Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “curation”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41

Tumor Volume Reduction Rate After Preoperative Chemoradiotherapy as a Prognostic Factor in Locally Advanced Rectal Cancer

Purpose: To investigate the prognostic significance of tumor volume reduction rate (TVRR) after preoperative chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC). Methods and Materials: In total, 430 primary LARC (cT3-4) patients who were treated with preoperative CRT and curative radical surgery between May 2002 and March 2008 were analyzed retrospectively. Pre- and post-CRT tumor volumes were measured using three-dimensional region-of-interest MR volumetry. Tumor volume reduction rate was determined using the equation TVRR (%) = (pre-CRT tumor volume - post-CRT tumor volume) Multiplication-Sign 100/pre-CRT tumor volume. The median follow-up period was 64 months (range, 27-99 months) for survivors. Endpoints were disease-free survival (DFS) and overall survival (OS). Results: The median TVRR was 70.2% (mean, 64.7% {+-} 22.6%; range, 0-100%). Downstaging (ypT0-2N0M0) occurred in 183 patients (42.6%). The 5-year DFS and OS rates were 77.7% and 86.3%, respectively. In the analysis that included pre-CRT and post-CRT tumor volumes and TVRR as continuous variables, only TVRR was an independent prognostic factor. Tumor volume reduction rate was categorized according to a cutoff value of 45% and included with clinicopathologic factors in the multivariate analysis; ypN status, circumferential resection margin, and TVRR were significant prognostic factors for both DFS and OS. Conclusions: Tumor volume reduction rate was a significant prognostic factor in LARC patients receiving preoperative CRT. Tumor volume reduction rate data may be useful for tailoring surgery and postoperative adjuvant therapy after preoperative CRT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Intensity-Modulated Radiation Therapy in Oropharyngeal Carcinoma: Effect of Tumor Volume on Clinical Outcomes

Purpose: To analyze the effect of primary gross tumor volume (pGTV) and nodal gross tumor volume (nGTV) on treatment outcomes in patients treated with definitive intensity-modulated radiation therapy (IMRT) for oropharyngeal cancer (OPC). Methods and Materials: Between September 1998 and April 2009, a total of 442 patients with squamous cell carcinoma of the oropharynx were treated with IMRT with curative intent at our center. Thirty patients treated postoperatively and 2 additional patients who started treatment more than 6 months after diagnosis were excluded. A total of 340 patients with restorable treatment plans were included in this present study. The majority of the patients underwent concurrent platinum-based chemotherapy. The pGTV and nGTV were calculated using the original clinical treatment plans. Cox proportional hazards models and log-rank tests were used to evaluate the correlation between tumor volumes and overall survival (OS), and competing risks analysis tools were used to evaluate the correlation between local failure (LF), regional failure (RF), distant metastatic failure (DMF) vs. tumor volumes with death as a competing risk. Results: Median follow-up among surviving patients was 34 months (range, 5-67). The 2-year cumulative incidence of LF, RF and DF in this cohort of patients was 6.1%, 5.2%, and 12.2%, respectively. The 2-year OS rate was 88.6%. Univariate analysis determined pGTV and T-stage correlated with LF (p < 0.0001 and p = 0.004, respectively), whereas nGTV was not associated with RF. On multivariate analysis, pGTV and N-stage were independent risk factors for overall survival (p = 0.0003 and p = 0.0073, respectively) and distant control (p = 0.0008 and p = 0.002, respectively). Conclusions: In this cohort of patients with OPC treated with IMRT, pGTV was found to be associated with overall survival, local failure, and distant metastatic failure.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Postoperative Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: Treatment Outcomes, Marginal Misses, and Perspective on Target Delineation

Purpose: To report outcomes of the rare disease of squamous cell carcinoma (SCC) of the external auditory canal (EAC) and middle ear treated with surgery and postoperative intensity-modulated radiotherapy (IMRT). Failure patterns related to spatial dose distribution were also analyzed to provide insight into target delineation. Methods and Materials: A retrospective review was conducted of the records of 11 consecutive patients with SCC of the EAC and middle ear who were treated with curative surgery and postoperative IMRT at one institution between January 2007 and February 2010. The prescribed IMRT dose was 60 to 66 Gy at 2 Gy per fraction. Three patients also received concurrent cisplatin-based chemotherapy, and 1 patient received concurrent oral tegafur/uracil. The median follow-up time was 19 months (range, 6-33 months). Results: Four patients had locoregional recurrence, yielding an estimated 2-year locoregional control rate of 70.7%. Among them, 1 patient had persistent disease after treatment, and 3 had marginal recurrence. Distant metastasis occurred in 1 patient after extensive locoregional recurrence, yielding an estimated 2-year distant control rate of 85.7%. The estimated 2-year overall survival was 67.5%. The three cases of marginal recurrence were near the preauricular space and glenoid fossa of the temporomandibular joint, adjacent to the apex of the ear canal and glenoid fossa of the temporomandibular joint, and in the postauricular subcutaneous area and ipsilateral parotid nodes, respectively. Conclusions: Marginal misses should be recognized to improve target delineation. When treating SCC of the EAC and middle ear, care should be taken to cover the glenoid fossa of the temporomandibular joint and periauricular soft tissue. Elective ipsilateral parotid irradiation should be considered. The treatment planning procedure should also be refined to balance subcutaneous soft-tissue dosimetry and toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Treatment Trends and Outcomes of Small-Cell Carcinoma of the Bladder

Purpose: Treatment for small-cell carcinoma of the bladder is largely guided by case reports, retrospective reviews, and small prospective trials. This study aimed to study outcomes using a large population-based database. Methods: The Surveillance, Epidemiology, and End Results-Medicare database (1991-2005) was used to analyze how different treatment combinations of specific bladder surgeries, chemotherapy, and radiation affected patient outcomes. Trends in the use of these combinations over time were also analyzed. Results: A total of 533 patients were retrieved from the database. A bladder-sparing approach involving transurethral resection of the bladder tumor (TURBT) combined with chemotherapy and radiation yielded no significant difference in overall survival compared with patients undergoing at least a cystectomy (of whom over 90% received radical cystectomy) with chemotherapy (p > 0.05). The analysis of treatment trends indicated that these two general strategies for cure combined to account for fewer than 20% of patients. A majority of patients (54%) received TURBT as their only surgical treatment, and a subset analysis of these patients indicated that chemotherapy played a role in all stages of disease (p < 0.05) whereas radiation improved overall survival in regional-stage disease (p < 0.05). Conclusion: Relatively few patients with small-cell carcinoma of the bladder receive potentially curative therapies. Chemotherapy should be a major component of treatment. Cystectomy and bladder-sparing approaches represent two viable strategies and deserve further investigation to identify the patients who may benefit from organ preservation or not. In addition, the role of radiation in regional-stage disease should be investigated further, because it positively affects survival after TURBT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Continuous-Course Reirradiation With Concurrent Carboplatin and Paclitaxel for Locally Recurrent, Nonmetastatic Squamous Cell Carcinoma of the Head-and-Neck

Purpose: To examine the efficacy and toxicity of continuous-course, conformal reirradiation with weekly paclitaxel and carboplatin for the treatment of locally recurrent, nonmetastatic squamous cell carcinoma of the head and neck (SCCHN) in a previously irradiated field. Methods and Materials: Patients treated with continuous course-reirradiation with concurrent carboplatin and paclitaxel at the Medical College of Wisconsin and the Clement J. Zablocki VA from 2001 through 2009 were retrospectively reviewed. Patients included in the analysis had prior radiation at the site of recurrence of at least 45 Gy. The analysis included patients who received either intensity-modulated radiotherapy (RT) or three-dimensional conformal RT techniques. All patients received weekly concurrent carboplatin (AUC2) and paclitaxel (30-50 mg/m{sup 2}). Results: Thirty-eight patients with nonmetastatic SCCHN met the entry criteria for analysis. The primary sites at initial diagnosis were oropharyngeal or laryngeal in most patients (66%). Median reirradiation dose was 60 Gy (range, 54-70 Gy). Acute toxicity included Grade 2 neutropenia (5%), Grade 3 neutropenia (15%), and Grade 1/2 thrombocytopenia (8%). No deaths occurred from hematologic toxicity. Chemotherapy doses held (50%) was more prevalent than radiation treatment break (8%). Sixty-eight percent of patients required a gastrostomy tube in follow-up. Significant late toxicity was experienced in 6 patients (16%): 1 tracheoesophageal fistula, 1 pharyngocutaneous fistula, 3 with osteoradionecrosis, and 1 patient with a lingual artery bleed. Patients treated with three-dimensional conformal RT had more frequent significant late toxicites than patients treated with intensity-modulated RT (44% and 7% respectively, p < 0.05). The median time to progression was 7 months and progression-free rates at 1, 2, and 5 years was 44%, 34%, and 29% respectively. The median overall survival was 16 months. Overall survival at 1, 3, and 5 years was 54%, 31%, and 20% respectively. Conclusions: Continuous-course, conformal reirradiation with weekly paclitaxel and carboplatin has an acceptable toxicity profile and offers a potentially curative option in a subset of patients with few other options.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Development and Impact Evaluation of an E-Learning Radiation Oncology Module

Purpose: Radiation oncologists are faced with the challenge of irradiating tumors to a curative dose while limiting toxicity to healthy surrounding tissues. This can be achieved only with superior knowledge of radiologic anatomy and treatment planning. Educational resources designed to meet these specific needs are lacking. A web-based interactive module designed to improve residents' knowledge and application of key anatomy concepts pertinent to radiotherapy treatment planning was developed, and its effectiveness was assessed. Methods and Materials: The module, based on gynecologic malignancies, was developed in collaboration with a multidisciplinary team of subject matter experts. Subsequently, a multi-centre randomized controlled study was conducted to test the module's effectiveness. Thirty-six radiation oncology residents participated in the study; 1920 were granted access to the module (intervention group), and 17 in the control group relied on traditional methods to acquire their knowledge. Pretests and posttests were administered to all participants. Statistical analysis was carried out using paired t test, analysis of variance, and post hoc tests. Results: The randomized control study revealed that the intervention group's pretest and posttest mean scores were 35% and 52%, respectively, and those of the control group were 37% and 42%, respectively. The mean improvement in test scores was 17% (p < 0.05) for the intervention group and 5% (p = not significant) for the control group. Retrospective pretest and posttest surveys showed a statistically significant change on all measured module objectives. Conclusions: The use of an interactive e-learning teaching module for radiation oncology is an effective method to improve the radiologic anatomy knowledge and treatment planning skills of radiation oncology residents.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Twenty-Five-Year Experience With Radical Chemoradiation for Anal Cancer

Purpose: To evaluate the prognostic factors, patterns of failure, and late toxicity in patients treated with chemoradiation (CRT) for anal cancer. Methods and Materials: Consecutive patients with nonmetastatic squamous cell carcinoma of the anus treated by CRT with curative intent between February 1983 and March 2008 were identified through the institutional database. Chart review and telephone follow-up were undertaken to collect demographic data and outcome. Results: Two hundred eighty-four patients (34% male; median age 62 years) were identified. The stages at diagnosis were 23% Stage I, 48% Stage II, 10% Stage IIIA, and 18% Stage IIIB. The median radiotherapy dose to the primary site was 54 Gy. A complete clinical response to CRT was achieved in 89% of patients. With a median follow-up time of 5.3 years, the 5-year rates of locoregional control, distant control, colostomy-free survival, and overall survival were 83% (95% confidence interval [CI] 78-88), 92% (95% CI, 89-96), 73% (95% CI, 68-79), and 82% (95% CI, 77-87), respectively. Higher T stage and male sex predicted for locoregional failure, and higher N stage predicted for distant metastases. Locoregional failure occurred most commonly at the primary site. Omission of elective inguinal irradiation resulted in inguinal failure rates of 1.9% and 12.5% in T1N0 and T2N0 patients, respectively. Pelvic nodal failures were very uncommon. Late vaginal and bone toxicity was observed in addition to gastrointestinal toxicity. Conclusions: CRT is a highly effective approach in anal cancer. However, subgroups of patients fare relatively poorly, and novel approaches are needed. Elective inguinal irradiation can be safely omitted only in patients with Stage I disease. Vaginal toxicity and insufficiency fractures of the hip and pelvis are important late effects that require prospective evaluation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Distant Metastases in Head-and-Neck Squamous Cell Carcinoma Treated With Intensity-Modulated Radiotherapy

Purpose: To determine the pattern and risk factors for distant metastases in head-and-neck squamous cell carcinoma (HNSCC) after curative treatment with intensity-modulated radiotherapy (IMRT). Methods and Materials: This was a retrospective study of 284 HNSCC patients treated in a single institution with IMRT. Sites included were oropharynx (125), oral cavity (70), larynx (55), hypopharynx (17), and unknown primary (17). American Joint Committee on Cancer stage distribution includes I (3), II (19), III (42), and IV (203). There were 224 males and 60 females with a median age of 57. One hundred eighty-six patients were treated with definitive IMRT and 98 postoperative IMRT. One hundred forty-nine patients also received concurrent cisplatin-based chemotherapy. Results: The median follow-up for all patients was 22.8 months (range, 0.07-77.3 months) and 29.5 months (4.23-77.3 months) for living patients. The 3-year local recurrence-free survival, regional recurrence-free survival, locoregional recurrence-free survival, distant metastasis-free survival, and overall survival were 94.6%, 96.4%, 92.5%, 84.1%, and 68.95%, respectively. There were 45 patients with distant metastasis. In multivariate analysis, distant metastasis was strongly associated with N stage (p = 0.046), T stage (p < 0.0001), and pretreatment maximum standardized uptake value of the lymph node (p = 0.006), but not associated with age, gender, disease sites, pretreatment standardized uptake value of the primary tumor, or locoregional control. The freedom from distant metastasis at 3 years was 98.1% for no factors, 88.6% for one factor, 68.3% for two factors, and 41.7% for three factors (p < 0.0001 by log-rank test). Conclusion: With advanced radiation techniques and concurrent chemotherapy, the failure pattern has changed with more patients failing distantly. The majority of patients with distant metastases had no local or regional failures, indicating that these patients might have microscopic distant disease before treatment. The clinical factors identified here should be incorporated in future clinical trials.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Treatment of Locally Advanced Pancreatic Cancer: The Role of Radiation Therapy

Pancreatic cancer remains associated with an extremely poor prognosis. Surgical resection can be curative, but the majority of patients present with locally advanced or metastatic disease. Treatment for patients with locally advanced disease is controversial. Therapeutic options include systemic therapy alone, concurrent chemoradiation, or induction chemotherapy followed by chemoradiation. We review the evidence to date regarding the treatment of locally advanced pancreatic cancer (LAPC), as well as evolving strategies including the emerging role of targeted therapies. We propose that if radiation is used for patients with LAPC, it should be delivered with concurrent chemotherapy and following a period of induction chemotherapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Implementation of High-Dose-Rate Brachytherapy and Androgen Deprivation in Patients With Prostate Cancer

Purpose: To evaluate outcome (overall survival [OS], the actuarial 5-year cancer-specific survival [CSS], disease-free survival [DFS], biochemical failure-free survival [BFS]), complications and morbidity in patients treated with high-dose-rate brachytherapy (HDR-BT) boost and hormonal treatment with curative aims. Methods: Between 2004 and 2009, 275 prospectively followed pN0/N0M0 patients were included: 19 patients (7%) with T2, Gleason score 7 and prostate-specific antigen (PSA) <10 and 256 patients (93%) with T3 or Gleason score 8-10 or PSA >20 received multimodal treatment with conformal four-field radiotherapy (prostate/vesiculae 2 Gy Multiplication-Sign 25) combined with HDR-BT (iridium 192; prostate 10 Gy Multiplication-Sign 2) with long-term androgen deprivation therapy (ADT). Results: After a median observation time of 44.2 months (range, 10.4-90.5 months) 12 patients had relapsed clinically and/or biochemically and 10 patients were dead, of which 2 patients died from prostate cancer. Five-year estimates of BFS, CSS, DFS, and OS rates were 98.5%, 99.3%, 95.6%, and 96.3%, respectively. None of the patients with either Gleason score <8 or with intermediate risk profile had relapsed. The number of HDR-BT treatments was not related to outcome. Despite of age (median, 65.7 years; range, 45.7-77 years) and considerable pretreatment comorbidity in 39 of 275 patients, Genitourinary treatment-related morbidity was moderate with long-lasting Radiation Therapy Oncology Group Grade 2 voiding problems in 26 patients (9.5%) and occasionally mucous discharge in 20 patients (7%), none with Grade >2 for gastrointestinal at follow-up. Complications during implantations were related to pubic arch interference (4 patients) and lithotomy time, causing 2 patients to develop compartment syndrome. Conclusion: Despite still preliminary observations, our 5-year outcome estimates favor the implementation of high-dose-rate brachytherapy in high-risk patients combined with conformal external radiotherapy and long-term ADT. High-quality implants can be achieved by a trained specialized team at a high-turnover center using transrectal ultrasound-based treatment plans with acceptable morbidity and complication rates.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Electron Irradiation of Conjunctival Lymphoma-Monte Carlo Simulation of the Minute Dose Distribution and Technique Optimization

Purpose: External beam radiotherapy is the only conservative curative approach for Stage I non-Hodgkin lymphomas of the conjunctiva. The target volume is geometrically complex because it includes the eyeball and lid conjunctiva. Furthermore, the target volume is adjacent to radiosensitive structures, including the lens, lacrimal glands, cornea, retina, and papilla. The radiotherapy planning and optimization requires accurate calculation of the dose in these anatomical structures that are much smaller than the structures traditionally considered in radiotherapy. Neither conventional treatment planning systems nor dosimetric measurements can reliably determine the dose distribution in these small irradiated volumes. Methods and Materials: The Monte Carlo simulations of a Varian Clinac 2100 C/D and human eye were performed using the PENELOPE and PENEASYLINAC codes. Dose distributions and dose volume histograms were calculated for the bulbar conjunctiva, cornea, lens, retina, papilla, lacrimal gland, and anterior and posterior hemispheres. Results: The simulated results allow choosing the most adequate treatment setup configuration, which is an electron beam energy of 6 MeV with additional bolus and collimation by a cerrobend block with a central cylindrical hole of 3.0 cm diameter and central cylindrical rod of 1.0 cm diameter. Conclusions: Monte Carlo simulation is a useful method to calculate the minute dose distribution in ocular tissue and to optimize the electron irradiation technique in highly critical structures. Using a voxelized eye phantom based on patient computed tomography images, the dose distribution can be estimated with a standard statistical uncertainty of less than 2.4% in 3 min using a computing cluster with 30 cores, which makes this planning technique clinically relevant.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Resected Pancreatic Neuroendocrine Tumors: Patterns of Failure and Disease-Related Outcomes With or Without Radiotherapy

Purpose: Pancreatic neuroendocrine tumors (NET) are rare and have better disease-related outcomes compared with pancreatic adenocarcinoma. Surgical resection remains the standard of care, although many patients present with locally advanced or metastatic disease. Little is known regarding the use of radiotherapy in the prevention of local recurrence after resection. To better define the role of radiotherapy, we performed an analysis of resected patients at our institution. Methods: Between 1994 and 2009, 33 patients with NET of the pancreatic head and neck underwent treatment with curative intent at Duke University Medical Center. Sixteen patients were treated with surgical resection alone while an additional 17 underwent resection with adjuvant or neoadjuvant radiation therapy, usually with concurrent fluoropyrimidine-based chemotherapy (CMT). Median radiation dose was 50.4 Gy and median follow-up 28 months. Results: Thirteen patients (39%) experienced treatment failure. Eleven of the initial failures were distant, one was local only and one was local and distant. Two-year overall survival was 77% for all patients. Two-year local control for all patients was 87%: 85% for the CMT group and 90% for the surgery alone group (p = 0.38). Two-year distant metastasis-free survival was 56% for all patients: 46% and 69% for the CMT and surgery patients, respectively (p = 0.10). Conclusions: The primary mode of failure is distant which often results in mortality, with local failure occurring much less commonly. The role of radiotherapy in the adjuvant management of NET remains unclear.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Individualized Dose Prescription for Hypofractionation in Advanced Non-Small-Cell Lung Cancer Radiotherapy: An in silico Trial

Purpose: Local tumor control and outcome remain poor in patients with advanced non-small-cell lung cancer (NSCLC) treated by external beam radiotherapy. We investigated the therapeutic gain of individualized dose prescription with dose escalation based on normal tissue dose constraints for various hypofractionation schemes delivered with intensity-modulated radiation therapy. Methods and Materials: For 38 Stage III NSCLC patients, the dose level of an existing curative treatment plan with standard fractionation (66 Gy) was rescaled based on dose constraints for the lung, spinal cord, esophagus, brachial plexus, and heart. The effect on tumor total dose (TTD) and biologic tumor effective dose in 2-Gy fractions (TED) corrected for overall treatment time (OTT) was compared for isotoxic and maximally tolerable schemes given in 15, 20, and 33 fractions. Rescaling was accomplished by altering the dose per fraction and/or the number of fractions while keeping the relative dose distribution of the original treatment plan. Results: For 30 of the 38 patients, dose escalation by individualized hypofractionation yielded therapeutic gain. For the maximally tolerable dose scheme in 33 fractions (MTD{sub 33}), individualized dose escalation resulted in a 2.5-21% gain in TTD. In the isotoxic schemes, the number of fractions could be reduced with a marginal increase in TED. For the maximally tolerable dose schemes, the TED could be escalated up to 36.6%, and for all patients beyond the level of the isotoxic and the MTD{sub 33} schemes (range, 3.3-36.6%). Reduction of the OTT contributed to the therapeutic gain of the shortened schemes. For the maximally tolerable schemes, the maximum esophageal dose was the dominant dose-limiting constraint in most patients. Conclusions: This modeling study showed that individualized dose prescription for hypofractionation in NSCLC radiotherapy, based on scaling of existing treatment plans up to normal tissue dose constraints, enables dose escalation with therapeutic gain in 79% of the cases.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Treatment Outcome of Medium-Dose-Rate Intracavitary Brachytherapy for Carcinoma of the Uterine Cervix: Comparison With Low-Dose-Rate Intracavitary Brachytherapy

Purpose: To evaluate and compare the efficacy of medium-dose-rate (MDR) and low-dose-rate (LDR) intracavitary brachytherapy (ICBT) for uterine cervical cancer. Methods and Materials: We evaluated 419 patients with squamous cell carcinoma of the cervix who were treated by radical radiotherapy with curative intent at Tokyo Women's Medical University from 1969 to 1999. LDR was used from 1969 to 1986, and MDR has been used since July 1987. When compared with LDR, fraction dose was decreased and fraction size was increased (1 or 2 fractions) for MDR to make the total dose of MDR equal to that of LDR. In general, the patients received a total dose of 60 to 70 Gy at Point A with external beam radiotherapy combined with brachytherapy according to the International Federation of Gynecology and Obstetrics stage. In the LDR group, 32 patients had Stage I disease, 81 had Stage II, 182 had Stage III, and 29 had Stage IVA; in the MDR group, 9 patients had Stage I disease, 19 had Stage II, 55 had Stage III, and 12 had Stage IVA. Results: The 5-year overall survival rates for Stages I, II, III, and IVA in the LDR group were 78%, 72%, 55%, and 34%, respectively. In the MDR group, the 5-year overall survival rates were 100%, 68%, 52%, and 42%, respectively. No significant statistical differences were seen between the two groups. The actuarial rates of late complications Grade 2 or greater at 5 years for the rectum, bladder, and small intestine in the LDR group were 11.1%, 5.8%, and 2.0%, respectively. The rates for the MDR group were 11.7%, 4.2%, and 2.6%, respectively, all of which were without statistical differences. Conclusion: These data suggest that MDR ICBT is effective, useful, and equally as good as LDR ICBT in daytime (about 5 hours) treatments of patients with cervical cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Outcome and Prognostic Factors in Endometrial Stromal Tumors: A Rare Cancer Network Study

Purpose: To provide further understanding regarding outcome and prognostic factors of endometrial stromal tumors (EST). Methods and Materials: A retrospective analysis was performed on the records of 59 women diagnosed with EST and treated with curative intent between 1983 and 2007 in the framework of the Rare Cancer Network. Results: Endometrial stromal sarcomas (ESS) were found in 44% and undifferentiated ESS (UES) in 49% of the cases. In 7% the grading was unclear. Of the total number of patients, 33 had Stage I, 4 Stage II, 20 Stage III, and 1 presented with Stage IVB disease. Adjuvant chemotherapy was administered to 12 patients, all with UES. External-beam radiotherapy (RT) was administered postoperatively to 48 women. The median follow-up was 41.4 months. The 5-year overall survival (OS) rate was 96.2% and 64.8% for ESS and UES, respectively, with a corresponding 5-year disease-free survival (DFS) rate of 49.4% and 43.4%, respectively. On multivariate analysis, adjuvant RT was an independent prognostic factor for OS (p = 0.007) and DFS (p = 0.013). Locoregional control, DFS, and OS were significantly associated with age ({<=}60 vs. >60 years), grade (ESS vs. UES), and International Federation of Gynecology and Obstetrics stage (I-II vs. III-IV). Positive lymph node staging had an impact on OS (p < 0.001). Conclusion: The prognosis of ESS differed from that of UES. Endometrial stromal sarcomas had an excellent 5-year OS, whereas the OS in UES was rather low. However, half of ESS patients had a relapse. For this reason, adjuvant treatment such as RT should be considered even in low-grade tumors. Multicenter randomized studies are still warranted to establish clear guidelines.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Impact of Pretreatment Body Mass Index on Patients With Head-and-Neck Cancer Treated With Radiation

Purpose: To investigate the association of pretreatment body mass index (preT BMI) with outcomes of head-and-neck cancer in patients treated with radiotherapy (RT). Methods and Materials: All 1,562 patients diagnosed with head-and-neck cancer and treated with curative-intent RT to a dose of 60 Gy or higher were retrospectively studied. Body weight was measured both at entry and at the end of RT. Cancer-specific survival (CSS), overall survival (OS), locoregional control (LRC), and distant metastasis (DM) were analyzed by preT BMI (<25 kg/m{sup 2} vs. {>=}25 kg/m{sup 2}). The median follow-up was 8.6 years. Results: Patients with lower preT BMI were statistically significantly associated with poorer CSS and OS than those with higher preT BMI. There was no significant difference between preT BMI groups in terms of LRC and DM. Body weight loss (BWL) during radiation did not influence survival outcomes. However, in the group with higher preT BMI, CSS, OS, and DM-free survival of patients with less BWL during radiation were statistically longer when compared with greater BWL. Conclusion: This study demonstrates that higher preT BMI positively influenced survival outcomes for patients with head-and-neck cancer. Patients with higher preT BMI who were able to maintain their weight during radiation had significantly better survival than patients with greater BWL.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Early Proctoscopy is a Surrogate Endpoint of Late Rectal Toxicity in Prostate Cancer Treated With Radiotherapy

Purpose: To predict the grade and incidence of late clinical rectal toxicity through short-term (1 year) mucosal alterations. Methods and Materials: Patients with prostate adenocarcinoma treated with curative or adjuvant radiotherapy underwent proctoscopy a year after the course of radiotherapy. Mucosal changes were classified by the Vienna Rectoscopy Score (VRS). Late toxicity data were analyzed according to the Kaplan-Meier method. Comparison between prognosis groups was performed by log-rank analysis. Results: After a median follow-up time of 45 months (range, 18-99), the 3-year incidence of grade {>=}2 rectal late toxicity according to the criteria of the European Organization for Research and Treatment of Cancer and the Radiation Therapy Oncology Group was 24%, with all patients (24/24; 100%) experiencing rectal bleeding. The occurrence of grade {>=}2 clinical rectal late toxicity was higher in patients with grade {>=}2 (32% vs. 15 %, p = 0.02) or grade {>=}3 VRS telangiectasia (47% vs. 17%, p {<=} 0.01) and an overall VRS score of {>=}2 (31% vs. 16 %, p = 0.04) or {>=}3 (48% vs. 17%, p = 0.01) at the 1-year proctoscopy. Conclusions: Early proctoscopy (1 year) predicts late rectal bleeding and therefore can be used as a surrogate endpoint for late rectal toxicity in studies aimed at reducing this frequent complication.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Severe Late Toxicities Following Concomitant Chemoradiotherapy Compared to Radiotherapy Alone in Cervical Cancer: An Inter-era Analysis

Purpose: To compare rates of severe late toxicities following concomitant chemoradiotherapy and radiotherapy alone for cervical cancer. Methods and Materials: Patients with cervical cancer were treated at a single institution with radiotherapy alone or concomitant chemoradiotherapy for curative intent. Severe late toxicity was defined as grade {>=}3 vaginal, urologic, or gastrointestinal toxicity or any pelvic fracture, using Common Terminology Criteria for Adverse Events version 4.0 (CTCAE), occurring {>=}6 months from treatment completion and predating any salvage therapy. Severe late toxicity rates were compared after adjusting for pertinent covariates. Results: At 3 years, probability of vaginal severe late toxicity was 20.2% for radiotherapy alone and 35.1% for concomitant chemoradiotherapy (P=.026). At 3 years, probability of skeletal severe late toxicity was 1.6% for radiotherapy alone and 7.5% for concomitant chemoradiotherapy (P=.010). After adjustment for case mix, concomitant chemoradiotherapy was associated with higher vaginal (hazard ratio [HR] 3.0, 95% confidence interval [CI], 1.7-5.2, P<.001), and skeletal (HR 7.0, 95% CI 1.4-34.1, P=.016) severe late toxicity. Compared to high dilator compliance, moderate (HR 3.6, 95% CI 2.0-6.5, P<.001) and poor (HR 8.5, 95% CI 4.3-16.9, P<.001) dilator compliance was associated with higher vaginal severe late toxicity. Age >50 was associated with higher vaginal (HR 1.8, 95% CI 1.1-3.0, P=.013) and skeletal (HR 5.7, 95% CI 1.2-27.0, P=.028) severe late toxicity. Concomitant chemoradiotherapy was not associated with higher gastrointestinal (P=.886) or urologic (unadjusted, P=.053; adjusted, P=.063) severe late toxicity. Conclusion: Compared to radiotherapy alone, concomitant chemoradiotherapy is associated with higher rates of severe vaginal and skeletal late toxicities. Other predictive factors include dilator compliance for severe vaginal late toxicity and age for severe vaginal and skeletal late toxicities.

62 RADIOLOGY AND NUCLEAR MEDICINE↗