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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 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
DOE OSTI2010

Survivin Is a Potential Mediator of Prostate Cancer Metastasis

Purpose: We examined whether Survivin expression is associated with an increased risk of metastasis in prostate cancer. Methods and Materials: A total of 205 patients with T1 (23%) and T2 (77%) prostate cancer were treated with conventional external beam radiation therapy from 1991 to 1993 at the Massachusetts General Hospital. Of the patients, 62 had adequate and suitable-stained tumor material for Survivin analysis. Median follow-up was 102 months (range, 5-127 months). Distant failure was determined on the basis of clinical criteria. In preclinical studies, replication-deficient adenovirus encoding phosphorylation-defective Survivin Thr34{yields}Ala dominant-negative mutant pAd-S(T34A) or short hairpin RNA (shRNA) was used to inhibit Survivin in prostate cancer models, and the cell motility, morphology, and metastasis were investigated. Results: Our correlative data on men with early-stage (T1/T2) prostate cancers treated at Massachusetts General Hospital by definitive radiotherapy indicated that overexpression of Survivin (positive staining in {>=}10% cells) was associated with a significantly increased risk for the subsequent development of distant metastasis (p = 0.016) in the univariate analysis. In the multivariate analysis, overexpression of Survivin remained an independent predictor of distant metastasis (p = 0.008). The inhibition of Survivin dramatically inhibited invasiveness of prostate cancer cells in the in vitro invasion assay and spontaneous metastasis in the Dunning prostate cancer in vivo model. Furthermore, attenuation of Survivin resulted in changes in the microtubule cytoskeleton, loss of cellular polarity, and loss of motility. Conclusions: This study suggests that Survivin may be a potentially important prognostic marker and promising therapeutic target in metastatic prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Predicting Late Effects of Pelvic Radiotherapy: Is There a Better Approach?

Purpose: Significant chronic symptoms following pelvic radiotherapy occur more frequently than commonly realized. Predictive factors for the development of late symptoms are poorly defined. Moderate sustained acute (cumulative) toxicity might predict severe late effects better than peak reaction. Methods and Materials: To determine prospectively whether peak or cumulative gastrointestinal (GI) acute symptoms better predict late symptoms in patients receiving pelvic radiotherapy. Symptom scores were measured weekly from the start of radiotherapy, and at 1 year using the Modified Inflammatory Bowel Disease Questionnaire-Bowel subset. The possible prognostic impact of patient-related factors was explored. Results: Three hundred and eight patients were recruited. 100 were excluded due to lack of follow-up data at one year resulting from death, too ill, stoma, relapsed, non-response or withdrawal. A further 15 were excluded for incomplete data, leaving 193 patients with evaluable data. Of these, 28 had GI, 101 urological, and 64 gynecological cancers. Patients' median age was 65 years (range, 23-82), and they were treated with median 60 Gy dose for a median of 6 weeks. Univariate analysis revealed a significant association between cumulative acute symptom scores and scores at 1 year (p < 0.001), which was dose-independent (p < 0.001). Acute peak and 1-year scores were not associated (p = 0.431). The correlation coefficient between cumulative acute symptoms and symptoms at 1 year was 0.367 and for peak acute symptoms was weaker at 0.057. Patients with an abnormal body mass index and current smokers were more likely to experience worse symptoms at 1 year. Conclusion: Cumulative acute symptoms are more predictive of late symptoms than peak acute changes in score. This association is independent of the radiotherapy dose delivered and is suggestive of a consequential late effect.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Local Response and Impact on Survival After Local Ablation of Liver Metastases From Colorectal Carcinoma by Computed Tomography-Guided High-Dose-Rate Brachytherapy

Purpose: To determine local tumor control after CT-guided brachytherapy at various dose levels and the prognostic impact of extensive cytoreduction in colorectal liver metastases. Methods and Materials: Seventy-three patients were treated on a single-center prospective trial that was initially designed to be randomized to three dose levels of 15 Gy, 20 Gy, or 25 Gy per lesion, delivered in a single fraction. However, because there was a high rate of cross-over of subjects from higher to lower dose levels, this study is better understood as a prospective trial with three dose levels. No upper size limit for the metastases was applied. We assessed time to local progression, progression-free survival, and overall survival. Results: According to safety constraints cross-over was performed. The final assignment was n = 98, n = 68, and n = 33 in the 15-Gy, 20-Gy, and 25-Gy groups, respectively. Median diameter of the largest tumor lesion in each patient was 5 cm (range, 1-13.5 cm). Estimated mean local recurrence-free survival for all lesions was 34 months (median not reached). The group assigned to 15 Gy after cross-over displayed 34 local recurrences out of 98 lesions; 20 Gy, 15 out of 68 lesions; 25 Gy, 1 out of 33 lesions. The difference between the 25-Gy and the 20-Gy or 15-Gy group was significant (p < 0.05). Repeated local tumor ablations were the most prominent factor for increased survival and dominated additional systemic antitumor treatments. Conclusions: Local tumor control after CT-guided brachytherapy of colorectal liver metastases demonstrated a strong dose dependency. The role of extensive minimally invasive tumor ablation in metastatic colorectal cancer needs to be further established.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Confirmation of a Low {alpha}/{beta} Ratio for Prostate Cancer Treated by External Beam Radiation Therapy Alone Using a Post-Treatment Repeated-Measures Model for PSA Dynamics

Purpose: To estimate the {alpha}/{beta} ratio of prostate cancer treated with external beam radiation only by use of a model of long-term prostate-specific antigen (PSA) dynamics. Methods and Materials: Repeated measures of PSA from 5,093 patients from 6 institutions treated for localized prostate cancer by external beam radiation therapy (EBRT) without planned androgen deprivation were analyzed. A biphasic linear mixed model described the post-treatment evolution of PSA, rather than a conventional model of time to biochemical recurrence. The model was adjusted for standard prognostic factors (T stage, initial PSA level, and Gleason score) and cohort-specific effects. The radiation dose fractionation effect was estimated from the long-term rate of rise of PSA level. Results: Adjusted for other factors, total dose of EBRT and sum of squared doses per fraction were associated with long-term rate of change of PSA level (p = 0.0017 and p = 0.0003, respectively), an increase of each being associated with a lower rate of rise. The {alpha}/{beta} ratio was estimated at 1.55 Gy (95% confidence band, 0.46-4.52 Gy). This estimate was robust to adjustment of the linear mixed model. Conclusions: By analysis of a large EBRT-only cohort along with a method that uses all the repeated measures of PSA after the end of treatment, a low and precise {alpha}/{beta} was estimated. These data support the use of hypofractionation at fractional doses up to 2.8 Gy but cannot presently be assumed to accurately represent higher doses per fraction.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Combined Modality Therapy Including Intraoperative Electron Irradiation for Locally Recurrent Colorectal Cancer

Purpose: To evaluate survival, relapse patterns, and prognostic factors in patients with colorectal cancer relapse treated with curative-intent therapy, including intraoperative electron radiation therapy (IOERT). Methods and Materials: From April 1981 through January 2008, 607 patients with recurrent colorectal cancer received IOERT as a component of treatment. IOERT was preceded or followed by external radiation (median dose, 45.5 Gy) in 583 patients (96%). Resection was classified as R0 in 227 (37%), R1 in 224 (37%), and R2 in 156 (26%). The median IOERT dose was 15 Gy (range, 7.5-30 Gy). Results: Median overall survival was 36 months. Five- and 10-year survival rates were 30% and 16%, respectively. Survival estimates at 5 years were 46%, 27%, and 16% for R0, R1, and R2 resection, respectively. Multivariate analysis revealed that R0 resection, no prior chemotherapy, and more recent treatment (in the second half of the series) were associated with improved survival. The 3-year cumulative incidence of central, local, and distant relapse was 12%, 23%, and 49%, respectively. Central and local relapse were more common in previously irradiated patients and in those with subtotal resection. Toxicity Grade 3 or higher partially attributable to IOERT was observed in 66 patients (11%). Neuropathy was observed in 94 patients (15%) and was more common with IOERT doses exceeding 12.5 Gy. Conclusions: Long-term survival and disease control was achievable in patients with locally recurrent colorectal cancer. Continued evaluation of curative-intent, combined-modality therapy that includes IOERT is warranted in this high-risk population.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Role of Adjuvant Radiotherapy in Granulosa Cell Tumors of the Ovary

Purpose: To review the role of adjuvant radiotherapy (RT) in the outcome and recurrence patterns of granulosa cell tumors (GCTs) of the ovary. Methods and Materials: The records of all patients with GCTs referred to the Princess Margaret Hospital University Health Network between 1961 and 2006 were retrospectively reviewed. The patient, tumor, and treatment factors were assessed by univariate and multivariate analyses using disease-free survival (DFS) as the endpoint. Results: A total of 103 patients with histologically confirmed GCTs were included in the present study. The mean duration of follow-up was 100 months (range, 1-399). Of the 103 patients, 31 received adjuvant RT. A total of 39 patients developed tumor recurrence. The tumor size, incidence of intraoperative rupture, and presence of concurrent endometrial cancer were not significant risk factors for DFS. The median DFS was 251 months for patients who underwent adjuvant RT compared with 112 months for patients who did not (p = .02). On multivariate analysis, adjuvant RT remained a significant prognostic factor for DFS (p = .004). Of the 103 patients, 12 had died and 44 were lost to follow-up. Conclusion: Ovarian GCTs can be indolent, with patients achieving long-term survival. In our series, adjuvant RT resulted in a significantly longer DFS. Ideally, randomized trials with long-term follow-up are needed to define the role of adjuvant RT for ovarian GCTs.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

High-Dose-Rate Brachytherapy for Non-Small-Cell Lung Carcinoma: A Retrospective Study of 226 Patients

Purpose: To evaluate the efficacy and toxicity of high-dose-rate (HDR) brachytherapy in patients with inoperable endobronchial carcinoma. Methods and Materials: We retrospectively reviewed the records (April 1991-May 2004) of patients with non-small-cell carcinoma, with no extrabronchial spread on computed tomography scans, who underwent HDR brachytherapy because of contraindications to surgery and external beam radiation therapy. Kaplan-Meier survival curves were compared by the log-rank test. Prognostic factors were analyzed by multivariate analysis. Results: 226 patients (223 men, 3 women, mean age: 62.2 years (range, 40-84)) were included. Of those, 217 (97%) had squamous cell carcinoma (Tis/T1/T2/Tx: 60/153/9/4). Dose was prescribed at 1 cm from the radius (24-35 Gy in 4-6 fractions). Mean follow-up was 30.4 months (range, 9-116). Complete endoscopic response rate was 93.6% at 3 months. One hundred twenty-eight patients (56%) died of intercurrent disease (n = 45), local failure (n = 36), metastasis (n = 10), local failure and metastasis (n = 11), complications (n = 13), and other causes (n = 12). The 2-year and 5-year survival rates were, respectively, 57% and 29% (overall) (median, 28.6 months), 81% and 56% (cancer-specific), and 68% and 50% (local disease-free). Acute toxicity included pneumothorax (1.5%) and mucosal inflammation (10%). Late complications were hemoptysis (6.6% with 5% of fatalities), bronchitis (19.5%), and necrosis (3.5%). In multivariate analysis, a distal tumor location and the use of two catheters were associated with improved local disease-free survival (p = 0.003 and p = 0.007, respectively) and a distal tumor location with improved overall survival (p = 0.0001). Conclusions: This large retrospective study confirms that HDR brachytherapy is an efficient and safe treatment in patients with inoperable endobronchial carcinoma.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Can the Analysis of ERCC1 Expression Contribute to Individualized Therapy in Nasopharyngeal Carcinoma?

Purpose: To analyze the expression of excision repair cross-complementation group 1 (ERCC1) protein in predicting the clinical outcome of nasopharyngeal carcinoma (NPC). Methods and Materials: The histologic specimens of 258 patients with Stage III to IVB nonkeratinizing NPC who were treated with radiotherapy alone (Group I) or concurrent-adjuvant chemoradiotherapy (Group II) were retrieved. Immunostaining on ERCC1 protein was performed. The relationship of ERCC1 expression and clinical outcomes was analyzed. Results: The median ERCC1 score (proportion score of positively stained cells times intensity) was 200 (range, 0-300), and ERCC1 expression was defined as high if the score was above the median. In Group I high-score tumor had a statistically lower locoregional failure-free rate (LRFFR) compared with low-score tumor (p < 0.05) but not distant failure-free rate (DFFR) and overall survival (OS). In Group II no statistically differences were noted in LRFFR, DFFR and OS with regard to the ERCC1 expression. Resistance to cisplatin-containing chemotherapy in high-ERCC1 score tumor was not observed in Group II. Interestingly, low-score tumor in Group I achieved similar local and distant control compared with Group II. Multivariate analysis showed that ERCC1 score was an independent prognostic factor in LRFFR (p < 0.05) and approached statistical significance in failure-free survival (p = 0.08) and OS (p = 0.07). Tumor with high ERCC1 score had a 2-fold (95% confidence interval, 1.02-3.85) increased risk of locoregional failure. This may imply an association of ERCC1 expression with the repair of radiation damage. Conclusions: High ERCC1 expression predicts poor locoregional control in NPC. Chemotherapy response is not affected by ERCC1 expression. Further validation is required.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

The Matrix Metalloproteinase-7 Polymorphism Rs10895304 Is Associated With Increased Recurrence Risk in Patients With Clinically Localized Prostate Cancer

Purpose: To evaluate whether selected high-risk matrix metalloproteinase-7 single nucleotide polymorphisms influence clinicopathologic outcomes in patients with early-stage prostate cancer. Methods and Materials: Two hundred twelve prostate cancer patients treated with radical prostatectomy were evaluated with a median follow-up of 9.8 years. Genotyping was performed using hybridization with custom-designed allele-specific probes. Three single nucleotide polymorphisms within the matrix metalloproteinase-7 gene were assessed with respect to age at diagnosis, margin status, extracapsular extension, lymph node involvement, recurrence-free survival, and overall survival in paraffin-embedded prostate tissue specimens from patients with early-stage prostate cancer who underwent radical prostatectomy. Results: Rs10895304 was the sole significant polymorphism. The A/G genotype of rs10895304 had a statistically significant association with recurrence-free survival in postprostatectomy patients (p = 0.0061, log-rank test). The frequency of the risk-reducing genotype (A/A) was 74%, whereas that of the risk-enhancing genotypes (A/G and G/G) were 20% and 6%, respectively. Multivariable Cox regression analyses detected a significant association between rs10895304 and recurrences after adjustment for known prognostic factors. The G allele of this polymorphism was associated with increased risk of prostate cancer recurrence (adjusted hazards ratio, 3.375; 95% confidence interval 1.567-7.269; p < 0.001). The other assayed polymorphisms were not significant, and no correlations were made to other clinical variables. Conclusions: The A/G genotype of rs10895304 is predictive of decreased recurrence-free survival in patients with clinically localized prostate cancer. Our data suggest that for this subset of patients, prostatectomy alone may not be adequate for local control. This is a novel and relevant marker that should be evaluated for improved risk stratification of patients who may be candidates for adjuvant radiation therapy to improve local control.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Risk of All-Cause and Prostate Cancer-Specific Mortality After Brachytherapy in Men With Small Prostate Size

Background: Brachytherapy for prostate cancer can be technically challenging in men with small prostates ({<=}20 cc), but it is unknown whether their outcomes are different than those of men with larger prostates. Methods and Materials: We studied 6,416 men treated with brachytherapy in one of 21 community-based practices. Cox regression and Fine and Gray's regression were used to determine whether volume {<=}20 cc was associated with a higher risk of all-cause mortality (ACM) or prostate cancer-specific mortality (PCSM), respectively, after adjustment for other known prognostic factors. Results: 443 patients (6.9%) had a prostate volume {<=}20 cc. After a median follow-up of 2.91 years (interquartile range, 1.06-4.79), volume {<=}20 cc was associated with a significantly higher risk of ACM (adjusted hazard ratio = 1.33 [95% CI 1.08-1.65], p = 0.0085) with 3-year estimates of ACM for {<=}20 cc vs. >20 cc of 13.0% vs. 6.9% (p = 0.028). Only 23 men (0.36%) have died of prostate cancer, and no difference was seen in PCSM by volume (p = 0.4). Conclusion: Men with small prostates at the time of implant had a 33% higher risk of ACM, and the underlying cause of this remains uncertain. No increase in PCSM was observed in men with volume {<=}20cc, suggesting that a small prostate should not in itself be a contraindication for brachytherapy, but inasmuch as absolute rates of PCSM were small, further follow-up will be needed to confirm this finding.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Validation of a Score Predicting Post-Treatment Ambulatory Status After Radiotherapy for Metastatic Spinal Cord Compression

Purpose: A score predicting post-radiotherapy (RT) ambulatory status was developed based on 2,096 retrospectively evaluated metastatic spinal cord compression (MSCC) patients. This study aimed to validate the score in a prospective series. Methods and Materials: The score included five factors associated with post-RT ambulatory status: tumor type, interval tumor diagnosis to MSCC, visceral metastases, pre-RT motor function, time developing motor deficits. Patients were divided into five groups: 21-28, 29-31, 32-34, 35-37, 38-44 points. In this study, 653 prospectively followed patients were divided into the same groups. Furthermore, the number of prognostic groups was reduced from five to three (21-28, 29-37, 38-44 points). Post-RT ambulatory rates from this series were compared with the retrospective series. Additionally, this series was compared with 104 patients receiving decompressive surgery plus RT (41 laminectomy, 63 laminectomy plus stabilization of vertebrae). Results: In this study, post-RT ambulatory rates were 10.6% (21-28 points), 43.5% (29-31 points), 71.0% (32-34 points), 89.5% (35-37 points), and 98.5% (38-44 points). Ambulatory rates from the retrospective study were 6.2%, 43.5%, 70.0%, 86.1%, and 98.7%. After regrouping, ambulatory rates were 10.6% (21-28 points), 70.9% (29-37 points), and 98.5% (38-44 points) in this series, and 6.2%, 68.4%, and 98.7% in the retrospective series. Ambulatory rates were 0%, 62.5%, and 90.9% in the laminectomy plus RT group, and 14.3%, 83.9%, and 100% in the laminectomy + stabilization plus RT group. Conclusions: Ambulatory rates in the different groups in this study were similar to those in the retrospective study demonstrating the validity of the score. Using only three groups is simplier for clinical routine.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Local Therapy for Rhabdomyosarcoma of the Hands and Feet: Is Amputation Necessary? A Report From the Children's Oncology Group

Purpose: To evaluate the outcome of children with rhabdomyosarcoma (RMS) of the hand or foot treated with surgery and/or local radiotherapy (RT). Methods and Materials: Forty-eight patients with nonmetastatic RMS of the hand or foot were enrolled on Intergroup Rhabdomyosarcoma Study III, IV-Pilot, and IV. Patients received multiagent chemotherapy with surgery and/or RT. Twenty-four patients (50%) underwent surgery without local RT, of whom 4 had complete resection and 20 had an amputation. The remaining 24 patients (50%) underwent local RT, of whom 2 required RT for microscopic residual disease after prior amputation. Median follow-up for surviving patients was 9.7 years. Results: Actuarial 10-year local control was 100%; 10-year event-free survival and overall survival rates were 62% and 63%, respectively. Poor prognostic factors for recurrence included gross residual (Group III) disease and nodal involvement (p = 0.01 and 0.05, respectively). More patients in the RT group had alveolar histology, Group III disease, and nodal involvement, as compared with the surgery group. There was no difference in 10-year event-free survival (57% vs. 66%) or overall survival (63% vs. 63%) between patients who underwent surgery or local RT. Among relapsing patients, there were no long-term survivors. No secondary malignancies have been observed. Conclusions: Despite having high-risk features, patients treated with local RT achieved excellent local control. Complete surgical resection without amputation is difficult to achieve in the hand or foot. Therefore, we recommend either definitive RT or surgical resection that maintains form and function as primary local therapy rather than amputation in patients with hand or foot RMS.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Impact of Cranial Irradiation Added to Intrathecal Conditioning in Hematopoietic Cell Transplantation in Adult Acute Myeloid Leukemia With Central Nervous System Involvement

Purpose: Neither the prognostic importance nor the appropriate management of central nervous system (CNS) involvement is known for patients with acute myeloid leukemia (AML) undergoing hematopoietic cell transplantation (HCT). We examined the impact of a CNS irradiation boost to standard intrathecal chemotherapy (ITC). Methods and Materials: From 1995 to 2005, a total of 648 adult AML patients received a myeloablative HCT: 577 patients were CNS negative (CNS-), and 71 were CNS positive (CNS+). Of the 71 CNS+ patients, 52 received intrathecal chemotherapy alone (CNS+ITC), and 19 received ITC plus an irradiation boost (CNS+RT). Results: The CNS-, CNS+ITC, and CNS+RT patients had 1- and 5-year relapse-free survivals (RFS) of 43% and 35%, 15% and 6%, and 37% and 32%, respectively. CNS+ITC patients had a statistically significant worse RFS compared with CNS- patients (hazard ratio [HR], 2.65; 95% confidence interval [CI], 2.0-3.6; p < 0.0001). CNS+RT patients had improved relapse free survival over that of CNS+ITC patients (HR, 0.45; 95% CI, 0.2-0.8; p = 0.01). The 1- and 5-year overall survivals (OS) of patients with CNS-, CNS+ITC, and CNS+RT, were 50% and 38%, 21% and 6%, and 53% and 42%, respectively. The survival of CNS+RT were significantly better than CNS+ITC patients (p = 0.004). After adjusting for known risk factors, CNS+RT patients had a trend toward lower relapse rates and reduced nonrelapse mortality. Conclusions: CNS+ AML is associated with a poor prognosis. The role of a cranial irradiation boost to intrathecal chemotherapy appears to mitigate the risk of CNS disease, and needs to be further investigated to define optimal treatment strategies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Intraoperative Radiotherapy for Unresectable Pancreatic Cancer: A Multi-Institutional Retrospective Analysis of 144 Patients

Purpose: To retrospectively analyze the results of intraoperative radiotherapy (IORT) + external beam radiotherapy (EBRT) for unresectable pancreatic cancer. Methods and Materials: The records of 144 patients treated with IORT, with or without, EBRT were reviewed. One hundred and thirteen patients (78.5%) were treated with IORT + EBRT and 114 patients (79.2%) were treated in conjunction with chemotherapy. The median doses of IORT and EBRT were 25 Gy and 45 Gy, respectively. The median follow-up of all 144 patients was 9.6 months (range, 0.5-69.7 months). Results: At the time of this analysis, 131 of 144 patients (91.0%) had disease recurrences. Local progression was observed in 60 patients (41.7%), and the 2-year local control (LC) rate in all patients was 44.6%. Patients treated with IORT, with or without, EBRT had significantly more favorable LC (2-year LC, 50.9%) than those treated with IORT without EBRT (p = 0.0004). The 2-year overall survival (OS) rate and the median survival time in all 144 patients were 14.7% and 10.5 months, respectively. Patients treated with chemotherapy had a significantly favorable OS than those treated without chemotherapy (p < 0.0001). On univariate analysis, chemotherapy use alone had a significant impact on OS and on multivariate analysis; chemotherapy use was a significant prognostic factor. Late gastrointestinal morbidity of National Cancer Institute-Common Terminology Criteria Grade 3 was observed in 2 patients (1.4%). Conclusion: IORT + EBRT yields a relatively favorable LC rate for unresectable pancreatic cancer with low frequency of severe late toxicity, and IORT combined with chemotherapy conferred a survival benefit compared with IORT without chemotherapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Monotherapeutic High-Dose-Rate Brachytherapy for Prostate Cancer: Five-Year Results of an Extreme Hypofractionation Regimen With 54 Gy in Nine Fractions

Purpose: To evaluate an extreme hypofractionation regimen with 54 Gy in nine fractions provided by high-dose-rate (HDR) brachytherapy as monotherapy for prostate cancer by reporting 5-year clinical results. Methods and Materials: Between 1996 and 2005, 112 patients with localized prostate cancer were treated with HDR brachytherapy without external beam radiotherapy. Of the 112 patients, 15 were considered low risk, 29 intermediate risk, and 68 as high risk. The prescribed dose was uniformly 54 Gy in nine fractions within 5 days. Of the 112 patients, 94 also received hormonal therapy. The median follow-up time was 5.4 years. Results: All the patients safely completed the treatment regimen. The 5-year prostate-specific antigen (PSA) failure-free, local control, disease-free survival, and overall survival rate was 83%, 97%, 87%, and 96%, respectively. The 5-year PSA failure-free rate for low-, intermediate-, and high-risk patients was 85% (95% confidence interval, 66-100%), 93% (95% confidence interval, 83-100%), and 79% (95% confidence interval, 69-89%), respectively. The significant prognostic factors for PSA failure were the initial PSA level (p = .029) and younger age (p = .019). The maximal toxicities observed were Grade 3 using the Common Terminology Criteria for Adverse Events, version 3.0, for both acute and late toxicity (6 and 3 patients had acute and late Grade 3 toxicity, respectively). Late Grade 2 toxicity was observed in 13 patients. Conclusion: Monotherapeutic HDR brachytherapy with an extreme hypofractionation regimen of 54 Gy in nine fractions associated with hormonal therapy was feasible, and its toxicity was acceptable. The interim tumor control rate at a median 5.4 years was promising, even for patients with locally advanced disease. This dose-fractionation scheme might be referred to by other terms, such as stereotactic body radiotherapy. Studies with longer follow-up periods and from multiple institutions are needed to confirm the efficacy of this novel approach.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Outcomes of Node-Negative Breast Cancer 5 Centimeters and Larger Treated With and Without Postmastectomy Radiotherapy

Purpose: The role of adjuvant postmastectomy radiotherapy (PMRT) remains controversial for the rare presentation of pT3pN0cM0 breast cancer. The present analysis examined locoregional recurrence (LRR) and breast cancer-specific survival (BCSS) in pT2 = 5.0-cm and pT3 >5.0-cm tumors treated with mastectomy, stratified by PMRT use. Materials and Methods: Between January 1, 1989 and December 31, 2000, the British Columbia provincial database yielded 100 node-negative patients with tumors {>=}5 cm of 19,846 nonmetastatic breast cancer patients (0.5%). Of these 100 patients, 44 (44%) had received adjuvant PMRT. Results: The PMRT group contained significantly more pT3 >5-cm cases (p = 0.001) and margin-positive cases (p = .03). With a median follow-up of 10 years, the cumulative 10-year LRR rate was 2.3% (95% confidence interval, 0.2-10.5) in the PMRT group vs. 8.9% (95% confidence interval, 3.2-18.2) in the no-PMRT group (p = .2). Regarding LRR in the no-PMRT group, all patients had Grade 3 histologic features (LRR 17%, 5 of 29) and had not received hormonal therapy (LRR 15%, 5 of 34). The 10-year breast cancer-specific survival rate was 85.8% (95% confidence interval 71.0-93.4) in the PMRT group vs. 74.6% (95% confidence interval 59.9-84.5) in the no-PMRT group (p = .2). On multivariate analysis, adjusted for the prognostic and predictive variables, PMRT did not significantly improve the LRR or breast cancer-specific survival rates. Conclusion: The present study demonstrated a low LRR rate for node-negative breast cancer {>=}5 cm. Our results indicate that PMRT should be considered for Grade 3 histologic features and patients not undergoing hormonal therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Greater Biopsy Core Number Is Associated With Improved Biochemical Control in Patients Treated With Permanent Prostate Brachytherapy

Purpose: Standard prostate biopsy schemes underestimate Gleason score in a significant percentage of cases. Extended biopsy improves diagnostic accuracy and provides more reliable prognostic information. In this study, we tested the hypothesis that greater biopsy core number should result in improved treatment outcome through better tailoring of therapy. Methods and Materials: From April 1995 to May 2006, 1,613 prostate cancer patients were treated with permanent brachytherapy. Patients were divided into five groups stratified by the number of prostate biopsy cores ({<=}6, 7-9, 10-12, 13-20, and >20 cores). Biochemical progression-free survival (bPFS), cause-specific survival (CSS), and overall survival (OS) were evaluated as a function of core number. Results: The median patient age was 66 years, and the median preimplant prostate-specific antigen was 6.5 ng/mL. The overall 10-year bPFS, CSS, and OS were 95.6%, 98.3%, and 78.6%, respectively. When bPFS was analyzed as a function of core number, the 10-year bPFS for patients with >20, 13-20, 10-12, 7-9 and {<=}6 cores was 100%, 100%, 98.3%, 95.8%, and 93.0% (p < 0.001), respectively. When evaluated by treatment era (1995-2000 vs. 2001-2006), the number of biopsy cores remained a statistically significant predictor of bPFS. On multivariate analysis, the number of biopsy cores was predictive of bPFS but did not predict for CSS or OS. Conclusion: Greater biopsy core number was associated with a statistically significant improvement in bPFS. Comprehensive regional sampling of the prostate may enhance diagnostic accuracy compared to a standard biopsy scheme, resulting in better tailoring of therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Tumor Volume and Metabolism of Prostate Cancer Determined by Proton Magnetic Resonance Spectroscopic Imaging at 3T Without Endorectal Coil Reveal Potential Clinical Implications in the Context of Radiation Oncology;Prostate cancer; Magnetic resonance spectroscopic imaging; Radiation oncology; Tumor volume; Biomarkers

Purpose: To determine whether a relationship exists between the tumor volume (TV) or relative choline content determined using magnetic resonance spectroscopy imaging (MRSI) at 3T and the clinical prognostic parameters for patients with localized prostate cancer (PCa). Methods and Materials: A total of 72 men (mean age, 67.8 {+-} 6.2 years) were stratified as having low-risk (n = 26), intermediate-risk (n = 24), or high-risk (n = 22) PCa. MRSI was performed at 3T using a phased-array coil. Spectra are expressed as the total choline/citrate, total choline plus creatine/citrate, and total choline plus polyamines plus creatine/citrate ratios. The mean ratio of the most pathologic voxels and the MRSI-based TV were also determined. Results: The mean values of the total choline/citrate, total choline plus creatine/citrate, and total choline plus polyamine plus creatine/citrate ratios were greater for Stage T2b or greater tumors vs. Stage T2a or less tumors: 7.53 {+-} 13.60 vs. 2.31 {+-} 5.65 (p = .018), 8.98 {+-} 14.58 vs. 2.56 {+-} 5.70 (p = .016), and 10.32 {+-} 15.47 vs. 3.55 {+-} 6.16 (p = .014), respectively. The mean MRSI-based TV for Stage T2b or greater and Stage T2a or less tumors was significantly different (2.23 {+-} 2.62 cm{sup 3} vs. 1.26 {+-} 2.06 cm{sup 3}, respectively; p = .030). This TV correlated with increased prostate-specific antigen levels (odds ratio, 1.293; p = .012). Patients with high-risk PCa had a larger TV than did the patients with intermediate-risk PCa. A similar result was found for the intermediate-risk group compared with the low-risk group (odds ratio, 1.225; p = .041). Conclusion: Biomarkers expressing the relative choline content and TV were significant parameters for the localization of PCa and could be helpful for determining the prognosis more accurately.

62 RADIOLOGY AND NUCLEAR MEDICINE↗