Standard Radiation Dose Research Articles

High-dose versus standard-dose radiation therapy for cervical esophageal cancer: Retrospective single-institution study.

To evaluate the role of definitive radiotherapy using higher-than-standard-dose radiation of 50 Gy for carcinoma of the cervical esophagus (CCE). We reviewed 79 patients with stage I-III CCE, treated between 2000 and 2012. Patients received 5-fluorouracil/cisplatin-based chemotherapy concurrently and were divided into high-dose (≥59.4 Gy, n = 44) and standard-dose (<59.4 Gy, n = 35) groups. The median follow-up was 35 months for surviving patients. The high-dose group had significantly better 3-year local (90.0% vs 60.4%, P = .001) and locoregional (70.4% vs 45.3%, P = .04) control. Progression-free (45.4% vs 37.5%, P = .32) and overall (58.4% vs 49.1%, P = .69) survival rates were not different. High-dose radiation was an independent prognostic factor for locoregional control (P = .04). No differences in late toxicities (esophageal stenosis or tracheoesophageal fistula) were observed. High-dose radiation for CCE improves local and locoregional control, without increasing severe toxicities.

Detection of Colorectal Hepatic Metastases Is Superior at Standard Radiation Dose CT versus Reduced Dose CT.

Purpose To evaluate colorectal cancer hepatic metastasis detection and characterization between reduced radiation dose (RD) and standard dose (SD) contrast material-enhanced CT of the abdomen and to qualitatively compare between filtered back projection (FBP) and iterative reconstruction algorithms. Materials and Methods In this prospective study (from May 2017 through November 2017), 52 adults with biopsy-proven colorectal cancer and suspected hepatic metastases at baseline CT underwent two portal venous phase CT scans: SD and RD in the same breath hold. Three radiologists, blinded to examination details, performed detection and characterization of 2-15-mm lesions on the SD FBP and RD adaptive statistical iterative reconstruction (ASIR)-V 60% series images. Readers assessed overall image quality and lesions between SD FBP and seven different iterative reconstructions. Two nonblinded consensus reviewers established the reference standard using the picture archiving and communication system lesion marks of each reader, multiple comparison examinations, and clinical data. Results RD CT resulted in a mean dose reduction of 54% compared with SD. Of the 260 lesions (233 metastatic, 27 benign), 212 (82%; 95% confidence interval [CI]: 76%, 86%) were detected with RD CT, whereas 252 (97%; 95% CI: 94%, 99%) were detected with SD (P < .001); per-lesion sensitivity was 79% (95% CI: 74%, 84%) and 94% (95% CI: 90%, 96%) (P < .001), respectively. Mean qualitative scores ranked SD images as higher quality than RD series images, and ASIR-V ranked higher than ASIR and Veo 3.0. Conclusion CT evaluation of colorectal liver metastases is compromised with modest radiation dose reduction, and the use of iterative reconstructions could not maintain observer performance. © RSNA, 2018.

Total Skin Electron Beam Therapy for Mycosis Fungoides Revisited With Adjuvant Systemic Therapy

BackgroundAlthough standard-dose total skin electron beam therapy (TSEBT) has been thought to provide the greatest clinical benefit for mycosis fungoides, recent studies have shown that low-dose TSEBT may also provide high rates of disease control. Materials and MethodsA retrospective chart review was conducted for patients receiving TSEBT for mycosis fungoides at a single institution from 2009 to 2017. Patients were evaluated for overall survival, progression-free survival, and duration of clinical benefit. Partial response was defined as any documented clinical regression of lesions, whereas complete response was defined as complete resolution of lesions. ResultsTwenty patients were included in the study. Twelve patients received low-dose radiation (≤ 12 Gy), and 8 received standard-dose radiation (> 12 Gy). Response rate was 100% in both groups. The rate of complete response was 38% in the standard-dose group and 25% in the low-dose group. There was no difference in overall survival between the 2 groups (P = .84). There was also no difference in median progression-free survival (P = .95) or duration of clinical benefit (P = .95) between the 2 groups. Of low-dose patients, 33% received immediate systemic therapy, whereas 92% received adjuvant topical or systemic therapy. In the standard-dose group, only 25% received systemic adjuvant therapy, and 63% received adjuvant topical or systemic therapy. ConclusionLow-dose TSEBT with adjuvant therapy results in adequate symptom palliation, comparable to standard-dose TSEBT. Low-dose TSEBT should be considered a standard treatment option in this population.

Induction Radiation Therapy for Esophageal Cancer: Does Dose Affect Outcomes?

Wide variation is seen in the dosage of preoperative induction radiation therapy for esophageal cancer. We investigated associations between outcomes after esophagectomy and dosage of induction radiation therapy. Patients undergoing induction radiation therapy (30 to 70 Gy), followed by esophagectomy, were identified from the National Cancer Database and classified as low (<40 Gy), standard (40 to 50.4 Gy), and high dose (>50.4 Gy). Perioperative outcomes and overall survival were compared. Subgroup analysis compared two common dosages: 45 Gy and 50.4 Gy. From 2004 to 2014, 10,738 patients (84.7%) received standard-dose radiation, increasing from 69.7% in 2004 to 93.6% in 2014 (p < 0.001), 1,329 (10.5%) received low-dose radiation, and 608 (4.8%) received high-dose radiation. Higher rates of pathologic complete response (pCR; low: 11.7%, standard: 16.2%, high: 21.0%; p < 0.001) and downstaging (low: 52.0%, standard: 56.4%, high: 63.1%, p= 0.001) were observed as the dosage increased. On multivariable analysis, compared with standard-dose, high-dose radiation was associated with higher 30-day mortality (odds ratio [OR], 2.11; p < 0.001) without a higher likelihood of downstaging or pCR. Low-dose radiation was associated with lower likelihood of downstaging (OR, 0.85; p= 0.04) and pCR (OR, 0.67; p<0.001) without lowering the risk of 30-day mortality. The dose of 50.4 Gy was associated with higher likelihood of pCR (OR, 1.12; p= 0.04), without affecting 30-day mortality, compared with 45 Gy. High-dose induction radiation (>50.4 Gy) is associated with increased perioperative death after esophagectomy, without a significant improvement in tumor response. Low-dose radiation (<30 Gy) is associated with worse tumor response without a lower risk of perioperative death. Within standard dosages, 50.4 Gy is associated with higher likelihood of pCR without adversely affecting perioperative mortality compared with 45 Gy.

Chest CT Scan at Radiation Dose of a Posteroanterior and Lateral Chest Radiograph Series: A Proof of Principle in Lymphangioleiomyomatosis

Given the rising utilization of medical imaging and the risks of radiation, there is increased interest in reducing radiation exposure. The objective of this study was to evaluate, as a proof of principle, CT scans performed at radiation doses equivalent to that of a posteroanterior and lateral chest radiograph series in the cystic lung disease lymphangioleiomyomatosis (LAM). From November 2016 to May 2018, 105 consecutive subjects with LAM received chest CT scans at standard and ultra-low radiation doses. Standard and ultra-low-dose images, respectively, were reconstructed with routine iterative and newer model-based iterative reconstruction. LAM severity can be quantified as cyst score (percentage of lung occupied by cysts), an ideal benchmark for validating CT scans performed at a reduced dose compared with a standard dose. Cyst scores were quantified using semi-automated software and evaluated by linear correlation and Bland-Altman analysis. Overall, ultra-low-dose CT scans represented a 96%dose reduction, with a median dose equivalent to 1 vs22 posteroanterior and lateral chest radiograph series (0.14 mSv; 5th-95th percentile, 0.10-0.20 vsstandard dose 3.4 mSv; 5th-95th percentile, 1.5-7.4; P< .0001). The mean difference in cyst scores between ultra-low- and standard-dose CT scans was 1.1%± 2.0%, with a relative difference in cyst score of 11%. Linear correlation coefficient was excellent at 0.97 (P< .0001). In LAM chest CT scan at substantial radiation reduction to doses equivalent to that of a posteroanterior and lateral chest radiograph series provides cyst score quantification similar to that of standard-dose CT scan. ClinicalTrials.gov; Nos.: NCT00001465 and NCT00001532; URL: www.clinicaltrials.gov.

720P - SCALOP-2: A multi-centre randomised trial of induction chemotherapy followed by capecitabine +/-nelfinavir with high or standard dose radiotherapy for locally advanced pancreatic cancer (LAPC): Results of stage 1 - the non-randomised dose-finding component

720P - SCALOP-2: A multi-centre randomised trial of induction chemotherapy followed by capecitabine +/-nelfinavir with high or standard dose radiotherapy for locally advanced pancreatic cancer (LAPC): Results of stage 1 - the non-randomised dose-finding component

Definitive radiotherapy dose escalation with chemotherapy for treating non-metastatic oesophageal cancer

The locoregional failure rate remains high after concurrent chemoradiotherapy with standard-dose radiotherapy (RT, 50–50.4 Gy) for oesophageal cancer (EC). This retrospective study evaluated whether RT dose escalation was effective among 115 consecutive patients with non-metastatic EC (July 2003 to November 2016). Forty-four patients received an RT dose of <66 Gy and 71 patients received ≥66 Gy, with most patients receiving concurrent cisplatin plus fluorouracil. The median follow-up was 12 months for all patients (52 months for 18 surviving patients). The ≥66 Gy group had significantly higher 3-year rates of overall survival (17.9% vs. 32.1%, p = 0.026) and local progression-free survival (46.1% vs. 72.1%, p = 0.005), but not disease progression-free survival (11.4% vs. 21.9%, p = 0.059) and distant metastasis-free survival (49% vs. 52.6%, p = 0.852). The ≥66 Gy group also had significantly better 5-year overall survival compared with 41.4–65.9 Gy. The only significant difference in treatment-related toxicities involved acute dermatitis (7% vs. 28%, p = 0.009). Inferior overall survival was associated with poor performance status, clinical N2–3 stage and not receiving maintenance chemotherapy. In conclusion, patients with inoperable EC experienced better survival outcomes and acceptable toxicities if they received higher dose RT (≥66 Gy) rather than lower dose RT (<66 Gy).

Dose-escalated radiotherapy improved survival for esophageal cancer patients with a clinical complete response after standard-dose radiotherapy with concurrent chemotherapy.

PurposeFor esophageal cancer patients with a clinical complete response (cCR) after standard-dose radiotherapy with concurrent chemotherapy, data on the survival outcomes and recurrence patterns remain scarce. To evaluate the impact of dose escalation on overall survival for this subset of patients, we carried out the current investigation.Materials and methodsMedical records of 80 esophageal cancer patients with a cCR after standard-dose radiotherapy with concurrent chemotherapy at our center from 2010 to 2014 were allocated into the standard-dose group (50.4 Gy, observation group) or the radiation dose-escalation group (59.4 Gy, control group). In this cohort study, we compared the outcomes between the 2 groups.ResultsThere were no differences in patient characteristics between the 2 groups. The median recurrence-free survival and overall survival times for all patients were 38 and 54 months, respectively. Patients in the control group had significantly better 5-year recurrence-free survival rate (12% vs 0%, p=0.019) and 5-year overall survival rate (42.8% vs 21.0%, p=0.028) than the observation group. Additionally, local control rate was significantly higher in the control group (p=0.04), and ~60% of treatment failures were local failures even for patients achieving cCR after chemoradiotherapy. There were no significant differences in treatment-related toxicities between the groups.ConclusionThe results of the current study suggest that for esophageal cancer patients with a cCR after standard-dose radiotherapy with concurrent chemotherapy, those with dose-escalated radiotherapy showed significantly better local control, recurrence-free survival, and overall survival than patients receiving 50.4 Gy radiotherapy.

The radiation therapy options of intracranial hemangiopericytoma: An overview and update on a rare vascular mesenchymal tumor.

Hemangiopericytoma (HPC) is an extremely rare hypervascular tumor of mesenchymal lineage. It tends to recur and to develop distant metastases even many years after primary surgical resection. The management of recurrent and metastatic disease is not always so well defined. A complete surgical resection does not eliminate the high risk of local recurrences that occur in the central nervous system, often in the same surgical bed. However, treatment with adjuvant radiotherapy even in cases of complete resection remains controversial. Because of its rarity, there is no standard for treatment. We focused on radiotherapy treatment options, analyzing the literature and making a base on conduct further studies to establish the standard radiation dose to be used for locoregional control of such a complex and extremely rare disease and to help specialists to take the most appropriate therapeutic option.

(P17) Standard Versus Dose-Escalated Radiation Therapy for Management of Esophageal Cancer: A Retrospective Review

High dose radiation therapy for esophageal cancer has not been shown to improve survival or locoregional control in prior studies. This study was aimed at comparing overall survival (OS), progression-free survival (PFS), and toxicity in patients treated with standard versus dose-escalated radiation therapy for esophageal cancer. Patients treated for Stage IA-IIIC adenocarcinoma or squamous cell carcinoma of the upper, mid, and lower esophagus or gastroesophageal junction between January 2008 and July 2014 were retrospectively reviewed. Patients included those treated with definitive and neoadjuvant chemoradiation. Patients with metastatic disease at presentation, and prior radiation to the esophagus were excluded. Dose-escalation was considered a total dose over 50.4Gy. Toxicity was graded per CTCAE version 4.03. Kaplan-Meier survival analysis was completed. Descriptive statistics and Fisher’s Exact tests were used where applicable. A total of 73 patients were included in the analysis. 55 patients received standard dose radiation (median 50Gy, range 45-50.4Gy), while 18 patients received dose-escalation (median 59.7Gy, range 51-68Gy). Median time to follow-up was 22.75 months. There was no significant difference in the curves for PFS (p=.70) or OS (p=.59). Median PFS was 30.3 (95% CI 15.2-51.2mo) in the standard dose group, and 47.0 (95% CI 16.3-47.0mo) in the dose-escalated group. Median OS was 68.6mo (95% CI 21.2-69.8mo) in the standard dose group, and 48.6mo (95% CI 18.6-57.5mo) in the dose-escalated group. When comparing only patients who received definitive chemoradiation (n=22 standard, 14 dose-escalated), there was a trend towards significance for PFS (p=.051), but OS was not significantly different (p=.60). Median PFS in this case was 7.2mo (95% CI 5.2-15.2mo) in the standard group and 33.7mo (95% CI 9.9-33.7mo) in the dose-escalated group, while median OS was 14.6mo (95% CI 10.1-68.6mo) in the standard group and 32.4mo (95% CI 16.8-51.2mo) in the dose-escalated group. The rate of any gastrointestinal toxicity did not differ significantly between the two groups (96.3% standard dose vs 94.4% dose-escalated, p=1.0). The rates of any esophagitis (56.3% standard dose vs 77.8% dose-escalated, p=.16) and grade 3 esophagitis (3.6% standard dose vs 16.7% dose-escalated, p=.09) did not differ significantly between the groups. The pathologic complete response rate was 30.3% in the standard dose group, and 25% in the small group of dose-escalated patients who underwent surgery (p=1.0). In this retrospective study, results indicated no significant difference in overall or progression-free survival when comparing standard and dose-escalated radiation for esophageal cancer. There was a trend towards significance for PFS when looking only at those patients who received definitive chemoradiation. There was no significant difference in the rates of esophagitis, or gastrointestinal toxicity overall. The rate of pathologic complete response did not differ. Further research is warranted, especially in patients undergoing definitive chemoradiation, but standard dosing should remain the standard of care in the interim.

Effect of solar ultraviolet radiation exposure on serum 25(OH)D concentration: a pilot randomised controlled trial.

Sunlight generates vitamin D, but there are scant human data from randomised trials on which to base health policy advice about how much sun exposure is necessary to change 25(OH)D concentrations. The purpose of the study was to evaluate the feasibility of using solar ultraviolet (UV) radiation exposure to generate a change in 25(OH)D concentration in a randomised controlled trial (RCT). The intervention tested in this RCT was supervised exposure to one standard erythemal dose (SED; 100 J m-2) of solar UV radiation three days per week for three weeks with approximately 35% of the body surface area not covered by clothing. Thirty-six fair-skinned (skin type II and III) indoor workers from Brisbane, Australia were randomised into either the intervention group (n = 16) or the control group (n = 20); the latter did not receive any supervised sun exposure. We asked both groups to use sunscreen and to minimise time outdoors during the study period. We collected blood samples at baseline, once per week during the three week intervention period, and four weeks after the intervention finished. The cumulative UV radiation exposure over the intervention period measured using polysulphone badges was higher in the intervention group than in the control group (median 8 vs. 4 SEDs, p = 0.14). After three weeks, the mean serum 25(OH)D concentration increased from 60 to 65 nmol l-1 in the intervention group and from 55 to 57 nmol l-1 in the control group. After adjustment for baseline 25(OH)D, the mean change per week during the intervention phase was non-significantly higher in the intervention than in the control group (0.7 vs. 0.3; p = 0.35). This difference was not sustained during the follow-up period. Large field trials are needed to inform policy about how much natural sun exposure is required to raise 25(OH)D concentrations. This pilot identified key issues that need to be considered in the design of such a trial.

The effect of dose escalation for large squamous cell carcinomas of the anal canal.

Chemoradiation allows for organ preservation in patients with anal cancer, but patients with large tumors (> 5cm) have elevated rates of locoregional recurrence. With conformal radiation techniques, there is interest in dose escalation to decrease local recurrence in patients with large tumor size. The National Cancer Database (NCDB) was used to identify patients with anal cancer from 2004 to 2013 with tumors > 5cm. Adult patients who received definitive chemoradiation were included. Patients with prior resection were excluded. High dose was defined as greater than or equal to 5940cGy. Statistical analyses were performed using logistic regression, Kaplan-Meier, and Cox proportional hazards for overall survival (OS). In total, 1349 patients were analyzed with 412 (30.5%) receiving high-dose radiation therapy (RT). 5-year OS was 58 and 60% for high and standard dose RT, respectively (p = 0.9887). On univariate analysis, high-dose RT was not associated with improved OS (HR = 0.998, CI 0.805-1.239, p = 0.9887). On multivariate analysis, high-dose RT (HR = 0.948, CI 0.757-1.187, p = 0.6420) was not associated with improved OS but older age (HR = 1.535, CI 1.233-1.911, p = 0.0001), male sex (HR = 1.695, CI 1.382-2.080, p < 0.0001), comorbidities (HR = 1.389, CI 1.097-1.759, p = 0.0064), and long RT (HR = 1.299, CI 1.047-1.611, p = 0.0173) were significantly associated with decreased OS. There was no observed difference in OS for dose escalation of anal cancers > 5cm in this population-based analysis. Differences in local control and salvage therapy cannot be assessed through the NCDB. Whether dose escalation of large tumors may improve local control and colostomy-free survival remains an important question and is the subject of ongoing trials.

What Is the Benefit of Adjuvant Radiation Doses Above 60 Gy in Head and Neck Cancer Patients?

Radiation dose response data in the postoperative management of Head and Neck Squamous Cell Carcinoma (HNSCC) are limited. We compared radiation dose trends and outcomes of HNSCC treated with adjuvant radiation, with or without concurrent chemotherapy. Patients with non-metastatic HNSCC who were treated between 2004 and 2014 with primary site surgery, lymph node dissection, and adjuvant radiation with an equivalent dose in 2 Gy (EQD2) of ≥ 56.64 Gy (equivalent to 57.6 Gy in 32 fractions) and ≤ 72 Gy were identified in the National Cancer Database. Radiation doses of EQD2 < 56.64 Gy and > 72 Gy were respectively interpreted to reflect incomplete radiation courses or attempted salvage of gross recurrences prior to the initiation of radiation and were excluded. Standard dose radiation was defined as an EQD2 of ≥ 56.64 Gy and ≤ 60 Gy and high dose radiation as an EQD2 of > 60 Gy and ≤ 72 Gy. Radiation regimens employed in < 10 patients were excluded. We used multivariate logistic regression to model receipt of high dose radiation, and multivariate cox proportional hazards regression to assess the association between dose and survival within the cohorts of interest. We identified 19,492 patients managed with adjuvant radiation. Oral cavity, oropharynx, larynx, hypopharynx, and nasal cavity comprised 43%, 38%, 14%, 3%, and 2% of the primary sites, respectively. HPV status was available for 3496 (47%) oropharynx patients. High dose radiation was prescribed to 52% of patients. Factors that predicted for increased use of high dose radiation included extra-nodal extension (ENE), positive or unknown surgical margins, fewer examined lymph nodes, increased number of positive lymph nodes, increased N staging, concurrent chemotherapy, and non-tonsil primary site. When adjusted for known poor prognostic factors to control for high dose being prescribed to a worse prognosis cohort, there was a decrease in overall survival (OS) in the high dose group (HR = 1.10; 95% CI 1.03-1.17). High dose radiation was independently associated with worse OS in HPV positive oropharynx patients when controlling for poor prognostic factors (HR = 2.03; 95% CI 1.22-3.37). In non-oropharynx primary or HPV negative oropharynx primary that had positive margins, ≥ 5 positive lymph nodes, and/or ENE, high dose radiation was not associated with improvement in OS (HR 1.03; 95% CI 0.94-1.13). Factors known to predict for poor outcomes are associated with higher rates of high dose adjuvant radiation in this large national cohort. However, when controlling for poor prognostic factors, there was no survival benefit from postoperative dose escalation above EQD2 of 60 Gy.

3:27 PM Abstract No. 124 MIRD-based activity calculation may improve outcomes over body surface area for resin microsphere radioembolization of metastatic colorectal carcinoma

To compare clinical outcomes of resin microsphere Y90 radioembolization (RE) using standard Body Surface Area (BSA) activity prescription versus Medical Internal Radiation Dose (MIRD) prescription for treatment of metastatic colorectal carcinoma (mCRC). Patients with mCRC treated with resin microsphere RE between 2004-2015 were retrospectively reviewed. Standard BSA activity prescription was used from 2004-2012. Starting 2013, MIRD-based activity prescription was substituted, with treated region absorbed doses ranging from 40-65 Gy depending on performance status, liver function, volume of treatment, hypervascularity, and previous treatment history. Radiographic, biochemical, and clinical outcomes were compared. 109 patients (61 M/48 F), median age 60, underwent 118 treatment sessions (96 BSA/ 22 MIRD). 77 underwent whole liver treatment, either single session (72) or staged (5). In the MIRD group, 7 (36%) patients had activity prescribed >10% greater and 3 (15%) had activity >10% lower than what would have been prescribed by BSA. Disease control rate (DCR) by RECIST 1.1 showed a trend favoring MIRD over BSA (71% vs 53%, p = 0.1). MIRD patients showed more mild laboratory toxicity changes at 90 days (CTCAE 4.03, ≤ 2 grade change from baseline) (28% vs 18%, p = NS), but slightly less moderate and severe toxicity changes than BSA patients (>2 grade change from baseline) (0% vs 3%, p = NS). Median changes in serum carcinoembryonic antigen (CEA) in MIRD and BSA groups at 8 weeks after RE were -16% and -8%, (p = NS). Differences in median hepatic progression-free survival did not reach statistical significance (MIRD 150 days vs BSA 90 days, p = 0.5). Likewise, the study was underpowered to show a difference in overall survival (210 vs 321 days, p = 0.4). Using MIRD rather than BSA for activity calculation for resin microsphere Y90 RE of mCRC resulted in increase in dose in 36% and decrease in 15% of patients. Although additional statistical power is needed, consideration of the target liver volume rather than body surface area is a promising approach to increase the efficacy and decrease the toxicity of resin microsphere RE.

Very low-dose versus standard dose radiation therapy for indolent primary cutaneous B-cell lymphomas: A retrospective study

Very low-dose versus standard dose radiation therapy for indolent primary cutaneous B-cell lymphomas: A retrospective study

Standard-dose versus high-dose radiotherapy with concurrent chemotherapy in esophageal cancer: A prospective randomized study.

Objective:The objective of this study is comparision of local and distant control rates with high-dose versus standard-dose radiotherapy along with concurrent chemotherapy in esophageal cancer – a prospective randomized study.Materials and Methods:Histologically proven Stage I–III patients with carcinoma esophagus were randomized into two groups. One group has been treated with standard-dose radiotherapy, i.e., a total dose of 50.4 Gy (1.8 Gy/day, 28#, 5 days/week). The other group (study arm) has received high-dose radiotherapy, i.e. a total dose of 64.8 Gy (1.8 Gy/day, 36#, 5 days/week). Both groups have received 2 cycles of 3 weekly concurrent chemotherapy (cisplatin 75 mg/m[2] on day 1 and 5-fluorouracil 750 mg/m[2] continuous intravenous infusion over 24 h on day 1–4). Follow-up response evaluation was done by both endoscopy and computed tomography scan after 6–8 weeks and after 2 months thereafter.Results:Out of a total of 28 patients, 68% showed a complete response, 14% showed partial response, and 18% patients developed progressive disease at first and subsequent follow up (median follow-up of 21 months). Among the complete response patients, rates were higher in high-dose group compared to standard-dose radiotherapy group (71% vs. 64%, P = 0.38). Treatment-related toxicities were acceptable in both groups.Conclusion:High-dose radiotherapy with concurrent chemotherapy seems to be more effective with acceptable toxicity in our study. However, further follow-up and large sample size may be required to validate the current study conclusion.

Radiotherapy for esophageal carcinoma: dose, response and survival.

Esophageal cancer (EC) is an extremely aggressive, lethal malignancy that is increasing in incidence worldwide. At present, definitive chemoradiotherapy is accepted as the standard treatment for locally advanced EC. The EC guidelines recommend a radiation dose of 50.4 Gy for definitive treatment, yet the outcomes for patients who have received standard-dose radiotherapy remain unsatisfactory. However, some studies indicate that a higher radiation dose could improve local tumor control, and may also confer survival benefits. Some studies, however, suggest that high-dose radiotherapy does not bring survival benefit. The available data show that most failures occurred in the gross target volume (especially in the primary tumor) after definitive chemoradiation. Based on those studies, we hypothesize that at least for some patients, more intense local therapy may lead to better local control and survival. The aim of this review is to evaluate the radiation dose, fractionation strategies, and predictive factors of response to therapy in functional imaging for definitive chemoradiotherapy in esophageal carcinoma, with an emphasis on seeking the predictive model of response to CRT and trying to individualize the radiation dose for EC patients.

Ablative Radiotherapy Doses for Locally Advanced: Pancreatic Cancer (LAPC).

Standard palliative doses of radiation for locally advanced unresectable pancreatic cancer have had minimal to no impact on survival. Randomized trials evaluating these palliative doses have not shown a significant survival benefit with the use of radiation as consolidation after chemotherapy. Results from nonrandomized studies of 3- to 5-fraction low-dose stereotactic radiation (SBRT) have likewise had a minimal impact, but with less toxicity and a shorter treatment time. Doses of SBRT have been reduced to half the level that is necessary (biological equivalent dose, BED of 53 Gy) to achieve tumor ablation in the treatment of other solid tumors (100 Gy BED) to protect the gastrointestinal (GI) tract. The survival benefit of these palliative options is modest. In contrast, ablative doses of radiation (100 Gy BED) can be delivered using the same SBRT technique in 15 to 25 fractions. In addition to precision tumor targeting and solutions for respiratory motion as with SBRT, the delivery of ablative doses takes advantage of heterogeneous dosing, increased fractionation, which allows higher doses to be given, as well as adaptive planning to address day-to-day GI tract motion in selected cases. These higher doses have resulted in encouraging long-term survival results in multiple studies. In this review, we discuss the critical concepts and components of techniques that can be used to deliver ablative radiotherapy doses for patients with pancreatic tumors: fractionation, intentional dose heterogeneity, respiratory gating, image guidance, and adaptive planning.

TCT-315 Safety and Feasibility of Low Dose Compared With Standard Dose Radiation for Cardiac Catheterization and Intervention

Radiation exposure from various imaging modalities increases the risk for malignancy. Coronary angiography is a common source of radiation. The safety and feasibility of low dose versus standard dose radiation in adult cardiac catheterization and intervention has not been previously evaluated. We

Radiation techniques for esophageal cancer.

Radiotherapy plays a crucial role in the curative management of localized esophageal cancer, both as definitive and preoperative therapy. For definitive therapy, the standard radiation dose is 50.4 Gy in 28 fractions and should be delivered with concurrent chemotherapy. Chemoradiotherapy also has a wellestablished benefit in the preoperative setting, as established in the CROSS randomized trial. Radiation fields are typically generous, to account for subclinical extension of disease along the esophagus and to regional nodes. Three-dimensional conformal radiation is the current standard technique for esophageal cancer, though intensity-modulated radiation therapy is increasingly utilized and may improve the outcomes of esophageal radiotherapy by reducing radiation dose to critical normal tissues.