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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Transcatheter Arterial Embolization with n-Butyl Cyanoacrylate for the Treatment of Acquired Uterine Vascular Malformations

PurposeThe purpose of the study was to evaluate the technique and outcomes of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate (NBCA) for the treatment of acquired uterine arteriovenous malformations (AVMs).Materials and methodsA retrospective review identified five women treated for suspected acquired uterine AVMs with TAE at our institution. Four women (80 %) presented with heavy or intermittent vaginal bleeding after obstetric manipulation. One woman (20 %) was treated for an incidental AVM discovered on ultrasound after an uncomplicated cesarean section. Three women underwent one embolization procedure and two women required two procedures. Embolization material included NBCA in six procedures (80 %) and gelatin sponge in one procedure (20 %).ResultsEmbolization resulted in angiographic stasis of flow in all seven procedures. Four women (80 %) presented with vaginal bleeding which was improved after treatment. One woman returned 24 days after unilateral embolization with recurrent bleeding, which resolved after retreatment. One woman underwent two treatments for an asymptomatic lesion identified on ultrasound. There were no major complications. Three women (60 %) experienced mild postembolization pelvic pain that was controlled with non-steroidal anti-inflammatory drugs. Three women (60 %) had pregnancies and deliveries after embolization.ConclusionsTAE is a safe alternative to surgical therapy for acquired uterine AVMs with the potential to maintain fertility. Experience from this case series suggests that NBCA provides predictable and effective occlusion.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Image-Guided Percutaneous Bleomycin and Bevacizumab Sclerotherapy of Orbital Lymphatic Malformations in Children

Purpose: To evaluate the effectiveness and safety of image-guided percutaneous sclerotherapy using bleomycin for macrocystic and bevacizumab (Avastin™) for microcystic orbital lymphatic malformations in children. Materials and Methods: Between October 2015 and July 2018, we prospectively evaluated 10 pediatric patients who presented clinically and radiologically with lymphatic malformations and were treated with percutaneous sclerotherapy. Patients with venous malformations were excluded. Eight females and two males with ages ranging from 3 to 17 years (mean: 8.8, SD: 4.9) were included. Guided with ultrasound and fluoroscopy, macrocysts were treated with bleomycin instillation. For microcystic components in three patients, bevacizumab was injected intralesional. All patients underwent ultrasound and non-contrast MRI to evaluate response to treatment after 6 weeks. Results: The malformations were macrocystic in seven patients and complex (macro/microcystic) in three. Twenty sclerotherapy sessions were performed, (range: 1–3 sessions, mean: 2, SD: 0.8). Clinically, there was a significant reduction in the proptosis after treatment (P = 0.007) and dystopia (P = 0.018). The local radiological response showed a reduction in the maximum lesions diameters and volumes after treatment (P = 0.005 and 0.005, respectively). Two of the three patients treated with bevacizumab showed a reduction in the lesions volumes by 90.4% and 63.4%, respectively, whereas one patient did not show volume reduction. Transient periorbital edema and ecchymosis occurred following the procedure with no major complications encountered. Follow-up ranged from 9–33 months, mean: 20.3, SD: 7.4. Conclusion: Bleomycin sclerotherapy is a safe and effective treatment for orbital macrocystic lymphatic malformations. Further use of bevacizumab for microcystic lesions in a larger series is required to outline its efficacy and safety.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Effects of Varicocele Treatment on Sperm Conventional Parameters: Surgical Varicocelectomy Versus Sclerotherapy

Introduction: Varicocele is often associated with impaired sperm parameters. Different procedures have been developed for varicocele treatment. The aim of this study was to evaluate the effects of varicocele treatment on conventional sperm parameters. Materials and Methods: We compared two different techniques of intervention: surgical varicocelectomy and sclerotherapy. We also evaluated the number of varicocele recurrences and the pregnancy rate. We included 102 patients (mean age 29.8 ± 0.8 years) with ultrasound diagnosis of varicocele. We excluded patients whose ultrasound evaluation and/or sperm parameters were not known before and after varicocele correction. We divided the patients (excluding 8 with azoospermia) into two subgroups: surgical varicocelectomy (n = 44) and sclerotherapy (n = 50). For each patient, we compared conventional sperm parameters before and after varicocele correction. Results: After varicocele correction, we found a significant improvement in sperm concentration, total count and total motility. Considering the two subgroups, baseline sperm parameters did not differ significantly. Sperm concentration and total count increased significantly after varicocele correction by varicocelectomy. Varicocele correction by sclerotherapy resulted in a significant increase in sperm concentration, progressive and total motility. We found varicocele recurrence in 32% of patients who underwent varicocelectomy and in 19.7% of patients undergoing sclerotherapy. The pregnancy rate was higher after sclerotherapy (28%) than after surgical varicocelectomy (13%). Conclusion: Varicocele treatment must be recommended when other causes of infertility have been treated. Our results suggest the use of sclerotherapy for varicocele repair. Level of Evidence: 2 b.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Fusion Imaging and Virtual Navigation to Guide Percutaneous Thermal Ablation of Hepatocellular Carcinoma: A Review of the Literature

As medical imaging advancements have improved the detectability of hepatocellular carcinoma (HCC) in early stages, the approach to percutaneous thermal ablation for curative treatment has concomitantly advanced. Although many centers are adopting cross-sectional imaging to guide percutaneous ablation, the majority of procedures are still performed under ultrasound (US) guidance worldwide. Challenges to ultrasound guidance may present due to relatively poor resolution particularly with small or isoechoic lesions, or due to intervening structures such as the bowel or diaphragm that obstruct lesional visualization. Fusion imaging (FI) systems have been employed to address these challenges. By merging or synchronizing the real-time images from US with a previously obtained cross-sectional study, FI mitigates the inherent limitations of each individual imaging modality and expands procedural feasibility and technical outcomes. This manuscript reviews the current literature on the use of FI during percutaneous thermal ablation of HCC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

BI-RADS 3: Current and Future Use of Probably Benign

Purpose of Review: Probably benign (BI-RADS 3) causes confusion for interpreting physicians and referring physicians and can induce significant patient anxiety. The best uses and evidence for using this assessment category in mammography, breast ultrasound, and breast MRI will be reviewed; the reader will have a better understanding of how and when to use BI-RADS 3. Recent Findings: Interobserver variability in the use of BI-RADS 3 has been documented. The 5th edition of the BI-RADS atlas details the appropriate use of BI-RADS 3 for diagnostic mammography, ultrasound, and MRI, and discourages its use in screening mammography. Data mining, elastography, and diffusion weighted MRI have been evaluated to maximize the accuracy of BI-RADS 3. Summary: BI-RADS 3 is an evolving assessment category. When used properly, it reduces the number of benign biopsies while allowing the breast imager to maintain a high sensitivity for the detection of early stage breast cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Imaging the Breast in Pregnant or Lactating Women

Purpose of Review: To describe the imaging evaluation of common benign and malignant breast lesions encountered in pregnant or lactating women. Recent Findings: There is increasing prevalence of pregnancy-associated breast cancer as the age of women during pregnancy increases. Women in the first 10 years following pregnancy demonstrate an elevated risk for breast cancer compared to the average population. MRI has been shown to be more sensitive for evaluating the extent of disease in lactating patients than mammography or ultrasound. Summary: The hormonal effects of pregnancy and lactation on the breast lead to distinct physiologic changes and pathologic lesions, which can manifest in unique imaging appearances. Most patients will undergo ultrasound for primary diagnostic evaluation. While mammography is not routinely utilized, it is not contraindicated even in pregnancy given the negligible radiation dose to the fetus. While most detected lesions are benign, pregnancy-associated breast cancer (PABC) is a rare diagnosis that must always be excluded. Women with PABC have a worse prognosis than age-matched controls partly due to delay in diagnosis. Thus prompt and accurate work-up of PABC is critical to improve outcomes.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Removal of inorganic mercury by selective extraction and coprecipitation for determination of methylmercury in mercury-contaminated soils by chemical vapor generation inductively coupled plasma mass spectrometry (CVG-ICP-MS)

A procedure is developed for selective extraction of methylmercury (CH 3 Hg + ) from heavily Hg-contaminated soils and sediments for determination by chemical vapor generation inductively coupled plasma mass spectrometry (CVG-ICP-MS). Soils artificially contaminated with 40 μg g –1 inorganic mercury (Hg 2+ ) or methylmercury chloride (CH 3 HgCl) were agitated by shaking or exposing to ultrasounds in dilute hydrochloric acid (HCl) or nitric acid (HNO 3 ) solutions at room temperature. Extractions in HCl (5 or 10% v/v) resulted in substantial leaching of Hg 2+ from soils, whereas 5% (v/v) HNO 3 provided selectivity for quantitative extraction of CH 3 Hg + with minimum Hg 2+ leaching. Agitation with ultrasounds in 5% (v/v) HNO 3 for about 3 min was sufficient for extraction of all CH 3 Hg + from soils. Coprecipitations with Fe(OH) 3 , Bi(OH) 3 and HgS were investigated for removal of residual Hg 2+ in soil extracts. Hydroxide precipitations were not effective. Thiourea or l-cysteine added to soil extracts prior to hydroxide precipitation improved precipitation of Hg 2+ , but also resulted in removal of CH 3 Hg + . HgS precipitation was made with dilute ammonium sulfide solution, (NH 4 ) 2 S. Adding 30 μL of 0.35 mol L –1 (NH 4 ) 2 S to soil extracts in 5% (v/v) HNO 3 resulted in removal of all residual Hg 2+ without impacting CH 3 Hg + levels. Vapor generation was carried out by reacting Hg 2+ -free soil extracts with 1% (m/v) NaBH 4 . No significant interferences were observed from (NH 4 ) 2 S on the vapor generation from CH 3 Hg + . The slopes of the calibration curves for CH 3 HgCl standard solutions in 5% (v/v) HNO 3 with and without (NH 4 ) 2 S were similar. Limits of detection (LOD, 3s method) were around 0.08 μg L –1 for 5% (v/v) HNO 3 blanks (n = 10) and 0.10 μg L –1 for 5% (v/v) HNO 3 + 0.005 mol L –1 (NH 4 ) 2 S blanks (n = 10). Percent relative standard deviation (%RSD) for five replicate measurements varied between 3.1% and 6.4% at 1.0 CH 3 HgCl level. The method is validated by analysis of two certified reference materials (CRM); purely Methylmercury sediment (SQC1238, 10.00 ± 0.291 ng g –1 CH 3 Hg + ) and Hg-contaminated Estuarine sediment (ERM – CC580, 75 ± 4 ng g–1 CH 3 Hg + and 132 ± 3 μg g –1 total Hg). CH 3 Hg + values for SQC1238 were between 13.0 and 13.2 ng g –1 , and 79 and 81 ng g –1 for ERM – CC580. Hg-contaminated soils (57–96 μg g –1 total Hg) collected from the floodplains of Oak Ridge, TN were analyzed for CH 3 Hg + using the procedure by CVG-ICPMS. CH 3 Hg + levels ranged from 30 to 51 ng g –1 and did not correlate with total Hg levels (R 2 = 0.01).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Self-powered Through-wall communication for dry cask storage monitoring

Many nuclear facilities, such as spent fuel storage dry casks and nuclear reactor pressure vessels, are entirely sealed by metal layers to prevent harmful radiation. For safety and security operations, the temperature, pressure, radiation, and humidity inside the vessel needs to be closely monitored. However, no practical technology is currently available to realize the through-wall data communication and monitoring for these vessels due to the inside harsh environment of high temperature and nuclear radiation. In this paper, an innovative self-powered wireless through-wall data communication system for the nuclear environment is presented, which demonstrates a successful solution to such challenges. The presented system is composed of four modules, i.e., energy harvester with power management circuits, ultrasound wireless communication using high-temperature piezoelectric transducers, electronic circuits for sensing and data transmission, and radiation shielding for electronics. Here, constitutive functions of each module were firstly designed and followed by the system integration. Experiments were conducted subsequently to validate the designed functions and evaluate the performance of the integrated system. Results showed that the average power of over 40 mW was harvested from the thermal flow inside the nuclear spent fuel canisters which could provide enough energy to operate the sensing and data communication systems. The gamma radiation test results showed that the thermoelectric energy harvester and ultrasound transceivers can withstand radiation dosing over 100 Mrad. Furthermore, temperature shock tests demonstrated that the entire system including the shielded electronics can survive and maintain their functionalities at temperatures as high as 195°C. Under the in-lab mocked-up high temperature conditions and radiation shielding, the proposed system is foreseen to survive and operate stably for fifty years inside a nuclear spent fuel canister, and send the frequency modulated data out of the canister for 3 s in every 10 min.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

The Coupled Adjoint-State Equation in forward and inverse linear elasticity: Incompressible plane stress

A persistent challenge present in inverse or parameter estimation problems with interior data is how to deal with uncertainty in the boundary conditions employed in the forward or state model. In this work we focus on a linear plane stress inverse elasticity problem with measured displacement data where one component of the measured displacement field is known with considerably greater precision than the other. This situation is commonly encountered when the displacement field is measured using ultrasound or optical coherence tomography. We present a novel computational formulation in which no displacement or traction boundary conditions are assumed. The formulation results in coupling the state and adjoint equations, that are typically uncoupled when a well-posed state model is available. Two variants of residual-based stabilization are added. Our approach is applied to a simulated data set and experimental data from an ultrasound phantom.

42 ENGINEERING↗
DOE OSTI2014

Secondhand tobacco exposure is associated with nonalcoholic fatty liver disease in children

Background: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of liver disease in children in the United States, and prevalence rates are rising. Smoking is associated with NAFLD, but the association of secondhand smoke exposure with NAFLD is unknown. Aims: To investigate the association of secondhand tobacco exposure with NAFLD in children. Methods: We surveyed parents/guardians of 304 children aged 3–12 years who had received an abdominal ultrasound at Penn State Hershey Medical Center. The survey addressed demographics, medical history, secondhand tobacco exposure, activity level, screen viewing time and other environmental exposures. A pediatric radiologist and sonographer reviewed the ultrasounds to grade the presence of bight liver compatible with NAFLD. We conducted logistic regression analysis to assess the association of secondhand tobacco exposure and NAFLD. Results: 54% of eligible potential participants responded to the survey. Fatty liver was present in 3% of the children. Increasing child age was associated with increased odds of NAFLD (OR 1.63 95% CI 1.1, 2.4). Reported child obesity was associated with increased odds of NAFLD (OR 44.5 95% CI 5.3, 371.7). The rate of NAFLD was higher in the smoke exposed group (6.7% vs. 1.7%). For every extra pack per day smoked at home, the odds of a child having NAFLD increased 1.8 times (AOR 1.8, 95% CI 1.2, 2.8), and any exposure increased a child's odds of NAFLD four-fold (AOR 4.0, 95% CI 1.02, 15.8). Conclusion: We found an association of secondhand smoke exposure and NAFLD in children. This may represent an area for future prevention efforts. - Highlights: • We evaluated the relation of tobacco exposure with nonalcoholic fatty liver disease. • Tobacco smoke exposure was associated with nonalcoholic fatty liver disease. • Tobacco smoke exposure may be an addressable risk factor.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2011

Cosmetic Outcomes for Accelerated Partial Breast Irradiation Before Surgical Excision of Early-Stage Breast Cancer Using Single-Dose Intraoperative Radiotherapy

Purpose: Determine cosmetic outcome and toxicity profile of intraoperative radiation delivered before tumor excision for patients with early-stage breast cancer. Methods and Materials: Patients age 48 or older with ultrasound-visible invasive ductal cancers <3 cm and clinically negative lymph nodes were eligible for treatment on this institutional review board-approved Phase II clinical trial. Treatment planning ultrasound was used to select an electron energy and cone size sufficient to cover the tumor plus a 1.5- to 2.0-cm circumferential margin laterally and a 1-cm-deep margin with the 90% isodose line. The dose was prescribed to a nominal 15 Gy and delivered using a Mobetron electron irradiator before tumor excision by segmental mastectomy. Physician- and patient-assessed cosmetic outcome and patient satisfaction were determined by questionnaire. Results: From March 2003 to July 2007, 71 patients were treated with intraoperative radiation therapy. Of those, 56 patients were evaluable, with a median follow-up of 3.1 years (minimum 1 year). Physician and patient assessment of cosmesis was 'good or excellent' (Radiation Therapy Oncology Group cosmesis scale) in 45/56 (80%) and 32/42 (76%) of all patients, respectively. Eleven patients who received additional whole breast radiation had similar rates of good or excellent cosmesis: 40/48 (83%) and 29/36 (81%), respectively). Grade 1 or 2 acute toxicities were seen in 4/71 (6%) patients. No Grade 3 or 4 toxicities or serious adverse events have been seen. Conclusion: Intraoperative radiotherapy delivered to an in situ tumor is feasible with acceptable acute tolerance. Patient and physician assessment of the cosmetic outcome is good to excellent.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

A Phase II Trial of Arc-Based Hypofractionated Intensity-Modulated Radiotherapy in Localized Prostate Cancer

Purpose: To evaluate acute and late genitourinary (GU) and gastrointestinal (GI) toxicity and biochemical control of hypofractionated, image-guided (fiducial markers or ultrasound guidance), simplified intensity-modulated arc therapy for localized prostate cancer. Methods and Materials: This Phase II prospective clinical trial for T1a-2cNXM0 prostate cancer enrolled 66 patients who received 63.2 Gy in 20 fractions over 4 weeks. Fiducial markers were used for image guidance in 30 patients and daily ultrasound for the remainder. Toxicity was scored according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Results: Median follow-up was 36 months. Acute Phase Grade 2 and 3 toxicity was 34% and 9% for GU vs. 25% and 10% for GI symptoms. One Grade 4 acute GI toxicity occurred in a patient with unrecognized Crohn's disease. Late Grade 2 and 3 toxicity for GU was 14% and 5%, and GI toxicity was 25% and 3%. One late GI Grade 4 toxicity was observed in a patient with significant comorbidities (anticoagulation, vascular disease). Acute GI toxicity {>=}Grade 2 was shown to be a predictor for late toxicity Grade {>=}2 (p < 0.001). The biochemical disease-free survival at 3 years was 95%. Conclusions: Hypofractionated simplified intensity-modulated arc therapy radiotherapy given as 63.2 Gy in 20 fractions demonstrated promising biochemical control rates; however, higher rates of acute Grade 3 GU and GI toxicity and higher late Grade 2 GU and GI toxicity were noted. Ongoing randomized controlled trials should ultimately clarify issues regarding patient selection and the true rate of severe toxicity that can be directly attributed to hypofractionated radiotherapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Pancreatic Cancer Tumor Size on CT Scan Versus Pathologic Specimen: Implications for Radiation Treatment Planning

Purpose: Pancreatic cancer primary tumor size measurements are often discordant between computed tomography (CT) and pathologic specimen after resection. Dimensions of the primary tumor are increasingly relevant in an era of highly conformal radiotherapy. Methods and Materials: We retrospectively evaluated 97 consecutive patients with resected pancreatic cancer at two Boston hospitals. All patients had CT scans before surgical resection. Primary endpoints were maximum dimension (in millimeters) of the primary tumor in any direction as reported by the radiologist on CT and by the pathologist for the resected gross fresh specimen. Endoscopic ultrasound (EUS) findings were analyzed if available. Results: Of the patients, 87 (90%) had preoperative CT scans available for review and 46 (47%) had EUS. Among proximal tumors (n = 69), 40 (58%) had pathologic duodenal invasion, which was seen on CT in only 3 cases. The pathologic tumor size was a median of 7 mm larger compared with CT size for the same patient (range, -15 to 43 mm; p < 0.0001), with 73 patients (84%) having a primary tumor larger on pathology than CT. Endoscopic ultrasound was somewhat more accurate, with pathologic tumor size being a median of only 5 mm larger compared with EUS size (range, -15 to 35 mm; p = 0.0003). Conclusions: Computed tomography scans significantly under-represent pancreatic cancer tumor size compared with pathologic specimens in resectable cases. We propose a clinical target volume expansion formula for the primary tumor based on our data. The high rate of pathologic duodenal invasion suggests a risk of duodenal undercoverage with highly conformal radiotherapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Progressive Muscle Atrophy and Weakness After Treatment by Mantle Field Radiotherapy in Hodgkin Lymphoma Survivors

Purpose: To describe the damage to the muscles and propose a pathophysiologic mechanism for muscle atrophy and weakness after mantle field radiotherapy in Hodgkin lymphoma (HL) survivors. Methods and Materials: We examined 12 patients treated by mantle field radiotherapy between 1969 and 1998. Besides evaluation of their symptoms, the following tests were performed: dynamometry; ultrasound of the sternocleidomastoid, biceps, and antebrachial flexor muscles; and needle electromyography of the neck, deltoid, and ultrasonographically affected arm muscles. Results: Ten patients (83%) experienced neck complaints, mostly pain and muscle weakness. On clinical examination, neck flexors were more often affected than neck extensors. On ultrasound, the sternocleidomastoid was severely atrophic in 8 patients, but abnormal echo intensity was seen in only 3 patients. Electromyography of the neck muscles showed mostly myogenic changes, whereas the deltoid, biceps, and antebrachial flexor muscles seemed to have mostly neurogenic damage. Conclusions: Many patients previously treated by mantle field radiotherapy develop severe atrophy and weakness of the neck muscles. Neck muscles within the radiation field show mostly myogenic damage, and muscles outside the mantle field show mostly neurogenic damage. The discrepancy between echo intensity and atrophy suggests that muscle damage is most likely caused by an extrinsic factor such as progressive microvascular fibrosis. This is also presumed to cause damage to nerves within the radiated field, resulting in neurogenic damage of the deltoid and arm muscles.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Improving Positioning in High-Dose Radiotherapy for Prostate Cancer: Safety and Visibility of Frequently Used Gold Fiducial Markers

Purpose: The use of gold fiducial markers (GFMs) for prostate positioning in high-dose radiotherapy is gaining interest. The purpose of this study was to compare five GFMs regarding feasibility of ultrasound-based implantation in the prostate and intraprostatic lesion (IPL); toxicity; visibility on transabdominal ultrasound (TU) and cone-beam CT (CBCT); reliability of automatic, soft tissue, and GFM-based CBCT patient positioning by comparing manual and automatic fusion CBCT. Methods and Materials: Twenty-five patients were included. Pain and toxicity were scored after implantation and high-dose radiotherapy. Fisher exact test was used to evaluate the correlation of patients' characteristics and prostatitis. Positioning was evaluated on TU and kilovoltage CBCT images. CBCT fusion was performed automatically (Elekta XVI technology, release 3.5.1 b27, based on grey values) and manually on soft tissue and GFMs. Pearson correlation statistics and Bland-Altman evaluation were used. Five GFMs were compared. Results: Twenty percent of the patients developed prostatitis despite antibiotic prophylaxis. Cigarette smoking was significantly correlated with prostatitis. The visualization of all GFMs on TU was disappointing. Consequently we cannot recommend the use of these GFMs for TU-based prostate positioning. For all GFMs, there was only fair to poor linear correlation between automatic and manual CBCT images, indicating that even when GFMs are used, an operator evaluation is imperative. However, when GFMs were analyzed individually, a moderate to very strong correlation between automatic and manual positioning was found for larger GFMs in all directions. Conclusion: The incidence of prostatitis in our series was high. Further research is imperative to define the ideal preparation protocol preimplantation and to select patients. Automatic fusion is more reliable with larger GFMs at the cost of more scatter. The stability of all GFMs was proven.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Positron Emission Tomography/Computed Tomography in the Staging and Treatment of Anal Cancer

Purpose: This study was intended to determine the role of PET/CT in the staging of anal cancer as a supplement to three-dimensional transanal ultrasound (TAUS) and inguinal ultrasound (US). The impact of the PET/CT on the initial stage and treatment plan proposed by TAUS/US was assessed. Methods and Materials: Ninety-five (95) patients referred to our clinic between July 1, 2005, and December 31, 2009, were retrospectively reviewed. All patients had biopsy-proven primary squamous cell cancer of the anal canal. There were 65 females (68%) and 30 males (32%), and the median age was 58 years (range, 35-88 years). Six (6%) of the patients were HIV positive. All patients were staged with TAUS/US and PET/CT. Results: Twenty-eight (28) patients were diagnosed with suspicious perirectal node metastases. TAUS visualized 24 of these, whereas PET/CT detected 15. Suspicious inguinal nodes were visualized on either US or PET/CT in 41 patients. Seventeen (17) of these had confirmed malignant disease on biopsy, and 15 had confirmed benign disease. All 17 patients (100%) with malignant inguinal nodes were diagnosed by PET/CT, whereas US identified 16 (94%). Ten patients were diagnosed with suspicious inguinal nodes on PET/CT that had not been seen on US. One of these was malignant, three were benign, and six were not biopsied. PET/CT diagnosed eight metastatic sites, whereas TAUS/US diagnosed three. PET/CT discovered three of the five synchronous cancers seen in this study. PET/CT upstaged the disease in 14% of the cases and changed the treatment plan proposed by TAUS/US in 17%. Conclusion: PET/CT has great potential influence on the staging and treatment of anal cancer. TAUS is important in the staging of the primary tumor and N1-stage, whereas PET/CT seems necessary for the N2/3-stage, the M-stage and synchronous cancers.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

High-Dose-Rate Prostate Brachytherapy Consistently Results in High Quality Dosimetry

Purpose: We performed a dosimetry analysis to determine how well the goals for clinical target volume coverage, dose homogeneity, and normal tissue dose constraints were achieved with high-dose-rate (HDR) prostate brachytherapy. Methods and Materials: Cumulative dose-volume histograms for 208 consecutively treated HDR prostate brachytherapy implants were analyzed. Planning was based on ultrasound-guided catheter insertion and postoperative CT imaging; the contoured clinical target volume (CTV) was the prostate, a small margin, and the proximal seminal vesicles. Dosimetric parameters analyzed for the CTV were D90, V90, V100, V150, and V200. Dose to the urethra, bladder, bladder balloon, and rectum were evaluated by the dose to 0.1 cm{sup 3}, 1 cm{sup 3}, and 2 cm{sup 3} of each organ, expressed as a percentage of the prescribed dose. Analysis was stratified according to prostate size. Results: The mean prostate ultrasound volume was 38.7 {+-} 13.4 cm{sup 3} (range: 11.7-108.6 cm{sup 3}). The mean CTV was 75.1 {+-} 20.6 cm{sup 3} (range: 33.4-156.5 cm{sup 3}). The mean D90 was 109.2% {+-} 2.6% (range: 102.3%-118.4%). Ninety-three percent of observed D90 values were between 105 and 115%. The mean V90, V100, V150, and V200 were 99.9% {+-} 0.05%, 99.5% {+-} 0.8%, 25.4% {+-} 4.2%, and 7.8% {+-} 1.4%. The mean dose to 0.1 cm{sup 3}, 1 cm{sup 3}, and 2 cm{sup 3} for organs at risk were: Urethra: 107.3% {+-} 3.0%, 101.1% {+-} 14.6%, and 47.9% {+-} 34.8%; bladder wall: 79.5% {+-} 5.1%, 69.8% {+-} 4.9%, and 64.3% {+-} 5.0%; bladder balloon: 70.3% {+-} 6.8%, 59.1% {+-} 6.6%, and 52.3% {+-} 6.2%; rectum: 76.3% {+-} 2.5%, 70.2% {+-} 3.3%, and 66.3% {+-} 3.8%. There was no significant difference between D90 and V100 when stratified by prostate size. Conclusions: HDR brachytherapy allows the physician to consistently achieve complete prostate target coverage and maintain normal tissue dose constraints for organs at risk over a wide range of target volumes.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Quantitative Ultrasonic Nakagami Imaging of Neck Fibrosis After Head and Neck Radiation Therapy

Purpose: To investigate the feasibility of ultrasound Nakagami imaging to quantitatively assess radiation-induced neck fibrosis, a common sequela of radiation therapy (RT) to the head and neck. Methods and Materials: In a pilot study, 40 study participants were enrolled and classified into 3 subgroups: (1) a control group of 12 healthy volunteers; (2) an asymptomatic group of 11 patients who had received intensity modulated RT for head and neck cancer and had experienced no neck fibrosis; and (3) a symptomatic group of 17 post-RT patients with neck fibrosis. Each study participant underwent 1 ultrasound study in which scans were performed in the longitudinal orientation of the bilateral neck. Three Nakagami parameters were calculated to quantify radiation-induced tissue injury: Nakagami probability distribution function, shape, and scaling parameters. Physician-based assessments of the neck fibrosis were performed according to the Radiation Therapy Oncology Group late morbidity scoring scheme, and patient-based fibrosis assessments were rated based on symptoms such as pain and stiffness. Results: Major discrepancies existed between physician-based and patient-based assessments of radiation-induced fibrosis. Significant differences in all Nakagami parameters were observed between the control group and 2 post-RT groups. Moreover, significant differences in Nakagami shape and scaling parameters were observed among asymptomatic and symptomatic groups. Compared with the control group, the average Nakagami shape parameter value increased by 32.1% (P<.001), and the average Nakagami scaling parameter increased by 55.7% (P<.001) for the asymptomatic group, whereas the Nakagami shape parameter increased by 74.1% (P<.001) and the Nakagami scaling parameter increased by 83.5% (P<.001) for the symptomatic group. Conclusions: Ultrasonic Nakagami imaging is a potential quantitative tool to characterize radiation-induced asymptomatic and symptomatic neck fibrosis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗