Combined External Beam Radiotherapy Research Articles

Survival outcomes of combined external beam radiotherapy and brachytherapy vs. brachytherapy alone for intermediate-risk prostate cancer patients using the National Cancer Data Base

PurposeThe purpose was to evaluate survival outcomes between external beam radiotherapy (EBRT) plus brachytherapy and brachytherapy alone for intermediate-risk prostate cancer, using the National Cancer Data Base. Methods and MaterialsThe National Cancer Data Base was queried for cN0M0 intermediate-risk patients treated from 2004 to 2006, with available data for Gleason score (GS), prostate-specific antigen (PSA), tumor stage, and receipt of radiation therapy (RT) and androgen deprivation therapy. RT comparison groups were the following: EBRT (40–50.4 Gy) plus brachytherapy and brachytherapy alone. ResultsA total of 10,571 patients were included: 3,148 received EBRT plus brachytherapy and 7,423 received brachytherapy alone. Median followup was 84 months (2–122 months); median age was 68 years (40–90 years). Unadjusted 5- and 7-year overall survival (OS) rates between EBRT plus brachytherapy vs. brachytherapy alone were 91.4% vs. 90.2% and 85.7% vs. 82.9%, respectively (p < 0.001). EBRT plus brachytherapy was associated with longer OS compared with brachytherapy alone under multivariate (hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.75–0.93; p = 0.001) and propensity score-matched analyses (HR, 0.85; 95% CI, 0.75–0.97; p = 0.006). Further subset analysis performed based on the Radiation Therapy Oncology Group 0232 inclusion criteria (GS 7 if PSA < 10 or GS < 7 if PSA 10–20) also demonstrated longer OS with EBRT plus brachytherapy (HR, 0.87; 95% CI, 0.77–0.98; p = 0.026). ConclusionsEBRT plus brachytherapy is associated with a modest OS improvement compared with brachytherapy alone in this population-based analysis. Although this benefit appears statistically significant, the relatively small difference in OS raises the question of overall clinical benefit with combined modality RT for intermediate-risk prostate cancer, given the potential increased risk for toxicities. Future results from Radiation Therapy Oncology Group 0232 should provide further insight on this topic.

Outcomes and patient-related reported urinary toxicity of low dose rate brachytherapy for localized prostate cancer.

29 Background: Brachytherapy (BT) is a common treatment modality for localized prostate cancer (LPCa). Here we report our institutional outcomes and patient-reported genitourinary (GU) toxicity following BT for LPCa. Methods: Medical records of patients with LPCa treated with low dose rate (LDR) BT at our institution from 1997-2011 were reviewed. BT prescriptions were 145 Gray (Gy) and 109Gy for mono- and combined iodine 125 (125I) therapy, and 125Gy and 100Gy for mono- and combined palladium 103 (103Pd) therapy. Biochemical failure was defined by the Phoenix definition. Kaplan Meier curves were used to compare biochemical relapse-free survival (bRFS), metastasis-free survival (MFS), and overall survival (OS). Patient-reported GU toxicity was evaluated by the American Urological Association Symptom Score (AUAS), and results binned into three time intervals, 1, 6, and 12 months post-BT. Repeated measures analysis determined a trend in AUAS score over time. Effect of age as a continuous variable, prostate specific antigen, Gleason score, clinical T stage, combined external beam radiotherapy + BT and use of neoadjuvant androgen deprivation therapy (nADT) on AUAS score was determined. Results: Of 459 patients identified, 400 received BT monotherapy and 8% received nADT. Median follow-up was 5.8 years. Nine-year bRFS, MFS, and OS were 92.8%, 97.9%, and 79.7%. Pretreatment AUAS scores were available for 252 patients. For 69 patients with all four values, median baseline AUAS scores rose from 6 to 14 at one month following BT (p &lt; 0.0001). AUAS scores did not change from one-month to 6 months post-BT (p = 0.99), but decreased to a median of 8 (p &lt; 0.0001) by 12 months post-BT. In the 69 patients with all values, no factors were found significant for change in AUAS scores. For 252 patients with pre-treatment AUAS and at least one additional value (assuming values missing at random), analysis revealed older age and use of nADT were associated with higher AUAS scores at all time points. Conclusions: LDRBT for LPCa offers excellent bRFS, MFS, and OS. AUAS scores rose in the first 6 months following BT but returned to pre-treatment baseline by 12 months post-BT. Older age and nADT use may be associated with higher AUAS scores.

High-dose-rate interstitial brachytherapy in early stage oral tongue cancer - 15 year experience from a tertiary care institute.

PurposeTo determine outcomes of interstitial high-dose-rate brachytherapy (HDR-BT) in patients with early stage oral tongue cancer.Material and methodsNinety-two patients with stage I and II oral tongue cancer were treated with HDR-BT between 1999 and 2014: brachytherapy alone = 62 (67.4%), and combination of external beam radiotherapy (EBRT) and brachytherapy = 30 (32.6%). Median follow-up was 53.5 months. Patterns of failure, overall survival (OS), disease-free survival (DFS), local control rates (LCR), and nodal control rates (NCR) were determined.Results5-year OS, DFS, LCR, and NCR were 73.2%, 58.2%, 64.2%, and 83.8%, respectively. In total, 43 patients (46.7%) failed treatment: isolated local failures = 28 (30.4%), isolated nodal failures = 8 (8.7%), both local and regional failures = 7 (7.6%). While in T1 stage, 5 year LCR were significantly higher in brachytherapy alone group compared to combined EBRT and brachytherapy group (81.7% vs. 62.5%, p = 0.04), the isolated nodal failure rates were not significantly different among the two groups. For T2 stage, NCR were higher in combined EBRT and brachytherapy group compared to brachytherapy alone (92.9% vs. 74.3%). Acute mucositis (grade ≥ 2) was seen more in brachytherapy alone group compared to the combined modality group (87% vs. 66%), and this correlated significantly with the higher biological equivalent dose (BED) in the brachytherapy alone group.ConclusionsOur study recommends treating patients with brachytherapy alone in T1 stage, and demonstrates the need for addressing nodal region either by neck dissection or nodal irradiation in T2 stage patients. Also, the study highlights the need for dose escalation (from the doses used in the study) in both T1 and T2 stage tumors when using interstitial brachytherapy either as sole modality or as a boost.

Resolving the brachytherapy challenges with government funded hospital.

The objective of this study is to rationalize the feasibility and cost-effectiveness of high dose rate (HDR) cobalt 60 (Co-60) source versus 192-Iridium (192-Ir) source brachytherapy in government funded hospitals and treatment interruption gap because of exchange of sources. A retrospective study of gynecological cancer patients, treated by radiotherapy with curative intent between April 2005 and September 2012 was conducted. We analyzed the total number of patients treated for external beam radiotherapy (EBRT) and brachytherapy (Intracavitary brachytherapy or cylindrical vaginal source). The dates for 192-Ir sources installation and the last date and first date of brachytherapy procedure before and after source installation respectively were also analyzed and calculated the gap in days for brachytherapy interruptions. The study was analyzed the records of 2005 to September 2012 year where eight 192-Ir sources were installed. The mean gap between treatment interruptions was 123.12 days (range 1-647 days). The Institutional incidence of gynecological cancer where radiotherapy was treatment modality (except ovary) is 34.9 percent. Around 52.25 percent of patients who received EBRT at this institute were referred to outside hospital for brachytherapy because of unavailability of Iridium source. The cost for 5 year duration for single cobalt source is approximately 20-22 lakhs while for 15 Iridium sources is approximately 52-53 lakhs. The combined HDR Co-60 brachytherapy and EBRT provide a useful modality in the treatment of gynecological cancer where radiotherapy is indicated, the treatment interruption because of source exchange is longer and can be minimized by using cobalt source as it is cost-effective and has 5 year working life. Thus, Co-60 source for brachytherapy is a feasible option for government funded hospitals in developing countries.

10 - Planning combined treatments of external beam radiation therapy and molecular radiotherapy

Molecular radiotherapy (MRT) with radiolabeled molecules has being constantly evolving, leading to notable results in cancer treatment. In some cases the absorbed doses delivered to tumors by MRT are sufficient to obtain complete responses, in other cases, instead, to be effective, MRT needs to be combined with other therapeutic approaches. Recently, several studies proposed the combination of MRT with external beam radiation therapy (EBRT). Some describe the theoretical basis within radiobiological models, others report the results of clinical phase I-II studies aimed to assess the feasibility and tolerability. The latter include the treatment of various tumors, such as meningiomas, paragangliomas, non-Hodgkin's lymphomas, bone, brain, hepatic and breast lesions. The underlying principle of combined MRT and EBRT is the possibility of exploiting the full potential of each modality, given the different organs at risk. Target tissues can indeed receive a higher irradiation, while respecting the threshold limits of more than one critical tissue. Nevertheless, clinical trials are empirical and optimization is still a theoretical issue. This paper describes the state of the art of combined MRT and EBRT as regards the rationale and the results of clinical studies, with special focus on the possibility of treatment improvement.

Cancer of the corpus uteri.

Cancer of the corpus uteri.

Survival Outcomes of Whole-Pelvic Versus Prostate-Only Radiation Therapy for High-Risk Prostate Cancer Patients With Use of the National Cancer Data Base

The addition of whole pelvic (WP) compared with prostate-only (PO) radiation therapy (RT) for clinically node-negative prostate cancer remains controversial. The purpose of our study was to evaluate the survival benefit of adding WPRT versus PO-RT for high-risk, node-negative prostate cancer, using the National Cancer Data Base (NCDB). Patients with high-risk prostate cancer treated from 2004 to 2006, with available data for RT volume, coded as prostate and pelvis (WPRT) or prostate alone (PO-RT) were included. Multivariate analysis (MVA) and propensity-score matched analysis (PSM) were performed. Recursive partitioning analysis (RPA) based on overall survival (OS) using Gleason score (GS), T stage, and pretreatment prostate-specific antigen (PSA) was also conducted. A total of 14,817 patients were included: 7606 (51.3%) received WPRT, and 7211 (48.7%) received PO-RT. The median follow-up time was 81 months (range, 2-122 months). Under MVA, the addition of WPRT for high-risk patients had no OS benefit compared with PO-RT (HR 1.05; P=.100). On subset analysis, patients receiving dose-escalated RT also did not benefit from WPRT (HR 1.01; P=.908). PSM confirmed no survival benefit with the addition of WPRT for high-risk patients (HR 1.05; P=.141). In addition, RPA was unable to demonstrate a survival benefit of WPRT for any subset. Other prognostic factors for inferior OS under MVA included older age (HR 1.25; P<.001), increasing comorbidity scores (HR 1.46; P<.001), higher T stage (HR 1.17; P<.001), PSA (HR 1.81; P<.001), and GS (HR 1.29; P<.001), and decreasing median county household income (HR 1.15; P=.011). Factors improving OS included the addition of androgen deprivation therapy (HR 0.92; P=.033), combination external beam RT plus brachytherapy boost (HR 0.71; P<.001), and treatment at an academic/research institution (HR 0.84; P=.002). In the largest reported analysis of WPRT for patients with high-risk prostate cancer treated in the dose-escalated era, the addition of WPRT demonstrated no survival advantage compared with PO-RT.

Postoperative external beam irradiation with and without brachytherapy in pelvic node-positive IB1-IIA2 cervical cancer patients: a retrospective clinical study.

BackgroundThis study assessed the survival outcomes and recurrent patterns in pelvic node-positive IB1-IIA2 cervical cancer patients treated with postoperative external beam irradiation with or without vaginal brachytherapy.MethodsThe records of 1149 cervical cancer patients received radical surgery between February 2008 and March 2010 were retrospectively reviewed. 126 stages IB1-IIA2 patients with positive pelvic lymph node (LN) were included and a total of 113 patients who received different postoperative radiation therapy were identified and analyzed. Of the enrolled patients, 55 patients received pelvic external beam radiotherapy (EBRT) without vaginal brachytherapy and 58 patients received pelvic EBRT with vaginal brachytherapy. Treatment-related toxicities were evaluated. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier estimates and statistical significance was determined using the log-rank test.ResultsWith a median follow-up of 47 months (range: 10–61 months), the group which had pelvic EBRT with brachytherapy had a significantly improved 5-year PFS rate (P = 0.044), but no significant difference in 5-year overall survival was found between the two groups (P = 0.437). In patients treated without brachytherapy, the most common site of relapse was the pelvis. No significant differences were found regards to acute and chronic radiation toxicities, including myelosuppression, dermatitis, enterocolitis, proctitis and cystitis (P = 0.485, 0.875, 0.671, 0.459 and 0.969 respectively) between the groups of pelvic EBRT with and without vaginal brachytherapy.ConclusionsTreated with pelvic EBRT in combination with vaginal brachytherapy, cervical cancer patients with positive pelvic lymph node had a reduced risk of locoregional recurrence without increased side effects compared with patients treated with pelvic EBRT without vaginal brachytherapy.

Clinicopathological characteristics and management of prostate cancer in the human immunodeficiency virus (HIV)-positive population: experience in an Australian major HIV centre.

To characterise clinicopathological characteristics of prostate cancer among human immunodeficiency virus (HIV)-positive men and to evaluate the current practice patterns in the management of prostate cancer in these men. We retrospectively reviewed all patients with HIV in the State-wide HIV referral centre in Victoria, who were diagnosed with prostate cancer from 2000 onwards. In all, 12 patients were identified, and the medical records were reviewed to collect data on HIV parameters at the time of prostate cancer diagnosis, as well as prostate cancer clinicopathological characteristics, treatment details and outcomes. At the time of prostate cancer diagnosis, eight patients had undetectable viral load, and the median cluster of differentiation 4 (CD4) count was 485 cells/μL. The average age at diagnosis of prostate cancer was 63 years and the median prostate-specific antigen (PSA) level of 11.1 ng/mL. Four patients had Gleason 6 prostate cancer, four Gleason 7, one Gleason 8 and three Gleason 9. Seven of the 12 patients had a positive family history for prostate cancer. Of the patients with clinically localised prostate cancer (10), most were treated with radiotherapy (RT): one permanent seed brachytherapy (BT), five external beam RT (EBRT), two open radical prostatectomies (RP), one active surveillance (AS), and one on watchful waiting (WW). For the two patients with metastatic disease, one had androgen-deprivation therapy and EBRT, while the other had a combination of EBRT and chemo-hormonal therapy with doxetacel. All patients were followed for a median of 46 months, with three deaths reported, none of which was a prostate cancer-specific death. This is the first Australasian series on prostate cancer management in a HIV population. With the prolonged survival among HIV-positive men in the highly active anti-retroviral therapy era, PSA testing should be offered to this group of patients, especially those with a positive family history. HIV-positive men should also be offered all treatment options in the same manner as men in the general population.

Research of efficacy of brachytherapy for localized prostate cancer

To investigate the efficacy of brachytherapy for patients with localized prostate cancer and the influence factors. There were 61 patients with localized prostate cancer were treated with brachytherapy between April 2001 and March 2011 in Department of Urology, Peking University First Hospital, including 11 patients who received combined external beam radiotherapy. The mean age was 75.2 years (range 57-84 years). Clinical stage was T1c in 12 patients, T2a in 18 patients, T2b in 17 patients, and T2c in 14 patients. Long-term follow-up was carried on all patients for prostate specific antigen (PSA) and adverse effects. Kaplan-Meier survival curves, Log-rank test and univariate Cox proportional hazard regression analysis was used to examine the factors associated with the treatment efficacy. The median follow-up was 49 months (range 9-126 months). The mean PSA before treatment and the mean nadir PSA after operation were (17.80 ± 14.44) µg/L and (1.16 ± 1.15) µg/L, respectively. The PSA of 58 patients (95.1%) reached a nadir < 4.0 µg/L, which was even < 1.0 µg/L in 37 patients (60.7%). The mean time to reach the nadir PSA was 11.6 months after operation. The short-term adverse events after operation included fever in 4 patients, hematuria in 7 patients, and hematochezia in 4 patients. The most common long-term adverse event was urinary irritation (31.1%); other long-term adverse events were rare, including hematochezia, hematuria, urinary incontinence, urinary retention, mild diarrhea and radiation enteritis. The estimated mean biochemical recurrence-free survival after brachytherapy was 41.0 months (95% CI: 31.05-50.94 months). The mean nadir PSA after operation were 1.32 µg/L in the 11 patients who received combined external beam radiotherapy, and their estimated mean biochemical recurrence-free survival was 38 months. Patients with nadir PSA < 1.0 µg/L had a significant longer biochemical recurrence-free survival than those with nadir PSA between 1.0 µg/L and 4.0 µg/L (42.9 vs. 32.0 months, χ² = 4.445, P = 0.035). Brachytherapy is an effective treatment strategy for localized prostate cancer, with relatively low rate of severe adverse events. After brachytherapy, a nadir PSA < 1.0 µg/L might indicate a better prognosis.

AB116. Research of efficacy of brachytherapy for localized prostate cancer.

ObjectiveTo investigate the efficacy of brachytherapy for patients with localized prostate cancer and the influence factors.MethodsA total of 61 patients with localized prostate cancer were treated with brachytherapy between 2001 and 2011, including 11 patients who received combined external beam radiotherapy. The mean age was 75.2 yr (range, 57-84 yr). Clinical stage was T1c in 12 patients, T2a in 18 patients, T2b in 17 patients, and T2c in 14 patients. Long-term follow-up was carried on all patients for PSA and adverse effects. Kaplan-Meier survival curves, Log-rank test and univariate Cox proportional hazard regression analysis was used to examine the factors associated with the treatment efficacy.ResultsThe median follow-up was 49 months (range, 9-126 months). The mean PSA before treatment and the mean nadir PSA after operation were 17.80 and 1.16 μg/L, respectively. The PSA of 58 patients (95.1%) reached a nadir below 4 μg/L, which was even below 1 μg/L in 37 patients (60.7%). The mean time to reach the nadir PSA was 11.6 months after operation. The short-term adverse events after operation included fever in 4 patients, hematuria in 7 patients, and hematochezia in 4 patients. The most common long-term adverse event was urinary irritation (31%); other long-term adverse events were rare, including hematochezia, hematuria, urinary incontinence, urinary retention, mild diarrhea and radiation enteritis. The estimated mean biochemical recurrence-free survival after brachytherapy was 41.0 months (95% CI: 31.05-50.94 months). The mean nadir PSA after operation were 1.32 μg/L in the 11 patients who received combined external beam radiotherapy, and their estimated mean biochemical recurrence-free survival was 38 months. Patients with nadir PSA below 1 μg/L had a significant longer biochemical recurrence-free survival than those with nadir PSA between 1 and 4 μg/L (42.9 vs. 32.0 months, χ2=4.445, P=0.035).ConclusionsBrachytherapy is an effective treatment strategy for localized prostate cancer, with relatively low rate of severe adverse events. After brachytherapy, a nadir PSA below 1 μg/L might indicate a better prognosis.

Trans-arterial chemoembolization and external beam radiation therapy for treatment of hepatocellular carcinoma with a tumor thrombus in the inferior vena cava and right atrium.

BackgroundHepatocellular carcinoma (HCC) with a tumor thrombus in the inferior vena cava (IVC) and right atrium (RA) rarely occurs and is usually associated with extremely poor prognosis, we carried out this study to evaluate the efficacy and safety of a combination of trans-arterial chemoembolization (TACE) and external beam radiation therapy (EBRT) in the treatment of HCC with a tumor thrombus in the IVC and RA.MethodsFrom September 2005 to September 2008, 11 cases of HCC with a tumor thrombus in the IVC and RA were treated with a combination of TACE and EBRT. Clinical adverse events, laboratory toxicity, and survival were retrospectively studied.ResultsThirty-one interventional procedures were conducted and EBRT was performed 11 times. All treatments were successful and without significant complications. No severe adverse effects were observed. The median survival time of the 11 cases was 21.0 months. One patient was monitored for 97 months and no recurrence was observed.ConclusionThe combination of TACE and EBRT can be safely performed and may improve the prognosis of the HCC cases with a tumor thrombus in the IVC and RA.

Consensus and differences in primary radiotherapy for localized and locally advanced prostate cancer in Switzerland: A survey on patterns of practice.

External beam radiotherapy (EBRT), with or without androgen deprivation therapy (ADT), is an established treatment option for nonmetastatic prostate cancer. Despite high-level evidence from several randomized trials, risk group stratification and treatment recommendations vary due to contradictory or inconclusive data, particularly with regard to EBRT dose prescription and ADT duration. Our aim was to investigate current patterns of practice in primary EBRT for prostate cancer in Switzerland. Treatment recommendations on EBRT and ADT for localized and locally advanced prostate cancer were collected from 23 Swiss radiation oncology centers. Written recommendations were converted into center-specific decision trees, and analyzed for consensus and differences using a dedicated software tool. Additionally, specific radiotherapy planning and delivery techniques from the participating centers were assessed. The most commonly prescribed radiation dose was 78 Gy (range 70-80 Gy) across all risk groups. ADT was recommended for intermediate-risk patients for 6 months in over 80 % of the centers, and for high-risk patients for 2 or 3 years in over 90 % of centers. For recommendations on combined EBRT and ADT treatment, consensus levels did not exceed 39 % in any clinical scenario. Arc-based intensity-modulated radiotherapy (IMRT) is implemented for routine prostate cancer radiotherapy by 96 % of the centers. Among Swiss radiation oncology centers, considerable ranges of radiotherapy dose and ADT duration are routinely offered for localized and locally advanced prostate cancer. In the vast majority of cases, doses and durations are within the range of those described in current evidence-based guidelines.

Prognostic Factors in Primary Vaginal Cancer: A Single Institute Experience and Review of Literature.

Primary vaginal carcinoma is rare, accounting for 1-2% of all gynecological malignancies. Being rare, most observations are based on retrospective and comparative analyses. This study was aimed to retrospectively analyze the prognostic factors and its relevance in the outcomes of primary vaginal cancers. Medical records of all cases of primary vaginal cancers, presented to Department of Oncology, from 2004 to 2012, at a tertiary care center in southern India, were retrieved from electronic medical records, and were analyzed. The total number of cases was 32. Median age at presentation was 64.28years. Squamous histology accounted for 84.4%, with the rest being adenocarcinoma. Surgery was offered for five (15.6%), and concurrent chemotherapy for 14 (43.8%) patients. Three patients had only surgery. All others received radiotherapy. Twenty received external beam radiation (EBRT) and vaginal brachytherapy (VBT); seven only EBRT and two, adjuvant radiation. Five patients had residual disease; two, stage III, and three stage IV. Median follow-up was 55.83months. Twelve patients were alive at last follow-up (37.5%), while 14 were dead (43.8%-8 of disease and 6 of other causes). Six patients were lost to follow-up (18.8%). Twenty patients were disease free. Seven had recurrence, three loco-regional and four distant. Median overall survival (OS) was 86.1months, disease-free survival (DFS) 90.17months, and disease-specific survival (DSS) 97.13months. When well and moderately differentiated tumors were taken together, the 5-year OS, DFS, and DSS rates were, 56.6, 64.3, and 82.3%. For poorly differentiated tumors, median OS, DFS, and DSS were, 20.9, 14.6, and 20.9months, with statistically significant advantage for better grade tumors, for DSS (p 0.050). Better 5-year OS, DFS, and DSS rates were observed for stage I+II group, with 54.9, 79.8, and 78.9%, compared with advanced stage where the same were 54.8, 38.2, and 68.6% (DFS-p 0.003, DSS-p 0.009). Grade and stage of tumor had statistically significant predictive value over the outcomes, while tumor size showed a significant trend. Patients treated with combination of EBRT and VBT fared well. Our study could conclude that grade of differentiation was a significant predictor of poor survival as was stage of disease. Combination of VBT and external beam radiotherapy provides good DFS.

External beam radiotherapy synergizes ¹⁸⁸Re-liposome against human esophageal cancer xenograft and modulates ¹⁸⁸Re-liposome pharmacokinetics.

External beam radiotherapy (EBRT) treats gross tumors and local microscopic diseases. Radionuclide therapy by radioisotopes can eradicate tumors systemically. Rhenium 188 (188Re)-liposome, a nanoparticle undergoing clinical trials, emits gamma rays for imaging validation and beta rays for therapy, with biodistribution profiles preferential to tumors. We designed a combinatory treatment and examined its effects on human esophageal cancer xenografts, a malignancy with potential treatment resistance and poor prognosis. Human esophageal cancer cell lines BE-3 (adenocarcinoma) and CE81T/VGH (squamous cell carcinoma) were implanted and compared. The radiochemical purity of 188Re-liposome exceeded 95%. Molecular imaging by NanoSPECT/CT showed that BE-3, but not CE81T/VGH, xenografts could uptake the 188Re-liposome. The combination of EBRT and 188Re-liposome inhibited tumor regrowth greater than each treatment alone, as the tumor growth inhibition rate was 30% with EBRT, 25% with 188Re-liposome, and 53% with the combination treatment at 21 days postinjection. Combinatory treatment had no additive adverse effects and significant biological toxicities on white blood cell counts, body weight, or liver and renal functions. EBRT significantly enhanced the excretion of 188Re-liposome into feces and urine. In conclusion, the combination of EBRT with 188Re-liposome might be a potential treatment modality for esophageal cancer.

Adjuvant radiotherapy in Stage II endometrial carcinoma: Is brachytherapy alone sufficient for local control?

To evaluate recurrence patterns and overall survival in patients treated with adjuvant radiation after surgical staging for Stage II endometrial carcinoma. Secondary goals include identification of prognostic factors for recurrence and toxicity assessment. The medical records of 41 patients treated with adjuvant radiotherapy at Washington University School of Medicine after surgical staging for endometrial cancer (total abdominal hysterectomy and bilateral salpingo-oophorectomy, peritoneal cytology, lymph node dissection) were reviewed. Nineteen were treated with a combination of external beam radiotherapy and vaginal brachytherapy (VB), and 22 patients were treated with postoperative VB alone. Median followup for all patients was 41 months. Median patient age was 59 years (range, 42-87 years). All tumors were of endometrioid histology. There were 20 Grade 1 tumors, 13 Grade 2 tumors, and 8 Grade 3 tumors. For all patients, the 5-year overall survival was 69.8%, and the 5-year recurrence-free survival was 89.0%. There was no statistically significant difference in overall survival (p = 0.510) or freedom from vaginal (p = 0.840), distant (p = 0.133), or any recurrence (p = 0.275) with respect to modality of treatment (external beam radiotherapy and VB vs. VB alone). There were no pelvic lymph node recurrences. In the univariate analysis, there were no risk factors influencing overall survival or recurrences. One patient experienced a toxicity requiring hospital admission. She was treated with pelvic external beam radiation plus brachytherapy. VB alone results in excellent local control for patients with Stage II endometrial cancer after surgical staging. Long-term toxicities are rare and more common in the group of patients who were treated with pelvic external beam plus brachytherapy.

SP-0002: The role of radiotherapy for the treatment of brain metastases

Background: External beam radiotherapy is an effective, time-efficient, safe, and cost effective palliative treatment for patients with painful bone metastases. The importance of this therapeutic approach, coupled with complexities of multidisciplinary care, has led to three International Consensus Conference Workshops on Palliative Radiotherapy beginning in 1990 and reconvening every ten years since. The Third International Consensus Conference Workshop was convened in San Diego, California in 2010, and it and paved the way for the publication of the American Society for Radiation Oncology Bone Metastases Guidelines that confirmed the pain relief equivalency between 30 Gy in 10 fractions, 24 Gy in 6 fractions, 20 Gy in 5 fractions, or a single 8 Gy fraction. Methods: Given the rapid rate of advancements in the management of these patients, the decision was made to shorten the interval between conferences and to host the Fourth International Consensus Conference Workshop at the 2015 European Society for Radiation Oncology Meeting. This group will have the opportunity to discuss research updates that have been published since the 2010 International Conference. Results: The recent update on the systemic review of palliative radiotherapy trials for bone metastases by Chow et al confirms previous conclusions regarding the most appropriate fractionation schema. The re-analysis of Radiation Therapy and Oncology Group 97-14 data by Howell et al helps allay fears about late spinal cord toxicity for patients who receive a single 8 Gy fraction for spine bone metastases. The first prospective, randomized data about the safety and efficacy of re-treatment with external beam radiotherapy published by Chow et al provides guidance for the management of patients with recurrent pain to the same skeletal site. Additionally, the growing data for the most appropriate use of highly conformal therapy allows for updated recommendations for the treatment of spine bone metastases, especially in the setting of patients with more favorable prognoses and oligometastases. Lastly, a growing body of data helps to more accurately define the effective combination of external beam radiotherapy with radionuclides, bone strengthening agents, and kyphoplasty or vertebroplasty. Conclusion: The results of the 2015 ESTRO International Consensus Conference Workshop will help to shape the pathways for palliative radiotherapy investigation in the coming years, and it will set the stage for the Fifth Conference to be held in 2020. SP-0002 The role of radiotherapy for the treatment of brain metastases D. Rades University of Lubeck, Radiation Oncology, Lubeck, Germany

PO-1040: Follow-up analysis of combined HDR-brachytherapy and external beam radiotherapy for prostate cancer patients

PO-1040: Follow-up analysis of combined HDR-brachytherapy and external beam radiotherapy for prostate cancer patients

Improving external beam radiotherapy by combination with internal irradiation.

The efficacy of external beam radiotherapy (EBRT) is dose dependent, but the dose that can be applied to solid tumour lesions is limited by the sensitivity of the surrounding tissue. The combination of EBRT with systemically applied radioimmunotherapy (RIT) is a promising approach to increase efficacy of radiotherapy. Toxicities of both treatment modalities of this combination of internal and external radiotherapy (CIERT) are not additive, as different organs at risk are in target. However, advantages of both single treatments are combined, for example, precise high dose delivery to the bulk tumour via standard EBRT, which can be increased by addition of RIT, and potential targeting of micrometastases by RIT. Eventually, theragnostic radionuclide pairs can be used to predict uptake of the radiotherapeutic drug prior to and during therapy and find individual patients who may benefit from this treatment. This review aims to highlight the outcome of pre-clinical studies on CIERT and resultant questions for translation into the clinic. Few clinical data are available until now and reasons as well as challenges for clinical implementation are discussed.

Combination external beam and brachytherapy for intermediate- to high-risk prostate cancer: Comparison of high-dose rate (HDR) and seed (LDR) implant methods.

90 Background: Maximizing the therapeutic ratio for intermediate to high risk localized prostate cancer may be accomplished by using a combination of external beam radiotherapy (EBRT) and radiation implant. Differences in implant methods could be expected to influence mortality. We compared outcomes for patients treated using combination EBRT and high dose rate (HDR) versus EBRT and low dose rate (LDR) seed implant methods. Methods: Between 12/1993 and 05/2010 there were 307 cases of combination therapy with analyzable data: 227 HDR + EBRT (HDRe) and 81 LDR + EBRT (LDRe) Intermediate risk patients had 1+ risk factors: PSA ≥ 10, Gleason score (GS) ≥ 7, or AJCC clinical stage ≥ T2b. High risk patients exhibited either 2+ of these risk factors or PSA ≥ 20, GS ≥ 8, or AJCC clinical stage ≥ T3. External beam radiation was 45 Gy in 1.8 Gy daily fractions using 3D conformal or IMRT methods. The prostate, seminal vesicles, and (in some patients) pelvic lymph nodes were treated. HDR brachytherapy was delivered one week prior to beginning EBRT. Afterloading HDR catheter needles were surgically implanted into the prostate. HDR dose was 21 Gy in three equal fractions of 7 Gy peripheral dose given over two days. LDR was performed 2-3 weeks after EBRT using I-125 or Pd-103 seeds and 109 or 90 Gy respectively. PSA failure was defined as “nadir plus two.” Results: HDRe and LDRe cases were well matched for pretreatment risk factors. There were 18 PSA failures in the HDRe group (7.9%) and 6 PSA failures in the LDRe group (7.4%). Adjusted Cox proportional hazard models showed no statistically significant difference between the treatment groups with regard to PSA failure. Hazard ratio for LDRe compared to HDRe was 0.82 (95% CI 0.28, 2.46; p=0.73). There were 26 deaths from any cause (11.45%) in the HDRe group and 11 deaths from any cause (13.58%) in the LDRe group. Adjusted Cox models showed no statistically significant difference between the treatment groups for survival. Hazard ratio for LDRe compared to HDRe was 1.49 (95% CI 0.68, 3.25; p=0.32). Conclusions: There were no statistically significant differences in PSA failure free survival or overall survival detected in LDRe versus HDRe patient groups.