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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 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Preoperative Chemoradiotherapy (CRT) Followed by Laparoscopic Surgery for Rectal Cancer: Predictors of the Tumor Response and the Long-Term Oncologic Outcomes

Purpose: We have evaluated the predictors of a tumor response to chemoradiotherapy (CRT) and the long-term oncologic outcomes of preoperative CRT and laparoscopic surgery for patients who suffer from rectal cancer. Methods and Materials: The study involved 274 patients with locally advanced rectal cancer and who had been treated with preoperative CRT and curative laparoscopic total mesorectal excision between January 2003 and January 2009. We assessed the long-term oncologic outcomes, in terms of recurrence and survival, of the treated patients. Results: Forty-two (15.3%) of the 274 patients had complete pathologic responses (pCR). The pre-CRT carcinoembryonic antigen level was the only significant predictor of a pCR on the multivariate analysis (p = 0.01). The overall survival at 5 years was 73.1%, with a mean survival period of 59.7 months (95% CI, 57.1-62.3). The disease-free survival at 5 years was 67.3% with a mean survival period of 54.7 months (95% CI, 51.7-57.8). The pCR group had a higher rate of overall survival at 5 years than did the non-pCR group, and the difference was significant (86.0% vs. 71.2%; hazard ratio = 0.87; 95% CI, 0.78-0.96; p = 0.03). The cumulative incidences of local and distant recurrences at 5 years were 5.8% and 28.3%, respectively. A total of 84.5% (234 of 274) of the patients had their anal sphincters preserved. Grade 3 or 4 acute and long-term toxic effects occurred in 22.2% and 8.4% of the patients, respectively. Conclusion: Preoperative CRT and laparoscopic surgery seems safe and feasible with favorable long-term outcomes and a high rate of sphincter preservation for the patients with low-lying tumors of the rectum.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Redefining High-Risk Prostate Cancer Based on Distant Metastases and Mortality After High-Dose Radiotherapy With Androgen Deprivation Therapy

Purpose: Modern outcomes of high-dose external beam radiotherapy (EBRT) with androgen deprivation therapy (ADT) for high-risk (HR) prostate cancer are not well described. Methods and Materials: We identified 585 patients who met HR criteria by 2010 National Comprehensive Cancer Network guidelines, who were treated with EBRT consisting of {>=}74 Gy from 1996 to 2008 at Cleveland Clinic, of whom 95% received ADT. We analyzed biochemical relapse-free survival (bRFS), distant metastases-free survival (DMFS), and prostate cancer-specific mortality (PCSM). Results: The median EBRT dose was 78 Gy, and median ADT duration was 6 months. At 10 years, the bRFS was 50.2%, the DMFS was 71.6%, and the PCSM was 14.4%. On multivariate analysis, significant predictors of bRFS were biopsy Gleason score (bGS) of 8 to 10, stage T3, and prostate-specific antigen (PSA) concentration; predictors of DMFS were bGS of 8 to 10 and stage T3; the only predictor of PCSM was bGS of 8 to 10. The duration of ADT was not predictive of any endpoint. We identified an unfavorable high-risk (UHR) group of stage T1-T2 tumors consisting of bGS of 8 with PSA of >10 ng/ml or bGS of 9 to 10 with any PSA level; the remaining clinically localized cancers comprised the favorable high-risk (FHR) group. Comparing FHR, UHR, and stage T3 groups, the DMFS rates were 81.4%, 57.8%, and 59.1% (p < 0.0001), and the PCSM rates were 7.5%, 28.4%, and 20.6% at 10 years, respectively (p = 0.006). Conclusion: A bGS of 8 to 10 is the strongest predictor of bRFS, DMFS, and PCSM after high-dose EBRT with ADT. The duration of ADT did not correlate with outcome. Future studies should account for the heterogeneity in HR prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Nomogram Prediction of Survival and Recurrence in Patients With Extrahepatic Bile Duct Cancer Undergoing Curative Resection Followed by Adjuvant Chemoradiation Therapy

Purpose: To develop nomograms for predicting the overall survival (OS) and relapse-free survival (RFS) in patients with extrahepatic bile duct cancer undergoing adjuvant chemoradiation therapy after curative resection. Methods and Materials: From January 1995 through August 2006, a total of 166 consecutive patients underwent curative resection followed by adjuvant chemoradiation therapy. Multivariate analysis using Cox proportional hazards regression was performed, and this Cox model was used as the basis for the nomograms of OS and RFS. We calculated concordance indices of the constructed nomograms and American Joint Committee on Cancer (AJCC) staging system. Results: The OS rate at 2 years and 5 years was 60.8% and 42.5%, respectively, and the RFS rate at 2 years and 5 years was 52.5% and 38.2%, respectively. The model containing age, sex, tumor location, histologic differentiation, perineural invasion, and lymph node involvement was selected for nomograms. The bootstrap-corrected concordance index of the nomogram for OS and RFS was 0.63 and 0.62, respectively, and that of AJCC staging for OS and RFS was 0.50 and 0.52, respectively. Conclusions: We developed nomograms that predicted survival and recurrence better than AJCC staging. With caution, clinicians may use these nomograms as an adjunct to or substitute for AJCC staging for predicting an individual's prognosis and offering tailored adjuvant therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Impact of the Radiation Boost on Outcomes After Breast-Conserving Surgery and Radiation

Purpose: We examined the impact of radiation tumor bed boost parameters in early-stage breast cancer on local control and cosmetic outcomes. Methods and Materials: A total of 3,186 women underwent postlumpectomy whole-breast radiation with a tumor bed boost for Tis to T2 breast cancer from 1970 to 2008. Boost parameters analyzed included size, energy, dose, and technique. Endpoints were local control, cosmesis, and fibrosis. The Kaplan-Meier method was used to estimate actuarial incidence, and a Cox proportional hazard model was used to determine independent predictors of outcomes on multivariate analysis (MVA). The median follow-up was 78 months (range, 1-305 months). Results: The crude cosmetic results were excellent in 54%, good in 41%, and fair/poor in 5% of patients. The 10-year estimate of an excellent cosmesis was 66%. On MVA, independent predictors for excellent cosmesis were use of electron boost, lower electron energy, adjuvant systemic therapy, and whole-breast IMRT. Fibrosis was reported in 8.4% of patients. The actuarial incidence of fibrosis was 11% at 5 years and 17% at 10 years. On MVA, independent predictors of fibrosis were larger cup size and higher boost energy. The 10-year actuarial local failure was 6.3%. There was no significant difference in local control by boost method, cut-out size, dose, or energy. Conclusions: Likelihood of excellent cosmesis or fibrosis are associated with boost technique, electron energy, and cup size. However, because of high local control and rare incidence of fair/poor cosmesis with a boost, the anatomy of the patient and tumor cavity should ultimately determine the necessary boost parameters.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Influence of Residual Tumor Volume and Radiation Dose Coverage in Outcomes for Clival Chordoma

Purpose: The purpose of this study was to evaluate factors associated with tumor control in clival chordomas. Methods and Materials: A retrospective review of 39 patients treated with surgery and proton therapy for clival chordomas between 2004 and 2014 was performed. The median prescribed dose was 77.4 Gy (relative biological effectiveness [RBE]); range was 70.2-79.2 Gy (RBE). Minimum and median doses to gross tumor volume (GTV), radiation dose received by 1 cm{sup 3} of GTV (D1cm{sup 3}), and the equivalent uniform dose were calculated. Receiver operating characteristics curves evaluated the predictive sensitivity and specificity for local failure of potential cutpoint values for GTV and D1cm{sup 3}. Results: After a median follow-up of 51 months, the 5-year estimate of local control (LC) was 69.6% (95% confidence interval [CI] 50.0%-89.2%), and overall survival (OS) was 81.4% (95% CI: 65.3%-97.5%). Tumor histology, GTV at the time of radiation, and prescribed radiation dose were significantly associated with local control on multivariate analysis, whereas D1cm{sup 3} was associated with overall survival. Compared to those patients whose conditions remained controlled, patients experiencing tumor failure had statistically significant larger GTVs and lower D1cm{sup 3}, and prescribed and median doses to GTV. A subset of 21 patients with GTV of ≤20 cm{sup 3} and D1cm{sup 3} of >67 Gy (RBE) had a median follow-up of 47 months. The 5-year estimate of local control in this subset was 81.1% (95% CI: 61.7%-100%; P=.004, overall comparison by GTV ≤20 cm{sup 3} stratified by D1cm{sup 3}). A D1cm{sup 3} of 74.5 Gy (RBE) had 80% sensitivity for local control and 60% specificity, whereas a GTV of 9.3 cm{sup 3} had 80% sensitivity for local control and 66.7% specificity. Conclusions: Local control of clival chordomas was associated with both smaller size of residual tumor and more complete high-dose coverage of residual tumor. Multidisciplinary care should seek maximal safe surgical resection, particularly to facilitate delivery of high-dose radiation therapy in proximity to critical structures. A D1cm{sup 3} ≥74.5 Gy (RBE) represents a proposed treatment planning objective.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Pathologic Response, When Increased by Longer Interval, Is a Marker but Not the Cause of Good Prognosis in Rectal Cancer: 17-year Follow-up of the Lyon R90-01 Randomized Trial

Purpose: The Lyon R90-01 randomized trial investigated whether the interval between preoperative radiation therapy and surgery influenced rectal cancer outcome. Long-term results are reported here after a median follow-up of 17 years. Methods and Materials: Between February 1991 and December 1995, 210 patients from 29 French centers were randomly assigned (ratio of 1:1) to groups that waited either 2 weeks (short interval [SI]) or 6 to 8 weeks (long interval [LI]) between neoadjuvant radiation therapy and surgery. The primary endpoint was sphincter-preserving surgery. Results: LI group showed a better pathologic response (complete response or few residual cells) after radiation therapy than the SI group (26% vs 10.3%, P=.015). A better pathologic response was associated in multivariate analysis with significant improvement of overall survival (pT: P=.0293 and pN: P=.0048) but it was irrespective of the interval duration. The median follow-up was 17.2 years. The 5-, 10-, 15-, and 17-year overall survival rates were, respectively, 66.8%, 48.7%, 40.0%, and 34.0% for the SI group and, respectively, 67.1%, 53.5%, 41.9%, and 34.0% for the LI group. There were no significant differences between groups in terms of survival (P=.7656) or local recurrence rates (SI: 14.4% vs LI: 12.1%, respectively; P=.6202). Of 24 local disease recurrences, 20 (83%) occurred during the first 2 postoperative years, and all but one (96%) occurred during the first 5 postoperative years. The rate of second new malignancies was 9.4% (19 patients). Conclusions: The radiation-induced sterilization rate of the preoperative cancer specimen was a marker of good prognosis. The interval duration (the treatment being the same) although it is modifying the sterilization rate has no impact on survival. Radiation therapy did not postpone local recurrence, because the rate of local relapse after 5 years was low. Radiation-induced cancers after radiation therapy were unusual and should not influence treatment decisions in adults.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Outcomes of Chemoradiotherapy in Cervical Cancer-The Western Australian Experience

Purpose: A retrospective review of patients with Stage IB1-IVA cervical cancer treated with combined chemoradiotherapy in Western Australia was conducted with the aim of assessing outcomes and patterns of recurrence. Multivariate analysis was performed to identify potential prognostic factors. Methods and Materials: Patients treated with radical chemoradiotherapy for cervical cancer in Western Australia between June 2005 and November 2008 were analyzed. Treatment consisted of external-beam radiotherapy with concurrent weekly cisplatin (40 mg/m{sup 2}), followed by high-dose-rate brachytherapy. The Kaplan-Meier method was used to determine overall survival and disease-free survival, and Cox regression analysis was used to identify potential prognostic factors. Results: Sixty-nine patients were included in the analysis. All patients completed external-beam radiotherapy; however, only 43.5% of patients completed the planned course of brachytherapy. At a median follow-up of 27 months, 24- and 48-month overall survival were 68.8% and 61.1%, respectively. Disease-free survival at 24 and 48 months was 59.4% and 56.7%, respectively. The 2-year local control rate was 70.1%. Nodal involvement resulted in increased risk of disease recurrence (hazard ratio [HR] 6.26, p = 0.002) and death (HR 5.15, p = 0.013). Pretreatment hemoglobin <120 g/L was a negative prognostic factor for disease recurrence (HR 4.20, p = 0.031) and death (HR 8.19, p = 0.020). Completion of brachytherapy improved overall survival (p = 0.039), with a trend to reducing disease recurrence (p = 0.052). The risk of relapse increased with treatment time over 8 weeks (HR 8.18, p = 0.019), however treatment time did not affect the risk of death (p = 0.245). Conclusion: The overall survival outcomes in this group of women with locally advanced cervical carcinomas treated with chemoradiotherapy are comparable to worldwide data. Despite the use of modern treatment protocols, a significant proportion of women developed locoregional recurrences and distant failures. Many poor prognostic factors have been identified as contributors to this, including pelvic nodal involvement, incomplete brachytherapy, pretreatment hemoglobin <120 g/L, and treatment time over 8 weeks.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Breast Conservation Therapy: The Influence of Molecular Subtype and Margins

Purpose: To evaluate treatment results and prognostic factors, especially margin status and molecular subtype, in early-stage breast cancer patients treated with breast conservation therapy (BCT). Methods and Materials: The records of 1,058 Stage I or II breast cancer patients treated with BCT (surgical excision plus radiotherapy) at Duke University Medical Center, Durham, North Carolina, from 1985-2005 were retrospectively reviewed. Conventional receptor analyses were used as surrogate markers for molecular subtype classification (luminal A, luminal B, Her2 positive, and basal like). Actuarial estimates of overall survival (OS), cause-specific survival (CSS), failure-free survival, and locoregional control (LRC) were computed by use of Kaplan-Meier plots. We analyzed prognostic variables for significance using Cox proportional hazards univariate and multivariate analysis. The study was approved by the Duke University Medical Center Institutional Review Board. Results: The median age of the patients was 56 years (range, 18-89 years). Of the patients, 80% had T1 disease and 66% N0 disease pathologically. With a median follow-up of 9.8 years, an in-breast recurrence developed in 53 patients and 10 patients had nodal failure. For all patients, the 10-year CSS rate was 94%; LRC rate, 94%; and failure-free survival rate, 88%. Luminal A patients had a CSS rate of 95% and LRC rate of 99%. Basal-type patients appeared to do worse, with regard to both CSS rate (74%) and LRC rate (76%), but the numbers were small and the difference was not statistically significant. LRC rates of patients with negative margins (widely negative, close, and extent of margin not known) were virtually identical (93%, 96%, and 94%, respectively). Those with positive margins appeared to fare slightly worse based on LRC rate (88%), but again, the numbers were small and the difference was not statistically significant. Conclusions: BCT remains the treatment of choice for early-stage breast cancer patients irrespective of molecular subtype. Negative margins of excision are desirable, but the width of the negative margin does not influence outcome.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Proposed Lymph Node Staging System Using the International Consensus Guidelines for Lymph Node Levels Is Predictive for Nasopharyngeal Carcinoma Patients From Endemic Areas Treated With Intensity Modulated Radiation Therapy

Purpose: To propose a lymph node (N) staging system for nasopharyngeal carcinoma (NPC) based on the International Consensus Guidelines for lymph node (LN) levels and MRI-determined nodal variables. Methods and Materials: The MRI scans and medical records of 749 NPC patients receiving intensity modulated radiation therapy with or without chemotherapy were retrospectively reviewed. The prognostic significance of nodal level, laterality, maximal axial diameter, extracapsular spread, necrosis, and Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) size criteria were analyzed. Results: Nodal level and laterality were the only independent prognostic factors for distant failure and disease failure in multivariate analysis. Compared with unilateral levels Ib, II, III, and/or Va involvement (hazard ratio [HR] 1), retropharyngeal lymph node involvement alone had a similar prognostic value (HR 0.71; 95% confidence interval [CI] 0.43-1.17; P=.17), whereas bilateral levels Ib, II, III, and/or Va involvement (HR 1.65; 95% CI 1.06-2.58; P=.03) and levels IV, Vb, and/or supraclavicular fossa involvement (HR 3.47; 95% CI 1.92-6.29; P<.01) both significantly increased the HR for distant failure. Thus we propose that the N category criteria could be revised as follows: N0, no regional LN metastasis; N1, retropharyngeal lymph node involvement, and/or unilateral levels Ib, II, III, and/or Va involvement; N2, bilateral levels Ib, II, III, and/or Va involvement; N3, levels IV, Vb, and/or supraclavicular fossa involvement. Compared with the 7th edition of the UICC/AJCC criteria, the proposed N staging system provides a more satisfactory distinction between the HRs for regional failure, distant failure, and disease failure in each N category. Conclusions: The proposed N staging system defined by the International Consensus Guidelines and laterality is predictive and practical. However, because of no measurements of the maximal nodal diameter on MRI slices, the prognostic significance of LN size needs further evaluation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

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

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.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Predictors of Urinary Morbidity in Cs-131 Prostate Brachytherapy Implants

Purpose: Cesium-131 is a newer radioisotope being used in prostate brachytherapy (PB). This study was conducted to determine the predictors of urinary morbidity with Cs-131 PB. Methods and Materials: A cohort of 159 patients underwent PB with Cs-131 at our institution and were followed by using Expanded Prostate Cancer Index Composite (EPIC) surveys to determine urinary morbidity over time. EPIC scores were obtained preoperatively and postoperatively at 2 and 4 weeks, and 3 and 6 months. Different factors were evaluated to determine their individual effect on urinary morbidity, including patient characteristics, disease characteristics, treatment, and dosimetry. Multivariate analysis of covariance was carried out to identify baseline determinants affecting urinary morbidity. Factors contributing to the need for postoperative catheterization were also studied and reported. Results: At 2 weeks, patient age, dose to 90% of the organ (D90), bladder neck maximum dose (D{sub max}), and external beam radiation therapy (EBRT) predicted for worse function. At 4 weeks, age and EBRT continued to predict for worse function. At the 3-month mark, better preoperative urinary function, preoperative alpha blockers, bladder neck D{sub max}, and EBRT predicted for worse urinary morbidity. At 6 months, better preoperative urinary function, preoperative alpha blockers, bladder neck D{sub max}, and EBRT were predictive of increased urinary problems. High bladder neck D{sub max} and poor preoperative urinary function predicted for the need for catheterization. Conclusions: The use of EBRT plus Cs-131 PB predicts for worse urinary toxicity at all time points studied. Patients should be cautioned about this. Age was a consistent predictor of worsened morbidity immediately following Cs-131 PB, while bladder D{sub max} was the only consistent dosimetric predictor. Paradoxically, patients with better preoperative urinary function had worse urinary morbidity at 3 and 6 months, consistent with recently published literature.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Stereotactic Radiosurgery for Patients With Brain Metastases From Small Cell Lung Cancer

Background: Patients with small-cell lung cancer have a high likelihood of developing brain metastases. Many of these patients will have prophylactic cranial irradiation (PCI) or eventually undergo whole brain radiation therapy (WBRT). Despite these treatments, a large number of these patients will have progression of their intracranial disease and require additional local therapy. Stereotactic radiosurgery (SRS) is an important treatment option for such patients. Methods: We retrospectively reviewed the charts of 44 patients with brain metastases from small-cell lung cancer treated with gamma knife SRS. Multivariate analysis was used to determine significant prognostic factors influencing survival. Results: The median follow-up from SRS in this patient population was 9 months (1-49 months). The median overall survival (OS) was 9 months after SRS. Karnofsky performance status (KPS) and combined treatment involving WBRT and SRS within 4 weeks were the two factors identified as being significant predictors of increased OS (p = 0.033 and 0.040, respectively). When comparing all patients, patients treated with a combined approach had a median OS of 14 months compared to 6 months if SRS was delivered alone. We also compared the OS times from the first definitive radiation: WBRT, WBRT and SRS if combined therapy was used, and SRS if the patient never received WBRT. The median survival for those groups was 12, 14, and 13 months, respectively, p = 0.19. Seventy percent of patients had follow-up magnetic resonance imaging available for review. Actuarial local control at 6 months and 12 months was 90% and 86%, respectively. Only 1 patient (2.2%) had symptomatic intracranial swelling related to treatment, which responded to a short course of steroids. New brain metastases outside of the treated area developed in 61% of patients at a median time of 7 months; 81% of these patients had received previous WBRT. Conclusions: Stereotactic radiosurgery for small-cell lung carcinoma brain metastases provided safe and effective local tumor control in the majority of patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Estimating the Need for Palliative Radiation Therapy: A Benchmarking Approach

Purpose: Palliative radiation therapy (PRT) benefits many patients with incurable cancer, but the overall need for PRT is unknown. Our primary objective was to estimate the appropriate rate of use of PRT in Ontario. Methods and Materials: The Ontario Cancer Registry identified patients who died of cancer in Ontario between 2006 and 2010. Comprehensive RT records were linked to the registry. Multivariate analysis identified social and health system-related factors affecting the use of PRT, enabling us to define a benchmark population of patients with unimpeded access to PRT. The proportion of cases treated at any time (PRT{sub lifetime}), the proportion of cases treated in the last 2 years of life (PRT{sub 2y}), and number of courses of PRT per thousand cancer deaths were measured in the benchmark population. These benchmarks were standardized to the characteristics of the overall population, and province-wide PRT rates were then compared to benchmarks. Results: Cases diagnosed at hospitals with no RT on-site and residents of poorer communities and those who lived farther from an RT center, were significantly less likely than others to receive PRT. However, availability of RT at the diagnosing hospital was the dominant factor. Neither socioeconomic status nor distance from home to nearest RT center had a significant effect on the use of PRT in patients diagnosed at a hospital with RT facilities. The benchmark population therefore consisted of patients diagnosed at a hospital with RT facilities. The standardized benchmark for PRT{sub lifetime} was 33.9%, and the corresponding province-wide rate was 28.5%. The standardized benchmark for PRT{sub 2y} was 32.4%, and the corresponding province-wide rate was 27.0%. The standardized benchmark for the number of courses of PRT per thousand cancer deaths was 652, and the corresponding province-wide rate was 542. Conclusions: Approximately one-third of patients who die of cancer in Ontario need PRT, but many of them are never treated.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Pancreatic Neuroendocrine Tumors With Involved Surgical Margins: Prognostic Factors and the Role of Adjuvant Radiotherapy

Purpose: Pancreatic neuroendocrine tumors (pNET) are rare neoplasms associated with poor outcomes without resection, and involved surgical margins are associated with a worse prognosis. The role of adjuvant radiotherapy (RT) in these patients has not been characterized. Methods and Materials: We retrospectively evaluated 46 consecutive patients with positive or close (<1 mm) margins after pNET resection, treated from 1983 to 2010, 16 of whom received adjuvant RT. Median RT dose was 50.4 Gy in 1.8-Gy fractions; half the patients received concurrent chemotherapy with 5-fluorouracil or capecitabine. No patients received adjuvant chemotherapy. Cox multivariate analysis (MVA) was used to analyze factors associated with overall survival (OS). Results: Median age at diagnosis was 56 years, and 52% of patients were female. Median tumor size was 38 mm, 57% of patients were node-positive, and 11% had a resected solitary liver metastasis. Patients who received RT were more likely to have larger tumors (median, 54 mm vs. 30 mm, respectively, p = 0.002) and node positivity (81% vs. 33%, respectively, p = 0.002) than those not receiving RT. Median follow-up was 39 months. Actuarial 5-year OS was 62% (95% confidence interval [CI], 41%-77%). In the group that did not receive RT, 3 patients (10%) experienced local recurrence (LR) and 5 patients (18%) developed new distant metastases, while in the RT group, 1 patient (6%) experienced LR and 5 patients (38%) developed distant metastases. Of all recurrences, 29% were LR. On MVA, male gender (adjusted hazard ratio [AHR] = 3.81; 95% CI, 1.21-11.92; p = 0.02) and increasing tumor size (AHR = 1.02; 95% CI, 1.01-1.04; p = 0.007) were associated with decreased OS. Conclusions: Long-term survival is common among patients with involved-margin pNET. Despite significantly worse pathologic features among patients receiving adjuvant RT, rates of LR between groups were similar, suggesting that RT might aid local control, and merits further evaluation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

High-Sensitivity C-Reactive Protein Complements Plasma Epstein-Barr Virus Deoxyribonucleic Acid Prognostication in Nasopharyngeal Carcinoma: A Large-Scale Retrospective and Prospective Cohort Study

Purpose: To evaluate the effects of combining the assessment of circulating high-sensitivity C-reactive protein (hs-CRP) with that of Epstein-Barr virus DNA (EBV DNA) in the pretherapy prognostication of nasopharyngeal carcinoma (NPC). Patients and Methods: Three independent cohorts of NPC patients (training set of n=3113, internal validation set of n=1556, and prospective validation set of n=1668) were studied. Determinants of disease-free survival, distant metastasis–free survival, and overall survival were assessed by multivariate analysis. Hazard ratios and survival probabilities of the patient groups, segregated by clinical stage (T1-2N0-1M0, T3-4N0-1M0, T1-2N2-3M0, and T3-4N2-3M0) and EBV DNA load (low or high) alone, and also according to hs-CRP level (low or high), were compared. Results: Elevated hs-CRP and EBV DNA levels were significantly correlated with poor disease-free survival, distant metastasis–free survival, and overall survival in both the training and validation sets. Associations were similar and remained significant after excluding patients with cardiovascular disease, diabetes, and chronic hepatitis B. Patients with advanced-stage disease were segregated by high EBV DNA levels and high hs-CRP level into a poorest-risk group, and participants with either high EBV DNA but low hs-CRP level or high hs-CRP but low EBV DNA values had poorer survival compared with the bottom values for both biomarkers. These findings demonstrate a significant improvement in the prognostic ability of conventional advanced NPC staging. Conclusion: Baseline plasma EBV DNA and serum hs-CRP levels were significantly correlated with survival in NPC patients. The combined interpretation of EBV DNA with hs-CRP levels led to refinement of the risks for the patient subsets, with improved risk discrimination in patients with advanced-stage disease.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
NASA NTRS1997

Chemical and physical gradients along the OMC-1 ridge

We present a survey of the distribution of 20 chemical and isotopic molecular species along the central ridge of the Orion molecular cloud from 6' north to 6' south of BN-KL observed with the QUARRY focal plane array on the FCRAO 14 m telescope, which provides an angular resolution of approximately 50" in the 3 mm wavelength region. We use standard tools of multivariate analysis for a systematic investigation of the similarities and differences among the maps of integrated intensities of the 32 lines observed. The maps fall in three broad classes: first, those strongly peaked toward BN-KL; second, those having rather flat distributions along the ridge; and third, those with a clear north-south gradient or contrast. We identify six positions or regions where we calculate relative abundances. Line velocities and line widths indicate that the optically thin lines generally trace the same volume of dense gas, except in the molecular bar, where C18O, C34S, H13CO+, CN, C2H, SO, and C3H2 have velocities characteristic of the bar itself, whereas the emission from other detected species is dominated by the background cloud. The strongest abundance variations in our data are the well-known enhancements seen in HCN, CH3OH, HC3N, and SO toward BN-KL and, less strongly, toward the Orion-South outflow 1'.3S. The principal result of this study is that along the extended quiescent ridge the chemical abundances, within factors of 3-4, exhibit an impressive degree of uniformity. The northern part of the ridge has a chemistry closest to that found in quiescent dense clouds. While temperature and density are similar around the northern radical-ion peak near 3'.5N and in the southern core near 4'.2S, some abundances, in particular, those of the ions HCO+ and N2H+, are significantly lower toward 4'.2S. The areas near 4.'2S and the molecular bar itself around (1'.7E, 2'.4S) stand out with peculiar and similar properties probably caused by stronger UV fields penetrating deeper into the clumpy molecular gas. This leads to higher electron abundances and thereby reduced abundances of the ions, as well as a lack of complex molecules.

NASA Discipline Exobiology↗
DOE OSTI2011

Prognostic Value of Pretreatment Carcinoembryonic Antigen After Definitive Radiotherapy With or Without Concurrent Chemotherapy for Squamous Cell Carcinoma of the Uterine Cervix

Purpose: To evaluate whether pretreatment carcinoembryonic antigen (CEA) levels have a prognostic role in patients after definitive radiotherapy for squamous cell carcinoma (SCC) of the uterine cervix. Methods and Materials: A retrospective study of 550 patients was performed. The SCC antigen (SCC-Ag) and CEA levels were regarded as elevated when they were {>=}2 and {>=}5 ng/mL, respectively. A total of 208 patients underwent concurrent chemoradiotherapy (CCRT). The Kaplan-Meier method was used to calculate the distant metastasis (DM), local failure (LF), disease-free survival (DFS), and overall survival (OS) rates. Multivariate analysis was performed using the Cox proportional hazards model. The hazard ratio (HR) with 95% confidence interval (CI) was evaluated for the risk of a poor prognosis. Results: Compared with the patients with normal CEA/SCC-Ag levels, CEA levels {>=}10 ng/mL but without elevated SCC-Ag levels was an independent factor for LF (HR, 51.81; 95% CI, 11.51-233.23; p < .001), DM (HR, 6.04; 95% CI, 1.58-23.01; p = .008), DFS (HR, 10.17; 95% CI, 3.18-32.56; p < .001), and OS (HR, 5.75; 95% CI, 1.82-18.18; p = .003) after RT alone. However, no significant role for CEA was noted in patients with SCC-Ag levels {>=}2 ng/mL. In patients undergoing CCRT, a CEA level {>=}10 ng/mL was an independent factor for LF (HR, 2.50; 95% CI, 1.01-6.21; p = .047), DM (HR, 3.41; 95% CI, 1.56-7.46; p = .002), DFS (HR, 2.73; 95% CI, 1.39-5.36; p = .003), and OS (HR, 3.93; 95% CI 1.99-7.75; p < .001). A SCC-Ag level of {>=}40 ng/mL was another prognostic factor for DM, DFS, and OS in patients undergoing not only CCRT, but also RT alone. The 5-year OS rate for CCRT patients with CEA <10 ng/mL and {>=}10 ng/mL was 75.3% and 35.8%, respectively (p < .001). CCRT was an independent factor for better OS (HR, 0.69; 95% CI, 0.50-0.97; p = .034). Conclusion: Pretreatment CEA levels in patients with SCC of the uterine cervix provide complementary information for predicting LF, DM, DFS, and OS, except for in patients with abnormal SCC-Ag levels before RT alone. More aggressive therapy might be advisable for patients with CEA levels of {>=}10 ng/mL.

62 RADIOLOGY AND NUCLEAR MEDICINE↗