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At least 1,567 records · Page 87
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Salvage Reirradiaton With Stereotactic Body Radiotherapy for Locally Recurrent Head-and-Neck Tumors

Purpose: In this study, we present our results of reirradiation of locally recurrent head-and-neck cancer with image-guided, fractionated, frameless stereotactic body radiotherapy technique. Methods and Materials: From July 2007 to February 2009, 46 patients were treated using the CyberKnife (Accuray, Sunnyvale, CA) at the Department of Radiation Oncology, Hacettepe University, Ankara, Turkey. All patients had recurrent, unresectable, and previously irradiated head-and-neck cancer. The most prominent site was the nasopharynx (32.6%), and the most common histopathology was epidermoid carcinoma. The planning target volume was defined as the gross tumor volume identified on magnetic resonance imaging and computed tomography. There were 22 female and 24 male patients. Median age was 53 years (range, 19-87 years). The median tumor dose with stereotactic body radiotherapy was 30 Gy (range, 18-35 Gy) in a median of five (range, one to five) fractions. Results: Of 37 patients whose response to therapy was evaluated, 10 patients (27%) had complete tumor regression, 11 (29.8%) had partial response, and 10 (27%) had stable disease. Ultimate local disease control was achieved in 31 patients (83.8%). The overall survival was 11.93 months in median (ranged, 11.4 - 17.4 months), and the median progression free survival was 10.5 months. One-year progression-free survival and overall survival were 41% and 46%, respectively. Grade II or greater long-term complications were observed in 6 (13.3%) patients. On follow-up, 8 (17.3%) patients had carotid blow-out syndrome, and 7 (15.2%) patients died of bleeding from carotid arteries. We discovered that this fatal syndrome occurred only in patients with tumor surrounding carotid arteries and carotid arteries receiving all prescribed dose. Conclusions: Stereotactic body radiotherapy is an appealing treatment option for patients with recurrent head-and-neck cancer previously treated with radiation to high doses. Good local control with considerable 1-year survival is achieved with a relatively high rate of morbidity and related mortality.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Local Setup Reproducibility of the Spinal Column When Using Intensity-Modulated Radiation Therapy for Craniospinal Irradiation With Patient in Supine Position

Purpose: To evaluate local positioning errors of the lumbar spine during fractionated intensity-modulated radiotherapy of patients treated with craniospinal irradiation and to assess the impact of rotational error correction on these uncertainties for one patient setup correction strategy. Methods and Materials: 8 patients (6 adults, 2 children) treated with helical tomotherapy for craniospinal irradiation were retrospectively chosen for this analysis. Patients were immobilized with a deep-drawn Aquaplast head mask. Additionally to daily megavoltage control computed tomography scans of the skull, once-a-week positioning of the lumbar spine was assessed. Therefore, patient setup was corrected by a target point correction, derived from a registration of the patient's skull. The residual positioning variations of the lumbar spine were evaluated applying a rigid-registration algorithm. The impact of different rotational error corrections was simulated. Results: After target point correction, residual local positioning errors of the lumbar spine varied considerably. Craniocaudal axis rotational error correction did not improve or deteriorate these translational errors, whereas simulation of a rotational error correction of the right-left and anterior-posterior axis increased these errors by a factor of 2 to 3. Conclusion: The patient fixation used allows for deformations between the patient's skull and spine. Therefore, for the setup correction strategy evaluated in this study, generous margins for the lumbar spinal target volume are needed to prevent a local geographic miss. With any applied correction strategy, it needs to be evaluated whether or not a rotational error correction is beneficial.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Combining Carbon Ion Radiotherapy and Local Injection of {alpha}-Galactosylceramide-Pulsed Dendritic Cells Inhibits Lung Metastases in an In Vivo Murine Model

Purpose: Our previous report indicated that carbon ion beam irradiation upregulated membrane-associated immunogenic molecules, underlining the potential clinical application of radioimmunotherapy. The antimetastatic efficacy of local combination therapy of carbon ion radiotherapy and immunotherapy was examined by use of an in vivo murine model. Methods and Materials: Tumors of mouse squamous cell carcinoma (NR-S1) cells inoculated in the legs of C3H/HeSlc mice were locally irradiated with a single 6-Gy dose of carbon ions (290 MeV/nucleon, 6-cm spread-out Bragg peak). Thirty-six hours after irradiation, {alpha}-galactosylceramide-pulsed dendritic cells (DCs) were injected into the leg tumor. We investigated the effects on distant lung metastases by counting the numbers of lung tumor colonies, making pathologic observations, and assessing immunohistochemistry. Results: The mice with no treatment (control) presented with 168 {+-} 53.8 metastatic nodules in the lungs, whereas the mice that received the combination therapy of carbon ion irradiation and DCs presented with 2.6 {+-} 1.9 (P = 0.009) at 2 weeks after irradiation. Immunohistochemistry showed that intracellular adhesion molecule 1, which activates DCs, increased from 6 h to 36 h after irradiation in the local tumors of the carbon ion-irradiated group. The expression of S100A8 in lung tissue, a marker of the lung pre-metastatic phase, was decreased only in the group with a combination of carbon ions and DCs. Conclusions: The combination of carbon ion radiotherapy with the injection of {alpha}-galactosylceramide-pulsed DCs into the primary tumor effectively inhibited distant lung metastases.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Relative Biological Effectiveness of Carbon Ions for Local Tumor Control of a Radioresistant Prostate Carcinoma in the Rat

Purpose: To study the relative biological effectiveness (RBE) of carbon ion beams relative to X-rays for local tumor control in a syngeneic rat prostate tumor (Dunning subline R3327-AT1). Methods and Materials: A total of 198 animals with tumors in the distal thigh were treated with increasing single and split doses of either {sup 12}C ions or photons using a 20-mm spread-out Bragg peak. Endpoints of the study were local control (no tumor recurrence within 300 days) and volumetric changes after irradiation. The resulting values for D{sub 50} (dose at 50% tumor control probability) were used to determine RBE values. Results: The D{sub 50} values for single doses were 32.9 {+-} 0.9 Gy for {sup 12}C ions and 75.7 {+-} 1.6 Gy for photons. The respective values for split doses were 38.0 {+-} 2.3 Gy and 90.6 {+-} 2.3 Gy. The corresponding RBE values were 2.30 {+-} 0.08 for single and 2.38 {+-} 0.16 for split doses. The most prominent side effects were dry and moist desquamation of the skin, which disappeared within weeks. Conclusion: The study confirmed the effectiveness of carbon ion therapy for severely radioresistant tumors. For 1- and 2-fraction photon and {sup 12}C ion radiation, we have established individual D{sub 50} values for local tumor control as well as related RBE values.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Boron Neutron Capture Therapy in the Treatment of Locally Recurred Head-and-Neck Cancer: Final Analysis of a Phase I/II Trial

Purpose: To investigate the efficacy and safety of boron neutron capture therapy (BNCT) in the treatment of inoperable head-and-neck cancers that recur locally after conventional photon radiation therapy. Methods and Materials: In this prospective, single-center Phase I/II study, 30 patients with inoperable, locally recurred head-and-neck cancer (29 carcinomas and 1 sarcoma) were treated with BNCT. Prior treatments consisted of surgery and conventionally fractionated photon irradiation to a cumulative dose of 50 to 98 Gy administered with or without concomitant chemotherapy. Tumor responses were assessed by use of the RECIST (Response Evaluation Criteria in Solid Tumors) and adverse effects by use of the National Cancer Institute common terminology criteria version 3.0. Intravenously administered L-boronophenylalanine-fructose (400 mg/kg) was administered as the boron carrier. Each patient was scheduled to be treated twice with BNCT. Results: Twenty-six patients received BNCT twice; four were treated once. Of the 29 evaluable patients, 22 (76%) responded to BNCT, 6 (21%) had tumor growth stabilization for 5.1 and 20.3 months, and 1 (3%) progressed. The median progression-free survival time was 7.5 months (95% confidence interval, 5.4-9.6 months). Two-year progression-free survival and overall survival were 20% and 30%, respectively, and 27% of the patients survived for 2 years without locoregional recurrence. The most common acute Grade 3 adverse effects were mucositis (54% of patients), oral pain (54%), and fatigue (32%). Three patients were diagnosed with osteoradionecrosis (each Grade 3) and one patient with soft-tissue necrosis (Grade 4). Late Grade 3 xerostomia was present in 3 of the 15 evaluable patients (20%). Conclusions: Most patients who have inoperable, locally advanced head-and-neck carcinoma that has recurred at a previously irradiated site respond to boronophenylalanine-mediated BNCT, but cancer recurrence after BNCT remains frequent. Toxicity was acceptable. Further research on novel modifications of the method is warranted.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

High-Dose-Rate Monotherapy: Safe and Effective Brachytherapy for Patients With Localized Prostate Cancer

Purpose: High-dose-rate (HDR) brachytherapy used as the only treatment (monotherapy) for early prostate cancer is consistent with current concepts in prostate radiobiology, and the dose is reliably delivered in a prospectively defined anatomic distribution that meets all the requirements for safe and effective therapy. We report the disease control and toxicity of HDR monotherapy from California Endocurietherapy (CET) and William Beaumont Hospital (WBH) in low- and intermediate-risk prostate cancer patients. Methods and Materials: There were 298 patients with localized prostate cancer treated with HDR monotherapy between 1996 and 2005. Two biologically equivalent hypofractionation protocols were used. At CET the dose was 42 Gy in six fractions (two implantations 1 week apart) delivered to a computed tomography-defined planning treatment volume. At WBH the dose was 38 Gy in four fractions (one implantation) based on intraoperative transrectal ultrasound real-time treatment planning. The bladder, urethral, and rectal dose constraints were similar. Toxicity was scored with the National Cancer Institute Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 5.2 years. The median age of the patients was 63 years, and the median value of the pretreatment prostate-specific antigen was 6.0 ng/mL. The 8-year results were 99% local control, 97% biochemical control (nadir +2), 99% distant metastasis-free survival, 99% cause-specific survival, and 95% overall survival. Toxicity was scored per event, meaning that an individual patient with more than one symptom was represented repeatedly in the morbidity data table. Genitourinary toxicity consisted of 10% transient Grade 2 urinary frequency or urgency and 3% Grade 3 episode of urinary retention. Gastrointestinal toxicity was <1%. Conclusions: High disease control rates and low morbidity demonstrate that HDR monotherapy is safe and effective for patients with localized prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Early-Stage Young Breast Cancer Patients: Impact of Local Treatment on Survival

Purpose: In young women, breast-conserving therapy (BCT), i.e., lumpectomy followed by radiotherapy, has been associated with an increased risk of local recurrence. Still, there is insufficient evidence that BCT impairs survival. The aim of our study was to compare the effect of BCT with mastectomy on overall survival (OS) in young women with early-stage breast cancer. Methods and Materials: From two Dutch regional population-based cancer registries (covering 6.2 million inhabitants) 1,453 women <40 years with pathologically T1N0-1M0 breast cancer were selected. Cox regression survival analysis was used to study the effect of local treatment (BCT vs. mastectomy) stratified for nodal stage on survival and corrected for tumor size, age, period of diagnosis, and use of adjuvant systemic therapy. Results: With a median follow-up of 9.6 years, 10-year OS was 83% after BCT and 78% after mastectomy, respectively (unadjusted hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.09-1.72). In N0-patients, 10-year OS was 84% after BCT and 81% after mastectomy and local treatment was not associated with differences in OS (HR 1.19; 95% CI, 0.89-1.58; p = 0.25). Within the N1-patient group, OS was better after BCT compared with mastectomy, 79% vs. 71% at 10 years (HR 1.91; 95% CI, 1.28-2.84; p = 0.001) and in patients treated with adjuvant hormonal therapy (HR 0.34; 95% CI, 0.18-0.66; p = 0.001). Conclusions: In this large population-based cohort of early-stage young breast cancer patients, 10-year OS was not impaired after BCT compared with mastectomy. Patients with 1 to 3 positive lymph nodes had better prognosis after BCT than after mastectomy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Phase II Study Evaluating the Addition of Cetuximab to the Concurrent Delivery of Weekly Carboplatin, Paclitaxel, and Daily Radiotherapy for Patients With Locally Advanced Squamous Cell Carcinomas of the Head and Neck

Purpose: To report the mature data of a prospective Phase II trial designed to evaluate the efficacy of an epidermal growth factor receptor inhibitor cetuximab (CTX) added to the concurrent therapy of weekly paclitaxel/carboplatin (PC) and daily radiation therapy (RT). Methods and Materials: From 2005 to 2009, a total of 43 patients were enrolled in the study. The median follow-up was 31 months (range, 9-59 months). All patients had Stage III/IV disease at presentation, and 67% had oropharyngeal primaries. The weekly IV dose schedules were CTX 250 mg/m{sup 2} (400 mg/m{sup 2} IV loading dose 1 week before RT), paclitaxel 40 mg/m{sup 2}, and carboplatin AUC 2. RT was given at 1.8 Gy per day to 70.2 Gy. Intensity-modulated RTwas used in 70% of cases. Results: All patients completed the planned RT dose, 74% without any treatment breaks. The planned CTX and PC cycles were completed in 70% (91% with at least seven of planned nine cycles) and 56% (93% with at least seven of planned eight cycles) of patients, respectively. Toxicity included Grade 3 mucositis (79%), rash (9%), leucopenia (19%), neutropenia (19%), and RT dermatitis (16%). The complete response (CR) rate at the completion of therapy was 84%. The estimated 3-year local regional control rate was 72%. Six patients with an initial CR subsequently experienced a local recurrence, 10 patients experienced distant progression. The median overall survival and disease-free survivals have not been reached. The 3-year actuarial overall survival and disease-free survival were 59% and 58%, respectively. Conclusions: The addition of CTX to weekly PC and daily RT was well tolerated and resulted in encouraging local control and survival rates.

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DOE OSTI2011

Pretreatment Carbohydrate Antigen 19-9 Level Indicates Tumor Response, Early Distant Metastasis, Overall Survival, and Therapeutic Selection in Localized and Unresectable Pancreatic Cancer

Purpose: The use of chemoradiotherapy (CRT) for localized and unresectable pancreatic cancer has been disputed because of high probability of distant metastasis. Thus, we analyzed the effect of clinical parameters on tumor response, early distant metastasis within 3 months (DM{sup 3m}), and overall survival to identify an indicator for selecting patients who would benefit from CRT. Methods and Materials: This study retrospectively analyzed the data from 84 patients with localized and unresectable pancreatic cancer who underwent CRT between August 2002 and October 2009. Sex, age, tumor size, histological differentiation, N classification, pre- and post-treatment carbohydrate antigen (CA) 19-9 level, and CA 19-9 percent decrease were analyzed to identify risk factors associated with tumor response, DM{sup 3m}, and overall survival. Results: For all 84 patients, the median survival time was 12.5 months (range, 2-31.9 months), objective response (complete response or partial response) to CRT was observed in 28 patients (33.3%), and DM{sup 3m} occurred in 24 patients (28.6%). Multivariate analysis showed that pretreatment CA 19-9 level ({<=}400 vs. >400 U/ml) was significantly associated with tumor response (45.1% vs. 15.2%), DM{sup 3m} (19.6% vs. 42.4%), and median overall survival time (15.1 vs. 9.7 months) (p < 0.05 for all three parameters). Conclusion: For patients with localized and unresectable pancreatic cancer, pretreatment CA 19-9 level could be helpful in predicting tumor response, DM{sup 3m}, and overall survival and identifying patients who will benefit from CRT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and organs at risk are in a comparable range. First clinical results indicate excellent LC. Further prospective multicenter studies are needed to establish this method and to confirm these results.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Localized Orbital Mucosa-Associated Lymphoma Tissue Lymphoma Managed With Primary Radiation Therapy: Efficacy and Toxicity

Purpose: To evaluate the clinical outcomes and late effects of radiation therapy (RT) in localized primary orbital mucosa-associated lymphoma tissue (MALT) lymphoma (POML). Methods and Materials: From 1989 to 2007, 89 patients with Stage IE POML received RT. The median age was 56 years old. Sites involved conjunctiva (59 patients [66%]), lacrimal gland (20 patients [23%]), and soft tissue (10 patients [11%]). Megavoltage beam(s) was used in 91%, electrons in 7%, and orthovoltage in 2% of cases. The dose given was 25 Gy in 97% and 30 Gy in 3% of patients. Lens shielding was possible in 57% of patients. Results: The median follow-up was 5.9 years. Complete response or unconfirmed complete response was seen in 88 patients (99%). Relapse occurred in 22 patients (25%). First relapse sites were local (2 patients [9%]), in the contralateral orbit (5 patients [23%]), and distant (15 patients [68%]). The 7-year overall survival (OS), cause-specific survival (CSS), relapse-free survival (RFS), and local control (LC) rates were 91%, 96%, 64%, and 97%, respectively. Radiation-related late sequelae were documented in 40 patients (45%). Cataracts were observed in 22 patients (Grade 1 in 2 patients; Grade 3 in 20 patients). The incidence of Grade 3 cataract at 7 years was 25%. Other late sequelae (n = 28) were dry eye(s) (22 patients [Grade 1 in 14 patients; Grade 2 in 2 patients; Grade 3 in 2 patients; n/s in 4 patients), keratitis (3 patients), macular degeneration/cystoid edema (2 patients), and vitreous detachment (1 patient). Five patients developed Grade 3 noncataract late effects. Lens shielding reduced the incidence of Grade 3 cataract and all Grade {>=}2 late sequelae. Seventeen patients (16 with cataracts) underwent surgery; 23 patients were treated conservatively. The outcome for managing late effects was generally successful, with 30 patients completely improved, and 9 patients with persisting late sequelae (10%). Conclusions: POML responds favorably to moderate doses of RT but results in significant late morbidity. The majority of late effects were successfully managed. Lens shielding reduced the risk of cataracts and other late sequelae.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Local Control With Reduced-Dose Radiotherapy for Low-Risk Rhabdomyosarcoma: A Report From the Children's Oncology Group D9602 Study

Purpose: To analyze the effect of reduced-dose radiotherapy on local control in children with low-risk rhabdomyosarcoma (RMS) treated in the Children's Oncology Group D9602 study. Methods and Materials: Patients with low-risk RMS were nonrandomly assigned to receive radiotherapy doses dependent on the completeness of surgical resection of the primary tumor (clinical group) and the presence of involved regional lymph nodes. After resection, most patients with microscopic residual and uninvolved nodes received 36 Gy, those with involved nodes received 41.4 to 50.4 Gy, and those with orbital primary tumors received 45 Gy. All patients received vincristine and dactinomycin, with cyclophosphamide added for patient subsets with a higher risk of relapse in Intergroup Rhabdomyosarcoma Study Group III and IV studies. Results: Three hundred forty-two patients were eligible for analysis; 172 received radiotherapy as part of their treatment. The cumulative incidence of local/regional failure was 15% in patients with microscopic involved margins when cyclophosphamide was not part of the treatment regimen and 0% when cyclophosphamide was included. The cumulative incidence of local/regional failure was 14% in patients with orbital tumors. Protocol-specified omission of radiotherapy in girls with Group IIA vaginal tumors (n = 5) resulted in three failures for this group. Conclusions: In comparison with Intergroup Rhabdomyosarcoma Study Group III and IV results, reduced-dose radiotherapy does not compromise local control for patients with microscopic tumor after surgical resection or with orbital primary tumors when cyclophosphamide is added to the treatment program. Girls with unresected nonbladder genitourinary tumors require radiotherapy for postsurgical residual tumor for optimal local control to be achieved.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Feasibility of Electromagnetic Transponder Use to Monitor Inter- and Intrafractional Motion in Locally Advanced Pancreatic Cancer Patients

Purpose: The primary objective of this study was to determine the feasibility of electromagnetic transponder implantation in patients with locally advanced unresectable pancreatic cancer. Secondarily, the use of transponders to monitor inter- and intrafractional motion, and the efficacy of breath holding for limiting target motion, were examined. Methods and Materials: During routine screening laparoscopy, 5 patients without metastatic disease were implanted with transponders peri-tumorally. The Calypso System's localization and tracking modes were used to monitor inter- and intrafractional motion, respectively. Intrafractional motion, with and without breath holding, was also examined using Calypso tracking mode. Results: Transponder implantation was well tolerated in all patients, with minimal migration, aside from 1 patient who expulsed a single transponder. Interfractional motion based on mean shifts from setup using tattoos/orthogonal imaging to transponder based localization from 164 treatments was significant in all dimensions. Mean shift (in millimeters), followed by the standard deviation and p value, were as follows: X-axis: 4.5 mm (1.0, p = 0.01); Y axis: 6.4 mm (1.9, p = 0.03); and Z-axis 3.9 mm (0.6, p = 0.002). Mean intrafractional motion was also found to be significant in all directions: superior, 7.2 mm (0.9, p = 0.01); inferior, 11.9 mm (0.9, p < 0.01); anterior: 4.9 mm (0.5, p = 0.01); posterior, 2.9 mm (0.5, p = 0.02); left, 2.2 mm (0.4, p = 0.02); and right, 3.1 mm (0.6, p = 0.04). Breath holding during treatment significantly decreased tumor motion in all directions. Conclusions: Electromagnetic transponder implantation appears to be safe and effective for monitoring inter- and intrafractional motion. Based on these results a larger clinical trial is underway.

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DOE OSTI2012

Intensity-Modulated Radiation Therapy With Concurrent Chemotherapy as Preoperative Treatment for Localized Gastric Adenocarcinoma

Purpose: The goal of this study was to evaluate dosimetric parameters, acute toxicity, pathologic response, and local control in patients treated with preoperative intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy for localized gastric adenocarcinoma. Methods: Between November 2007 and April 2010, 25 patients with localized gastric adenocarcinoma were treated with induction chemotherapy, followed by preoperative IMRT and concurrent chemotherapy and, finally, surgical resection. The median radiation therapy dose was 45 Gy. Concurrent chemotherapy was 5-fluorouracil and oxaliplatin in 18 patients, capecitabine in 3, and other regimens in 4. Subsequently, resection was performed with total gastrectomy in 13 patients, subtotal gastrectomy in 7, and other surgeries in 5. Results: Target coverage, expressed as the ratio of the minimum dose received by 99% of the planning target volume to the prescribed dose, was a median of 0.97 (range, 0.92-1.01). The median V{sub 30} (percentage of volume receiving at least 30 Gy) for the liver was 26%; the median V{sub 20} (percentage of volume receiving at least 20 Gy) for the right and left kidneys was 14% and 24%, respectively; and the median V{sub 40} (percentage of volume receiving at least 40 Gy) for the heart was 18%. Grade 3 acute toxicity developed in 14 patients (56%), including dehydration in 10, nausea in 8, and anorexia in 5. Grade 4 acute toxicity did not develop in any patient. There were no significant differences in the rates of acute toxicity, hospitalization, or feeding tube use in comparison to those in a group of 50 patients treated with preoperative three-dimensional conformal radiation therapy with concurrent chemotherapy. R0 resection was obtained in 20 patients (80%), and pathologic complete response occurred in 5 (20%). Conclusions: Preoperative IMRT for gastric adenocarcinoma was well tolerated, accomplished excellent target coverage and normal structure sparing, and led to appropriate pathologic outcomes.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

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↗
DOE OSTI2012

High-dose Helical Tomotherapy With Concurrent Full-dose Chemotherapy for Locally Advanced Pancreatic Cancer

Purpose: To improve poor therapeutic outcome of current practice of chemoradiotherapy (CRT), high-dose helical tomotherapy (HT) with concurrent full-dose chemotherapy has been performed on patients with locally advanced pancreatic cancer (LAPC), and the results were analyzed. Methods and Materials: We retrospectively reviewed 39 patients with LAPC treated with radiotherapy using HT (median, 58.4 Gy; range, 50.8-59.9 Gy) and concomitant chemotherapy between 2006 and 2009. Radiotherapy was directed to the primary tumor with a 0.5-cm margin without prophylactic nodal coverage. Twenty-nine patients (79%) received full-dose (1000 mg/m{sup 2}) gemcitabine-based chemotherapy during HT. After completion of CRT, maintenance chemotherapy was administered to 37 patients (95%). Results: The median follow-up was 15.5 months (range, 3.4-43.9) for the entire cohort, and 22.5 months (range, 12.0-43.9) for the surviving patients. The 1- and 2-year local progression-free survival rates were 82.1% and 77.3%, respectively. Eight patients (21%) were converted to resectable status, including 1 with a pathological complete response. The median overall survival and progression-free survival were 21.2 and 14.0 months, respectively. Acute toxicities were acceptable with no gastrointestinal (GI) toxicity higher than Grade 3. Severe late GI toxicity ({>=}Grade 3) occurred in 10 patients (26%); 1 treatment-related death from GI bleeding was observed. Conclusion: High-dose helical tomotherapy with concurrent full-dose chemotherapy resulted in improved local control and long-term survival in patients with LAPC. Future studies are needed to widen the therapeutic window by minimizing late GI toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Does Local Recurrence of Prostate Cancer After Radiation Therapy Occur at the Site of Primary Tumor? Results of a Longitudinal MRI and MRSI Study

Purpose: To determine if local recurrence of prostate cancer after radiation therapy occurs at the same site as the primary tumor before treatment, using longitudinal magnetic resonance (MR) imaging and MR spectroscopic imaging to assess dominant tumor location. Methods and Materials: This retrospective study was HIPAA compliant and approved by our Committee on Human Research. We identified all patients in our institutional prostate cancer database (1996 onward) who underwent endorectal MR imaging and MR spectroscopic imaging before radiotherapy for biopsy-proven prostate cancer and again at least 2 years after radiotherapy (n = 124). Two radiologists recorded the presence, location, and size of unequivocal dominant tumor on pre- and postradiotherapy scans. Recurrent tumor was considered to be at the same location as the baseline tumor if at least 50% of the tumor location overlapped. Clinical and biopsy data were collected from all patients. Results: Nine patients had unequivocal dominant tumor on both pre- and postradiotherapy imaging, with mean pre- and postradiotherapy dominant tumor diameters of 1.8 cm (range, 1-2.2) and 1.9 cm (range, 1.4-2.6), respectively. The median follow-up interval was 7.3 years (range, 2.7-10.8). Dominant recurrent tumor was at the same location as dominant baseline tumor in 8 of 9 patients (89%). Conclusions: Local recurrence of prostate cancer after radiation usually occurs at the same site as the dominant primary tumor at baseline, suggesting supplementary focal therapy aimed at enhancing local tumor control would be a rational addition to management.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Current Dosing Paradigm for Stereotactic Radiosurgery Alone After Surgical Resection of Brain Metastases Needs to Be Optimized for Improved Local Control

Purpose: To describe the use of radiosurgery (RS) alone to the resection cavity after resection of brain metastases as an alternative to adjuvant whole-brain radiotherapy (WBRT). Methods and Materials: Sixty-two patients with 64 cavities were treated with linear accelerator-based RS alone to the resection cavity after surgical removal of brain metastases between March 2007 and August 2010. Fifty-two patients (81%) had a gross total resection. Median cavity volume was 8.5 cm{sup 3}. Forty-four patients (71%) had a single metastasis. Median marginal and maximum doses were 18 Gy and 20.4 Gy, respectively. Sixty-one cavities (95%) had gross tumor volume to planning target volume expansion of {>=}1 mm. Results: Six-month and 1-year actuarial local recurrence rates were 14% and 22%, respectively, with a median follow-up period of 9.7 months. Six-month and 1-year actuarial distant brain recurrence, total intracranial recurrence, and freedom from WBRT rates were 31% and 51%, 41% and 63%, and 91% and 74%, respectively. The symptomatic cavity radiation necrosis rate was 8%, with 2 patients (3%) undergoing surgery. Of the 11 local failures, 8 were in-field, 1 was marginal, and 2 were both (defined as in-field if {>=}90% of recurrence within the prescription isodose and marginal if {>=}90% outside of the prescription isodose). Conclusions: The high rate of in-field cavity failure suggests that geographic misses with highly conformal RS are not a major contributor to local recurrence. The current dosing regimen derived from Radiation Therapy Oncology Group protocol 90-05 should be optimized in this patient population before any direct comparison with WBRT.

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