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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Evaluation of Aroclor 1260 exposure in a mouse model of diet-induced obesity and non-alcoholic fatty liver disease

Polychlorinated biphenyls (PCBs) are persistent organic pollutants associated with non-alcoholic fatty liver disease (NAFLD) in epidemiologic studies. The purpose of this study was to evaluate the hepatic effects of a PCB mixture, Aroclor 1260, whose composition mimics human bioaccumulation patterns, in a mouse model of diet-induced obesity (DIO). Male C57Bl/6J mice were fed control diet or 42% high fat diet (HFD) and exposed to Aroclor 1260 (20 mg/kg or 200 mg/kg in corn oil) for 12 weeks. A glucose tolerance test was performed; plasma/tissues were obtained at necropsy for measurements of adipocytokine levels, histology, and gene expression. Aroclor 1260 exposure was associated with decreased body fat in HFD-fed mice but had no effect on blood glucose/lipid levels. Paradoxically, Aroclor 1260 + HFD co-exposed mice demonstrated increased hepatic inflammatory foci at both doses while the degree of steatosis did not change. Serum cytokines, ALT levels and hepatic expression of IL-6 and TNFα were increased only at 20 mg/kg, suggesting an inhibition of pro-inflammatory cytokine production at the 200 mg/kg exposure. Aroclor 1260 induced hepatic expression of cytochrome P450s including Cyp3a11 (Pregnane-Xenobiotic Receptor target) and Cyp2b10 (constitutive androstane receptor target) but Cyp2b10 inducibility was diminished with HFD-feeding. Cyp1a2 (aryl hydrocarbon Receptor target) was induced only at 200 mg/kg. In summary, Aroclor 1260 worsened hepatic and systemic inflammation in DIO. The results indicated a bimodal response of PCB-diet interactions in the context of inflammation which could potentially be explained by xenobiotic receptor activation. Thus, PCB exposure may be a relevant “second hit” in the transformation of steatosis to steatohepatitis. - Highlights: • Aroclor 1260 exposure decreased adiposity in mice fed with high fat diet • Aroclor 1260 exposure induced steatohepatitis in diet-induced obese mice • Aroclor 1260 (20 and 200 mg/kg) induced Cyp2b10 and Cyp3a11 (CAR/PXR target genes) • Aroclor 1260 at 200 mg/kg induced Cyp1a2 (AhR target gene)

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Sex-related differences in murine hepatic transcriptional and proteomic responses to TCDD

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant that produces myriad toxicities in most mammals. In rodents alone, there is a huge divergence in the toxicological response across species, as well as among different strains within a species. But there are also significant differences between males and females animals of a single strain. These differences are inconsistent across model systems: the severity of toxicity is greater in female rats than males, while male mice and guinea pigs are more sensitive than females. Because the specific events that underlie this difference remain unclear, we characterized the hepatic transcriptional response of adult male and female C57BL/6 mice to 500 μg/kg TCDD at multiple time-points. The transcriptional profile diverged significantly between the sexes. Female mice demonstrated a large number of altered transcripts as early as 6 h following treatment, suggesting a large primary response. Conversely, male animals showed the greatest TCDD-mediated response 144 h following exposure, potentially implicating significant secondary responses. Nr1i3 was statistically significantly induced at all time-points in the sensitive male animals. This mRNA encodes the constitutive androstane receptor (CAR), a transcription factor involved in the regulation of xenobiotic metabolism, lipid metabolism, cell cycle and apoptosis. Surprisingly though, changes at the protein level (aside from the positive control, CYP1A1) were modest, with only FMO3 showing clear induction, and no genes with sex-differences. Thus, while male and female mice show transcriptional differences in their response to TCDD, their association with TCDD-induced toxicities remains unclear. - Highlights: • Differences exist between the toxicity phenotypes to TCDD in male and female mice. • TCDD-mediated transcriptomic differences were identified between the sexes. • Resistant female mice displayed a large, early-onset, transcriptomic response. • Sensitive male mice displayed a large, late-onset, transcriptomic response. • Fmo2, Fmo3 and Nr1i3 were induced across the time-course in only male mice.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Heterodimerization of Retinoid X Receptor with Xenobiotic Receptor partners occurs in the cytoplasmic compartment: Mechanistic insights of events in living cells

Retinoid X Receptor (RXR) serves as the heterodimeric partner of two major xenobiotic nuclear receptors, Pregnane and Xenobiotic Receptor (PXR) and Constitutive Androstane Receptor (CAR). These receptors are primarily involved in the metabolism and clearance of endobiotics and xenobiotics (including clinical drugs) from the body. Here, we report for the first time that intermolecular interactions between RXR-PXR and RXR-CAR occurs in the cytoplasmic compartment of the cell in a ligand-independent manner. These interactions lead to nuclear import of the heterodimeric complex thereby making them competent for chromatin binding and transactivation of target genes. To explore the cellular site involved in the process of heterodimerization we created various RFP- and GFP-tagged receptor chimeras and also the mutants of their nuclear localization signal (NLS). From the study it is apparent that NLS of PXR/CAR/RXR play a major role in the import of the heterodimeric complex from the cytoplasm to the nucleus in a ligand-independent manner. We observed that along with the heterodimeric partner and/or respective ligand a functional NLS is necessary for activation of target gene. The data suggests that RXR is the major driving force to import the heterodimeric complex into the nucleus since the mutation in the NLS region of RXR weakens this import process dramatically, whereas mutations in the NLS regions of PXR and CAR have little or no significant effect. This RXR-dependent nuclear translocation of the heterodimeric complex also modulates the individual transcriptional activity of PXR and CAR by increasing the basal transcriptional activity. Finally, it is documented that the heterodimerization of RXR with both the partners (PXR, CAR) occurs in the cytoplasm and implies that these dynamic interactions have functional and regulatory attributes in gene expression. In addition, this RXR-dependent enhancement of the transcriptional activity of PXR and CAR may be utilized for evaluating the receptor-drug interactions. - Highlights: • RFP-tagged RXR, PXR and CAR are used to study receptor heterodimerization. • Tagged receptors shifted to cytoplasm and imported to nucleus after heterodimerization. • Wild-type nuclear receptor can translocate cytoplasmic NLS-mutant to the nucleus. • Receptor heterodimerization is a ligand-independent event and occurs in cytoplasm. • Transcriptional activity of nuclear receptor is enhanced by heterodimerization.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Calculated solvent reorganization entropies, free energies, and fluctuations of the energy gaps for intramolecular electron transfer and excitation of the solvatochromic dye B30

Intramolecular electron transfer between two biphenyl groups linked by an androstane spacer and excitation of the pyridinium-N-phenolate betaine dye B30 to the first excited singlet state are studied by quantum/classical molecular-dynamics simulations at temperatures between 150 and 300 K in solvents with a range of polarities. Temperature dependences of the solvent reorganization energies, free energies, entropies, and the inhomogeneous broadening of B30’s absorption band are examined. The variances of fluctuations of the energy gap between the reactant and product states do not have the direct proportionality to temperature that often is assumed to hold. An explanation for the observations is suggested.

Chemistry↗
DOE OSTI2022

Molecular basis of crosstalk in nuclear receptors: heterodimerization between PXR and CAR and the implication in gene regulation

The 48 human nuclear receptors (NRs) form a superfamily of transcription factors that regulate major physiological and pathological processes. Emerging evidence suggests that NR crosstalk can fundamentally change our understanding of NR biology, but detailed molecular mechanisms of crosstalk are lacking. Here, we report the molecular basis of crosstalk between the pregnane X receptor (PXR) and constitutive androstane receptor (CAR), where they form a novel heterodimer, resulting in their mutual inhibition. PXR and CAR regulate drug metabolism and energy metabolism. Although they have been broadly perceived as functionally redundant, a growing number of reports suggests a mutual inhibitory relation, but their precise mode of coordinated action remains unknown. Using methods including RNA sequencing, small-angle X-ray scattering and crosslinking mass spectrometry we demonstrate that the mutual inhibition altered gene expression globally and is attributed to the novel PXR–CAR heterodimerization via the same interface used by each receptor to heterodimerize with its functional partner, retinoid X receptor (RXR). These findings establish an unexpected functional relation between PXR, CAR and RXR, change the perceived functional relation between PXR and CAR, open new perspectives on elucidating their role and designing approaches to regulate them, and highlight the importance to comprehensively investigate nuclear receptor crosstalk.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1972

C-13 nuclear magnetic resonance in organic geochemistry.

Study of C-13 nuclear magnetic resonance (NMR) spectra of polycyclic fused systems. The fingerprint qualities of the natural abundance in C-13 NMR spectra permitting unequivocal identification of these compounds is discussed. The principle of structural additivity of C-13 NMR information is exemplified on alpha and beta androstanes, alpha and beta cholestanes, ergostanes, sitostanes, and isodecanes.

Balogh, B.↗
DOE OSTI2010

Combined Adrenal and Ovarian Venous Sampling to Localize an Androgen Producing Tumor

A postmenopausal woman presented with hirsutism and elevated serum testosterone levels. A 1-cm adrenal adenoma was noted on computed tomography. Combined adrenal and ovarian venous sampling was performed to localize an androgen producing tumor to the left ovary. The patient underwent a bilateral salpingo-oophrectomy and was spared an unnecessary adrenalectomy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

CAR-mediated repression of Cdkn1a(p21) is accompanied by the Akt activation

Highlights: • CAR-mediated liver growth is accompanied by the decrease in PTEN. • CAR-mediated liver growth is accompanied by the Akt activation. • CAR-mediated Akt activation is accompanied by the decrease in Foxo1. • CAR activation decreased the level of p21. It was shown that CAR participates in the regulation of many cell processes. Thus, the activation of CAR causes a proliferating effect in the liver, which provides grounds to consider CAR as a therapeutic target when having a partial resection of this organ. Even though a lot of work has been done on the function of CAR in regulating hepatocyte proliferation, very little has been done on its complex mediating mechanism. This study, therefore, showed that the liver growth resulting from CAR activation leads to the decline in the level of PTEN protein and subsequent Akt activation in mouse liver. The increase of Akt activation produced by CAR agonist was accompanied by a decrease in the level of Foxo1, which was correlated with decreased expression of Foxo1 target genes, including Cdkn1a(p21). Moreover, the study also demonstrated that there exists a negative regulatory impact of CAR on the relationship between Foxo1 and targeted Cdkn1a(p21) promoter. Therefore, the study results revealed an essential function of CAR-Akt-Foxo1 signalling pathway in controlling hepatocyte proliferation by repressing the cell cycle regulator Cdkn1a (p21).

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Expression of Bcl-2, p53, and MDM2 in Localized Prostate Cancer With Respect to the Outcome of Radical Radiotherapy Dose Escalation

Purpose: Established prognostic factors in localized prostate cancer explain only a moderate proportion of variation in outcome. We analyzed tumor expression of apoptotic markers with respect to outcome in men with localized prostate cancer in two randomized controlled trials of radiotherapy dose escalation. Methods and Materials: Between 1995 and 2001, 308 patients with localized prostate cancer received neoadjuvant androgen deprivation and radical radiotherapy at our institution in one of two dose-escalation trials. The biopsy specimens in 201 cases were used to make a biopsy tissue microarray. We evaluated tumor expression of Bcl-2, p53, and MDM2 by immunohistochemistry with respect to outcome. Results: Median follow-up was 7 years, and 5-year freedom from biochemical failure (FFBF) was 70.4% (95% CI, 63.5-76.3%). On univariate analysis, expression of Bcl-2 (p < 0.001) and p53 (p = 0.017), but not MDM2 (p = 0.224), was significantly associated with FFBF. Expression of Bcl-2 remained significantly associated with FFBF (p = 0.001) on multivariate analysis, independently of T stage, Gleason score, initial prostate-specific antigen level, and radiotherapy dose. Seven-year biochemical control was 61% vs. 41% (p = 0.0122) for 74 Gy vs. 64 Gy, respectively, among patients with Bcl-2-positive tumors and 87% vs. 81% (p = 0.423) for 74 Gy vs. 64 Gy, respectively, among patients with Bcl-2-negative tumors. There was no statistically significant interaction between dose and Bcl-2 expression. Conclusions: Bcl-2 expression was a significant, independent determinant of biochemical control after neoadjuvant androgen deprivation and radical radiotherapy for prostate cancer. These data generate the hypothesis that Bcl-2 expression could be used to inform the choice of radiotherapy dose in individual patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

PSA Decrease During Combined-Modality Radiotherapy Predicts for Treatment Outcome

Purpose: Prostate-specific antigen (PSA) is the well-used marker in the diagnosis, prognosis, and follow-up for prostate cancer patients. Although reports have focused on the importance of pretreatment PSA levels, doubling time, and posttreatment nadirs, there is little information on the value of PSA during the course of radiotherapy. Methods and Materials: Retrospective review of PSA values obtained midway through a course of radiotherapy treatment for prostate cancer. Patients had a PSA (midPSA) measured after a course of external beam radiation (EBRT) before planned transperineal low-dose-rate brachytherapy implant (LDR). Results: A total of 717 patients were analyzed with a median follow-up of 5.8 years, all censored patients had a minimum follow-up of 2 years. A total of 277 patients had low-risk disease, 267 patients had intermediate risk, and 173 patients had high-risk disease. Androgen blockade was used in 512 patients. A total of 653 patients had a midPSA decrease after EBRT, the median decrease was 6.2 ng/mL. Patients who had a midPSA decrease {>=}25% compared with pretreatment PSA had improved overall survival of 10.0 vs. 7.4 years (p < 0.0004) and improved disease-free survival of 9.8 vs. 7.3 years (p < 0.01). When stratified by use of androgen blockade, midPSA remained significant for both androgen and non-androgen patients. Conclusions: PSA response after EBRT before brachytherapy predicts for long-term outcome; this may allow for risk stratification and intervention with higher LDR doses to improve outcomes.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Baseline Serum Testosterone in Men Treated With Androgen Deprivation Therapy and Radiotherapy for Localized Prostate Cancer

Introduction: It is believed that men diagnosed with prostate cancer and a low baseline serum testosterone (BST) may have more aggressive disease, and it is frequently recommended they forgo testosterone replacement therapy. We used two large Phase III trials involving androgen deprivation therapy and external beam radiation therapy to assess the significance of a BST. Methods and Materials: All patients with a BST and complete data (n = 2,478) were included in this analysis and divided into four categories: 'Very Low BST' (VLBST) {<=}16.5th percentile of BST ({<=}248 ng/dL; n = 408); 'Low BST' (LBST) >16.5th percentile and {<=}33rd percentile (>248 ng/dL but {<=}314 ng/dL; n = 415); 'Average BST' (ABST) >33rd percentile and {<=}67th percentile (314-437 ng/dL; n = 845); and 'High BST' (HBST) >67th percentile (>437 ng/dL; n = 810). Outcomes included overall survival, distant metastasis, biochemical failure, and cause-specific survival. All outcomes were adjusted for the following covariates: treatment arm, BST, age (<70 vs. {>=}70), prostate-specific antigen (PSA; <10 vs. 10 {<=} PSA <20 vs. 20 {<=}), Gleason score (2-6 vs. 7 vs. 8-10); T stage (T1-T2 vs. T3-T4), and Karnofsky Performance Status (60-90 vs. 100). Results: On multivariable analysis age, Gleason score, and PSA were independently associated with an increased risk of biochemical failure, distant metastasis and a reduced cause-specific and overall survival (p < 0.05), but BST was not. Conclusions: BST does not affect outcomes in men treated with external beam radiation therapy and androgen deprivation therapy for prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Timing of Salvage Hormonal Therapy in Prostate Cancer Patients With Unfavorable Prognosis Treated With Radiotherapy: A Secondary Analysis of Radiation Therapy Oncology Group 85-31

Purpose: Radiation Therapy Oncology Group 85-31 was a randomized trial comparing radiotherapy (RT) alone vs. RT plus adjuvant androgen suppression for life in unfavorable-prognosis carcinoma of the prostate. We examined the impact of early initiation of salvage hormonal therapy (HT) in relapsing patients randomized to RT alone arm. Methods and Materials: Patients were divided into two groups: early salvage HT and late salvage HT. The early salvage group was defined as receiving HT with a prostate-specific antigen (PSA) level of less than 10 ng/mL, and the late salvage HT group had a PSA level of 10 ng/mL or greater. The outcomes were overall survival (OS), cause-specific mortality (CSM), and local failure (LF). The Kaplan-Meier estimation and log-rank test were used for OS, and the cumulative incidence estimation and Gray's test were used for CSM and LF. Proportional hazards regression models were used to compare the outcomes adjusted for other covariates. Results: The median follow-up times of surviving patients in the early and late salvage HT groups were about 11 and 13 years, respectively. The late salvage HT group had significantly more post-prostatectomy patients and patients with high Gleason scores. After adjustment for all covariates, OS was significantly longer in the early salvage HT group (hazard ratio, 1.5; p = 0.01). However, there were no statistically significant differences in LF or CSM between the groups. Conclusions: The early introduction of salvage HT resulted in improved OS but not improved CSM and LF. A randomized trial to define the optimal salvage hormonal timing is warranted in this group of patients with PSA recurrence after RT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

A Comparison of the Prognostic Value of Early PSA Test-Based Variables Following External Beam Radiotherapy, With or Without Preceding Androgen Deprivation: Analysis of Data From the TROG 96.01 Randomized Trial

Purpose: We sought to compare the prognostic value of early prostate-specific antigen (PSA) test-based variables for the 802 eligible patients treated in the Trans-Tasman Radiation Oncology Group 96.01 randomized trial. Methods and Materials: Patients in this trial had T2b, T2c, T3, and T4 N0 prostate cancer and were randomized to 0, 3, or 6 months of neoadjuvant androgen deprivation therapy (NADT) prior to and during radiation treatment at 66 Gy to the prostate and seminal vesicles. The early PSA test-based variables evaluated were the pretreatment initial PSA (iPSA) value, PSA values at 2 and 4 months into NADT, the PSA nadir (nPSA) value after radiation in all patients, and PSA response signatures in men receiving radiation. Comparisons of endpoints were made using Cox models of local progression-free survival, distant failure-free survival, biochemical failure-free survival, and prostate cancer-specific survival. Results: The nPSA value was a powerful predictor of all endpoints regardless of whether NADT was given before radiation. PSA response signatures also predicted all endpoints in men treated by radiation alone. iPSA and PSA results at 2 and 4 months into NADT predicted biochemical failure-free survival but not any of the clinical endpoints. nPSA values correlated with those of iPSA, Gleason grade, and T stage and were significantly higher in men receiving radiation alone than in those receiving NADT. Conclusions: The postradiation nPSA value is the strongest prognostic indicator of all early PSA-based variables. However, its use as a surrogate endpoint needs to take into account its dependence on pretreatment variables and treatment method.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Predictors of Androgen Deprivation Therapy Efficacy Combined With Prostatic Irradiation: The Central Role of Tumor Stage and Radiation Dose

Purpose: To evaluate the response of clinically localized prostate cancer to various durations of planned androgen deprivation therapy (ADT) and to investigate subgroups predicting response. Methods and Materials: Data of 3,666 prostate cancer patients treated with either combined ADT and external beam radiotherapy (EBRT) or EBRT alone at four institutions were examined. ADT consisted of neoadjuvant, concurrent, or adjuvant ADT or combinations of these regimens. The primary endpoint was time to biochemical failure (nadir plus 2 ng/ml), assessed from the end of therapy. Factors predictive for the need for ADT were examined with interaction analyses. Results: The impact of increasing ADT duration was nonlinear with, on average, 6 months of adjuvant ADT resulting in a reduction of the risk of biochemical failure by 38% (95% confidence interval [CI], 29%-46%), while 12, 24, and 36 months of ADT resulted in a 58% (95% CI, 47%-67%), 66% (95% CI, 55%-75%), and 66% (95% CI, 51%-77%) relative failure reduction, respectively. Patients with higher T stage cancers and those treated with lower radiation doses had a significantly greater benefit for increasing ADT duration (interaction, p = 0.016 and p = 0.007, respectively). Pretreatment prostate-specific antigen values, Gleason score, age, and risk group did not modify the response to ADT. Conclusions: The known ADT efficacy derived from randomized studies can be generalized to patients with different features, and individual predictions of potential benefit from ADT use and duration may be calculated to aid patient and physician decision making. Tumor stage and radiation dose variations were related to significantly different ADT duration effects. The validity of these predictive factors requires prospective evaluation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Prostate-Specific Antigen Halving Time While on Neoadjuvant Androgen Deprivation Therapy Is Associated With Biochemical Control in Men Treated With Radiation Therapy for Localized Prostate Cancer

Purpose: To assess whether the PSA response to neoadjuvant androgen deprivation therapy (ADT) is associated with biochemical control in men treated with radiation therapy (RT) for prostate cancer. Methods and Materials: In a cohort of men treated with curative-intent RT for localized prostate cancer between 1988 and 2005, 117 men had PSA values after the first and second months of neoadjuvant ADT. Most men had intermediate-risk (45%) or high-risk (44%) disease. PSA halving time (PSAHT) was calculated by first order kinetics. Median RT dose was 76 Gy and median total duration of ADT was 4 months. Freedom from biochemical failure (FFBF, nadir + 2 definition) was analyzed by PSAHT and absolute PSA nadir before the start of RT. Results: Median follow-up was 45 months. Four-year FFBF was 89%. Median PSAHT was 2 weeks. A faster PSA decline (PSAHT {<=}2 weeks) was associated with greater FFBF (96% vs. 81% for a PSAHT >2 weeks, p = 0.0110). Those within the fastest quartile of PSAHTs ({<=} 10 days) achieved a FFBF of 100%. Among high-risk patients, a PSAHT {<=}2 weeks achieved a 4-yr FFBF of 93% vs. 70% for those with PSAHT >2 weeks (p = 0.0508). Absolute PSA nadir was not associated with FFBF. On multivariable analysis, PSAHT (p = 0.0093) and Gleason score (p = 0.0320) were associated with FFBF, whereas T-stage (p = 0.7363) and initial PSA level (p = 0.9614) were not. Conclusions: For men treated with combined ADT and RT, PSA response to the first month of ADT may be a useful criterion for prognosis and treatment modification.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Acute and Late Toxicity in a Randomized Trial of Conventional Versus Hypofractionated Three-Dimensional Conformal Radiotherapy for Prostate Cancer

Purpose: To compare the toxicity between hypofractionation vs. conventional fractionation schedules in patients with high-risk prostate cancer. Methods and Materials: Between January 2003 and December 2007, 168 patients were randomized to receive either hypofractionated (62 Gy in 20 fractions within 5 weeks, 4 fractions/wk) or conventionally fractionated (80 Gy in 40 fractions within 8 weeks) three-dimensional conformal radiotherapy to the prostate and seminal vesicles. All patients had undergone a 9-month course of total androgen deprivation, with radiotherapy starting 2 months after initiation of the total androgen deprivation. Results: The median follow-up was 32 and 35 months in the hypofractionation and conventional fractionation arms, respectively. For the patients developing acute toxicity, no difference between the two fractionation groups was found in either severity or duration of gastrointestinal or genitourinary toxicity. Also, no difference was found in the incidence and severity of late gastrointestinal and genitourinary toxicity between the two treatment schedules, with a 3-year rate of Grade 2 or greater toxicity of 17% and 16% for the hypofractionation arm and 14% and 11% for the conventional fractionation arm, respectively. A statistically significant correlation between acute and late gastrointestinal toxicity was found only in the conventional fractionation group. Conclusion: Our findings suggest that the hypofractionation regimen used in our study is safe, with only a slight, nonsignificant increase in tolerable and temporary acute toxicity compared with the conventional fractionation schedule. The severity and frequency of late complications was equivalent between the two treatment groups.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Acupuncture for the Alleviation of Hot Flashes in Men Treated With Androgen Ablation Therapy

Purpose: Hot flashes are common side effect due to androgen ablation therapy (AAT). The utility of acupuncture for hot flashes in men has not been thoroughly studied. We prospectively studied the effect of acupuncture in men with hot flashes. Methods and Materials: The study was approved by internal review board. Seventeen men with hot flashes and history of AAT for prostate cancer were enrolled. Three men declined participation before receiving any treatment. A hot flash score (HFS) was used to measure daily hot flashes. The composite daily score was calculated as the product of frequency x severity. The baseline daily scores were compared with scores taken at 2 and 6 weeks and at 8-month average follow-up. Results: No side effects were encountered during, immediately after treatment, or at 8 months. The mean initial HFS was 28.3; it dropped to 10.3 (p = 0.0001) at 2 weeks posttreatment, 7.5 (p = 0.0001) at 6 weeks, and 7.0 (p = 0.001) at 8 months. Clinical improvement for each patient is defined as the percent decrease in the mean HFS at each time point. The mean improvement at Weeks 2 and 6 was 68.4% (mean HFS decreased from 37.409 to 11.836, p = 0.001) and 89.2% (mean HFS decreased from 37.409 to 4.05, p = 0.0078) respectively. The improvement at 8 months was 80.3% (mean HFS decreased from 37.409 to 7.385, p = 0.002). Conclusions: Acupuncture provides excellent control of hot flashes in men with a history of AAT. The absence of side effects and the durable response at 8 months are likely to be appealing to patients. Prospective randomized study is warranted to further evaluate this modality against medical therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Intensity-Modulated Radiotherapy Reduces Gastrointestinal Toxicity in Patients Treated With Androgen Deprivation Therapy for Prostate Cancer

Purpose: Androgen deprivation therapy (AD) has been shown to increase late Grade 2 or greater rectal toxicity when used concurrently with three-dimensional conformal radiotherapy (3D-CRT). Intensity-modulated radiotherapy (IMRT) has the potential to reduce toxicity by limiting the radiation dose received by the bowel and bladder. The present study compared the genitourinary and gastrointestinal (GI) toxicity in men treated with 3D-CRT+AD vs. IMRT+AD. Methods and Materials: Between July 1992 and July 2004, 293 men underwent 3D-CRT (n = 170) or IMRT (n = 123) with concurrent AD (<6 months, n = 123; {>=}6 months, n = 170). The median radiation dose was 76 Gy for 3D-CRT (International Commission on Radiation Units and Measurements) and 76 Gy for IMRT (95% to the planning target volume). Toxicity was assessed by a patient symptom questionnaire that was completed at each visit and recorded using a Fox Chase Modified Late Effects Normal Tissue Task radiation morbidity scale. Results: The mean follow-up was 86 months (standard deviation, 29.3) for the 3D-CRT group and 40 months (standard deviation, 9.7) for the IMRT group. Acute GI toxicity (odds ratio, 4; 95% confidence interval, 1.6-11.7; p = .005) was significantly greater with 3D-CRT than with IMRT and was independent of the AD duration (i.e., <6 vs. {>=}6 months). The interval to the development of late GI toxicity was significantly longer in the IMRT group. The 5-year Kaplan-Meier estimate for Grade 2 or greater GI toxicity was 20% for 3D-CRT and 8% for IMRT (p = .01). On multivariate analysis, Grade 2 or greater late GI toxicity (hazard ratio, 2.1; 95% confidence interval, 1.1-4.3; p = .04) was more prevalent in the 3D-CRT patients. Conclusion: Compared with 3D-CRT, IMRT significantly decreased the acute and late GI toxicity in patients treated with AD.

62 RADIOLOGY AND NUCLEAR MEDICINE↗