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At least 523 records · Page 29

Disparities in the Use of Postmastectomy Radiation Therapy for Inflammatory Breast Cancer

Purpose: Although radiation therapy improves locoregional control and survival for inflammatory breast cancer (IBC), it is underused in this population. The purpose of this study was to identify variables associated with the underuse of postmastectomy radiation therapy (PMRT) for IBC. Methods and Materials: Using the 1998 to 2011 National Cancer Data Base, we identified 8273 women who underwent mastectomy for nonmetastatic IBC. We used logistic regression modeling to determine the demographic, tumor, and treatment variables associated with the underuse of PMRT. Results: Although the use of PMRT increased over time, a total of 30.3% of our cohort did not receive PMRT. On multivariate analysis, variables associated with the underuse of PMRT for IBC included the following (all P<.05): Medicare insurance (odds ratio [OR] = 0.70), annual income <$34,999 (<$30,000: OR=0.79; $30,000-$34,999: OR=0.82), cN2 and cN0 disease (cN2: OR=0.71; cN0: OR=0.63), failure to receive chemotherapy and hormone therapy (chemotherapy: OR=0.15; hormone therapy: OR=0.35), treatment at lower-volume centers (OR=0.83), and treatment in the South and West (South: OR=0.73; West: OR=0.80). Greater distance between patient's residence and radiation facility was also associated with the underuse of PMRT (P=.0001). Conclusions: Although the use of PMRT for IBC has increased over time, it continues to be underused. Disparities related to a variety of variables impact which IBC patients receive PMRT. A concerted effort must be made to address these disparities in order to optimize the outcomes for IBC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Long-Term Outcomes in Patients With Isolated Supraclavicular Nodal Recurrence After Mastectomy and Doxorubicin-Based Chemotherapy for Breast Cancer

Purpose: To examine the outcome of patients who developed an isolated locoregional recurrence (LRR) involving the supraclavicular fossa (SCV) after initial treatment with modified radical mastectomy and chemotherapy. Methods and Materials: Records from 140 breast cancer patients treated on five prospective trials with mastectomy and doxorubicin-based chemotherapy, with or without radiation, who developed a LRR were reviewed. Kaplan-Meier survival times were calculated using date of LRR as time zero. Results: The median follow-up after LRR was 2.9 years (N = 140; interquartile range, 1.3-6.6 years). In all, 47 of 140 patients (34%) had an SCV component to their LRR. These patients had lower 3-y distant metastasis-free survival (40% vs. 54%, p = 0.003) and overall survival (49% vs. 69%, p = 0.04) than patients without an SCV component. Multivariate analysis revealed that LRR involving an SCV component (hazard ratio, 1.96, p = 0.004) and patients with lymphovascular space invasion in their primary tumors (hazard ratio, 1.65, p = 0.029) were independently associated with a poor distant metastasis-free survival. However, among 23 patients with isolated SCV recurrence, Overall survival was not statistically significantly different between isolated chest wall recurrence and isolated SCV recurrence. Patients with isolated SCV recurrence displayed a median follow-up of 3.3 years (IR, 1.2-5.2). Only 6 LRR of 23 patients were treated with aggressive local therapy, including surgery, chemotherapy, and radiation (alone or in combination). Conclusions: Although breast cancer recurrence with SCV involvement carries a high risk of distant metastasis and death, among women with recurrence limited to the SCV alone, overall survival after isolated SCV recurrence can be long (25% >5 years).

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Reirradiation of Head and Neck Cancers With Intensity Modulated Radiation Therapy: Outcomes and Analyses

Purpose: To review our 15-year institutional experience using intensity modulated radiation therapy (IMRT) to reirradiate patients with head and neck squamous cell carcinomas (HNSCC) and identify predictors of outcomes and toxicity. Methods and Materials: We retrospectively reviewed the records of 227 patients who received head and neck reirradiation using IMRT from 1999 to 2014. Patients treated with noncurative intent were excluded. Radiation-related acute and late toxicities were recorded. Prognostic variables included performance status, disease site, disease-free interval, chemotherapy, and RT dose and volume. Correlative analyses were performed separately for surgery and nonsurgery patients. Results: Two hundred six patients (91%) were retreated with curative intent, and 173 had HNSCC histology; 104 (50%) underwent salvage resection, and 135 (66%) received chemotherapy. Median follow-up after reirradiation was 24.7 months. Clinical outcomes were worse for HNSCC patients, with 5-year locoregional control, progression-free survival, and overall survival rates of 53%, 22%, and 32%, respectively, compared with 74%, 59%, and 79%, respectively, for non-HNSCC patients. On multivariate analysis, concurrent chemotherapy and retreatment site were associated with tumor control, whereas performance status was associated with survival. Favorable prognostic factors specific to surgery patients were neck retreatment and lack of extracapsular extension, whereas for nonsurgery patients, these were a nasopharynx subsite and complete response to induction chemotherapy. Actuarial rates of grade ≥3 toxicity were 32% at 2 years and 48% at 5 years, with dysphagia or odynophagia being most common. Increased grade ≥3 toxicity was associated with retreatment volume >50 cm{sup 3} and concurrent chemotherapy. Conclusions: Reirradiation with IMRT either definitively or after salvage surgery can produce promising local control and survival in selected patients with head and neck cancers. Treatment-related toxicity remains significant. Prognostic factors are emerging to guide multidisciplinary treatment approaches and clinical trial design.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Role of Systemic Therapy in the Development of Lung Sequelae After Conformal Radiotherapy in Breast Cancer Patients

Purpose: To analyze the risk of radiogenic lung damage in breast cancer patients after conformal radiotherapy and different forms of systemic treatment. Methods and Materials: In 328 patients receiving sequential taxane-based chemotherapy, concomitant hormone therapy (tamoxifen or aromatase inhibitors), or no adjuvant systemic therapy, symptomatic and asymptomatic lung sequelae were prospectively evaluated via the detection of visible CT abnormalities, 3 months or 1 year after the completion of the radiotherapy. Results: Significant positive associations were detected between the development of both pneumonitis and fibrosis of Grade 1 and patient age, ipsilateral mean lung dose, volume of the ipsilateral lung receiving 20 Gy, and irradiation of the regional lymph nodes. In multivariate analysis, age and mean lung dose proved to be independent predictors of early (odds ratio [OR] = 1.035, 95% confidence interval [CI] 1.011-1.061 and OR = 1.113, 95% CI 1.049-1.181, respectively) and late (OR = 1.074, 95% CI 1.042-1.107 and OR = 1.207, 95% CI 1.124-1.295, respectively) radiogenic lung damage, whereas the role of systemic therapy was significant in the development of Grade 1 lung fibrosis (p = 0.01). Among the various forms of systemic therapy, tamoxifen increased the risk of late lung sequelae (OR = 2.442, 95% CI 1.120-5.326, p = 0.025). No interaction was demonstrated between the administration of systemic therapy and the other above-mentioned parameters as regards the risk of radiogenic lung damage. Conclusions: Our analyses demonstrate the independent role of concomitant tamoxifen therapy in the development of radiogenic lung fibrosis but do not suggest such an effect for the other modes of systemic treatment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Disordered glycometabolism involved in pathogenesis of Kashin–Beck disease, an endemic osteoarthritis in China

Kashin–Beck disease (KBD) is a chronic endemic osteoarthritis in China. Previous studies have suggested a role of metabolic dysfunction in causation of this disease. In this investigation, the metabolomics approach and cell experiments were used to discover the metabolic changes and their effects on KBD chondrocytes. Nuclear magnetic resonance ({sup 1}H NMR) spectroscopy was used to examine serum samples from both the KBD patients and normal controls. The pattern recognition multivariate analysis (OSC–PLS) and quantitative analysis (QMTLS iterator) revealed altered glycometabolism in KBD, with increased glucose and decreased lactate and citrate levels. IPA biological analysis showed the centric location of glucose in the metabolic network. Massive glycogen deposits in chondrocytes and increased uptake of glucose by chondrocytes further confirmed disordered glycometabolism in KBD. An in vitro study showed the effects of disordered glycometabolism in chondrocytes. When chondrocytes were treated with high glucose, expression of type II collagen and aggrecan were decreased, while TNF-α expression, the level of cellular reactive oxygen species and cell apoptosis rates all were increased. Therefore, our results demonstrated that disordered glycometabolism in patients with KBD was linked to the damage of chondrocytes. This may provide a new basis for understanding the pathogenesis of KBD. - Highlights: • Disordered glycometabolism in KBD was demonstrated by combining serum metabolomics and chondrocyte studies. • Glucose and TNF-α were key molecules linked to altered metabolism and inflammation in the pathophysiology of KBD. • The glycometabolism disorder was linked to expression of type II collagen and aggrecan, ROS and apoptosis of KBD chondrocytes.

60 APPLIED LIFE SCIENCES↗

Microscopic Disease Extension in Three Dimensions for Non-Small-Cell Lung Cancer: Development of a Prediction Model Using Pathology-Validated Positron Emission Tomography and Computed Tomography Features

Purpose: One major uncertainty in radiotherapy planning of non-small-cell lung cancer concerns the definition of the clinical target volume (CTV), meant to cover potential microscopic disease extension (MDE) around the macroscopically visible tumor. The primary aim of this study was to establish pretreatment risk factors for the presence of MDE. The secondary aim was to establish the impact of these factors on the accuracy of positron emission tomography (PET) and computed tomography (CT) to assess the total tumor-bearing region at pathologic examination (CTV{sub path}). Methods and Materials: 34 patients with non-small-cell lung cancer who underwent CT and PET before lobectomy were included. Specimens were examined microscopically for MDE. The gross tumor volume (GTV) on CT and PET (GTV{sub CT} and GTV{sub PET}, respectively) was compared with the GTV and the CTV at pathologic examination, tissue deformations being taken into account. Using multivariate logistic regression, image-based risk factors for the presence of MDE were identified, and a prediction model was developed based on these factors. Results: MDE was found in 17 of 34 patients (50%). The MDE did not exceed 26 mm in 90% of patients. In multivariate analysis, two parameters (mean CT tumor density and GTV{sub CT}) were significantly associated with MDE. The area under the curve of the two-parameter prediction model was 0.86. Thirteen tumors (38%, 95% CI: 24-55%) were identified as low risk for MDE, being potential candidates for reduced-intensity therapy around the GTV. In the low-risk group, the effective diameter of the GTV{sub CT/PET} accurately represented the CTV{sub path}. In the high-risk group, GTV{sub CT/PET} underestimated the CTV{sub path} with, on average, 19.2 and 26.7 mm, respectively. Conclusions: CT features have potential to predict the presence of MDE. Tumors identified as low risk of MDE show lower rates of disease around the GTV than do high-risk tumors. Both CT and PET accurately visualize the CTV{sub path} in low-risk tumors but underestimate it in high-risk tumors.

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Predictors of Survival in Contemporary Practice After Initial Radiosurgery for Brain Metastases

Purpose: The number of brain metastases (BM) is a major consideration in determining patient eligibility for stereotactic radiosurgery (SRS), but the evidence for this popular practice is equivocal. The purpose of this study was to determine whether, following multivariate adjustment, the number and volume of BM held prognostic significance in a cohort of patients initially treated with SRS alone. Methods and Materials: A total of 251 patients with primary malignancies, including non-small cell lung cancer (34%), melanoma (30%), and breast carcinoma (16%), underwent SRS for initial treatment of BM. SRS was used as the sole management (62% of patients) or was combined with salvage treatment with SRS (22%), whole-brain radiation therapy (WBRT; 13%), or resection (3%). Median follow-up time was 9.4 months. Survival was determined using the Kaplan-Meier method. Cox regression was used to assess the effects of patient factors on distant brain failure (DBF), local control (LC), and overall survival (OS). Results: LC at 1 year was 94.6%, and median time to DBF was 10 months. Median OS was 11.1 months. On multivariate analysis, statistically significant predictors of OS were presence of extracranial disease (hazard ratio [HR], 4.2, P<.001), total tumor volume greater than 2 cm{sup 3} (HR, 1.98; P<.001), age ≥60 years (HR, 1.67; P=.002), and diagnosis-specific graded prognostic assessment (HR, 0.71; P<.001). The presence of extracranial disease was a statistically significant predictor of DBF (HR, 2.15), and tumor volume was predictive of LC (HR, 4.56 for total volume >2 cm{sup 3}). The number of BM was not predictive of DBF, LC, or OS. Conclusions: The number of BM is not a strong predictor for clinical outcomes following initial SRS for newly diagnosed BM. Other factors including total treatment volume and systemic disease status are better determinants of outcome and may facilitate appropriate use of SRS or WBRT.

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The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis

HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression. - Highlights: • HOTAIR overexpression correlates with an aggressive tumour phenotype and a poor prognosis in SOC. • HOTAIR promotes SOC cell proliferation both in vitro and in vivo. • The proliferative role of HOTAIR is associated with regulation of the cell cycle and apoptosis.

60 APPLIED LIFE SCIENCES↗

High-Density and Very-Low-Density Lipoprotein Have Opposing Roles in Regulating Tumor-Initiating Cells and Sensitivity to Radiation in Inflammatory Breast Cancer

Purpose: We previously demonstrated that cholesterol-lowering agents regulate radiation sensitivity of inflammatory breast cancer (IBC) cell lines in vitro and are associated with less radiation resistance among IBC patients who undergo postmastectomy radiation. We hypothesized that decreasing IBC cellular cholesterol induced by treatment with lipoproteins would increase radiation sensitivity. Here, we examined the impact of specific transporters of cholesterol (ie lipoproteins) on the responses of IBC cells to self-renewal and to radiation in vitro and on clinical outcomes in IBC patients. Methods and Materials: Two patient-derived IBC cell lines, SUM 149 and KPL4, were incubated with low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL), or high-density lipoproteins (HDL) for 24 hours prior to irradiation (0-6 Gy) and mammosphere formation assay. Cholesterol panels were examined in a cohort of patients with primary IBC diagnosed between 1995 and 2011 at MD Anderson Cancer Center. Lipoprotein levels were then correlated to patient outcome, using the log rank statistical model, and examined in multivariate analysis using Cox regression. Results: VLDL increased and HDL decreased mammosphere formation compared to untreated SUM 149 and KPL4 cells. Survival curves showed enhancement of survival in both of the IBC cell lines when pretreated with VLDL and, conversely, radiation sensitization in all cell lines when pretreated with HDL. In IBC patients, higher VLDL values (>30 mg/dL) predicted a lower 5-year overall survival rate than normal values (hazard ratio [HR] = 1.9 [95% confidence interval [CI]: 1.05-3.45], P=.035). Lower-than-normal patient HDL values (<60 mg/dL) predicted a lower 5-year overall survival rate than values higher than 60 mg/dL (HR = 3.21 [95% CI: 1.25-8.27], P=.015). Conclusions: This study discovered a relationship among the plasma levels of lipoproteins, overall patient response, and radiation resistance in IBC patients and IBC patient-derived cell lines. A more expansive study is needed to verify these observations.

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Improved Clinical Outcomes With High-Dose Image Guided Radiotherapy Compared With Non-IGRT for the Treatment of Clinically Localized Prostate Cancer

Purpose: To compare toxicity profiles and biochemical tumor control outcomes between patients treated with high-dose image-guided radiotherapy (IGRT) and high-dose intensity-modulated radiotherapy (IMRT) for clinically localized prostate cancer. Materials and Methods: Between 2008 and 2009, 186 patients with prostate cancer were treated with IGRT to a dose of 86.4 Gy with daily correction of the target position based on kilovoltage imaging of implanted prostatic fiducial markers. This group of patients was retrospectively compared with a similar cohort of 190 patients who were treated between 2006 and 2007 with IMRT to the same prescription dose without, however, implanted fiducial markers in place (non-IGRT). The median follow-up time was 2.8 years (range, 2-6 years). Results: A significant reduction in late urinary toxicity was observed for IGRT patients compared with the non-IGRT patients. The 3-year likelihood of grade 2 and higher urinary toxicity for the IGRT and non-IGRT cohorts were 10.4% and 20.0%, respectively (p = 0.02). Multivariate analysis identifying predictors for grade 2 or higher late urinary toxicity demonstrated that, in addition to the baseline Internatinoal Prostate Symptom Score, IGRT was associated with significantly less late urinary toxicity compared with non-IGRT. The incidence of grade 2 and higher rectal toxicity was low for both treatment groups (1.0% and 1.6%, respectively; p = 0.81). No differences in prostate-specific antigen relapse-free survival outcomes were observed for low- and intermediate-risk patients when treated with IGRT and non-IGRT. For high-risk patients, a significant improvement was observed at 3 years for patients treated with IGRT compared with non-IGRT. Conclusions: IGRT is associated with an improvement in biochemical tumor control among high-risk patients and a lower rate of late urinary toxicity compared with high-dose IMRT. These data suggest that, for definitive radiotherapy, the placement of fiducial markers and daily tracking of target positioning may represent the preferred mode of external-beam radiotherapy delivery for the treatment of prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Late Radiation and Cardiovascular Adverse Effects After Androgen Deprivation and High-Dose Radiation Therapy in Prostate Cancer: Results From the DART 01/05 Randomized Phase 3 Trial

Purpose: To present data on the late toxicity endpoints of a randomized trial (DART 01/05) conducted to determine whether long-term androgen deprivation (LTAD) was superior to short-term AD (STAD) when combined with high-dose radiation therapy (HDRT) in patients with prostate cancer (PCa). Patients and Methods: Between November 2005 and December 2010, 355 eligible men with cT1c-T3aN0M0 PCa and intermediate-risk and high-risk factors (2005 National Comprehensive Cancer Network criteria) were randomized to 4 months of AD combined with HDRT (median dose, 78 Gy) (STAD) or the same treatment followed by 24 months of AD (LTAD). Treatment-related complications were assessed using European Organization for Research and Treatment of Cancer–Radiation Therapy Oncology Group and Common Terminology Criteria for Adverse Events v3.0 scoring schemes. Multivariate analyses for late toxicity were done using the Fine-Gray method. Results: The 5-year incidence of grade ≥2 rectal and urinary toxicity was 11.1% and 8.2% for LTAD and 7.6% and 7.3% for STAD, respectively. Compared with STAD, LTAD was not significantly associated with a higher risk of late grade ≥2 rectal toxicity (hazard ratio [HR] 1.360, 95% confidence interval [CI] 0.660-2.790, P=.410) or urinary toxicity (HR 1.028, 95% CI 0.495-2.130, P=.940). The multivariate analysis showed that a baseline history of intestinal comorbidity (HR 3.510, 95% CI 1.560-7.930, P=.025) and the rectal volume receiving >60 Gy (Vr60) (HR 1.030, 95% CI 1.001-1.060, P=.043) were the only factors significantly correlated with the risk of late grade ≥2 rectal complications. A history of previous surgical prostate manipulations was significantly associated with a higher risk of grade ≥2 urinary complications (HR 2.427, 95% CI 1.051-5.600, P=.038). Long-term AD (HR 2.090; 95% CI 1.170-3.720, P=.012) and a history of myocardial infarction (HR 2.080; 95% CI 1.130-3.810, P=.018) were significantly correlated with a higher probability of cardiovascular events. Conclusion: Long-term AD did not significantly impact urinary or rectal radiation-induced toxicity, although it was associated with a higher risk of cardiovascular events. Longer follow-up is needed to measure the impact of AD on late morbidity and non-PCa mortality.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

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.

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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↗

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↗

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↗

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↗

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↗

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↗