. Most intriguingly, complete tumor elimination was achieved by intravenous injection of HSA@CySCOOH (CySCOOH, 1 mg/kg; 808 nm, 1.0 W/cm2 for 5 min) on 4T1 tumor-bearing mice, with no weight loss, noticeable toxicity, or tumor recurrence being observed. This as-prepared protein-based nanotheranostics exhibits high water dispersibility, no off target cytotoxicity, good biodegradability and biocompatibility, thus facilitating its clinical translation for cancer photothermal theranostics. PMID:26382146

  12. Image-Guided Intervention of the Postoperative Foot and Ankle After Ligament and Tendon Repair.

    PubMed

    Khanna, Monica; Walker, Miny; Amiras, Dimitri; Rosenfeld, Peter

    2016-02-01

    This review article describes the potential range of image-guided interventional procedures performed following foot and ankle ligament and/or tendon repair. Diagnosis of the cause of recurrent or persistent pain/symptoms in this postoperative group is challenging and requires a coordinated clinical and radiologic assessment. This directs appropriate treatment including image-guided intervention that may be used both as a diagnostic tool and a therapeutic option. There is a paucity of high-quality studies on the role of image-guided intervention in the foot and ankle after ligament/tendon repair. Many of the procedures used in this group are extrapolated from other areas of the body or the preoperative scenario. We review the role of imaging to identify the cause of postsurgical symptoms and to direct appropriate image-guided intervention. The available injectables and their roles are discussed. Specific surgical procedures are described including lateral ligament repair, Achilles repair, posterior tibialis tendon surgery, and peroneal tendon surgery. PMID:27077592

  13. Critical parameters for parallel interconnects using VCSEL arrays and fiber image guides

    NASA Astrophysics Data System (ADS)

    Mukherjee, Sayan D.; Hadley, G. Ronald; Geib, Kent M.; Choquette, Kent D.; Carter, Tony R.; Fischer, Arthur J.; Robinson, Matthew; Sullivan, Charles T.

    2003-04-01

    Several thousand glass optical fibers fused together is routinely used as fiber image guides for medical and other image remoting applications. Fiber image guides also offer possibility for flexible optical interconnect links with potentially thousands of bi-directional parallel channels with data rates as high as 10 Gbps per channel, leading to more than Tera bits per second aggregate data transfer rates. A fair number of fiber image guide based link demonstrations using vertical cavity surface emitting lasers have been reported. However, little is known about designable parameters and optimization paradigms for applications to massively parallel optical interconnects. This paper discusses critical optical parameters that characterize a massively parallel link. Experimental characterizations were carried out to explore some of the fundamental interactions between single-mode 850 nm VCSELs and fiber image guides having different numerical apertures, 0.25, 0.55 and 1.00. Preliminary optical simulation results are given. Finally, potential directions for further experimental and analytical explorations, and for applicability into designable link systems are suggested.

  14. Ultra-high intensity laser plasma interactions

    NASA Astrophysics Data System (ADS)

    Langdon, A. Bruce; Hinkel, D. E.; Lasinski, Barbara F.; Still, C. H.

    1997-11-01

    In current studies of plasma interactions relevant to the fast ignitor concept,footnote M. Tabak, et al., Phys. Plasmas 1, 1626 (1994). an ultra-high intensity beam propagates through underdense, relativistically transparent, and then near solid density plasmas to create a channel. The ultra-high intensity beam propagates through this channel toward the compressed core where it creates hot electrons as it is absorbed. Three-dimensional fluid simulation(R. L. Berger et al), Phys. Fluids B, 2243 (1993). (with relativistic enhancements) studies of self-focusing in the underdense plasma will be reported and compared to PIC simulations in the same parameter regime. Beam structure near focus detracts from channel formation. Modeling in support of upcoming 100TW will be presented.

  15. Magnets for high intensity proton synchrotrons

    SciTech Connect

    Jean-Francois Ostiguy, Vladimir Kashikhine and Alexander Makarov

    2002-09-19

    Recently, there has been considerable interest at Fermilab for the Proton Driver, a future high intensity proton machine. Various scenarios are under consideration, including a superconducting linac. Each scenario present some special challenges. We describe here the magnets proposed in a recent study, the Proton Driver Study II, which assumes a conventional warm synchrotron, roughly of the size of the existing FNAL booster, but capable of delivering 380 kW at 8 GeV.

  16. Positron microanalysis with high intensity beams

    SciTech Connect

    Hulett, L.D. Jr.; Donohue, D.L.

    1990-01-01

    One of the more common applications for a high intensity slow positron facility will be microanalysis of solid materials. In the first section of this paper some examples are given of procedures that can be developed. Since most of the attendees of this workshop are experts in positron spectroscopy, comprehensive descriptions will be omitted. With the exception of positron emission microscopy, most of the procedures will be based on those already in common use with broad beams. The utility of the methods have all been demonstrated, but material scientists use very few of them because positron microbeams are not generally available. A high intensity positron facility will make microbeams easier to obtain and partially alleviate this situation. All microanalysis techniques listed below will have a common requirement, which is the ability to locate the microscopic detail or area of interest and to focus the positron beam exclusively on it. The last section of this paper is a suggestion of how a high intensity positron facility might be designed so as to have this capability built in. The method will involve locating the specimen by scanning it with the microbeam of positrons and inducing a secondary electron image that will immediately reveal whether or not the positron beam is striking the proper portion of the specimen. This scanning positron microscope' will be a somewhat prosaic analog of the conventional SEM. It will, however, be an indispensable utility that will enhance the practicality of positron microanalysis techniques. 6 refs., 1 fig.

  17. Evaluation of Image-Guided Positioning for Frameless Intracranial Radiosurgery

    SciTech Connect

    Lamba, Michael Breneman, John C.; Warnick, Ronald E.

    2009-07-01

    Purpose: The standard for target alignment and immobilization in intracranial radiosurgery is frame-based alignment and rigid immobilization using a stereotactic head ring. Recent improvements in image-guidance systems have introduced the possibility of image-guided radiosurgery with nonrigid immobilization. We present data on the alignment accuracy and patient stability of a frameless image-guided system. Methods and Materials: Isocenter alignment errors were measured for in vitro studies in an anthropomorphic phantom for both frame-based stereotactic and frameless image-guided alignment. Subsequently, in vivo studies assessed differences between frame-based and image-guided alignment in patients who underwent frame-based intracranial radiosurgery. Finally, intratreatment target stability was determined by image-guided alignment performed before and after image-guided mask immobilized radiosurgery. Results: In vitro hidden target localization errors were comparable for the framed (0.7 {+-} 0.5 mm) and image-guided (0.6 {+-} 0.2 mm) techniques. The in vivo differences in alignment were 0.9 {+-} 0.5 mm (anteroposterior), -0.2 {+-} 0.4 mm (superoinferior), and 0.3 {+-} 0.5 mm (lateral). For in vivo stability tests, the mean distance differed between the pre- and post-treatment positions with mask-immobilized radiosurgery by 0.5 {+-} 0.3 mm. Conclusion: Frame-based and image-guided alignment accuracy in vitro was comparable for the system tested. In vivo tests showed a consistent trend in the difference of alignment in the anteroposterior direction, possibly due to torque to the ring and mounting system with frame-based localization. The mask system as used appeared adequate for patient immobilization.

  18. Enhanced thermal stability of silica-coated gold nanorods for photoacoustic imaging and image-guided therapy

    PubMed Central

    Chen, Yun-Sheng; Frey, Wolfgang; Kim, Seungsoo; Homan, Kimberly; Kruizinga, Pieter; Sokolov, Konstantin; Emelianov, Stanislav

    2010-01-01

    Photothermal stability and, therefore, consistency of both optical absorption and photoacoustic response of the plasmonic nanoabsorbers is critical for successful photoacoustic image-guided photothermal therapy. In this study, silica-coated gold nanorods were developed as a multifunctional molecular imaging and therapeutic agent suitable for image-guided photothermal therapy. The optical properties and photothermal stability of silica-coated gold nanorods under intense irradiation with nanosecond laser pulses were investigated by UV-Vis spectroscopy and transmission electron microscopy. Silica-coated gold nanorods showed increased photothermal stability and retained their superior optical properties under much higher fluences. The changes in photoacoustic response of PEGylated and silica-coated nanorods under laser pulses of various fluences were compared. The silica-coated gold nanorods provide a stable photoacoustic signal, which implies better imaging capabilities and make silica-coated gold nanorods a promising imaging and therapeutic nano-agent for photoacoustic imaging and image-guided photothermal therapy. PMID:20588732

  19. Beam halo in high-intensity beams

    SciTech Connect

    Wangler, T.P. )

    1993-12-25

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. The beam-halo is of concern for a next generation of cw, high-power proton linacs that could be applied to intense neutron generators for nuclear materials processing. We describe what has been learned about beam halo and the evolution of space-charge dominated beams using numerical simulations of initial laminar beams in uniform linear focusing channels. We present initial results from a study of beam entropy for an intense space-charge dominated beam.

  20. Beam halo in high-intensity beams

    SciTech Connect

    Wangler, T.P.

    1993-06-01

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. The beam-halo is of concern for a next generation of cw, high-power proton linacs that could be applied to intense neutron generators for nuclear materials processing. The author describes what has been learned about beam halo and the evolution of space-charge dominated beams using numerical simulations of initial laminar beams in uniform linear focusing channels. Initial results are presented from a study of beam entropy for an intense space-charge dominated beam.

  1. Beam halo in high-intensity beams

    SciTech Connect

    Wangler, T.P.

    1993-01-01

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. The beam-halo is of concern for a next generation of cw, high-power proton linacs that could be applied to intense neutron generators for nuclear materials processing. The author describes what has been learned about beam halo and the evolution of space-charge dominated beams using numerical simulations of initial laminar beams in uniform linear focusing channels. Initial results are presented from a study of beam entropy for an intense space-charge dominated beam.

  2. Image-guided spine surgery: state of the art and future directions

    PubMed Central

    Shafizadeh, Sven; Rixen, Dieter; Paffrath, Thomas; Bouillon, Bertil; Steinhausen, Eva S.; Baethis, Holger

    2009-01-01

    Navigation technology is a widely available tool in spine surgery and has become a part of clinical routine in many centers. The issue of where and when navigation technology should be used is still an issue of debate. It is the aim of this study to give an overview on the current knowledge concerning the technical capabilities of image-guided approaches and to discuss possible future directions of research and implementation of this technique. Based on a Medline search total of 1,462 publications published until October 2008 were retrieved. The abstracts were scanned manually for relevance to the topics of navigated spine surgery in the cervical spine, the thoracic spine, the lumbar spine, as well as ventral spine surgery, radiation exposure, tumor surgery and cost-effectivity in navigated spine surgery. Papers not contributing to these subjects were deleted resulting in 276 papers that were included in the analysis. Image-guided approaches have been investigated and partially implemented into clinical routine in virtually any field of spine surgery. However, the data available is mostly limited to small clinical series, case reports or retrospective studies. Only two RCTs and one metaanalysis have been retrieved. Concerning the most popular application of image-guided approaches, pedicle screw insertion, the evidence of clinical benefit in the most critical areas, e.g. the thoracic spine, is still lacking. In many other areas of spine surgery, e.g. ventral spine surgery or tumor surgery, image-guided approaches are still in an experimental stage. The technical development of image-guided techniques has reached a high level as the accuracies that can be achieved technically meet the anatomical demands. However, there is evidence that the interaction between the surgeon (‘human factor’) and the navigation system is a source of inaccuracy. It is concluded that more effort needs to be spend to understand this interaction. PMID:19763640

  3. High intensity, pulsed thermal neutron source

    DOEpatents

    Carpenter, J.M.

    1973-12-11

    This invention relates to a high intensity, pulsed thermal neutron source comprising a neutron-producing source which emits pulses of fast neutrons, a moderator block adjacent to the last neutron source, a reflector block which encases the fast neutron source and the moderator block and has a thermal neutron exit port extending therethrough from the moderator block, and a neutron energy- dependent decoupling reflector liner covering the interior surfaces of the thermal neutron exit port and surrounding all surfaces of the moderator block except the surface viewed by the thermal neutron exit port. (Official Gazette)

  4. Diagnostics of High-Intensity-Discharges

    NASA Astrophysics Data System (ADS)

    Adler, Helmar G.

    1996-05-01

    High intensity light sources have come a long way since the introduction of high pressure discharges in mercury and later in sodium. The introduction of other species (e.g. metal halides) into the discharge chemistry led to marked improvements in light intensity (lumens per watt or LPW) and the appearance of the light output (color rendering index or CRI). Many of these improvements have been achieved through qualitative understanding of the discharge and good engineering. The accurate predictions of discharge behavior and spectral power distribution through HID-models remains a difficult and challenging goal for lighting scientists. Modelling of a real lamp is complicated due to the high pressures in the discharge, the geometric influences of the discharge vessel, and the interactions between fills, wall materials and electrodes. The simultaneous use of solid-, liquid-, gaseous- and plasma-state descriptions, including for example effects of radiation transport, becomes necessary. Spectroscopic measurements have been and are still of highest value, not only to determine practical parameters like LPW and CRI, but also to determine species distributions and temperatures, eventually as a function of location in the discharge and time. These measurements are necessary not only for the quantitative understanding of the discharge mechanisms, but also to serve as a testbed for all simulation efforts. This paper will focus on diagnostic possibilities and opportunities using imaging data acquisition systems.

  5. A small animal image guided irradiation system study using 3D dosimeters

    NASA Astrophysics Data System (ADS)

    Qian, Xin; Admovics, John; Wuu, Cheng-Shie

    2015-01-01

    In a high resolution image-guided small animal irradiation platform, a cone beam computed tomography (CBCT) is integrated with an irradiation unit for precise targeting. Precise quality assurance is essential for both imaging and irradiation components. The conventional commissioning techniques with films face major challenges due to alignment uncertainty and labour intensive film preparation and scanning. In addition, due to the novel design of this platform the mouse stage rotation for CBCT imaging is perpendicular to the gantry rotation for irradiation. Because these two rotations are associated with different mechanical systems, discrepancy between rotation isocenters exists. In order to deliver x-ray precisely, it is essential to verify coincidence of the imaging and the irradiation isocenters. A 3D PRESAGE dosimeter can provide an excellent tool for checking dosimetry and verifying coincidence of irradiation and imaging coordinates in one system. Dosimetric measurements were performed to obtain beam profiles and percent depth dose (PDD). Isocentricity and coincidence of the mouse stage and gantry rotations were evaluated with starshots acquired using PRESAGE dosimeters. A single PRESAGE dosimeter can provide 3 -D information in both geometric and dosimetric uncertainty, which is crucial for translational studies.

  6. Real-time Fluorescence Image-Guided Oncologic Surgery

    PubMed Central

    Mondal, Suman B.; Gao, Shengkui; Zhu, Nan; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

    2014-01-01

    Medical imaging plays a critical role in cancer diagnosis and planning. Many of these patients rely on surgical intervention for curative outcomes. This requires a careful identification of the primary and microscopic tumors, and the complete removal of cancer. Although there have been efforts to adapt traditional imaging modalities for intraoperative image guidance, they suffer from several constraints such as large hardware footprint, high operation cost, and disruption of the surgical workflow. Because of the ease of image acquisition, relatively low cost devices and intuitive operation, optical imaging methods have received tremendous interests for use in real-time image-guided surgery. To improve imaging depth under low interference by tissue autofluorescence, many of these applications utilize light in the near-infra red (NIR) wavelengths, which is invisible to human eyes. With the availability of a wide selection of tumor-avid contrast agents, advancements in imaging sensors, electronic and optical designs, surgeons are able to combine different attributes of NIR optical imaging techniques to improve treatment outcomes. The emergence of diverse commercial and experimental image guidance systems, which are in various stages of clinical translation, attests to the potential high impact of intraoperative optical imaging methods to improve speed of oncologic surgery with high accuracy and minimal margin positivity. PMID:25287689

  7. High intensity discharge device containing oxytrihalides

    DOEpatents

    Lapatovich, W.P.; Keeffe, W.M.; Liebermann, R.W.; Maya, J.

    1987-06-09

    A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO[sub 2], with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube. 7 figs.

  8. High intensity discharge device containing oxytrihalides

    DOEpatents

    Lapatovich, Walter P.; Keeffe, William M.; Liebermann, Richard W.; Maya, Jakob

    1987-01-01

    A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO.sub.2, with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube.

  9. Preliminary experience on the implementation of computed tomography (CT)-based image guided brachytherapy (IGBT) of cervical cancer using high-dose-rate (HDR) Cobalt-60 source in University of Malaya Medical Centre (UMMC)

    NASA Astrophysics Data System (ADS)

    Jamalludin, Z.; Min, U. N.; Ishak, W. Z. Wan; Malik, R. Abdul

    2016-03-01

    This study presents our preliminary work of the computed tomography (CT) image guided brachytherapy (IGBT) implementation on cervical cancer patients. We developed a protocol in which patients undergo two Magnetic Resonance Imaging (MRI) examinations; a) prior to external beam radiotherapy (EBRT) and b) prior to intra-cavitary brachytherapy for tumour identification and delineation during IGBT planning and dosimetry. For each fraction, patients were simulated using CT simulator and images were transferred to the treatment planning system. The HR-CTV, IR-CTV, bladder and rectum were delineated on CT-based contouring for cervical cancer. Plans were optimised to achieve HR-CTV and IR-CTV dose (D90) of total EQD2 80Gy and 60Gy respectively, while limiting the minimum dose to the most irradiated 2cm3 volume (D2cc) of bladder and rectum to total EQD2 90Gy and 75Gy respectively. Data from seven insertions were analysed by comparing the volume-based with traditional point- based doses. Based on our data, there were differences between volume and point doses of HR- CTV, bladder and rectum organs. As the number of patients having the CT-based IGBT increases from day to day in our centre, it is expected that the treatment and dosimetry accuracy will be improved with the implementation.

  10. High-power, high-intensity laser propagation and interactions

    SciTech Connect

    Sprangle, Phillip; Hafizi, Bahman

    2014-05-15

    This paper presents overviews of a number of processes and applications associated with high-power, high-intensity lasers, and their interactions. These processes and applications include: free electron lasers, backward Raman amplification, atmospheric propagation of laser pulses, laser driven acceleration, atmospheric lasing, and remote detection of radioactivity. The interrelated physical mechanisms in the various processes are discussed.

  11. Image-guided therapy: evolution and breakthrough.

    PubMed

    Haigron, Pascal; Dillenseger, Jean-Louis; Luo, Limin; Coatrieux, Jean-Louis

    2010-01-01

    Beyond the advances made in computer-assisted interventions and robotic systems, the demand for more efficient and safer therapies remains challenging. Thus, if it is possible to improve the instrument tracking, steering, and target localization, to miniaturize the sensors and actuators, and to conduct preoperatively planned minimally invasive therapies, we still need new resources to achieve permanent destruction of abnormal tissues or suppression of pathological processes. Most of the physics-based (or energy-based) therapeutic principles at our disposal have been established a long time ago, but their actions on basic cellular and molecular mechanisms are not yet fully understood. They all have a wide spectrum of clinical targets in terms of organs and pathologies, modes of application (external, interstitial, intraluminal, etc.) with advantages and side-effect drawbacks, proven indications, and contraindications. Some of them may still face controversies regarding their outcomes. This short article, mainly focused on tumor destruction, briefly reviews in its first part some of these techniques and sketches the next generation under investigation. The former include radio frequency (RF), high-intensity focused ultrasound (HiFU), microwaves, and cryotherapy, of which all are temperature based. Laser-based approaches [e.g., photodynamic therapy (PDT) at large] are also discussed. Radiotherapy and its variants (hadrontherapy, brachytherapy, Gamma Knife, and CyberKnife) remain, of course, as the reference technique in cancer treatment. The next breakthroughs are examined in the second part of the article. They are based on the close association between imaging agents, drugs, and some stimulation techniques. The ongoing research efforts in that direction show that, if they are still far from clinical applications, strong expectations are made. From the point of view of interventional planning and image guidance, all of them share a lot of concerns. PMID:20176527

  12. Computational challenges for image-guided radiation therapy: framework and current research.

    PubMed

    Xing, Lei; Siebers, Jeffrey; Keall, Paul

    2007-10-01

    It is arguable that the imaging and delivery hardware necessary for delivering real-time adaptive image-guided radiotherapy is available on high-end linear accelerators. Robust and computationally efficient software is the limiting factor in achieving highly accurate and precise radiotherapy to the constantly changing anatomy of a cancer patient. The limitations are not caused by the availability of algorithms but rather issues of reliability, integration, and calculation time. However, each of the software components is an active area of research and development at academic and commercial centers. This article describes the software solutions in 4 broad areas: deformable image registration, adaptive replanning, real-time image guidance, and dose calculation and accumulation. Given the pace of technological advancement, the integration of these software solutions to develop real-time adaptive image-guided radiotherapy and the associated challenges they bring will be implemented to varying degrees by all major manufacturers over the coming years. PMID:17903702

  13. A multimodal nano agent for image-guided cancer surgery.

    PubMed

    Zheng, Jinzi; Muhanna, Nidal; De Souza, Raquel; Wada, Hironobu; Chan, Harley; Akens, Margarete K; Anayama, Takashi; Yasufuku, Kazuhiro; Serra, Stefano; Irish, Jonathan; Allen, Christine; Jaffray, David

    2015-10-01

    Intraoperative imaging technologies including computed tomography and fluorescence optical imaging are becoming routine tools in the cancer surgery operating room. They constitute an enabling platform for high performance surgical resections that assure local control while minimizing morbidity. New contrast agents that can increase the sensitivity and visualization power of existing intraoperative imaging techniques will further enhance their clinical benefit. We report here the development, detection and visualization of a dual-modality computed tomography and near-infrared fluorescence nano liposomal agent (CF800) in multiple preclinical animal models of cancer. We describe the successful application of this agent for combined preoperative computed tomography based three-dimensional surgical planning and intraoperative target mapping (>200 Hounsfield Units enhancement), as well as near-infrared fluorescence guided resection (>5-fold tumor-to-background ratio). These results strongly support the clinical advancement of this agent for image-guided surgery with potential to improve lesion localization, margin delineation and metastatic lymph node detection. PMID:26218742

  14. Image-guided interventional therapy for cancer with radiotherapeutic nanoparticles✩

    PubMed Central

    Phillips, William T.; Bao, Ande; Brenner, Andrew J.; Goins, Beth A.

    2015-01-01

    One of the major limitations of current cancer therapy is the inability to deliver tumoricidal agents throughout the entire tumor mass using traditional intravenous administration. Nanoparticles carrying beta-emitting therapeutic radionuclides that are delivered using advanced image-guidance have significant potential to improve solid tumor therapy. The use of image-guidance in combination with nanoparticle carriers can improve the delivery of localized radiation to tumors. Nanoparticles labeled with certain beta-emitting radionuclides are intrinsically theranostic agents that can provide information regarding distribution and regional dosimetry within the tumor and the body. Image-guided thermal therapy results in increased uptake of intravenous nanoparticles within tumors, improving therapy. In addition, nanoparticles are ideal carriers for direct intratumoral infusion of beta-emitting radionuclides by convection enhanced delivery, permitting the delivery of localized therapeutic radiation without the requirement of the radionuclide exiting from the nanoparticle. With this approach, very high doses of radiation can be delivered to solid tumors while sparing normal organs. Recent technological developments in image-guidance, convection enhanced delivery and newly developed nanoparticles carrying beta-emitting radionuclides will be reviewed. Examples will be shown describing how this new approach has promise for the treatment of brain, head and neck, and other types of solid tumors. PMID:25016083

  15. Magnetic resonance imaging for image-guided implantology

    NASA Astrophysics Data System (ADS)

    Eggers, Georg; Kress, Bodo; Fiebach, Jochen; Rieker, Marcus; Spitzenberg, Doreen; Marmulla, Rüdiger; Dickhaus, Hartmut; Mühling, Joachim

    2006-03-01

    Image guided implantology using navigation systems is more accurate than manual dental implant insertion. The underlying image data are usually derived from computer tomography. The suitability of MR imaging for dental implant planning is a marginal issue so far. MRI data from cadaver heads were acquired using various MRI sequences. The data were assessed for the quality of anatomical imaging, geometric accuracy and susceptibility to dental metal artefacts. For dental implant planning, 3D models of the jaws were created. A software system for segmentation of the mandible and maxilla MRI data was implemented using c++, mitk, and qt. With the VIBE_15 sequence, image data with high geometric accuracy were acquired. Dental metal artefacts were lower than in CT data of the same heads. The segmentation of the jaws was feasible, in contrast to the segmentation of the dentition, since there is a lack of contrast to the intraoral soft tissue structures. MRI is a suitable method for imaging of the region of mouth and jaws. The geometric accuracy is excellent and the susceptibility to artefacts is low. However, there are yet two limitations: Firstly, the imaging of the dentition needs further improvement to allow accurate segmentation of these regions. Secondly, the sequence used in this study takes several minutes and hence is susceptible to motion artefacts.

  16. IMRT for Image-Guided Single Vocal Cord Irradiation

    SciTech Connect

    Osman, Sarah O.S.; Astreinidou, Eleftheria; Boer, Hans C.J. de; Keskin-Cambay, Fatma; Breedveld, Sebastiaan; Voet, Peter; Al-Mamgani, Abrahim; Heijmen, Ben J.M.; Levendag, Peter C.

    2012-02-01

    Purpose: We have been developing an image-guided single vocal cord irradiation technique to treat patients with stage T1a glottic carcinoma. In the present study, we compared the dose coverage to the affected vocal cord and the dose delivered to the organs at risk using conventional, intensity-modulated radiotherapy (IMRT) coplanar, and IMRT non-coplanar techniques. Methods and Materials: For 10 patients, conventional treatment plans using two laterally opposed wedged 6-MV photon beams were calculated in XiO (Elekta-CMS treatment planning system). An in-house IMRT/beam angle optimization algorithm was used to obtain the coplanar and non-coplanar optimized beam angles. Using these angles, the IMRT plans were generated in Monaco (IMRT treatment planning system, Elekta-CMS) with the implemented Monte Carlo dose calculation algorithm. The organs at risk included the contralateral vocal cord, arytenoids, swallowing muscles, carotid arteries, and spinal cord. The prescription dose was 66 Gy in 33 fractions. Results: For the conventional plans and coplanar and non-coplanar IMRT plans, the population-averaged mean dose {+-} standard deviation to the planning target volume was 67 {+-} 1 Gy. The contralateral vocal cord dose was reduced from 66 {+-} 1 Gy in the conventional plans to 39 {+-} 8 Gy and 36 {+-} 6 Gy in the coplanar and non-coplanar IMRT plans, respectively. IMRT consistently reduced the doses to the other organs at risk. Conclusions: Single vocal cord irradiation with IMRT resulted in good target coverage and provided significant sparing of the critical structures. This has the potential to improve the quality-of-life outcomes after RT and maintain the same local control rates.

  17. Image-guided urological interventions: What the urologists must know

    PubMed Central

    Das, Chandan J.; Baliyan, Vinit; Sharma, Sanjay

    2015-01-01

    Advances in imaging technology, especially in the last two decades, have led to a paradigm shift in the field of image-guided interventions in urology. While the traditional biopsy and drainage techniques are firmly established, image-based stone management and endovascular management of hematuria have evolved further. Ablative techniques for renal and prostate cancer and prostate artery embolization for benign prostatic hypertrophy have evolved into viable alternative treatments. Many urologic diseases that were earlier treated surgically are now effectively managed using minimally invasive image-guided techniques, often on a day care basis using only local anesthesia or conscious sedation. This article presents an overview of the technique and status of various image-guided urological procedures, including recent emerging techniques. PMID:26166963

  18. HIGH-INTENSITY, HIGH CHARGE-STATE HEAVY ION SOURCES

    SciTech Connect

    ALESSI,J.G.

    2004-08-16

    There are many accelerator applications for high intensity heavy ion sources, with recent needs including dc beams for RIA, and pulsed beams for injection into synchrotrons such as RHIC and LHC. The present status of sources producing high currents of high charge state heavy ions is reviewed. These sources include ECR, EBIS, and Laser ion sources. Benefits and limitations for these type sources are described. Possible future improvements in these sources are also mentioned.

  19. The management of imaging dose during image-guided radiotherapy: Report of the AAPM Task Group 75

    SciTech Connect

    Murphy, Martin J.; Balter, James; Balter, Stephen; BenComo, Jose A. Jr.; Das, Indra J.; Jiang, Steve B.; Ma, C.-M.; Olivera, Gustavo H.; Rodebaugh, Raymond F.; Ruchala, Kenneth J.; Shirato, Hiroki; Yin, Fang-Fang

    2007-10-15

    Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common--they can give a significant radiation dose to the patient. As with all medical uses of ionizing radiation, the general view is that this exposure should be carefully managed. The philosophy for dose management adopted by the diagnostic imaging community is summarized by the acronym ALARA, i.e., as low as reasonably achievable. But unlike the general situation with diagnostic imaging and image-guided surgery, image-guided radiotherapy (IGRT) adds the imaging dose to an already high level of therapeutic radiation. There is furthermore an interplay between increased imaging and improved therapeutic dose conformity that suggests the possibility of optimizing rather than simply minimizing the imaging dose. For this reason, the management of imaging dose during radiotherapy is a different problem than its management during routine diagnostic or image-guided surgical procedures. The imaging dose received as part of a radiotherapy treatment has long been regarded as negligible and thus has been quantified in a fairly loose manner. On the other hand, radiation oncologists examine the therapy dose distribution in minute detail. The introduction of more intensive imaging procedures for IGRT now obligates the clinician to evaluate therapeutic and imaging doses in a more balanced manner. This task group is charged with addressing the issue of radiation dose delivered via image guidance techniques during radiotherapy. The group has developed this charge into three objectives: (1) Compile an overview of image-guidance techniques and their associated radiation dose levels, to provide the clinician using a particular set of image guidance techniques with enough data to estimate the total diagnostic dose for a specific

  20. Microencapsulation of Indocyanine Green for potential applications in image-guided drug delivery†

    PubMed Central

    Zhu, Zhiqiang

    2015-01-01

    We present a novel process to encapsulate Indocyanine Green (ICG) in liposomal droplets at high concentration for potential applications in image-guided drug delivery. The microencapsulation process follows two consecutive steps of droplet formation by liquid-driving coaxial flow focusing (LDCFF) and solvent removal by oil phase dewetting. These biocompatible lipid vesicles may have important applications in drug delivery and fluorescence imaging. PMID:25450664

  1. Applications of High Intensity Proton Accelerators

    NASA Astrophysics Data System (ADS)

    Raja, Rajendran; Mishra, Shekhar

    2010-06-01

    Superconducting radiofrequency linac development at Fermilab / S. D. Holmes -- Rare muon decay experiments / Y. Kuno -- Rare kaon decays / D. Bryman -- Muon collider / R. B. Palmer -- Neutrino factories / S. Geer -- ADS and its potential / J.-P. Revol -- ADS history in the USA / R. L. Sheffield and E. J. Pitcher -- Accelerator driven transmutation of waste: high power accelerator for the European ADS demonstrator / J. L. Biarrotte and T. Junquera -- Myrrha, technology development for the realisation of ADS in EU: current status & prospects for realisation / R. Fernandez ... [et al.] -- High intensity proton beam production with cyclotrons / J. Grillenberger and M. Seidel -- FFAG for high intensity proton accelerator / Y. Mori -- Kaon yields for 2 to 8 GeV proton beams / K. K. Gudima, N. V. Mokhov and S. I. Striganov -- Pion yield studies for proton driver beams of 2-8 GeV kinetic energy for stopped muon and low-energy muon decay experiments / S. I. Striganov -- J-Parc accelerator status and future plans / H. Kobayashi -- Simulation and verification of DPA in materials / N. V. Mokhov, I. L. Rakhno and S. I. Striganov -- Performance and operational experience of the CNGS facility / E. Gschwendtner -- Particle physics enabled with super-conducting RF technology - summary of working group 1 / D. Jaffe and R. Tschirhart -- Proton beam requirements for a neutrino factory and muon collider / M. S. Zisman -- Proton bunching options / R. B. Palmer -- CW SRF H linac as a proton driver for muon colliders and neutrino factories / M. Popovic, C. M. Ankenbrandt and R. P. Johnson -- Rapid cycling synchrotron option for Project X / W. Chou -- Linac-based proton driver for a neutrino factory / R. Garoby ... [et al.] -- Pion production for neutrino factories and muon colliders / N. V. Mokhov ... [et al.] -- Proton bunch compression strategies / V. Lebedev -- Accelerator test facility for muon collider and neutrino factory R&D / V. Shiltsev -- The superconducting RF linac for muon

  2. Structure-constrained image-guided inversion of geophysical data

    NASA Astrophysics Data System (ADS)

    Zhou, Jieyi

    The regularization term in the objective function of an inverse problem is equivalent to the "model covariance" in Tarantola's wording. It is not entirely reasonable to consider the model covariance to be isotropic and homogenous, as done in classical Tikhonov regularization, because the correlation relationships among model cells are likely to change with different directions and locations. The structure-constrained image-guided inversion method, presented in this thesis, aims to solve this problem, and can be used to integrate different types of geophysical data and geological information. The method is first theoretically developed and successfully tested with electrical resistivity data. Then it is applied to hydraulic tomography, and promising hydraulic conductivity models are obtained as well. With a correct guiding image, the image-guided inversion results not only follow the correct structure patterns, but also are closer to the true model in terms of parameter values, when compared with the conventional inversion results. To further account for the uncertainty in the guiding image, a Bayesian inversion scheme is added to the image-guided inversion algorithm. Each geophysical model parameter and geological (structure) model parameter is described by a probability density. Using the data misfit of image-guided inversion of the geophysical data as criterion, a stochastic (image-guided) inversion algorithm allows one to optimize both the geophysical model and the geological model at the same time. The last problem discussed in this thesis is, image-guided inversion and interpolation can help reduce non-uniqueness and improve resolution when utilizing spectral induced polarization data and petrophysical relationships to estimate permeability.

  3. SU-E-T-157: Evaluation and Comparison of Doses to Pelvic Lymph Nodes and to Point B with 3D Image Guided Treatment Planning for High Dose Brachytherapy for Treatment of Cervical Cancer

    SciTech Connect

    Bhandare, N.

    2014-06-01

    Purpose: To estimate and compare the doses received by the obturator, external and internal iliac lymph nodes and point Methods: CT-MR fused image sets of 15 patients obtained for each of 5 fractions of HDR brachytherapy using tandem and ring applicator, were used to generate treatment plans optimized to deliver a prescription dose to HRCTV-D90 and to minimize the doses to organs at risk (OARs). For each set of image, target volume (GTV, HRCTV) OARs (Bladder, Rectum, Sigmoid), and both left and right pelvic lymph nodes (obturator, external and internal iliac lymph nodes) were delineated. Dose-volume histograms (DVH) were generated for pelvic nodal groups (left and right obturator group, internal and external iliac chains) Per fraction DVH parameters used for dose comparison included dose to 100% volume (D100), and dose received by 2cc (D2cc), 1cc (D1cc) and 0.1 cc (D0.1cc) of nodal volume. Dose to point B was compared with each DVH parameter using 2 sided t-test. Pearson correlation were determined to examine relationship of point B dose with nodal DVH parameters. Results: FIGO clinical stage varied from 1B1 to IIIB. The median pretreatment tumor diameter measured on MRI was 4.5 cm (2.7– 6.4cm).The median dose to bilateral point B was 1.20 Gy ± 0.12 or 20% of the prescription dose. The correlation coefficients were all <0.60 for all nodal DVH parameters indicating low degree of correlation. Only 2 cc of obturator nodes was not significantly different from point B dose on t-test. Conclusion: Dose to point B does not adequately represent the dose to any specific pelvic nodal group. When using image guided 3D dose-volume optimized treatment nodal groups should be individually identified and delineated to obtain the doses received by pelvic nodes.

  4. Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation

    PubMed Central

    Kim, Terrence T.; Johnson, J. Patrick; Pashman, Robert; Drazin, Doniel

    2016-01-01

    We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy. PMID:27213152

  5. Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation.

    PubMed

    Kim, Terrence T; Johnson, J Patrick; Pashman, Robert; Drazin, Doniel

    2016-01-01

    We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy. PMID:27213152

  6. Image-Guided Tumor Ablation: Emerging Technologies and Future Directions

    PubMed Central

    McWilliams, Justin P.; Lee, Edward W.; Yamamoto, Shota; Loh, Christopher T.; Kee, Stephen T.

    2010-01-01

    As the trend continues toward the decreased invasiveness of medical procedures, image-guided percutaneous ablation has begun to supplant surgery for the local control of small tumors in the liver, kidney, and lung. New ablation technologies, and refinements of existing technologies, will enable treatment of larger and more complex tumors in these and other organs. At the same time, improvements in intraprocedural imaging promise to improve treatment accuracy and reduce complications. In this review, the latest advancements in clinical and experimental ablation technologies will be summarized, and new applications of image-guided tumor ablation will be discussed. PMID:22550370

  7. High intensity neutrino oscillation facilities in Europe

    NASA Astrophysics Data System (ADS)

    Edgecock, T. R.; Caretta, O.; Davenne, T.; Densam, C.; Fitton, M.; Kelliher, D.; Loveridge, P.; Machida, S.; Prior, C.; Rogers, C.; Rooney, M.; Thomason, J.; Wilcox, D.; Wildner, E.; Efthymiopoulos, I.; Garoby, R.; Gilardoni, S.; Hansen, C.; Benedetto, E.; Jensen, E.; Kosmicki, A.; Martini, M.; Osborne, J.; Prior, G.; Stora, T.; Melo Mendonca, T.; Vlachoudis, V.; Waaijer, C.; Cupial, P.; Chancé, A.; Longhin, A.; Payet, J.; Zito, M.; Baussan, E.; Bobeth, C.; Bouquerel, E.; Dracos, M.; Gaudiot, G.; Lepers, B.; Osswald, F.; Poussot, P.; Vassilopoulos, N.; Wurtz, J.; Zeter, V.; Bielski, J.; Kozien, M.; Lacny, L.; Skoczen, B.; Szybinski, B.; Ustrycka, A.; Wroblewski, A.; Marie-Jeanne, M.; Balint, P.; Fourel, C.; Giraud, J.; Jacob, J.; Lamy, T.; Latrasse, L.; Sortais, P.; Thuillier, T.; Mitrofanov, S.; Loiselet, M.; Keutgen, Th.; Delbar, Th.; Debray, F.; Trophine, C.; Veys, S.; Daversin, C.; Zorin, V.; Izotov, I.; Skalyga, V.; Burt, G.; Dexter, A. C.; Kravchuk, V. L.; Marchi, T.; Cinausero, M.; Gramegna, F.; De Angelis, G.; Prete, G.; Collazuol, G.; Laveder, M.; Mazzocco, M.; Mezzetto, M.; Signorini, C.; Vardaci, E.; Di Nitto, A.; Brondi, A.; La Rana, G.; Migliozzi, P.; Moro, R.; Palladino, V.; Gelli, N.; Berkovits, D.; Hass, M.; Hirsh, T. Y.; Schaumann, M.; Stahl, A.; Wehner, J.; Bross, A.; Kopp, J.; Neuffer, D.; Wands, R.; Bayes, R.; Laing, A.; Soler, P.; Agarwalla, S. K.; Cervera Villanueva, A.; Donini, A.; Ghosh, T.; Gómez Cadenas, J. J.; Hernández, P.; Martín-Albo, J.; Mena, O.; Burguet-Castell, J.; Agostino, L.; Buizza-Avanzini, M.; Marafini, M.; Patzak, T.; Tonazzo, A.; Duchesneau, D.; Mosca, L.; Bogomilov, M.; Karadzhov, Y.; Matev, R.; Tsenov, R.; Akhmedov, E.; Blennow, M.; Lindner, M.; Schwetz, T.; Fernández Martinez, E.; Maltoni, M.; Menéndez, J.; Giunti, C.; González García, M. C.; Salvado, J.; Coloma, P.; Huber, P.; Li, T.; López Pavón, J.; Orme, C.; Pascoli, S.; Meloni, D.; Tang, J.; Winter, W.; Ohlsson, T.; Zhang, H.; Scotto-Lavina, L.; Terranova, F.; Bonesini, M.; Tortora, L.; Alekou, A.; Aslaninejad, M.; Bontoiu, C.; Kurup, A.; Jenner, L. J.; Long, K.; Pasternak, J.; Pozimski, J.; Back, J. J.; Harrison, P.; Beard, K.; Bogacz, A.; Berg, J. S.; Stratakis, D.; Witte, H.; Snopok, P.; Bliss, N.; Cordwell, M.; Moss, A.; Pattalwar, S.; Apollonio, M.

    2013-02-01

    The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fréjus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of μ+ and μ- beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular He6 and Ne18, also stored in a ring. The far detector is also the MEMPHYS detector in the Fréjus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive.

  8. Tissue feature-based intra-fractional motion tracking for stereoscopic x-ray image guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Xie, Yaoqin; Xing, Lei; Gu, Jia; Liu, Wu

    2013-06-01

    Real-time knowledge of tumor position during radiation therapy is essential to overcome the adverse effect of intra-fractional organ motion. The goal of this work is to develop a tumor tracking strategy by effectively utilizing the inherent image features of stereoscopic x-ray images acquired during dose delivery. In stereoscopic x-ray image guided radiation delivery, two orthogonal x-ray images are acquired either simultaneously or sequentially. The essence of markerless tumor tracking is the reliable identification of inherent points with distinct tissue features on each projection image and their association between two images. The identification of the feature points on a planar x-ray image is realized by searching for points with high intensity gradient. The feature points are associated by using the scale invariance features transform descriptor. The performance of the proposed technique is evaluated by using images of a motion phantom and four archived clinical cases acquired using either a CyberKnife equipped with a stereoscopic x-ray imaging system, or a LINAC equipped with an onboard kV imager and an electronic portal imaging device. In the phantom study, the results obtained using the proposed method agree with the measurements to within 2 mm in all three directions. In the clinical study, the mean error is 0.48 ± 0.46 mm for four patient data with 144 sequential images. In this work, a tissue feature-based tracking method for stereoscopic x-ray image guided radiation therapy is developed. The technique avoids the invasive procedure of fiducial implantation and may greatly facilitate the clinical workflow.

  9. Portable, high intensity isotopic neutron source provides increased experimental accuracy

    NASA Technical Reports Server (NTRS)

    Mohr, W. C.; Stewart, D. C.; Wahlgren, M. A.

    1968-01-01

    Small portable, high intensity isotopic neutron source combines twelve curium-americium beryllium sources. This high intensity of neutrons, with a flux which slowly decreases at a known rate, provides for increased experimental accuracy.

  10. In vivo 808 nm image-guided photodynamic therapy based on an upconversion theranostic nanoplatform

    NASA Astrophysics Data System (ADS)

    Liu, Xiaomin; Que, Ivo; Kong, Xianggui; Zhang, Youlin; Tu, Langping; Chang, Yulei; Wang, Tong Tong; Chan, Alan; Löwik, Clemens W. G. M.; Zhang, Hong

    2015-09-01

    A new strategy for efficient in vivo image-guided photodynamic therapy (PDT) has been demonstrated utilizing a ligand-exchange constructed upconversion-C60 nanophotosensitizer. This theranostic platform is superior to the currently reported nanophotosensitizers in (i) directly bonding photosensitizer C60 to the surface of upconversion nanoparticles (UCNPs) by a smart ligand-exchange strategy, which greatly shortened the energy transfer distance and enhanced the 1O2 production, resulting in the improvement of the therapeutic effect; (ii) realizing in vivo NIR 808 nm image-guided PDT with both excitation (980 nm) and emission (808 nm) light falling in the biological window of tissues, which minimized auto-fluorescence, reduced light scatting and improved the imaging contrast and depth, and thus guaranteed noninvasive diagnostic accuracy. In vivo and ex vivo tests demonstrated its favorable bio-distribution, tumor-selectivity and high therapeutic efficacy. Owing to the effective ligand exchange strategy and the excellent intrinsic photophysical properties of C60, 1O2 production yield was improved, suggesting that a low 980 nm irradiation dosage (351 J cm-2) and a short treatment time (15 min) were sufficient to perform NIR (980 nm) to NIR (808 nm) image-guided PDT. Our work enriches the understanding of UCNP-based PDT nanophotosensitizers and highlights their potential use in future NIR image-guided noninvasive deep cancer therapy.A new strategy for efficient in vivo image-guided photodynamic therapy (PDT) has been demonstrated utilizing a ligand-exchange constructed upconversion-C60 nanophotosensitizer. This theranostic platform is superior to the currently reported nanophotosensitizers in (i) directly bonding photosensitizer C60 to the surface of upconversion nanoparticles (UCNPs) by a smart ligand-exchange strategy, which greatly shortened the energy transfer distance and enhanced the 1O2 production, resulting in the improvement of the therapeutic effect; (ii

  11. High-Intensity Sweeteners and Energy Balance

    PubMed Central

    Swithers, Susan E.; Martin, Ashley A.; Davidson, Terry L.

    2010-01-01

    Recent epidemiological evidence points to a link between a variety of negative health outcomes (e.g. metabolic syndrome, diabetes and cardiovascular disease) and the consumption of both calorically sweetened beverages and beverages sweetened with high-intensity, non-caloric sweeteners. Research on the possibility that non-nutritive sweeteners promote food intake, body weight gain, and metabolic disorders has been hindered by the lack of a physiologically-relevant model that describes the mechanistic basis for these outcomes. We have suggested that based on Pavlovian conditioning principles, consumption of non-nutritive sweeteners could result in sweet tastes no longer serving as consistent predictors of nutritive postingestive consequences. This dissociation between the sweet taste cues and the caloric consequences could lead to a decrease in the ability of sweet tastes to evoke physiological responses that serve to regulate energy balance. Using a rodent model, we have found that intake of foods or fluids containing non-nutritive sweeteners was accompanied by increased food intake, body weight gain, accumulation of body fat, and weaker caloric compensation, compared to consumption of foods and fluids containing glucose. Our research also provided evidence consistent with the hypothesis that these effects of consuming saccharin may be associated with a decrement in the ability of sweet taste to evoke thermic responses, and perhaps other physiological, cephalic phase, reflexes that are thought to help maintain energy balance. PMID:20060008

  12. High-intensity sweeteners and energy balance.

    PubMed

    Swithers, Susan E; Martin, Ashley A; Davidson, Terry L

    2010-04-26

    Recent epidemiological evidence points to a link between a variety of negative health outcomes (e.g. metabolic syndrome, diabetes and cardiovascular disease) and the consumption of both calorically sweetened beverages and beverages sweetened with high-intensity, non-caloric sweeteners. Research on the possibility that non-nutritive sweeteners promote food intake, body weight gain, and metabolic disorders has been hindered by the lack of a physiologically-relevant model that describes the mechanistic basis for these outcomes. We have suggested that based on Pavlovian conditioning principles, consumption of non-nutritive sweeteners could result in sweet tastes no longer serving as consistent predictors of nutritive postingestive consequences. This dissociation between the sweet taste cues and the caloric consequences could lead to a decrease in the ability of sweet tastes to evoke physiological responses that serve to regulate energy balance. Using a rodent model, we have found that intake of foods or fluids containing non-nutritive sweeteners was accompanied by increased food intake, body weight gain, accumulation of body fat, and weaker caloric compensation, compared to consumption of foods and fluids containing glucose. Our research also provided evidence consistent with the hypothesis that these effects of consuming saccharin may be associated with a decrement in the ability of sweet taste to evoke thermic responses, and perhaps other physiological, cephalic phase, reflexes that are thought to help maintain energy balance. PMID:20060008

  13. BEAM LOSS MECHANISMS IN HIGH INTENSITY LINACS

    SciTech Connect

    Plum, Michael A

    2012-01-01

    In the present operation of the Oak Ridge Spallation Neutron Source, 60-Hz, 825-us H beam pulses are accelerated to 910 MeV, and then compressed to less than a microsecond in the storage ring, to deliver 1 MW of beam power to the spallation target. The beam loss in the superconducting portion of the linac is higher than expected, and it has shown a surprising counter-intuitive correlation with quadrupole magnetic fields, with a loss minimum occurring when the quadrupoles are set to approximately half their design values. This behavior can now be explained by a recent set of experiments that show the beam loss is primarily due to intra-beam stripping. Beam halo is another important beam loss contributor, and collimation in the 2.5 MeV Medium Energy Beam Transport has proven to be an effective mitigation strategy. In this presentation, we will summarize these and other beam loss mechanisms that are important for high intensity linacs.

  14. Physics of intense, high energy radiation effects.

    SciTech Connect

    Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

    2011-02-01

    This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic calculations, the

  15. Image-guided surgery using multimodality strategy and molecular probes.

    PubMed

    Xi, Lei; Jiang, Hubei

    2016-01-01

    The ultimate goal of cancer surgery is to maximize the excision of tumorous tissue with minimal damage to the collateral normal tissues, reduce the postoperative recurrence, and improve the survival rate of patients. In order to locate tumor lesions, highlight tumor margins, visualize residual disease in the surgical wound, and map potential lymph node metastasis, various imaging techniques and molecular probes have been investigated to assist surgeons to perform more complete tumor resection. Combining imaging techniques with molecular probes is particularly promising as a new approach for image-guided surgery. Considering inherent limitations of different imaging techniques and insufficient sensitivity of nonspecific molecular probes, image-guided surgery with multimodality strategy and specific molecular probes appears to be an optimal choice. In this article, we briefly describe typical imaging techniques and molecular probes followed by a focused review on the current progress of multimodal image-guided surgery with specific molecular navigation. We also discuss optimal strategy that covers all stages of image-guided surgery including preoperative scanning of tumors, intraoperative inspection of surgical bed and postoperative care of patients. PMID:26053199

  16. Polymer fiber-image-guide-based embedded optical circuit board.

    PubMed

    Ai, J; Li, Y

    1999-01-10

    We propose a poly(methyl methacrylate) fiber-image-guide-based embedded optical circuit board for future optoelectronic array-interconnection applications. An experimental prototypical board that embeds perfect-shuffle and banyan interconnect patterns of 16 x 16 parallel links, each of which offers a fiber pixel density of >1000 pixels/mm(2), are demonstrated experimentally. PMID:18305618

  17. High-speed analog achromatic intensity modulator.

    PubMed

    Stockley, J E; Sharp, G D; Doroski, D; Johnson, K M

    1994-05-15

    We report what is to our knowledge the first implementation of a broadband analog intensity modulator composed of two chiral smectic liquid-crystal half-wave retarders. A reflection-mode intensity modulator employing a single active device has also demonstrated achromatic transmission. A quantitative theory for chromatic compensation is presented. By optimum selection of liquid-crystal retardance and orientation, intensity transmission is uniform throughout the visible. The chiral smectic liquid-crystal devices used in the implementation are capable of switching in less than 20 micros. PMID:19844436

  18. Polydopamine Nanoparticles as a Versatile Molecular Loading Platform to Enable Imaging-guided Cancer Combination Therapy

    PubMed Central

    Dong, Ziliang; Gong, Hua; Gao, Min; Zhu, Wenwen; Sun, Xiaoqi; Feng, Liangzhu; Fu, Tingting; Li, Yonggang; Liu, Zhuang

    2016-01-01

    Cancer combination therapy to treat tumors with different therapeutic approaches can efficiently improve treatment efficacy and reduce side effects. Herein, we develop a theranostic nano-platform based on polydopamine (PDA) nanoparticles, which then are exploited as a versatile carrier to allow simultaneous loading of indocyanine green (ICG), doxorubicin (DOX) and manganese ions (PDA-ICG-PEG/DOX(Mn)), to enable imaging-guided chemo & photothermal cancer therapy. In this system, ICG acts as a photothermal agent, which shows red-shifted near-infrared (NIR) absorbance and enhanced photostability compared with free ICG. DOX, a model chemotherapy drug, is then loaded onto the surface of PDA-ICG-PEG with high efficiency. With Mn2+ ions intrinsically chelated, PDA-ICG-PEG/DOX(Mn) is able to offer contrast under T1-weighted magnetic resonance (MR) imaging. In a mouse tumor model, the MR imaging-guided combined chemo- & photothermal therapy achieves a remarkable synergistic therapeutic effect compared with the respective single treatment modality. This work demonstrates that PDA nanoparticles could serve as a versatile molecular loading platform for MR imaging guided combined chemo- & photothermal therapy with minimal side effects, showing great potential for cancer theranostics. PMID:27217836

  19. Patient-specific Deformation Modelling via Elastography: Application to Image-guided Prostate Interventions

    PubMed Central

    Wang, Yi; Ni, Dong; Qin, Jing; Xu, Ming; Xie, Xiaoyan; Heng, Pheng-Ann

    2016-01-01

    Image-guided prostate interventions often require the registration of preoperative magnetic resonance (MR) images to real-time transrectal ultrasound (TRUS) images to provide high-quality guidance. One of the main challenges for registering MR images to TRUS images is how to estimate the TRUS-probe-induced prostate deformation that occurs during TRUS imaging. The combined statistical and biomechanical modeling approach shows promise for the adequate estimation of prostate deformation. However, the right setting of the biomechanical parameters is very crucial for realistic deformation modeling. We propose a patient-specific deformation model equipped with personalized biomechanical parameters obtained from shear wave elastography to reliably predict the prostate deformation during image-guided interventions. Using data acquired from a prostate phantom and twelve patients with suspected prostate cancer, we compared the prostate deformation model with and without patient-specific biomechanical parameters in terms of deformation estimation accuracy. The results show that the patient-specific deformation model possesses favorable model ability, and outperforms the model without patient-specific biomechanical parameters. The employment of the patient-specific biomechanical parameters obtained from elastography for deformation modeling shows promise for providing more precise deformation estimation in applications that use computer-assisted image-guided intervention systems. PMID:27272239

  20. Patient-specific Deformation Modelling via Elastography: Application to Image-guided Prostate Interventions.

    PubMed

    Wang, Yi; Ni, Dong; Qin, Jing; Xu, Ming; Xie, Xiaoyan; Heng, Pheng-Ann

    2016-01-01

    Image-guided prostate interventions often require the registration of preoperative magnetic resonance (MR) images to real-time transrectal ultrasound (TRUS) images to provide high-quality guidance. One of the main challenges for registering MR images to TRUS images is how to estimate the TRUS-probe-induced prostate deformation that occurs during TRUS imaging. The combined statistical and biomechanical modeling approach shows promise for the adequate estimation of prostate deformation. However, the right setting of the biomechanical parameters is very crucial for realistic deformation modeling. We propose a patient-specific deformation model equipped with personalized biomechanical parameters obtained from shear wave elastography to reliably predict the prostate deformation during image-guided interventions. Using data acquired from a prostate phantom and twelve patients with suspected prostate cancer, we compared the prostate deformation model with and without patient-specific biomechanical parameters in terms of deformation estimation accuracy. The results show that the patient-specific deformation model possesses favorable model ability, and outperforms the model without patient-specific biomechanical parameters. The employment of the patient-specific biomechanical parameters obtained from elastography for deformation modeling shows promise for providing more precise deformation estimation in applications that use computer-assisted image-guided intervention systems. PMID:27272239

  1. Percutaneous inner-ear access via an image-guided industrial robot system

    PubMed Central

    Baron, S; Eilers, H; Munske, B; Toennies, JL; Balachandran, R; Labadie, RF; Ortmaier, T; Webster, RJ

    2014-01-01

    Image-guided robots have been widely used for bone shaping and percutaneous access to interventional sites. However, due to high-accuracy requirements and proximity to sensitive nerves and brain tissues, the adoption of robots in inner-ear surgery has been slower. In this paper the authors present their recent work towards developing two image-guided industrial robot systems for accessing challenging inner-ear targets. Features of the systems include optical tracking of the robot base and tool relative to the patient and Kalman filter-based data fusion of redundant sensory information (from encoders and optical tracking systems) for enhanced patient safety. The approach enables control of differential robot positions rather than absolute positions, permitting simplified calibration procedures and reducing the reliance of the system on robot calibration in order to ensure overall accuracy. Lastly, the authors present the results of two phantom validation experiments simulating the use of image-guided robots in inner-ear surgeries such as cochlear implantation and petrous apex access. PMID:20718268

  2. Pleural controversies: image guided biopsy vs. thoracoscopy for undiagnosed pleural effusions?

    PubMed

    Dixon, Giles; de Fonseka, Duneesha; Maskell, Nick

    2015-06-01

    Undiagnosed pleural effusions present an increasing diagnostic burden upon healthcare providers internationally. The investigation of pleural effusions often requires the acquisition of tissue for histological analysis and diagnosis. Historically there were two options for tissue biopsy: a 'gold standard' surgical biopsy or a "blind" closed pleural biopsy. Over the last decade however, image-guided Tru-cut biopsies and local anaesthetic thoracoscopic (local anaesthetic thoracoscopy) biopsies have become more widespread. Image-guided techniques acquire samples under ultrasound (US) or computed tomography (CT) guidance whereas LAT involves the direct visualisation and biopsy of the pleura with pleuroscopy. Both techniques have been shown to be superior to 'blind' closed pleural biopsy for the diagnosis of pleural or metastatic malignancy. However, closed biopsy remains a viable method of investigation in areas of high incidence of tuberculosis (TB). Beyond this, each investigative technique has its own advantages and disadvantages. Image-guided biopsy is less invasive, usually carried out as an outpatient procedure, and enables tissue biopsy in frail patients and those with pleural thickening but no pleural fluid. Local anaesthetic thoracoscopy (LAT) provides diagnostic and therapeutic capabilities in one procedure. Large volume thoracentesis, multiple pleural biopsies and talc poudrage can be carried out in a single procedure. The overall diagnostic yield is similar for both techniques, although there are no large-scale direct comparisons. Both techniques share low complication rates. PMID:26150917

  3. Pleural controversies: image guided biopsy vs. thoracoscopy for undiagnosed pleural effusions?

    PubMed Central

    Dixon, Giles; de Fonseka, Duneesha

    2015-01-01

    Undiagnosed pleural effusions present an increasing diagnostic burden upon healthcare providers internationally. The investigation of pleural effusions often requires the acquisition of tissue for histological analysis and diagnosis. Historically there were two options for tissue biopsy: a ‘gold standard’ surgical biopsy or a “blind” closed pleural biopsy. Over the last decade however, image-guided Tru-cut biopsies and local anaesthetic thoracoscopic (local anaesthetic thoracoscopy) biopsies have become more widespread. Image-guided techniques acquire samples under ultrasound (US) or computed tomography (CT) guidance whereas LAT involves the direct visualisation and biopsy of the pleura with pleuroscopy. Both techniques have been shown to be superior to ‘blind’ closed pleural biopsy for the diagnosis of pleural or metastatic malignancy. However, closed biopsy remains a viable method of investigation in areas of high incidence of tuberculosis (TB). Beyond this, each investigative technique has its own advantages and disadvantages. Image-guided biopsy is less invasive, usually carried out as an outpatient procedure, and enables tissue biopsy in frail patients and those with pleural thickening but no pleural fluid. Local anaesthetic thoracoscopy (LAT) provides diagnostic and therapeutic capabilities in one procedure. Large volume thoracentesis, multiple pleural biopsies and talc poudrage can be carried out in a single procedure. The overall diagnostic yield is similar for both techniques, although there are no large-scale direct comparisons. Both techniques share low complication rates. PMID:26150917

  4. Image-Guided Local Delivery Strategies Enhance Therapeutic Nanoparticle Uptake in Solid Tumors

    PubMed Central

    Mouli, Samdeep K.; Tyler, Patrick; McDevitt, Joseph L.; Eifler, Aaron C.; Guo, Yang; Nicolai, Jodi; Lewandowski, Robert .J.; Li, Weiguo; Procissi, Daniel; Ryu, Robert K.; Wang, Y. Andrew; Salem, Riad; Larson, Andrew C.; Omary, Reed A.

    2013-01-01

    Nanoparticles (NP) have emerged as a novel class of therapeutic agents that overcome many of the limitations of current cancer chemotherapeutics. However, a major challenge to many current NP platforms is unfavorable biodistribution, and limited tumor uptake, upon systemic delivery. Delivery, therefore, remains a critical barrier to widespread clinical adoption of NP therapeutics. To overcome these limitations, we have adapted the techniques of image-guided local drug delivery to develop nano-ablation and nano-embolization. Nano-ablation is a tumor ablative strategy that employs image-guided placement of electrodes into tumor tissue to electroporate tumor cells, resulting in rapid influx of NPs that is not dependent on cellular uptake machinery or stage of the cell cycle. Nano-embolization involves the image-guided delivery of NPs and embolic agents directly into the blood supply of tumors. We describe the design and testing of our innovative local delivery strategies using doxorubicin functionalized superparamagnetic iron oxide nanoparticles (DOX-SPIOs) in cell culture, and the N1S1 hepatoma and VX2 tumor models, imaged by high resolution 7T MRI. We demonstrate that local delivery techniques result in significantly increased intra-tumoral DOX-SPIO uptake, with limited off-target delivery in tumor bearing animal models. The techniques described are versatile enough to be extended to any NP platform, targeting any solid organ malignancy that can be accessed via imaging guidance. PMID:23952712

  5. High intensity ultrasound effects on meat brining.

    PubMed

    Cárcel, J A; Benedito, J; Bon, J; Mulet, A

    2007-08-01

    Pork loin (longissimus dorsi) samples of two different geometries, cylinders and slabs, were immersed in saturated NaCl brine for 45min under different conditions: without brine agitation (STAT), with brine agitation (AG) and with ultrasound application (US) at eight levels of ultrasonic intensity. Moisture content change and NaCl gain were considered in order to evaluate the difference in the brining treatments. No significant differences were found in moisture and NaCl content of samples treated under STAT conditions and AG conditions, while the influence of ultrasound on the mass transfer process during meat brining depended on the intensity applied. There was an ultrasonic intensity threshold above which the influence of ultrasound appeared. At the highest level of intensity studied, the water content of samples was significantly higher than the initial water content of meat. As regards NaCl transfer, once above the intensity threshold, the increase in the NaCl content was proportional to the applied ultrasonic intensity. Not statistically significant differences were found for sample geometry. PMID:22061236

  6. Proton shock acceleration using a high contrast high intensity laser

    NASA Astrophysics Data System (ADS)

    Gauthier, Maxence; Roedel, Christian; Kim, Jongjin; Aurand, Bastian; Curry, Chandra; Goede, Sebastian; Propp, Adrienne; Goyon, Clement; Pak, Art; Kerr, Shaun; Ramakrishna, Bhuvanesh; Ruby, John; William, Jackson; Glenzer, Siegfried

    2015-11-01

    Laser-driven proton acceleration is a field of intense research due to the interesting characteristics of this novel particle source including high brightness, high maximum energy, high laminarity, and short duration. Although the ion beam characteristics are promising for many future applications, such as in the medical field or hybrid accelerators, the ion beam generated using TNSA, the acceleration mechanism commonly achieved, still need to be significantly improved. Several new alternative mechanisms have been proposed such as collisionless shock acceleration (CSA) in order to produce a mono-energetic ion beam favorable for those applications. We report the first results of an experiment performed with the TITAN laser system (JLF, LLNL) dedicated to the study of CSA using a high intensity (5x1019W/cm2) high contrast ps laser pulse focused on 55 μm thick CH and CD targets. We show that the proton spectrum generated during the interaction exhibits high-energy mono-energetic features along the laser axis, characteristic of a shock mechanism.

  7. Intensity correlation of ionizing background at high redshifts

    NASA Technical Reports Server (NTRS)

    Zuo, Lin

    1993-01-01

    Intensity correlation of ionizing background at high redshifts is discussed. The intensity correlation function xi(sub j) and the absorption line equivalent width correlation xi(sub 1/W) are discussed.

  8. Testicular Doses in Image-Guided Radiotherapy of Prostate Cancer

    SciTech Connect

    Deng Jun; Chen Zhe; Yu, James B.; Roberts, Kenneth B.; Peschel, Richard E.; Nath, Ravinder

    2012-01-01

    Purpose: To investigate testicular doses contributed by kilovoltage cone-beam computed tomography (kVCBCT) during image-guided radiotherapy (IGRT) of prostate cancer. Methods and Materials: An EGS4 Monte Carlo code was used to calculate three-dimensional dose distributions from kVCBCT on 3 prostate cancer patients. Absorbed doses to various organs were compared between intensity-modulated radiotherapy (IMRT) treatments and kVCBCT scans. The impact of CBCT scanning mode, kilovoltage peak energy (kVp), and CBCT field span on dose deposition to testes and other organs was investigated. Results: In comparison with one 10-MV IMRT treatment, a 125-kV half-fan CBCT scan delivered 3.4, 3.8, 4.1, and 5.7 cGy to the prostate, rectum, bladder, and femoral heads, respectively, accounting for 1.7%, 3.2%, 3.2%, and 8.4% of megavoltage photon dose contributions. However, the testes received 2.9 cGy from the same CBCT scan, a threefold increase as compared with 0.7 cGy received during IMRT. With the same kVp, full-fan mode deposited much less dose to organs than half-fan mode, ranging from 9% less for prostate to 69% less for testes, except for rectum, where full-fan mode delivered 34% more dose. As photon beam energy increased from 60 to 125 kV, kVCBCT-contributed doses increased exponentially for all organs, irrespective of scanning mode. Reducing CBCT field span from 30 to 10 cm in the superior-inferior direction cut testicular doses from 5.7 to 0.2 cGy in half-fan mode and from 1.5 to 0.1 cGy in full-fan mode. Conclusions: Compared with IMRT, kVCBCT-contributed doses to the prostate, rectum, bladder, and femoral heads are clinically insignificant, whereas dose to the testes is threefold more. Full-fan CBCT usually deposits much less dose to organs (except for rectum) than half-fan mode in prostate patients. Kilovoltage CBCT-contributed doses increase exponentially with photon beam energy. Reducing CBCT field significantly cuts doses to testes and other organs.

  9. Design, implementation and investigation of an image guide-based optical flip-flop array

    NASA Technical Reports Server (NTRS)

    Griffith, P. C.

    1987-01-01

    Presented is the design for an image guide-based optical flip-flop array created using a Hughes liquid crystal light valve and a flexible image guide in a feedback loop. This design is used to investigate the application of image guides as a communication mechanism in numerical optical computers. It is shown that image guides can be used successfully in this manner but mismatch match between the input and output fiber arrays is extremely limiting.

  10. Performances of BNL high-intensity synchrotrons

    SciTech Connect

    Weng, W.T.

    1998-03-01

    The AGS proton synchrotron was completed in 1960 with initial intensity in the 10 to the 10th power proton per pulse (ppp) range. Over the years, through many upgrades and improvements, the AGS now reached an intensity record of 6.3 {times} 10{sup 13} ppp, the highest world intensity record for a proton synchrotron on a single pulse basis. At the same time, the Booster reached 2.2 {times} 10{sup 13} ppp surpassing the design goal of 1.5 {times} 10{sup 13} ppp due to the introduction of second harmonic cavity during injection. The intensity limitation caused by space charge tune spread and its relationship to injection energy at 50 MeV, 200 MeV, and 1,500 MeV will be presented as well as many critical accelerator manipulations. BNL currently participates in the design of an accumulator ring for the SNS project at Oak Ridge. The status on the issues of halo formation, beam losses and collimation are also presented.

  11. Exposure Risks Among Children Undergoing Radiation Therapy: Considerations in the Era of Image Guided Radiation Therapy.

    PubMed

    Hess, Clayton B; Thompson, Holly M; Benedict, Stanley H; Seibert, J Anthony; Wong, Kenneth; Vaughan, Andrew T; Chen, Allen M

    2016-04-01

    Recent improvements in toxicity profiles of pediatric oncology patients are attributable, in part, to advances in the field of radiation oncology such as intensity modulated radiation (IMRT) and proton therapy (IMPT). While IMRT and IMPT deliver highly conformal dose to targeted volumes, they commonly demand the addition of 2- or 3-dimensional imaging for precise positioning--a technique known as image guided radiation therapy (IGRT). In this manuscript we address strategies to further minimize exposure risk in children by reducing effective IGRT dose. Portal X rays and cone beam computed tomography (CBCT) are commonly used to verify patient position during IGRT and, because their relative radiation exposure is far less than the radiation absorbed from therapeutic treatment beams, their sometimes significant contribution to cumulative risk can be easily overlooked. Optimizing the conformality of IMRT/IMPT while simultaneously ignoring IGRT dose may result in organs at risk being exposed to a greater proportion of radiation from IGRT than from therapeutic beams. Over a treatment course, cumulative central-axis CBCT effective dose can approach or supersede the amount of radiation absorbed from a single treatment fraction, a theoretical increase of 3% to 5% in mutagenic risk. In select scenarios, this may result in the underprediction of acute and late toxicity risk (such as azoospermia, ovarian dysfunction, or increased lifetime mutagenic risk) in radiation-sensitive organs and patients. Although dependent on variables such as patient age, gender, weight, body habitus, anatomic location, and dose-toxicity thresholds, modifying IGRT use and acquisition parameters such as frequency, imaging modality, beam energy, current, voltage, rotational degree, collimation, field size, reconstruction algorithm, and documentation can reduce exposure, avoid unnecessary toxicity, and achieve doses as low as reasonably achievable, promoting a culture and practice of "gentle IGRT

  12. BOOK REVIEW: Image-Guided IMRT

    NASA Astrophysics Data System (ADS)

    Mayles, P.

    2006-12-01

    This book provides comprehensive coverage of the subject of intensity modulated radiotherapy and the associated imaging. Most of the names associated with advanced radiotherapy can be found among the 80 authors and the book is therefore an authoritative reference text. The early chapters deal with the basic principles and include an interesting comparison between views of quality assurance for IMRT from Europe and North America. It is refreshing to see that the advice given has moved on from the concept of individual patient based quality control to more generic testing of the delivery system. However, the point is made that the whole process including the data transfer needs to be quality assured and the need for thorough commissioning of the process is emphasised. The `tricks' needed to achieve a dose based IMRT plan are well covered by the group at Ghent and there is an interesting summary of biological aspects of treatment planning for IMRT by Andrzej Niemierko. The middle section of the book deals with advanced imaging aspects of both treatment planning and delivery. The contributions of PET and MR imaging are well covered and there is a rather rambling section on molecular imaging. Image guidance in radiotherapy treatment is addressed including the concept of adaptive radiotherapy. The treatment aspects could perhaps have merited some more coverage, but there is a very thorough discussion of 4D techniques. The final section of the book considers each site of the body in turn. This will be found useful by those wishing to embark on IMRT in a new area, although some of the sections are more comprehensive than others. The book contains a wealth of interesting and thought provoking articles giving details as well as broad principles, and would be a useful addition to every departmental library. The editors have done a good job of ensuring that the different chapters are complementary, and of encouraging a systematic approach to the descriptions of IMRT in

  13. Solid Lipid Nanoparticles for Image-Guided Therapy of Atherosclerosis.

    PubMed

    Oumzil, Khalid; Ramin, Michael A; Lorenzato, Cyril; Hémadou, Audrey; Laroche, Jeanny; Jacobin-Valat, Marie Josée; Mornet, Stephane; Roy, Claude-Eric; Kauss, Tina; Gaudin, Karen; Clofent-Sanchez, Gisèle; Barthélémy, Philippe

    2016-03-16

    Although the application of nanotechnologies to atherosclerosis remains a young field, novel strategies are needed to address this public health issue. In this context, the magnetic resonance imaging (MRI) approach has been gradually investigated in order to enable image-guided treatments. In this contribution, we report a new approach based on nucleoside-lipids allowing the synthesis of solid lipid nanoparticles (SLN) loaded with iron oxide particles and therapeutic agents. The insertion of nucleoside-lipids allows the formation of stable SLNs loaded with prostacycline (PGI2) able to inhibit platelet aggregation. The new SLNs feature better relaxivity properties in comparison to the clinically used contrast agent Feridex, indicating that SLNs are suitable for image-guided therapy. PMID:26751997

  14. Image-Guided Radiotherapy and -Brachytherapy for Cervical Cancer

    PubMed Central

    Dutta, Suresh; Nguyen, Nam Phong; Vock, Jacqueline; Kerr, Christine; Godinez, Juan; Bose, Satya; Jang, Siyoung; Chi, Alexander; Almeida, Fabio; Woods, William; Desai, Anand; David, Rick; Karlsson, Ulf Lennart; Altdorfer, Gabor

    2015-01-01

    Conventional radiotherapy for cervical cancer relies on clinical examination, 3-dimensional conformal radiotherapy (3D-CRT), and 2-dimensional intracavitary brachytherapy. Excellent local control and survival have been obtained for small early stage cervical cancer with definitive radiotherapy. For bulky and locally advanced disease, the addition of chemotherapy has improved the prognosis but toxicity remains significant. New imaging technology such as positron-emission tomography and magnetic resonance imaging has improved tumor delineation for radiotherapy planning. Image-guided radiotherapy (IGRT) may decrease treatment toxicity of whole pelvic radiation because of its potential for bone marrow, bowel, and bladder sparring. Tumor shrinkage during whole pelvic IGRT may optimize image-guided brachytherapy (IGBT), allowing for better local control and reduced toxicity for patients with cervical cancer. IGRT and IGBT should be integrated in future prospective studies for cervical cancer. PMID:25853092

  15. Recent advances in image-guided targeted prostate biopsy.

    PubMed

    Brown, Anna M; Elbuluk, Osama; Mertan, Francesca; Sankineni, Sandeep; Margolis, Daniel J; Wood, Bradford J; Pinto, Peter A; Choyke, Peter L; Turkbey, Baris

    2015-08-01

    Prostate cancer is a common malignancy in the United States that results in over 30,000 deaths per year. The current state of prostate cancer diagnosis, based on PSA screening and sextant biopsy, has been criticized for both overdiagnosis of low-grade tumors and underdiagnosis of clinically significant prostate cancers (Gleason score ≥7). Recently, image guidance has been added to perform targeted biopsies of lesions detected on multi-parametric magnetic resonance imaging (mpMRI) scans. These methods have improved the ability to detect clinically significant cancer, while reducing the diagnosis of low-grade tumors. Several approaches have been explored to improve the accuracy of image-guided targeted prostate biopsy, including in-bore MRI-guided, cognitive fusion, and MRI/transrectal ultrasound fusion-guided biopsy. This review will examine recent advances in these image-guided targeted prostate biopsy techniques. PMID:25596716

  16. Image-guided radiotherapy and -brachytherapy for cervical cancer.

    PubMed

    Dutta, Suresh; Nguyen, Nam Phong; Vock, Jacqueline; Kerr, Christine; Godinez, Juan; Bose, Satya; Jang, Siyoung; Chi, Alexander; Almeida, Fabio; Woods, William; Desai, Anand; David, Rick; Karlsson, Ulf Lennart; Altdorfer, Gabor

    2015-01-01

    Conventional radiotherapy for cervical cancer relies on clinical examination, 3-dimensional conformal radiotherapy (3D-CRT), and 2-dimensional intracavitary brachytherapy. Excellent local control and survival have been obtained for small early stage cervical cancer with definitive radiotherapy. For bulky and locally advanced disease, the addition of chemotherapy has improved the prognosis but toxicity remains significant. New imaging technology such as positron-emission tomography and magnetic resonance imaging has improved tumor delineation for radiotherapy planning. Image-guided radiotherapy (IGRT) may decrease treatment toxicity of whole pelvic radiation because of its potential for bone marrow, bowel, and bladder sparring. Tumor shrinkage during whole pelvic IGRT may optimize image-guided brachytherapy (IGBT), allowing for better local control and reduced toxicity for patients with cervical cancer. IGRT and IGBT should be integrated in future prospective studies for cervical cancer. PMID:25853092

  17. Image-guided drainage of cystic vestibular schwannomata.

    PubMed

    Barrett, Chris; Prasad, K S Manjunath; Hill, John; Johnson, Ian; Heaton, Judith M; Crossman, John E; Mendelow, Alexander D

    2010-01-01

    The management of vestibular schwannomata is controversial. Surveillance remains an acceptable option for elderly patients or those with small lesions. Stereoradiosurgery is also an option, while surgery is often preferred in younger patients with larger lesions. In elderly patients with lesions causing brainstem compression, craniotomy is a major undertaking. We report two cases of cystic cerebellopontine angle tumours in patients with co-morbidity, who were managed successfully with image-guided insertion of a cystoperitoneal shunt. PMID:19693430

  18. Image-Guided Abdominal Surgery and Therapy Delivery

    PubMed Central

    Galloway, Robert L.; Herrell, S. Duke; Miga, Michael I.

    2013-01-01

    Image-Guided Surgery has become the standard of care in intracranial neurosurgery providing more exact resections while minimizing damage to healthy tissue. Moving that process to abdominal organs presents additional challenges in the form of image segmentation, image to physical space registration, organ motion and deformation. In this paper, we present methodologies and results for addressing these challenges in two specific organs: the liver and the kidney. PMID:25077012

  19. Novel Image-Guided Management of a Uterine Arteriovenous Malformation

    SciTech Connect

    Przybojewski, Stefan J. Sadler, David J.

    2011-02-15

    The investigators present a novel image-guided embolization, not previously described, of a uterine arteriovenous malformation (AVM) resistant to endovascular management. The uterus was exposed surgically, and Histoacryl (Braun, Fulda, Germany) was injected directly into the nidus using ultrasound guidance and fluoroscopy. The patient had a successful full-term pregnancy after this procedure. This technique may be a useful alternative management strategy in patients with uterine AVM who fail traditional endovascular embolization and who still desire fertility.

  20. Sensor technology for image-guided surgery

    NASA Astrophysics Data System (ADS)

    Zinreich, S. J.; Helm, Patrick

    1998-06-01

    The advances in radiographic imaging techniques that have occurred within the past decades have significantly enhanced our abilities to display anatomy as well as pathology. Although image acquisition commonly generates three-dimensional datasets, limitation in user interfaces generally requires that this information be presented clinically as a series of two dimensional images. Consequently, during preoperative planning, surgeons are required to mentally transform a wealth of two dimensional hard copy images qualitatively into three-dimensional concepts that are used as a road map to surgery. The sugeron's success is dependent on the accurate mental transfer of Computer Tomographic X-ray (CT) and Magnetic Resonance (MR) imaging information to the operative site to assist direct visual perception of the procedure. Thus, the surgical procedure is performed with the surgeon intuitively transferring radiographic information to the surgical site. Neurosurgeons, for example, are especially hampered because of limited ability to visually distinguish tumor tissue, peritumoral edema, and normal brain parenchyma. This limitation at least partially accounts for the relatively high incidence of subtotal tumor excision. Based on the need to assit the surgeon transform the preoperative scans to the operative site, stereotactic systems were developed and would evolve into frameless stereotaxy with the advance of various sensors.

  1. Salivary Cortisol Responses and Perceived Exertion during High Intensity and Low Intensity Bouts of Resistance Exercise

    PubMed Central

    McGuigan, Michael R.; Egan, Alison D.; Foster, Carl

    2004-01-01

    The purpose of this study was to measure the salivary cortisol response to different intensities of resistance exercise. In addition, we wanted to determine the reliability of the session rating of perceived exertion (RPE) scale to monitor resistance exercise intensity. Subjects (8 men, 9 women) completed 2 trials of acute resistance training bouts in a counterbalanced design. The high intensity resistance exercise protocol consisted of six, ten-repetition sets using 75% of one repetition maximum (RM) on a Smith machine squat and bench press exercise (12 sets total). The low intensity resistance exercise protocol consisted of three, ten-repetition sets at 30% of 1RM of the same exercises as the high intensity protocol. Both exercise bouts were performed with 2 minutes of rest between each exercise and sessions were repeated to test reliability of the measures. The order of the exercise bouts was randomized with least 72 hours between each session. Saliva samples were obtained immediately before, immediately after and 30 mins following each resistance exercise bout. RPE measures were obtained using Borg’s CR-10 scale following each set. Also, the session RPE for the entire exercise session was obtained 30 minutes following completion of the session. There was a significant 97% increase in the level of salivary cortisol immediately following the high intensity exercise session (P<0.05). There was also a significant difference in salivary cortisol of 145% between the low intensity and high intensity exercise session immediately post-exercise (P<0.05). The low intensity exercise did not result in any significant changes in cortisol levels. There was also a significant difference between the session RPE values for the different intensity levels (high intensity 7.1 vs. low intensity 1.9) (P<0.05). The intraclass correlation coefficient for the session RPE measure was 0.95. It was concluded that the session RPE method is a valid and reliable method of quantifying

  2. Light shield and cooling apparatus. [high intensity ultraviolet lamp

    NASA Technical Reports Server (NTRS)

    Meador, T. G., Jr. (Inventor)

    1974-01-01

    A light shield and cooling apparatus was developed for a high intensity ultraviolet lamp including water and high pressure air for cooling and additional apparatus for shielding the light and suppressing the high pressure air noise.

  3. Aluminium plasma production at high laser intensity

    SciTech Connect

    Torrisi, L.; Cutroneo, M.

    2014-02-28

    Thick and thin films of Al targets were irradiated in vacuum with iodine laser at 1315 nm wavelength, 300 ps pulse duration at a maximum intensity of about 10{sup 16} W/cm{sup 2} by varying the pulse energy and focal position. The laser-generated plasma was monitored in forward and backward directions by using ion collectors, SiC detectors, Thomson parabola spectrometer, and X-ray streak camera. Ion emission shows maximum proton energy of about 4 MeV in self-focusing conditions and a maximum Al ion energy of about 50 MeV. An evaluation of the electric field driving ions in conditions of target normal sheath acceleration is given.

  4. FLASH requirements for the high intensity radiated field electromagnetic environment

    NASA Astrophysics Data System (ADS)

    Murdock, John K.

    1995-05-01

    The worldwide proliferation of high intensity emitting sources and the more electric aircraft increase the intensity of the Electromagnetic Environment (EME) in which aircraft must operate. A FLASH program HIRF (High Intensity Radiated Field) EME requirement is derived to cover both commercial and military fixed and rotary wing aircraft. This requirement is derived from the radiated susceptibility requirement documents of both the FAA and U.S. military. Specific test data and analysis will show that we can meet this requirement.

  5. Imaging guided mediastinal percutaneal core biopsy--technique and complications.

    PubMed

    Azrumelashvili, T; Mizandari, M; Magalashvili, D; Dundua, T

    2015-05-01

    165 percutaneous biopsies of anterior, middle and posterior mediastinum lesions were performed to 156 patients. Procedure was guided by US in 40 cases, by CT - in 125 cases. Hydrodissection was used in 5 cases, artificial pneumothorax - in 3 cases in order to avoid transpulmonary needle pass. Post-biopsy CT scan was performed and patients observed for any complications. Adequate tissue for histological diagnosis was obtained in 156 (94.5%) cases at the first attempt; in 9 (5.5%) cases the repeated procedure was needed. No major complications were detected after biopsy procedures; minor complications (pneumothorax, hemothorax and hemophtysis) were detected in 23 (13.9%) cases. No complications were detected after US guided procedures; In 17 (10.3% of all complications) cases pneumothorax, in 4 (2.4%) cases - hemothorax and in 2 (1.2%) cases hemophtisis was detected on CT guided procedures. All hemothorax and hemophtisis and 10 pneumothorax cases happened to be self-limited; in 3 pneumothorax cases aspiration and in 4 cases - pleural drainage was needed. Percutaneous image-guided core biopsy of mediastinal lesions is an accurate and safe procedure, which enables to get the tissue material from all mediastinum compartments. Ultrasound is the most efficient for biopsy guidance, if the target is adequately imaged by it; the advantages of US guidance are: a) possibility of real-time needle movement control b) possibility of real-time blood flow imaging b) noninvasiveness c) cost-effectiveness d) possibility to perform the biopsy at the bedside, in a semiupright position; so, ultrasound is a "Gold Standard" for procedure guidance if the 'target" can be adequately imaged by this technique. If US guidance is impossible biopsy should be performed under CT guidance. Hydrodissection and artificial pneumothorax enables to avoid the lung tissue penetration related complications. Pneumothorax was associated with multiple Needle passes and larger diameter needle use. The safety

  6. Image-guided surgery using near-infrared fluorescent light: from bench to bedside

    NASA Astrophysics Data System (ADS)

    Boogerd, Leonora S. F.; Handgraaf, Henricus J. M.; van de Velde, Cornelis J. H.; Vahrmeijer, Alexander L.

    2015-03-01

    Due to its relatively high tissue penetration, near-infrared (NIR; 700-900 nm) fluorescent light has the potential to visualize structures that need to be resected (e.g. tumors, lymph nodes) and structures that need to be spared (e.g. nerves, ureters, bile ducts). Until now, most clinical trials have focused on suboptimal, non-targeted dyes. Although successful, a new era in image-guided surgery has begun by the introduction of tumor-targeted agents. In this paper, we will describe how tumor-targeted NIR fluorescent imaging can be applied in a clinical setting.

  7. Sample handler for x-ray tomographic microscopy and image-guided failure assessment

    SciTech Connect

    Wyss, Peter; Thurner, Philipp; Broennimann, Rolf; Sennhauser, Urs; Stampanoni, Marco; Abela, Rafael; Mueller, Ralph

    2005-07-15

    X-ray tomographic microscopy (XTM) yields a three-dimensional data model of an investigated specimen. XTM providing micrometer resolution requires synchrotron light, high resolution area detectors, and a precise sample handler. The sample handler has a height of 270 mm only, is usable for 1 {mu}m resolution, and is able to carry loading machines with a weight of up to 20 kg. This allows exposing samples to load between scans for image-guided failure assessment. This system has been used in the XTM end station of the materials science beamline of the Swiss Light Source at the Paul Scherrer Institut.

  8. Current external beam radiation therapy quality assurance guidance: does it meet the challenges of emerging image-guided technologies?

    PubMed

    Palta, Jatinder R; Liu, Chihray; Li, Jonathan G

    2008-01-01

    The traditional prescriptive quality assurance (QA) programs that attempt to ensure the safety and reliability of traditional external beam radiation therapy are limited in their applicability to such advanced radiation therapy techniques as three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, inverse treatment planning, stereotactic radiosurgery/radiotherapy, and image-guided radiation therapy. The conventional QA paradigm, illustrated by the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 40 (TG-40) report, consists of developing a consensus menu of tests and device performance specifications from a generic process model that is assumed to apply to all clinical applications of the device. The complexity, variation in practice patterns, and level of automation of high-technology radiotherapy renders this "one-size-fits-all" prescriptive QA paradigm ineffective or cost prohibitive if the high-probability error pathways of all possible clinical applications of the device are to be covered. The current approaches to developing comprehensive prescriptive QA protocols can be prohibitively time consuming and cost ineffective and may sometimes fail to adequately safeguard patients. It therefore is important to evaluate more formal error mitigation and process analysis methods of industrial engineering to more optimally focus available QA resources on process components that have a significant likelihood of compromising patient safety or treatment outcomes. PMID:18406911

  9. The use of virtual fiducials in image-guided kidney surgery

    NASA Astrophysics Data System (ADS)

    Glisson, Courtenay; Ong, Rowena; Simpson, Amber; Clark, Peter; Herrell, S. D.; Galloway, Robert

    2011-03-01

    The alignment of image-space to physical-space lies at the heart of all image-guided procedures. In intracranial surgery, point-based registrations can be used with either skin-affixed or bone-implanted extrinsic objects called fiducial markers. The advantages of point-based registration techniques are that they are robust, fast, and have a well developed mathematical foundation for the assessment of registration quality. In abdominal image-guided procedures such techniques have not been successful. It is difficult to accurately locate sufficient homologous intrinsic points in imagespace and physical-space, and the implantation of extrinsic fiducial markers would constitute "surgery before the surgery." Image-space to physical-space registration for abdominal organs has therefore been dominated by surfacebased registration techniques which are iterative, prone to local minima, sensitive to initial pose, and sensitive to percentage coverage of the physical surface. In our work in image-guided kidney surgery we have developed a composite approach using "virtual fiducials." In an open kidney surgery, the perirenal fat is removed and the surface of the kidney is dotted using a surgical marker. A laser range scanner (LRS) is used to obtain a surface representation and matching high definition photograph. A surface to surface registration is performed using a modified iterative closest point (ICP) algorithm. The dots are extracted from the high definition image and assigned the three dimensional values from the LRS pixels over which they lie. As the surgery proceeds, we can then use point-based registrations to re-register the spaces and track deformations due to vascular clamping and surgical tractions.

  10. High-intensity beam collimation and targetry

    SciTech Connect

    Mokhov, N.V.; /Fermilab

    2006-11-01

    Principles, design criteria and realization of reliable collimation systems for the high-power accelerators and hadron colliders are described. Functionality of collimators as the key elements of the machine protection system are discussed along with the substantial progress on the crystal collimation front. The key issues are considered in design of high-power target systems and achieving their best performance. Simulation code requirements are presented.

  11. Charge Strippers of Heavy Ions for High Intensity Accelerators

    NASA Astrophysics Data System (ADS)

    Nolen, Jerry A.; Marti, Felix

    2014-02-01

    Charge strippers play a critical role in many high intensity heavy ion accelerators. Here we present some history of recent stripper technology development and indicate the capabilities and limitations of the various approaches. The properties of solid, gaseous, and liquid strippers are covered. In particular, the limitations of solid strippers for high intensity, high atomic number heavy ions and the unique features of helium gas and liquid lithium for high intensity applications are covered. The need for high quality simulation of stripper performance as important input for system optimization is explained and examples of the current simulation codes are given.

  12. Engineering Food Ingredients with High-Intensity Ultrasound

    NASA Astrophysics Data System (ADS)

    Weiss, Jochen; Kristbergsson, Kristberg; Kjartansson, Gunnar Thor

    The use of ultrasound in the food industry has increased in the last decades. Ultrasound has been used both to analyze food structure and composition at low ultrasonic intensities and high frequencies and to modify ingredients at high ultrasonic intensities and low frequencies. Application of the latter is referred to as high-intensity (power) ultrasonication and is generally carried out at frequencies of =0.1 MHz and ultrasonic intensities of 10-100 W cm-2. In the food industry, power ultrasonication has proved to be a highly effective food processing and preservation technology, and use of high-intensity ultrasound with or without heat may be used, for example, to denature enzymes, aid in the extraction of valuable compounds from plants and seeds, tenderize meat, and homogenize or disperse two-phase systems such as emulsions or suspensions (Mason et al., 1996).

  13. A compact high intensity cooler (CHIC)

    NASA Astrophysics Data System (ADS)

    Bland, T. J.; Niggemann, R. E.; Parekh, M. B.

    1983-07-01

    A unique heat exchanger has been developed with potential applications for cooling high power density electronics and perhaps high energy laser mirrors. The device was designed to absorb heat fluxes of approximately 50 w/sq cm (158,000 Btu/hr sq ft), with a low thermal resistance, a high surface temperature uniformity, and very low hydraulic pumping power. A stack of thin copper orifice plates and spacers was bonded together and arranged to provide liquid jet impingement heat transfer on successive plates. This configuration resulted in effective heat transfer coefficients, based on the prime surface, of about 85,000 w/sq m deg C (15,000 Btu/hr sq ft deg F) and 1.8 watts (0.002 hp) hydraulic power with liquid Freon 11 as coolant.

  14. Final focus system for high intensity beams

    SciTech Connect

    Henestroza, E.; Bieniosek, F.M.; Eylon, S.; Roy, P.K.; Yu, S.S.

    2003-05-01

    The NTX experiment at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high perveance heavy ion beams. The NTX final focus system produces a converging beam at the entrance to the neutralized drift section where it focuses to a small spot. The final focus lattice consists of four pulsed quadrupole magnets. The main issues are the control of emittance growth due to high order fields from magnetic multipoles and image fields. We will present experimental results from NTX on beam envelope and phase space distributions, and compare these results with particle simulations using the particle-in-cell code WARP.

  15. Deformable registration for image-guided spine surgery: preserving rigid body vertebral morphology in free-form transformations

    NASA Astrophysics Data System (ADS)

    Reaungamornrat, S.; Wang, A. S.; Uneri, A.; Otake, Y.; Zhao, Z.; Khanna, A. J.; Siewerdsen, J. H.

    2014-03-01

    Purpose: Deformable registration of preoperative and intraoperative images facilitates accurate localization of target and critical anatomy in image-guided spine surgery. However, conventional deformable registration fails to preserve the morphology of rigid bone anatomy and can impart distortions that confound high-precision intervention. We propose a constrained registration method that preserves rigid morphology while allowing deformation of surrounding soft tissues. Method: The registration method aligns preoperative 3D CT to intraoperative cone-beam CT (CBCT) using free-form deformation (FFD) with penalties on rigid body motion imposed according to a simple intensity threshold. The penalties enforced 3 properties of a rigid transformation - namely, constraints on affinity (AC), orthogonality (OC), and properness (PC). The method also incorporated an injectivity constraint (IC) to preserve topology. Physical experiments (involving phantoms, an ovine spine, and a human cadaver) as well as digital simulations were performed to evaluate the sensitivity to registration parameters, preservation of rigid body morphology, and overall registration accuracy of constrained FFD in comparison to conventional unconstrained FFD (denoted uFFD) and Demons registration. Result: FFD with orthogonality and injectivity constraints (denoted FFD+OC+IC) demonstrated improved performance compared to uFFD and Demons. Affinity and properness constraints offered little or no additional improvement. The FFD+OC+IC method preserved rigid body morphology at near-ideal values of zero dilatation (D = 0.05, compared to 0.39 and 0.56 for uFFD and Demons, respectively) and shear (S = 0.08, compared to 0.36 and 0.44 for uFFD and Demons, respectively). Target registration error (TRE) was similarly improved for FFD+OC+IC (0.7 mm), compared to 1.4 and 1.8 mm for uFFD and Demons. Results were validated in human cadaver studies using CT and CBCT images, with FFD+OC+IC providing excellent preservation

  16. An improved high intensity recycling helium-3 beam source

    SciTech Connect

    Hedgeland, H.; Kole, P. R.; Allison, W.; Ellis, J.; Jardine, A. P.

    2009-07-15

    We describe an improved high intensity, recycling, supersonic atomic beam source. Changes address several issues previously limiting performance and reliability of the apparatus, including the use of newly available vacuum pumps and modifications to the recycling system. We achieve a source intensity of 2.5x10{sup 19} atoms/s/sr, almost twice that previously achievable during recycling. Current limits on intensity are discussed.

  17. An improved high intensity recycling helium-3 beam source.

    PubMed

    Hedgeland, H; Kole, P R; Allison, W; Ellis, J; Jardine, A P

    2009-07-01

    We describe an improved high intensity, recycling, supersonic atomic beam source. Changes address several issues previously limiting performance and reliability of the apparatus, including the use of newly available vacuum pumps and modifications to the recycling system. We achieve a source intensity of 2.5 x 10(19) atoms/s/sr, almost twice that previously achievable during recycling. Current limits on intensity are discussed. PMID:19655995

  18. High intensity anthropogenic sound damages fish ears

    NASA Astrophysics Data System (ADS)

    McCauley, Robert D.; Fewtrell, Jane; Popper, Arthur N.

    2003-01-01

    Marine petroleum exploration involves the repetitive use of high-energy noise sources, air-guns, that produce a short, sharp, low-frequency sound. Despite reports of behavioral responses of fishes and marine mammals to such noise, it is not known whether exposure to air-guns has the potential to damage the ears of aquatic vertebrates. It is shown here that the ears of fish exposed to an operating air-gun sustained extensive damage to their sensory epithelia that was apparent as ablated hair cells. The damage was regionally severe, with no evidence of repair or replacement of damaged sensory cells up to 58 days after air-gun exposure.

  19. Image-guided breast biopsy: state-of-the-art.

    PubMed

    O'Flynn, E A M; Wilson, A R M; Michell, M J

    2010-04-01

    Percutaneous image-guided breast biopsy is widely practised to evaluate predominantly non-palpable breast lesions. There has been steady development in percutaneous biopsy techniques. Fine-needle aspiration cytology was the original method of sampling, followed in the early 1990s by large core needle biopsy. The accuracy of both has been improved by ultrasound and stereotactic guidance. Larger bore vacuum-assisted biopsy devices became available in the late 1990s and are now commonplace in most breast units. We review the different types of breast biopsy devices currently available together with various localization techniques used, focusing on their advantages, limitations and current controversial clinical management issues. PMID:20338392

  20. Robotic Image-Guided Needle Interventions of the Prostate

    PubMed Central

    Mozer, Pierre C; Partin, Alan W; Stoianovici, Dan

    2009-01-01

    Prostate biopsy and needle-directed prostate therapies are currently performed free-handed or with needle external templates under ultrasound guidance. Direct image-guided intervention robots are modern instruments that have the potential to substantially enhance these procedures. These may increase the accuracy and repeatability with which needles are placed in the gland. The authors’ group has developed a robot for precise prostate targeting that operates remotely alongside the patient in the magnetic resonance imaging scanner, as guided according to the image. PMID:19390670

  1. Medical applications of fast 3D cameras in real-time image-guided radiotherapy (IGRT) of cancer

    NASA Astrophysics Data System (ADS)

    Li, Shidong; Li, Tuotuo; Geng, Jason

    2013-03-01

    Dynamic volumetric medical imaging (4DMI) has reduced motion artifacts, increased early diagnosis of small mobile tumors, and improved target definition for treatment planning. High speed cameras for video, X-ray, or other forms of sequential imaging allow a live tracking of external or internal movement useful for real-time image-guided radiation therapy (IGRT). However, none of 4DMI can track real-time organ motion and no camera has correlated with 4DMI to show volumetric changes. With a brief review of various IGRT techniques, we propose a fast 3D camera for live-video stereovision, an automatic surface-motion identifier to classify body or respiratory motion, a mechanical model for synchronizing the external surface movement with the internal target displacement by combination use of the real-time stereovision and pre-treatment 4DMI, and dynamic multi-leaf collimation for adaptive aiming the moving target. Our preliminary results demonstrate that the technique is feasible and efficient in IGRT of mobile targets. A clinical trial has been initiated for validation of its spatial and temporal accuracies and dosimetric impact for intensity-modulated RT (IMRT), volumetric-modulated arc therapy (VMAT), and stereotactic body radiotherapy (SBRT) of any mobile tumors. The technique can be extended for surface-guided stereotactic needle insertion in biopsy of small lung nodules.

  2. Voxel-based 2-D/3-D registration of fluoroscopy images and CT scans for image-guided surgery.

    PubMed

    Weese, J; Penney, G P; Desmedt, P; Buzug, T M; Hill, D L; Hawkes, D J

    1997-12-01

    Registration of intraoperative fluoroscopy images with preoperative three-dimensional (3-D) CT images can be used for several purposes in image-guided surgery. On the one hand, it can be used to display the position of surgical instruments, which are being tracked by a localizer, in the preoperative CT scan. On the other hand, the registration result can be used to project preoperative planning information or important anatomical structures visible in the CT image onto the fluoroscopy image. For this registration task, a novel voxel-based method in combination with a new similarity measure (pattern intensity) has been developed. The basic concept of the method is explained at the example of two-dimensional (2-D)/3-D registration of a vertebra in an X-ray fluoroscopy image with a 3-D CT image. The registration method is described, and the results for a spine phantom are presented and discussed. Registration has been carried out repeatedly with different starting estimates to study the capture range. Information about registration accuracy has been obtained by comparing the registration results with a highly accurate "ground-truth" registration, which has been derived from fiducial markers attached to the phantom prior to imaging. In addition, registration results for different vertebrae have been compared. The results show that the rotation parameters and the shifts parallel to the projection plane can accurately be determined from a single projection. Because of the projection geometry, the accuracy of the height above the projection plane is significantly lower. PMID:11020832

  3. Neutralized transport of high intensity beams

    SciTech Connect

    Henestroza, E.; Yu, S.S.; Eylon, S.; Roy, P.K.; Anders, A.; Sharp, W.; Efthimion, P.; Gilson, E.; Welch, D.; Rose, D.

    2003-05-01

    The NTX experiment at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high perveance heavy ion beams. A converging ion beam at the exit of the final focus magnetic system is injected into a neutralized drift section. The neutralization is provided by a metal arc source and an RF plasma source. Effects of a ''plasma plug'', where electrons are extracted from a localized plasma in the upstream end of the drift section, and are then dragged along by the ion potential, as well as the ''volumetric plasma'', where neutralization is provided by the plasma laid down along the ion path, are both studied and their relative effects on the beam spot size are compared. Comparisons with 3-D PIC code predictions will also be presented.

  4. Precise image-guided irradiation of small animals: a flexible non-profit platform.

    PubMed

    Tillner, Falk; Thute, Prasad; Löck, Steffen; Dietrich, Antje; Fursov, Andriy; Haase, Robert; Lukas, Mathias; Rimarzig, Bernd; Sobiella, Manfred; Krause, Mechthild; Baumann, Michael; Bütof, Rebecca; Enghardt, Wolfgang

    2016-04-21

    Preclinical in vivo studies using small animals are essential to develop new therapeutic options in radiation oncology. Of particular interest are orthotopic tumour models, which better reflect the clinical situation in terms of growth patterns and microenvironmental parameters of the tumour as well as the interplay of tumours with the surrounding normal tissues. Such orthotopic models increase the technical demands and the complexity of preclinical studies as local irradiation with therapeutically relevant doses requires image-guided target localisation and accurate beam application. Moreover, advanced imaging techniques are needed for monitoring treatment outcome. We present a novel small animal image-guided radiation therapy (SAIGRT) system, which allows for precise and accurate, conformal irradiation and x-ray imaging of small animals. High accuracy is achieved by its robust construction, the precise movement of its components and a fast high-resolution flat-panel detector. Field forming and x-ray imaging is accomplished close to the animal resulting in a small penumbra and a high image quality. Feasibility for irradiating orthotopic models has been proven using lung tumour and glioblastoma models in mice. The SAIGRT system provides a flexible, non-profit academic research platform which can be adapted to specific experimental needs and therefore enables systematic preclinical trials in multicentre research networks. PMID:27008208

  5. Precise image-guided irradiation of small animals: a flexible non-profit platform

    NASA Astrophysics Data System (ADS)

    Tillner, Falk; Thute, Prasad; Löck, Steffen; Dietrich, Antje; Fursov, Andriy; Haase, Robert; Lukas, Mathias; Rimarzig, Bernd; Sobiella, Manfred; Krause, Mechthild; Baumann, Michael; Bütof, Rebecca; Enghardt, Wolfgang

    2016-04-01

    Preclinical in vivo studies using small animals are essential to develop new therapeutic options in radiation oncology. Of particular interest are orthotopic tumour models, which better reflect the clinical situation in terms of growth patterns and microenvironmental parameters of the tumour as well as the interplay of tumours with the surrounding normal tissues. Such orthotopic models increase the technical demands and the complexity of preclinical studies as local irradiation with therapeutically relevant doses requires image-guided target localisation and accurate beam application. Moreover, advanced imaging techniques are needed for monitoring treatment outcome. We present a novel small animal image-guided radiation therapy (SAIGRT) system, which allows for precise and accurate, conformal irradiation and x-ray imaging of small animals. High accuracy is achieved by its robust construction, the precise movement of its components and a fast high-resolution flat-panel detector. Field forming and x-ray imaging is accomplished close to the animal resulting in a small penumbra and a high image quality. Feasibility for irradiating orthotopic models has been proven using lung tumour and glioblastoma models in mice. The SAIGRT system provides a flexible, non-profit academic research platform which can be adapted to specific experimental needs and therefore enables systematic preclinical trials in multicentre research networks.

  6. High-intensity drying processes: Impulse drying

    SciTech Connect

    Orloff, D.I.

    1989-05-01

    Impulse drying is an innovative process for drying paper that holds great promise for reducing the energy consumed during manufacture of paper and similar web products. Impulse drying occurs when a wet paper web passes through a press nip where one of the rolls is heated to a very high temperature. Steam generated by contact with the hot roll expands and displaces water from the sheet in a very efficient manner. The energy required for water removal is much lower than that required for conventional evaporative drying. Tests have been completed that elucidate the unique displacement mechanism of water removal in the impulse drying process. A pilot roll press has been designed, installed and used to examine impulse drying under conditions that simulate commercial press conditions. The results of this earlier work have been reported in three previous reports. During this report period October, 1987 to September, 1988, the pilot press was equipped with a second impulse drying roll to facilitate studies of surface uniformity in impulse dried paper. Studies have also been completed which examine the origins of sheet delamination that has been been encountered during impulse drying of certain heavyweight paper grades, and which investigate approaches to prevent delamination in these grades. Finally, an experimental plan has been formalized to examine impulse drying of lightweight grades which are candidates for early commercialization. 7 refs., 30 figs., 3 tabs.

  7. High-intensity drying processes: Impulse drying

    SciTech Connect

    Orloff, D.I.

    1990-09-01

    Impulse drying is an innovative process for drying paper that holds great promise for reducing the energy consumed during the manufacture of paper and similar web products. Impulse drying occurs when a wet paper web passes through a press nip in which one of the rolls is heated to a high temperature. A steam layer adjacent to the heated surface grows and displaces water from the sheet in a very efficient manner. The energy required for water removal is very much less than that required for conventional evaporative drying. Hence, it has been projected that wide commercialization of impulse drying would result in at least a 10% industry-wide energy saving. This report covers work completed between October, 1988 and September, 1989. During this period, pilot press trails demonstrated that newsprint as well as linerboard experience delamination. Hence, the major focus of the research was the resolution of the delamination problem. In order to document potential process improvements, measurement methods were developed to quantify sheet delamination. Using these methods, low thermal diffusivity ceramic roll surfaces were shown to extend the range of impulse drying operating conditions while avoiding sheet delamination. As compared to steel surfaces, ceramics were found to provide significantly higher water volume without inducing sheet delamination. 46 figs., 4 tabs.

  8. Light-intensity modulator withstands high heat fluxes

    NASA Technical Reports Server (NTRS)

    Maples, H. G.; Strass, H. K.

    1966-01-01

    Mechanism modulates and controls the intensity of luminous radiation in light beams associated with high-intensity heat flux. This modulator incorporates two fluid-cooled, externally grooved, contracting metal cylinders which when rotated about their longitudinal axes present a circular aperture of varying size depending on the degree of rotation.

  9. High Intensity heavy ion Accelerator Facility (HIAF) in China

    NASA Astrophysics Data System (ADS)

    Yang, J. C.; Xia, J. W.; Xiao, G. Q.; Xu, H. S.; Zhao, H. W.; Zhou, X. H.; Ma, X. W.; He, Y.; Ma, L. Z.; Gao, D. Q.; Meng, J.; Xu, Z.; Mao, R. S.; Zhang, W.; Wang, Y. Y.; Sun, L. T.; Yuan, Y. J.; Yuan, P.; Zhan, W. L.; Shi, J.; Chai, W. P.; Yin, D. Y.; Li, P.; Li, J.; Mao, L. J.; Zhang, J. Q.; Sheng, L. N.

    2013-12-01

    HIAF (High Intensity heavy ion Accelerator Facility), a new facility planned in China for heavy ion related researches, consists of two ion sources, a high intensity Heavy Ion Superconducting Linac (HISCL), a 45 Tm Accumulation and Booster Ring (ABR-45) and a multifunction storage ring system. The key features of HIAF are unprecedented high pulse beam intensity and versatile operation mode. The HIAF project aims to expand nuclear and related researches into presently unreachable region and give scientists possibilities to conduct cutting-edge researches in these fields. The general description of the facility is given in this article with a focus on the accelerator design.

  10. High intensity, argon ion laser-jet photochemistry

    NASA Astrophysics Data System (ADS)

    Wilson, R. Marshall; Schnapp, Karlyn A.; Hannemann, Klaus; Ho, Douglas M.; Memarian, Hamid R.; Azadnia, Ardeshir; Pinhas, Allan R.; Figley, Timothy M.

    A new technique for the study of high intensity solution photochemistry has been developed. With this laser-jet technique, a high velocity microjet is irradiated with the focussed output of an argon ion laser. Under these extremely high intensity conditions, photochemically generated transient species with suitable absorption properties are excited further and produce relatively large amounts of photoproducts which are not observed under low intensity conditions. The application of this laser-jet technique in the study of the photochemistry of radicals, biradicals, photoenols and the higher excited states of carbonyl and polycyclic aromatic compounds is described.