Gy External Beam Radiotherapy Research Articles

Clinical applications of custom-made vaginal cylinders constructed using three-dimensional printing technology.

PurposeThree-dimensional (3D) printing technology allows physicians to rapidly create customized devices for patients. We report our initial clinical experience using this technology to create custom applicators for vaginal brachytherapy.Material and methodsThree brachytherapy patients with unique clinical needs were identified as likely to benefit from a customized vaginal applicator. Patient 1 underwent intracavitary vaginal cuff brachytherapy after hysterectomy and chemotherapy for stage IA papillary serous endometrial cancer using a custom printed 2.75 cm diameter segmented vaginal cylinder with a central channel. Patient 2 underwent interstitial brachytherapy for a vaginal cuff recurrence of endometrial cancer after prior hysterectomy, whole pelvis radiotherapy, and brachytherapy boost. We printed a 2 cm diameter vaginal cylinder with one central and six peripheral catheter channels to fit a narrow vaginal canal. Patient 3 underwent interstitial brachytherapy boost for stage IIIA vulvar cancer with vaginal extension. For more secure applicator fit within a wide vaginal canal, we printed a 3.5 cm diameter solid cylinder with one central tandem channel and ten peripheral catheter channels. The applicators were printed in a biocompatible, sterilizable thermoplastic.ResultsPatient 1 received 31.5 Gy to the surface in three fractions over two weeks. Patient 2 received 36 Gy to the CTV in six fractions over two implants one week apart, with interstitial hyperthermia once per implant. Patient 3 received 18 Gy in three fractions over one implant after 45 Gy external beam radiotherapy. Brachytherapy was tolerated well with no grade 3 or higher toxicity and no local recurrences.ConclusionsWe established a workflow to rapidly manufacture and implement customized vaginal applicators that can be sterilized and are made of biocompatible material, resulting in high-quality brachytherapy for patients whose anatomy is not ideally suited for standard, commercially available applicators.

高リスク前立腺癌に対するネオアジュバント内分泌療法併用外照射放射線療法の治療成績と予後関連因子の検討

(Purpose) We investigated the outcome of external-beam radiotherapy (EBRT) with neoadjuvant androgen deprivation therapy (NeoADT) for high-risk prostate cancer defined by National Comprehensive Cancer Network (NCCN) guideline. (Patients and method) From 2002 to 2013, 70 patients with high-risk prostate cancer (PSA ≥20 ng/ml or clinical T stage ≥T3a, Gleason score ≥8) were treated with NeoADT and EBRT. EBRT consisted of three-dimensional conformal or intensity modulated radiotherapy with or without whole-pelvic radiation. Biochemical failure was defined according to the Phoenix definition. Biochemical progression-free survival (bPFS) and overall survival (OS) were calculated by Kaplan-Meier method, and prognostic factors for bPFS were analyzed by using the Cox proportional hazard model. (Result) The median age and initial prostate-specific antigen (PSA) level were 72 years old and 25.2 ng/ml, respectively. 43 patients had PSA level ≥20 ng/ml, 51 patients had clinical stage ≥T3a, 27 patients had Gleason score ≥8. The number of risk factors patients possessed was 1 (RiskN-1) in 31 patients, 2 (RiskN-2) in 27 patients and 3 (RiskN-3) in 12 patients. Median EBRT dose and duration of Neo ADT were 74 Gy and13.0 months, respectively. Whole-pelvic radiation was administered in 7 patients. After median follow-up of 4.8 years, biochemical and clinical failure occurred in 23 and 2 patients, respectively. No patients died of cancer. Five-year/8-year bPFS and OS were 63%/54% and 100%/91%, respectively. In multivariate analysis, three high-risk factor of NCCN guideline (PSA, clinical stage, Gleason score) did not predict outcome after EBRT independently, but RiskN (-1 vs -2, 3, HR 35.35, 95%CI 2.51-498.05, p<0.01) and pre-EBRT PSA (continuous, hazard ratio 1.31, 95%CI 1.01-1.71, p<0.05) were the significant predictors of bPFS. Five-year/8-year bPFS in RiskN-1 group and RiskN-2 or -3 group were 89%/79% and 47%/39%, respectively. Grade 3/4 adverse events (CTCAE ver4.0-JCOG) occurred in 2 patients. (Conclusion) Median dose of 74 Gy EBRT with intermediate-term NeoADT was safe and beneficial for high-risk prostate cancer. The number of risk factors and pre-EBRT PSA level were the independent prognostic factors for biochemical progression-free survival.

Survival Outcomes of Dose-Escalated External Beam Radiotherapy versus Combined Brachytherapy for Intermediate and High Risk Prostate Cancer Using the National Cancer Data Base

We evaluated survival outcomes between dose-escalated EBRT (external beam radiotherapy) vs EBRT plus brachytherapy for intermediate and high risk prostate cancer using NCDB (National Cancer Data Base). Patients with cN0M0 prostate cancer treated from 2004 to 2006 were divided into radiotherapy comparison groups, including EBRT alone (75.6 to 81 Gy) and EBRT (40 to 50.4 Gy) plus brachytherapy with EBRT delivered at 1.8 to 2.0 Gy per fraction. Brachytherapy data were limited to yes/no with no information on modality, dose or schedule. Eligible patients were known to have received androgen deprivation therapy. Overall survival was evaluated using multivariate Cox regression and propensity score matched analyses. Of the 20,279 study patients with prostate cancer, including 12,617 at intermediate risk and 7,662 at high risk, 71.3% received EBRT alone and 28.7% received EBRT plus brachytherapy. Median followup was 82 months (range 3 to 120) and median age was 70 years (range 36 to 90). On multivariate analysis compared to EBRT alone (75.6 to 81 Gy) EBRT plus brachytherapy was associated with improved survival (HR 0.75, p <0.001). This significance remained consistent for intermediate and high risk when analyzed separately (HR 0.73 and 0.76, respectively, each p <0.001). However on subset analysis compared to very high dose EBRT alone (79.2 to 81 Gy) in all patients combined EBRT plus brachytherapy was not associated with improved survival (HR 0.91, p = 0.083). Compared to EBRT (75.6 to 81 Gy) we observed an association of EBRT plus brachytherapy with a decreased risk of death in men with intermediate and high risk prostate cancer. However this association was no longer significant when EBRT doses of 79.2 to 81 Gy were used.

Association of Androgen Deprivation Therapy With Overall Survival in Men With Prostate Cancer Receiving Dose-Escalated Radiation

Association of Androgen Deprivation Therapy With Overall Survival in Men With Prostate Cancer Receiving Dose-Escalated Radiation

Assessing the Quality of Life in Patients With Endometrial Cancer Treated With Adjuvant Radiotherapy.

The current study evaluates long-term quality of life (QOL) and sexual function of patients with endometrial cancer who received adjuvant pelvic external beam radiotherapy (EBRT) and/or vaginal brachytherapy (BRT). One hundred forty-four endometrial cancer survivors who were treated between January 2000 and December 2009 in our department were included in this study. Median follow-up was 79 months (range, 31-138 months). Fifty-two patients were treated with 45 to 50.4 Gy EBRT, 76 were with BRT, and 16 were with both EBRT and BRT. Brachytherapy was in the form of vaginal cuff BRT with 5 × 550 cGy high dose rate BRT, prescribed to the first 4 cm and whole wall thickness of vagina. Quality of life was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and subscales from the supplemental 24-item Cervical Cancer Module. Vaginal BRT patients reported better physical functioning (P = 0.01), role functioning (P = 0.03), and sexual enjoyment (P = 0.01) compared to EBRT group. Symptom score (P = 0.01), lymphedema (P = 0.03), pain (P = 0.02), and diarrhea (P = 0.009) scores were also higher with EBRT. Vaginal BRT did not worsen symptom scores or sexual functions when added to EBRT. Obese patients experienced higher rates of lymphedema (P = 0.008). Cognitive and role functioning scores were significantly higher in patients with normal body mass index. External beam radiotherapy negatively affects long-term QOL and sexual functions in endometrial cancer survivors. Vaginal BRT provides higher QOL. Patients with body mass index within normal limits have improved QOL.

Impact of dose-escalated radiation on overall survival in men with nonmetastatic prostate cancer.

28 Background: Infive publishedRCTs, dose-escalated external beam radiation therapy (EBRT) for prostate cancer resulted in improved biochemical and local control. However, the question of whether dose escalation improves overall survival (OS) remains unanswered. We examined OS among men with non-metastatic prostate cancer undergoing EBRT in the modern era. Methods: Using the National Cancer Database (NCDB), we conducted non-randomized comparative effectiveness studies of dose-escalated versus standard-dose EBRT in men diagnosed from 2004-2006 in three analytic cohorts defined by NCCN risk category: low- (N=12,848), intermediate- (N=14,966) or high-risk (N=14,587) prostate cancer. We categorized patients in each risk cohort into 2 treatment groups: standard-dose (68.4 Gy to &lt;75.6 Gy) or dose-escalated (≥75.6 Gy to 90 Gy) EBRT. The primary outcome was time to death from any cause, measured from diagnosis to NCDB date of death or end of follow-up (December 31, 2011). We compared OS between treatment groups in the three analytic cohorts using Cox proportional hazard models. Inverse probability weighted propensity score methods were used to balance differences between treatment groups in age, race, year of diagnosis, AJCC T- and N-stage, PSA, Gleason score, androgen deprivation therapy, IMRT use, comorbid disease, income, insurance, urban/rural location, facility type and facility volume. In secondary analyses, we evaluated dose response for survival by categorizing dose in approximately 2 Gy increments. Results: Median follow up for survivors was between 73 and 74 months in all three risk cohorts. Dose-escalated EBRT was associated with improved survival in the intermediate-risk (adjusted HR 0.81, 95% CI 0.77 and 0.85, p&lt;0.0001) and high-risk groups (aHR 0.85, 95% CI 0.81 and 0.89, p&lt;0.0001), but not the low-risk group (aHR 0.99, 95% CI 0.92-1.06, p=0.803). For every incremental ~2Gy increase in dose, there was a 9% (95% CI 6% – 11%, p&lt;0.0001) and 7% (95% CI 3% - 10%, p=0.004) reduction in the hazard of death for intermediate- and high-risk patients, respectively. Conclusions: Dose-escalated EBRT is associated with improved survival in men with intermediate- and high-risk, but not low-risk, prostate cancer.

Long-Term Clinical Responses of Neoadjuvant Dendritic Cell Infusions and Radiation in Soft Tissue Sarcoma.

Purpose. Patients with large >5 cm, high-grade resectable soft tissue sarcomas (STS) have the highest risk of distant metastases. Previously we have shown that dendritic cell (DC) based vaccines show consistent immune responses. Methods. This was a Phase I single institution study of neoadjuvant radiation with DC injections on 18 newly diagnosed high-risk STS patients. Neoadjuvant treatment consisted of 50 Gy of external beam radiation (EBRT), given in 25 fractions delivered five days/week, combined with four intratumoral injections of DCs followed by complete resection. The primary endpoint was to establish the immunological response to neoadjuvant therapy and obtain data on its clinical safety and outcomes. Results. There were no unexpected toxicities or serious adverse events. Twelve out of 18 (67%) patients were alive, of which an encouraging 11/18 (61%) were alive with no systemic recurrence over a period of 2–8 years. Favorable immunological responses correlated with clinical responses in some cases. Conclusions. This study provides clinical support to using dendritic cell injections along with radiation in sarcomas, which when used optimally in combination can help clinical outcomes in soft tissue sarcoma. Study registration number is NCT00365872.

CT based three dimensional dose-volume evaluations for high-dose rate intracavitary brachytherapy for cervical cancer.

BackgroundIn this study, high risk clinical target volumes (HR-CTVs) according to GEC-ESTRO guideline were contoured retrospectively based on CT images taken at the time of high-dose rate intracavitary brachytherapy (HDR-ICBT) and correlation between clinical outcome and dose of HR-CTV were analyzed.MethodsOur study population consists of 51 patients with cervical cancer (Stages IB-IVA) treated with 50 Gy external beam radiotherapy (EBRT) using central shield combined with 2–5 times of 6 Gy HDR-ICBT with or without weekly cisplatin. Dose calculation was based on Manchester system and prescribed dose of 6 Gy were delivered for point A. CT images taken at the time of each HDR-ICBT were reviewed and HR-CTVs were contoured. Doses were converted to the equivalent dose in 2 Gy (EQD2) by applying the linear quadratic model (α/β = 10 Gy).ResultsThree-year overall survival, Progression-free survival, and local control rate was 82.4%, 85.3% and 91.7%, respectively. Median cumulative dose of HR-CTV D90 was 65.0 Gy (52.7-101.7 Gy). Median length from tandem to the most lateral edge of HR-CTV at the first ICBT was 29.2 mm (range, 18.0-51.9 mm). On univariate analysis, both LCR and PFS was significantly favorable in those patients D90 for HR-CTV was 60 Gy or greater (p = 0.001 and 0.03, respectively). PFS was significantly favorable in those patients maximum length from tandem to edge of HR-CTV at first ICBT was shorter than 3.5 cm (p = 0.042).ConclusionVolume-dose showed a relationship to the clinical outcome in CT based brachytherapy for cervical carcinoma.

SU‐C‐16A‐05: OAR Dose Tolerance Recommendations for Prostate and Cervical HDR Brachytherapy: Dose Versus Volume Metrics

Purpose:HDR brachytherapy consensus dose tolerance recommendations for organs at risk (OARs) remain widely debated. Prospective trials reporting metrics must be sufficiently data‐dense to assess adverse affects and identify optimally predictive tolerances. We explore the tradeoffs between reporting dose‐metrics versus volume‐metrics and the potential impact on trial outcome analysis and tolerance recommendations.Methods:We analyzed 26 prostate patients receiving 15 Gy HDR single‐fraction brachytherapy boost to 45 Gy external beam radiation therapy and 28 cervical patients receiving 28 Gy HDR brachytherapy monotherapy in 4 fractions using 2 implants. For each OAR structure, a robust linear regression fit was performed for the dose‐metrics as a function of the volume‐metrics. The plan quality information provided by recommended dose‐metric and volume‐metric values were compared.Results:For prostate rectal dose, D2cc and V75 lie close to the regression line, indicating they are similarly informative. Two outliers for prostate urethral dose are substantially different from the remaining cohort in terms of D0.1cc and V75, but not D1cc, suggesting the choice of reporting dose metric is essential. For prostate bladder and cervical bladder, rectum, and bowel, dose outliers are more apparent via V75 than recommended dose‐metrics. This suggests that for prostate bladder dose and all cervical OAR doses, the recommended volume‐metrics may be better predictors of clinical outcome than dose‐metrics.Conclusion:For plan acceptance criteria, dose and volume‐metrics are reciprocally equivalent. However, reporting dosemetrics or volume‐metrics alone provides substantially different information. Our results suggest that volume‐metrics may be more sensitive to differences in planned dose, and if one metric must be chosen, volumemetrics are preferable. However, reporting discrete DVH points severely limits the ability to identify planning tolerances most predictive of adverse effects. Thus, we recommend that full OAR DVH reporting be required for future prospective trials.

Radiation-Induced Modulation of Costimulatory and Coinhibitory T-Cell Signaling Molecules on Human Prostate Carcinoma Cells Promotes Productive Antitumor Immune Interactions

We sought to determine if single-dose external beam radiation therapy (EBRT) could modulate the expression signature of T-cell costimulatory and coinhibitory molecules in human prostate cancer (PCa) cell lines in vitro. We investigated the functional impact of irradiated PCa cells with a modulated costimulatory profile on responder T-cell activity. We used three PCa cell lines (DU145, PC3, and LNCaP) and two epithelial cell lines from noncancerous prostate and lung tissue. After 72 hours of EBRT, surface expression of four immunostimulatory molecules (CD70, CD275/ICOSL, CD134L/OX40L, and CD137L/41BBL) and two immunosuppressive markers (CTLA-4/CD152 and PD-L1/CD274) were evaluated by flow cytometry. We evaluated the impact of several radiation doses and the longevity of modulated expression. We examined the functional impact of radiation-induced modulation of cancer cells by cytotoxic T cells (CTL) cytotoxicity and ELISPOT assay for interferon-gamma (IFN-γ) production. Last, we evaluated whether IFN-γ-induced PD-L1 expression could be reversed by EBRT. After 10 Gy EBRT, expression of OX40L and 41BBL increased in all three PCa cell lines; expression of CD70 and ICOSL increased in PC3 cells. Conversely, a decrease in PD-L1 expression in DU145 and PC3 cells was detectable up to 144 hours after EBRT. No PD-L1 was detected in LNCaP. Epithelial cells from normal prostate were not modulated by radiation. CTL cytolytic activity and IFN-γ production were enhanced by interaction with irradiated PCa cells. Finally, EBRT failed to prevent IFN-γ-induced upregulation of PD-L1. We demonstrate that a single dose of EBRT increased surface expression of costimulatory molecules and decreased the expression of coinhibitory molecules in human PCa cell lines. Changes in irradiated tumor cells led to functional enhancement of T-cell activity, despite EBRT failing to reduce IFN-γ-induced expression of PD-L1. These data suggest that combining radiotherapy with T-cell stimulating immunotherapy may be an attractive strategy for cancer treatment.

The Investigation of 125I Seed Implantation as a Salvage Modality for Unresectable Pancreatic Carcinoma

To assess the efficacy of intraoperative ultrasound-guided implantation of 125I seeds for the treatment of unresectable pancreatic carcinoma, and analyze the associated prognostic factors. Twenty-eight patients with pancreatic carcinoma who underwent laparotomy and were considered to have unresectable tumors were included in this study. Nine patients were pathologically diagnosed with Stage II disease, and nineteen patients with Stage III disease. Twenty-eight patients received intraoperative ultrasound-guided 125I seed implantation and received a D90 (at least 90% of the tumor volume received the reference dose) ranging from 60 to 163 Gy, with a median of 120 Gy. Seven patients received an additional 35–50 Gy external beam radiotherapy after seed implantation, and ten patients received two to ten cycles of chemotherapy. Overall survival of the patients was calculated and prognostic factors were evaluated. Of the patients, 94.1% (16/17) achieved good to medium pain relief. The tumor response rate was 78.6% (22/28), and local control was achieved in 85.7% (24/28) of patients. The 1-, 2- and 3-year survival rates were 30%, 11% and 4%, and the median survival was 10.1 months (95% CI: 9.0-10.9). Analysis using the Cox proportional hazards model suggested that patients younger than 60 years and patients who received a D90 higher than 110 Gy may survive for a longer period. I seed implantation provides a safe and effective method to relieve pain, control local tumor growth and, to some extent, prolong the survival of patients with stage II and III pancreatic disease, without additional complications. Age and accumulated dose may be factors predictive of a favorable outcome for patients with unresectable pancreatic carcinoma treated with 125I seeds. These findings need to be validated by conducting further studies with larger cohorts.

Bulky Aggressive B-Cell Lymphoma: To Radiate or Not to Radiate—That Is the Question

Bulky Aggressive B-Cell Lymphoma: To Radiate or Not to Radiate—That Is the Question

High-dose-rate brachytherapy in the treatment of uterine cervical cancer using cobalt-60 radionuclide source: Three years treatment outcome

Background: The Iridium-192 radionuclide source is commonly used for high-dose-rate brachytherapy of uterine cervical cancer. The cobalt-60 radionuclide source, which is more economical, is now available with dosimetric properties similar to iridium-192. Objective: To evaluate late gastrointestinal and genitourinary complications, and also the survival pattern in cervical cancer patients treated with cobalt-60 high-dose-rate brachytherapy, three years after treatment. Materials and Methods: Seventy patients, who were treated with high-dose-rate brachytherapy using the cobalt-60 radionuclide source were followed up for three years. All the patients received 45 Gy of external beam radiotherapy in 22 daily fractions, with 19.5 Gy from high-dose-rate brachytherapy, in three fractions, over three weeks, using the cobalt-60 radio nuclide source. The patients also received concurrent cisplatin-based chemotherapy. Late complications were assessed every three months, using Radiation Therapy Oncology Group (RTOG) late toxicity criteria. The pattern of disease control was also assessed. Results: Late complications in the bowel were, six (9%) grade 1, four (6%) grade 2, one (1%) grade 3, and one (1%) grade 4. The late complications affecting the bladder were 5 (7%) grade 1 and 1 (1%) grade 4. Twenty-eight patients (40%) were alive without disease, seven (10%) were alive with disease, seven (10%) died of persistent disease, four (6%) died of metastatic disease, while 24 (34%) were lost to follow-up. Conclusion: The late complications were similar to those reported for Iridium-192 as a source of high-dose brachytherapy. Cobalt-60 high-dose-rate brachytherapy is tolerable, effective, and economical for low resource settings.

Combined cryotherapy and external beam radiation therapy for the treatment of intermediate-risk localized prostate cancer: A case series

Introduction: Routine PSA screening for prostate cancer (PCa) has increased the detection of intermediate-risk, localized disease. Conventional treatments for localized PCa include surgery, brachytherapy, cryotherapy or external beam radiotherapy (EBRT). However, for intermediate risk patients, rates of recurrence are moderately high and a multi-modal treatment approach for these patients may be necessary. We treated patients with a combination of cryotherapy and low dose EBRT to assess the safety and feasibility of this combinatory approach as well as to evaluate early oncological outcomes. Case Presentation: Men with intermediate risk (PSA = 10-20 ng/ml and/or Gleason = 7 and/or clinical T2b) localized PCa were prospectively enrolled in this study. Patients underwent cryotherapy and then 39 Gy EBRT 4-6 weeks after surgery. After completing EBRT, the men were followed every 3 months for 2 years. Adverse events, PSA, urinary and erectile function were assessed during each follow-up. Three patients completed the study. Preoperative PSA ranged from 3.5 to 7.9 ng/ml. There were no intraoperative complications and the treatment was well tolerated. Following cryotherapy and EBRT, all patients were pad-free within 6 months and remained continent for the duration of the study. Bother index remained stable throughout the study for all patients. No urethral strictures or rectal toxicities were observed. PSA remained undetectable for all patients. Conclusions: In this prospective study, cryotherapy combined with low dose EBRT was a safe approach for the treatment of intermediate-risk, localized PCa. Early oncological outcomes appeared to be favorable with all patients having undetectable PSA during the 2-year follow-up period. Further studies are warranted to confirm these preliminary results.

The investigation of 125I seed implantation as a salvage modality for unresectable pancreatic carcinoma.

BackgroundTo assess the efficacy of intraoperative ultrasound-guided implantation of 125I seeds for the treatment of unresectable pancreatic carcinoma, and analyze the associated prognostic factors.MethodsTwenty-eight patients with pancreatic carcinoma who underwent laparotomy and were considered to have unresectable tumors were included in this study. Nine patients were pathologically diagnosed with Stage II disease, and nineteen patients with Stage III disease. Twenty-eight patients received intraoperative ultrasound-guided 125I seed implantation and received a D90 (at least 90% of the tumor volume received the reference dose) ranging from 60 to 163 Gy, with a median of 120 Gy. Seven patients received an additional 35–50 Gy external beam radiotherapy after seed implantation, and ten patients received two to ten cycles of chemotherapy. Overall survival of the patients was calculated and prognostic factors were evaluated.ResultsOf the patients, 94.1% (16/17) achieved good to medium pain relief. The tumor response rate was 78.6% (22/28), and local control was achieved in 85.7% (24/28) of patients. The 1-, 2- and 3-year survival rates were 30%, 11% and 4%, and the median survival was 10.1 months (95% CI: 9.0-10.9). Analysis using the Cox proportional hazards model suggested that patients younger than 60 years and patients who received a D90 higher than 110 Gy may survive for a longer period.ConclusionsI seed implantation provides a safe and effective method to relieve pain, control local tumor growth and, to some extent, prolong the survival of patients with stage II and III pancreatic disease, without additional complications. Age and accumulated dose may be factors predictive of a favorable outcome for patients with unresectable pancreatic carcinoma treated with 125I seeds. These findings need to be validated by conducting further studies with larger cohorts.

Patterns of care in patients with cervical cancer 2012

Platinum-based primary or adjuvant chemoradiation is the treatment of choice for patients with cervical cancer. However, despite national guidelines and international recommendations, many aspects in diagnosis, therapy, and follow-up of patients with cervical cancer are not based on valid data. To evaluate the current patterns of care for patients with cervical cancer in Germany, a questionnaire with 25 items was sent to 281 radiooncologic departments and out-patient health care centers. The response rate was 51%. While 87% of institutions treat 0-25 patients/year, 12 % treat between 26 and 50 and only 1% treat more than 50 patients/year. In 2011, the stage distribution of 1,706 treated cervical cancers were IB1, IB2, IIA, IIB, IIIA/IIIB, and IV in 11, 12, 11, 22, 28, and 16%, respectively. CT (90%) and MRI (86%) are mainly used as staging procedures in contrast to PET-CT with 14%. Interestingly, 27% of institutions advocate surgical staging prior to chemoradiation. In the majority of departments 3D-based (70%) and intensity-modulated radiotherapy (76%) are used for percutaneous radiation, less frequently volumetric arc techniques (26%). Nearly all colleagues (99.3%) apply conventional fractioning of 1.8-2 Gy for external-beam radiotherapy, in 19% combined with a simultaneous integrated boost. Cisplatinum mono is used as a radiosensitizer with 40 mg/m(2) weekly by 90% of radiooncologists. For boost application in the primary treatment, HDR (high-dose rate) brachytherapy is the dominant technique (84%). In patients after radical hysterectomy pT1B1/1B2, node negative and resection in sound margins adjuvant chemoradiation is applied due to the occurrence of 1-4 other risk factors in 16-97%. There is a broad spectrum of recommended primary treatment strategies in stages IIB and IVA. Results of the survey underline the leading role but also differences in the use of chemoradiation in the treatment of cervical cancer patients in Germany.

SU-E-T-296: A Few Dosimetric Quality Indicators Provide Enough Dose Volume Histogram Information to Calculate Accurate Radiobiological Parameters in a Randomized Prostate Brachytherapy Trial

Purpose: To use 6 brachytherapy dosimetric quality indicators to compare radiobiological indices between two arms of a randomized trial. Methods: A 246 patient trial added 90 Gy 103Pd to 44 Gy external beam radiotherapy (EBRT) versus 115 Gy 103Pd added to 20 Gy EBRT. Six dosimetric quality indicators, D100, D90, V90, V100, V150, and V200, help define the shape of the brachytherapy dose volume histogram (DVH). Using TG-137 methodology, biological equivalent dose (BED) and tumor control probability (TCP) were calculated for each patient by applying an appropriate volume increment to each quality indicator. This approach was validated in 33 patients with accurate BEDs and TCPs calculated from the full DVH. Results: In the validation group, paired t-tests showed no differences between BEDs calculated by the 6-indicator or detailed DVH approaches. There were significant differences between cohorts in the full population. In the 44 Gy arm, the total BED was 162 ± 7 Gy compared to 143 ± 8 Gy in the 20 Gy arm (p < 0.001). The TCPs also differed significantly, with TCP of 1.000 ± 0.001 in the 44 Gy arm vs. 0.994 ± 0.010 in the 20 Gy arm. In sensitivity analysis, V150, and V200 comprised > 75% of the volume but contributed < 1% of the BED. D100 and V90 accounted for < 2% of the volume but contributed most of the BED. Conclusion: BEDs and TCPs calculated from 6 brachytherapy dosimetric quality indicators were nearly the same as those derived from detailed DVH analysis. Despite the clinically large difference of 19 Gy in total BED between arms, the difference in total TCP was small, 0.005. This is consistent with published trial outcomes showing no significant difference between the arms at any post-treatment time point, with 10-year progression free survival at 93% for both arms.

Complete Resolution of a Malignant Biliary Stricture Using Combined Neoadjuvant Chemoradiation and Brachytherapy Boost Prior to Orthotopic Liver Transplantation

Complete Resolution of a Malignant Biliary Stricture Using Combined Neoadjuvant Chemoradiation and Brachytherapy Boost Prior to Orthotopic Liver Transplantation To limit recurrence and intra-operative tumor dissemination at the time of transplant, there is increasing evidence that neoadjuvant chemoradiation and brachytherapy boost helps facilitate successful liver transplantation in patients with earlystage unresectable hilar cholangiocarcinoma. In published reports, a complete response to neoadjuvant therapy frequently limits the ability to detect residual disease in the hepatectomy specimen, thereby inviting criticism over whether published results are due to the neoadjuvant protocol per se, or selection of patients with earlystage or pre-malignant disease. In this report, a 41 year old male with a malignant biliary stricture received 45 Gy external beam radiation in conjunction with 5-fluoruracil as a prelude to transplant. This was followed by a transluminal boost of radiation (2000 cGy) using an Iridium-192 brachytherapy wire inserted through percutaneously-placed biliary catheters. Using this approach, we document the complete resolution of the patient’s malignant stricture, thereby objectively quantifying tumor response prior to orthotopic liver transplantation.

Surgical site infection following colorectal cancer surgery: Observations from Zaria, Northern Nigeria

Background: Management of colorectal cancer (CRC) in Nigeria is associated with such challenges as operating on locally advanced tumors. We performed a prospective observational study to assess the prevalence of surgical site infection (SSI) following CRC resection in a low resource setting. Materials and Methods: Consecutive patients, who had standard oncologic resection for CRC at Ahmadu Bello University Teaching Hospital, Zaria over a 5-year period from 2008 to 2012, were enrolled into the study. From 2010, patients with locally advanced rectal cancers were given neoadjuvant chemoradiation with concurrent 45 Gy external beam radiation over 5 weeks and fortnightly FOLFOX 4 regimen to downstage tumor followed 6 weeks later by surgery. Surgical resections were performed through open laparotomy. The outcome of interest was the development of SSI within 30 days of surgery. Patient and surgical variables were evaluated for association with SSI. Results: Of 188 patients seen with CRC, 78 (41.5%) had surgical resection and 75 were analyzed for SSI. The prevalence of SSI was 13.7% following transabdominal colectomy, 50% following abdominoperineal resection and 25.3% following overall CRC resection (P Conclusion: We observed that the prevalence of SSI in our setting is high and is possibly due to the difficulties of surgical resection of tumors most of which were locally advanced at the time of surgery among other factors.

Intraoperative Electron Beam Radiotherapy for Primary Treatment of Stage IIB Cervical Cancer: A Retrospective Study

A retrospective study to evaluate intraoperative electron beam radiotherapy (IOERT) as a primary treatment modality for stage IIB cervical squamous cell carcinoma. Patients underwent treatment with IOERT (n = 78) or radical radiotherapy (RT; n = 89). Patients in the IOERT group received 20 Gy external beam radiotherapy (EBRT) in 10 fractions, intracavitary brachytherapy (7-14 Gy, in patients with tumours ≥ 4 cm in diameter) and simple hysterectomy/selective lymphadenectomy with 18 - 20 Gy IOERT. Patients in the RT group received 50 Gy EBRT in 25 fractions followed by intracavitary brachytherapy (35-40 Gy). Median duration of follow-up was 92 months. IOERT resulted in significantly better 5- and 10-year overall survival, disease-free survival and local control rates, as well as fewer rectal and bladder complications, compared with RT. IOERT is an effective primary treatment for stage IIB cervical squamous cell carcinoma.