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Results for “BETA-PLUS DECAY RADIOISOTOPES”

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DOE OSTI2012

Uptake of chloride and carbonate ions by calcium monosulfoaluminate hydrate

Decommissioning of old nuclear reactors may produce waste streams containing chlorides and carbonates, including radioactive {sup 36}Cl{sup -} and {sup 14}CO{sub 3}{sup 2-}. Their insolubilization by calcium monosulfoaluminate hydrate was investigated. Carbonates were readily depleted from the solution, giving at thermodynamic equilibrium monocarboaluminate, monocarboaluminate + calcite, or calcite only, depending on the initial ratio between the anion and calcium monosulfoaluminate hydrate. Chloride ions reacted more slowly and were precipitated as Kuzel's salt, Kuzel's and Friedel's salts, or Friedel's salt only. Rietveld refinement of X-Ray powder diffraction patterns was successfully used to quantify the phase distributions, which were compared to thermodynamic calculations. Moreover, analysing the lattice parameters of Kuzel's salt as a function of its chloride content showed the occurrence of a restricted solid solution towards the sulfate side with general formula 3CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}xCaCl{sub 2}{center_dot}(1 - x)CaSO{sub 4}{center_dot}(12 - 2x){center_dot}H{sub 2}O (0.36 {<=} x {<=} 0.50).

36 MATERIALS SCIENCE↗

DOE OSTI2011

Association Between Pulmonary Uptake of Fluorodeoxyglucose Detected by Positron Emission Tomography Scanning After Radiation Therapy for Non-Small-Cell Lung Cancer and Radiation Pneumonitis

Purpose: To study the relationship between fluorodeoxyglucose (FDG) uptake in pulmonary tissue after radical radiation therapy (RT) and the presence and severity of radiation pneumonitis. Methods and Materials: In 88 consecutive patients, {sup 18}F-FDG-positron emission tomography was performed at a median of 70 days after completion of RT. Patients received 60 Gy in 30 fractions, and all but 15 had concurrent platinum-based chemotherapy. RT-induced pulmonary inflammatory changes occurring within the radiation treatment volume were scored, using a visual (0 to 3) radiotoxicity grading scale, by an observer blinded to the presence or absence of clinical radiation pneumonitis. Radiation pneumonitis was retrospectively graded using the Radiation Therapy Oncology Group (RTOG) scale by an observer blinded to the PET radiotoxicity score. Results: There was a significant association between the worst RTOG pneumonitis grade occurring at any time after RT and the positron emission tomograph (PET) radiotoxicity grade (one-sided p = 0.033). The worst RTOG pneumonitis grade occurring after the PET scan was also associated with the PET radiotoxicity grade (one-sided p = 0.035). For every one-level increase in the PET toxicity scale, the risk of a higher RTOG radiation pneumonitis score increased by approximately 40%. The PET radiotoxicity score showed no significant correlation with the duration of radiation pneumonitis. Conclusions: The intensity of FDG uptake in pulmonary tissue after RT determined using a simple visual scoring system showed significant correlation with the presence and severity of radiation pneumonitis. {sup 18}F-FDG-PET may be useful in the prediction, diagnosis and therapeutic monitoring of radiation pneumonitis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

Usefulness of Interim FDG-PET After Induction Chemotherapy in Patients With Locally Advanced Squamous Cell Carcinoma of the Head and Neck Receiving Sequential Induction Chemotherapy Followed by Concurrent Chemoradiotherapy

Purpose: Induction chemotherapy (ICT) has been used to select patients for organ preservation and determine subsequent treatments in patients with locally advanced squamous cell carcinoma of the head and neck (LASCCHN). Still, the clinical outcomes of LASCCHN patients who showed response to ICT are heterogeneous. We evaluated the efficacy of interim 18-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) after ICT in this specific subgroup of LASCCHN patients who achieved partial response (PR) after ICT to predict clinical outcomes after concurrent chemoradiotherapy (CCRT). Methods and Materials: Twenty-one patients with LASCCHN who showed PR to ICT by Response Evaluation Criteria In Solid Tumors before definitive CCRT were chosen in this retrospective analysis. FDG-PET was performed before and 2-4 weeks after ICT to assess the extent of disease at baseline and the metabolic response to ICT, respectively. We examined the correlation of the metabolic response by the percentage decrease of maximum standardized uptake value (SUVmax) on the primary tumor or lymph node after ICT or a specific threshold of SUVmax on interim FDG-PET with clinical outcomes including complete response (CR) rate to CCRT, progression-free survival (PFS), and overall survival (OS). Results: A SUVmax of 4.8 on interim FDG-PET could predict clinical CR after CCRT (100% vs. 20%, p = 0.001), PFS (median, not reached vs. 8.5 mo, p < 0.001), and OS (median, not reached vs. 12.0 months, p = 0.001) with a median follow-up of 20.3 months in surviving patients. A 65% decrease in SUVmax after ICT from baseline also could predict clinical CR after CCRT (100% vs. 33.3%, p = 0.003), PFS (median, not reached vs. 8.9 months, p < 0.001) and OS (median, not reached vs. 24.4 months, p = 0.001) of the patients. Conclusion: These data suggest that interim FDG-PET after ICT might be a useful determinant to predict clinical outcomes in patients with LASCCHN receiving sequential ICT followed by CCRT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

Contrast-Enhanced [{sup 18}F]fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Staging and Radiotherapy Planning in Patients With Anal Cancer

Purpose: The practice of surgical staging and treatment of anal cancer has been replaced by noninvasive staging and combined modality therapy. For appropriate patient management, accurate lymph node staging is crucial. The present study evaluated the feasibility and diagnostic accuracy of contrast-enhanced [{sup 18}F]fluoro-2-deoxy-D-glucose ([{sup 18}F]FDG)-positron emission tomography/computed tomography (PET/CT) for staging and radiotherapy planning of anal cancer. Methods and Materials: A total of 22 consecutive patients (median age, 61 years old) with anal cancer underwent complete staging evaluation including physical examination, biopsy of the primary tumor, and contrast-enhanced (ce)-PET/CT. Patients were positioned as they would be for their subsequent radiotherapy. PET and CT images were evaluated independently for detectability and localization of the primary tumor, pelvic and inguinal lymph nodes, and distant metastasis. The stage, determined by CT or PET alone, and the proposed therapy planning were compared with the stage and management determined by ce-PET/CT. Data from ce-PET/CT were used for radiotherapy planning. Results: ce-PET/CT revealed locoregional lymph node metastasis in 11 of 22 patients (50%). After simultaneous reading of PET and CT data sets by experienced observers, 3 patients (14%) were found to have sites of disease not seen on CT that were identified on PET. Two patients had sites of disease not seen on PET that were identified on CT. In summary, 2 patients were upstaged, and 4 patients were downstaged due to ce-PET/CT. However, radiotherapy fields were changed due to the results from ce-PET/CT in 23% of cases compared to CT or PET results alone. Conclusions: ce-PET/CT is superior to PET or CT alone for staging of anal cancer, with significant impact on therapy planning.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

Prognostic Utility of Squamous Cell Carcinoma Antigen in Carcinoma of the Cervix: Association With Pre- and Posttreatment FDG-PET

Purpose: Squamous cell carcinoma antigen (SCC Ag) is a serum biomarker for squamous cell carcinoma (SCC) of the cervix. We investigated the prognostic significance of SCC Ag levels before and at the completion of chemoradiotherapy and compared these levels with the results of pre- and posttreatment positron emission tomography/computed tomography (PET/CT) using [{sup 18}F]fluorodeoxyglucose (FDG). Methods and Materials: The records of 63 women who underwent definitive chemoradiotherapy for SCC of the cervix were reviewed. SCC Ag levels were obtained before and at the completion of radiotherapy. Patients were divided into two groups on the basis of their pretreatment SCC Ag level (>30 ng/mL vs. {<=}30 ng/mL). Pre- and posttreatment FDG-PET/CT characteristics and progression-free survival (PFS) were analyzed according to SCC Ag groups. Results: Median follow-up was 12 months. Women with SCC Ag >30 ng/mL at diagnosis had more advanced lymph node disease on pretreatment FDG-PET/CT than those with SCC Ag {<=}30 ng/mL (p = .002). Women whose SCC Ag normalized at the completion of chemoradiotherapy were more likely to have a complete metabolic response on their 3-month posttreatment FDG-PET/CT than those whose SCC Ag did not normalize (p = .006). The 2-year PFS was 73% for patients with a SCC Ag level {<=}30 ng/mL at diagnosis compared with 0% for those with a SCC Ag level >30 ng/mL at diagnosis (p < .0001). The 2-year PFS was 62% for patients whose SCC Ag normalized at the completion of chemoradiotherapy compared with 0% for those whose SCC Ag did not normalize (p = .0004). Conclusion: Elevated SCC Ag at diagnosis and failure of the SCC Ag to normalize at the completion of treatment are associated with incomplete metabolic response and decreased PFS.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

[{sup 18}F]fluorodeoxyglucose Uptake Patterns in Lung Before Radiotherapy Identify Areas More Susceptible to Radiation-Induced Lung Toxicity in Non-Small-Cell Lung Cancer Patients

Purpose: Our hypothesis was that pretreatment inflammation in the lung makes pulmonary tissue more susceptible to radiation damage. The relationship between pretreatment [{sup 18}F]fluorodeoxyglucose ([{sup 18}F]FDG) uptake in the lungs (as a surrogate for inflammation) and the delivered radiation dose and radiation-induced lung toxicity (RILT) was investigated. Methods and Materials: We retrospectively studied a prospectively obtained cohort of 101 non-small-cell lung cancer patients treated with (chemo)radiation therapy (RT). [{sup 18}F]FDG-positron emission tomography-computed tomography (PET-CT) scans used for treatment planning were studied. Different parameters were used to describe [{sup 18}F]FDG uptake patterns in the lungs, excluding clinical target volumes, and the interaction with radiation dose. An increase in the dyspnea grade of 1 (Common Terminology Criteria for Adverse Events version 3.0) or more points compared to the pre-RT score was used as an endpoint for analysis of RILT. The effect of [{sup 18}F]FDG and CT-based variables, dose, and other patient or treatment characteristics that effected RILT was studied using logistic regression. Results: Increased lung density and pretreatment [{sup 18}F]FDG uptake were related to RILT after RT with univariable logistic regression. The 95th percentile of the [{sup 18}F]FDG uptake in the lungs remained significant in multivariable logistic regression (p = 0.016; odds ratio [OR] = 4.3), together with age (p = 0.029; OR = 1.06), and a pre-RT dyspnea score of {>=}1 (p = 0.005; OR = 0.20). Significant interaction effects were demonstrated among the 80th, 90th, and 95th percentiles and the relative lung volume receiving more than 2 and 5 Gy. Conclusions: The risk of RILT increased with the 95th percentile of the [{sup 18}F]FDG uptake in the lungs, excluding clinical tumor volume (OR = 4.3). The effect became more pronounced as the fraction of the 5%, 10%, and 20% highest standardized uptake value voxels that received more than 2 Gy to 5 Gy increased. Therefore, the risk of RILT may be decreased by applying sophisticated radiotherapy techniques to avoid areas in the lung with high [{sup 18}F]FDG uptake.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

[{sup 18}F]FDG-Positron Emission Tomography Coregistration With Computed Tomography Scans for Radiation Treatment Planning of Lymphoma and Hematologic Malignancies

Purpose: Positron emission-tomography (PET) using 2-[{sup 18}F]fluoro-2-deoxyglucose (FDG-PET) increases sensitivity and specificity of disease detection in lymphoma and thus is standard in lymphoma management. This study examines the effects of coregistering FDG-PET and computed tomography (CT) (PET/CT) scans on treatment planning for lymphoma patients. Methods and Materials: Twenty-nine patients (30 positive PET scans) underwent PET/CT treatment planning from July 2004 to February 2007 and were retrospectively studied. For each patient, gross tumor volume was blindly contoured on the CT-only and PET/CT studies by a radiation oncologist. Treatment plans were generated for both the CT-only and PET/CT planning target volumes (PTVs) for all patients. Normal tissue doses and PTV coverage were evaluated using dose--volume histograms for all sites. Results: Thirty-two treatment sites were evaluated. Twenty-one patients had non-Hodgkin lymphoma, 5 patients had Hodgkin lymphoma, and 3 patients had plasma cell neoplasms. Previously undetected FDG-avid sites were identified in 3 patients during PET/CT simulation, resulting in one additional treatment field. Due to unexpected PET/CT simulation findings, 2 patients did not proceed with radiation treatment. The addition of PET changed the volume of 23 sites (72%). The PTV was increased in 15 sites (47%) by a median of 11% (range, 6-40%) and reduced in 8 sites (25%) by a median of 20% (range, 6%-75%). In six (19%) replanned sites, the CT-based treatment plan would not have adequately covered the PTV defined by PET/CT. Conclusions: Incorporation of FDG-PET into CT-based treatment planning for lymphoma patients resulted in considerable changes in management, volume definition, and normal tissue dosimetry for a significant number of patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

Simultaneous {sup 68}Ga-DOTATOC-PET/MRI for IMRT Treatment Planning for Meningioma: First Experience

Purpose: To evaluate intensity-modulated radiotherapy (IMRT) treatment planning based on simultaneous positron-emission tomography and magnetic resonance imaging (PET/MRI) of meningioma. Methods and Materials: A meningioma patient was examined prior to radiotherapy with dedicated planning computed tomography (CT), MRI, PET/CT with gallium-68-labeled DOTATOC ({sup 68}Ga-DOTATOC), and simultaneous {sup 68}Ga-DOTATOC-PET/MRI. The first gross target volume (GTV) was defined based on a combination of separate MR and {sup 68}Ga-DOTATOC-PET/CT imaging (GTV{sub PET/CT+MR}). Then, the simultaneous PET/MR images were used to delineate a second GTV (GTV{sub PET/MR}) by following exactly the same delineation strategy. After an isotropic expansion of those volumes by a 4-mm safety margin, the resulting planning target volumes (PTVs) were compared by calculating the intersection volume and the relative complements. A cross-evaluation of IMRT plans was performed, where the treatment plan created for the PTV{sub PET/CT+MR} was applied to the PET/MR-based PTV{sub PET/MR}. Results: Generally, target volumes for IMRT treatment planning did not differ between MRI plus {sup 68}Ga-DOTATOC-PET/CT and simultaneous PET/MR imaging. Only in certain regions of the GTV were differences observed. The overall volume of the PET/MR-based PTV was approximately the same as that obtained from PET/CT data. A small region of infiltrative tumor growth next to the main tumor mass was better visualized with combined PET/MR due to smaller PET voxel sizes and improved recovery. An IMRT treatment plan was optimized for the PTV{sub PET/CT+MR}. The evaluation of this plan with respect to the PTV{sub PET/MR} showed parts of the target volume that would not have received the full radiation dose after delineation of the tumor, based on simultaneous PET/MR. Conclusion: This case showed that differences in target volumes delineated on the basis of separate MR and PET/CT and simultaneous PET/MR may be observed that can have significant consequences for an effectively applied radiotherapy treatment plan.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

3'-deoxy-3'-[{sup 18}F]fluorothymidine PET Quantification of Bone Marrow Response to Radiation Dose

Purpose: The purpose of this study was to quantify the relationship of bone marrow response to radiation dose, using 3'-deoxy-3'-[{sup 18}F]fluorothymidine ([{sup 18}F]FLT)-labeled uptake quantified in positron-emission tomography (PET) scans. Methods and Materials: Pre- and post-Week 1 treatment [{sup 18}F]FLT PET images were registered to the CT images used to create the radiation treatment plan. Changes in [{sup 18}F]FLT uptake values were measured using profile data of standardized uptake values (SUVs) and doses along the vertebral bodies located at a field border where a range of radiation doses were present for 10 patients. Data from the profile measurements were grouped into 1 Gy dose bins from 1 to 9 Gy to compare SUV changes for all patients. Additionally, the maximum pretreatment, the post-Week 1 treatment, and the dose values located within the C6-T7 vertebrae that straddled the field edge were measured for all patients. Results: Both the profile and the individual vertebral data showed a strong correlation between SUV change and radiation dose. Relative differences in SUVs between bins >1 Gy and <7 Gy were statistically significant (p < 0.01, two-sample t test). The reduction in SUV was approximately linear until it reached a reduction threshold of 75%-80% in SUV for doses greater than 6 Gy/week for both the dose-binned data and the vertebral maximum SUVs. Conclusions: The change in SUV observed in head and neck cancer patients treated with chemoradiation shows the potential for using [{sup 18}F]FLT PET images for identifying active bone marrow and monitoring changes due to radiation dose. Additionally, the change in [{sup 18}F]FLT uptake observed in bone marrow for different weekly doses suggests potential dose thresholds for reducing bone marrow toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

Nuclear Data Sheets for A = 27

Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for {sup 27}F, {sup 27}Ne, {sup 27}Na, {sup 27}Mg, {sup 27}Al, {sup 27}Si, {sup 27}P, and {sup 27}S. This evaluation for A=27 supersedes the earlier evaluation by P.M. Endt (1998En04 and 1990En08).