Liver function after combined selective internal radiation therapy or sorafenib monotherapy in advanced hepatocellular carcinoma.

BACKGROUND & AIMS: SORAMIC is a previously published randomised controlled trial assessing survival in patients with advanced hepatocellular carcinoma who received sorafenib with or without selective internal radiation therapy (SIRT). Based on the per-protocol (PP) population, we assessed whether the outcome of patients receiving SIRT+sorafenib vs. sorafenib alone was affected by adverse effects of SIRT on liver function. METHODS: The PP population consisted of 109 (SIRT+sorafenib) vs. 173 patients (sorafenib alone). Comparisons were made between subgroups who achieved a significant survival benefit or trend towards improved survival with SIRT and the inverse group without a survival benefit: <65 years-old vs. ≥65 years-old, Child-Pugh 5 vs. 6, no transarterial chemoembolisation (TACE) vs. prior TACE, no cirrhosis vs. cirrhosis, non-alcohol- vs. alcohol-related aetiology. The albumin-bilirubin (ALBI) score was used to monitor liver function over time during follow-up. RESULTS: ALBI scores increased in all patient groups during follow-up. In the PP population, ALBI score increases were higher in the SIRT+sorafenib than the sorafenib arm (p = 0.0021 month 4, p <0.0001 from month 6). SIRT+sorafenib conferred a survival benefit compared to sorafenib alone in patients aged <65 years-old, those without cirrhosis, those with Child-Pugh 5, and those who had not received TACE. A higher increase in ALBI score was observed in the inverse subgroups in whom survival was not improved by adding SIRT (age ≥65 years-old, p <0.05; cirrhosis, p = 0.07; Child-Pugh 6, p <0.05; prior TACE, p = 0.08). CONCLUSION: SIRT frequently has a negative, often subclinical, effect on liver function in patients with hepatocellular carcinoma, which may impair prognosis after treatment. Careful patient selection for SIRT as well as prevention of clinical and subclinical liver damage by selective treatments, high tumour uptake ratio, and medical prophylaxis could translate into better efficacy. CLINICAL TRIAL NUMBER: EudraCT 2009-012576-27, NCT01126645 LAY SUMMARY: This study of treatments in patients with hepatocellular carcinoma found that selective internal radiation therapy (SIRT) has an adverse effect on liver function that may affect patient outcomes. Patients should be carefully selected before they undergo SIRT and the treatment technique should be optimised for maximum protection of non-target liver parenchyma.

Co-treatment with Ginsenoside 20(S)-Rg3 and Curcumin increases Radiosensitivity of MDA-MB-231 Cancer Cell Line.

Background: Breast cancer is the second most common cancer in women worldwide. Developing drugs increase the radiosensitivity effect of tumoral tissue, while protecting normal tissues has gained much attention. Ginsenoside Rg3, one of the active components of ginseng, has been shown to possess various pharmacological effects and antiproliferation activity on cancer cell lines. In this study, we assessed the anti-cancer effect of co-treatment with ginsenoside 20(S)-Rg3 and curcumin on MDA-MB-231 breast cancer cells with and without radiotherapy. Methods: MTT assay was applied using different concentrations of ginsenoside 20(S)-Rg3 (0, 10, 80, 150 µmol/l) and curcumin (0, 10, 30, 50, 90 µg/mL). The inhibitory effect of co-treatment with these herbal drugs with and without 4 Gy radiotherapy on the MDA-MB-231 cell line was examined. Flow cytometry was applied to measure the effect of co-treatment of the drugs on radiation-induced apoptosis. The data were analyzed using ANOVA and Kruskal-Wallis tests. P values<0.05 were considered statistically significant. Results: The results of the MTT assay showed that ginsenoside 20(S)-Rg3 and curcumin had an inhibitory effect on the MDA-MB-231 cell line in a concentration-dependent manner. Ginsenoside 20(S)-Rg3 and curcumin inhibited tumor cell development and proliferation at concentrations of 80 µmol/L and 30 µg/mL, respectively, with 50% cell viability (P=0.018, P=0.01, respectively) at 48 hour incubation time. Conclusion: Ginsenoside 20(S)-Rg3 and curcumin inhibited MDA-MB-231 cell growth in a dose- and time-dependent manner and increased the radiosensitivity of cancer cells. These herbal drugs can be considered as a radiosensitizer in radiotherapy.

Comparison of Multimodal Therapies and Outcomes Among Patients With High-Risk Prostate Cancer With Adverse Clinicopathologic Features.

Importance: The optimal management strategy for high-risk prostate cancer and additional adverse clinicopathologic features remains unknown. Objective: To compare clinical outcomes among patients with high-risk prostate cancer after definitive treatment. Design, Setting, and Participants: This retrospective cohort study included patients with high-risk prostate cancer (as defined by the National Comprehensive Cancer Network [NCCN]) and at least 1 adverse clinicopathologic feature (defined as any primary Gleason pattern 5 on biopsy, clinical T3b-4 disease, ≥50% cores with biopsy results positive for prostate cancer, or NCCN ≥2 high-risk features) treated between 2000 and 2014 at 16 tertiary centers. Data were analyzed in November 2020. Exposures: Radical prostatectomy (RP), external beam radiotherapy (EBRT) with androgen deprivation therapy (ADT), or EBRT plus brachytherapy boost (BT) with ADT. Guideline-concordant multimodal treatment was defined as RP with appropriate use of multimodal therapy (optimal RP), EBRT with at least 2 years of ADT (optimal EBRT), or EBRT with BT with at least 1 year ADT (optimal EBRT with BT). Main Outcomes and Measures: The primary outcome was prostate cancer-specific mortality; distant metastasis was a secondary outcome. Differences were evaluated using inverse probability of treatment weight-adjusted Fine-Gray competing risk regression models. Results: A total of 6004 men (median [interquartile range] age, 66.4 [60.9-71.8] years) with high-risk prostate cancer were analyzed, including 3175 patients (52.9%) who underwent RP, 1830 patients (30.5%) who underwent EBRT alone, and 999 patients (16.6%) who underwent EBRT with BT. Compared with RP, treatment with EBRT with BT (subdistribution hazard ratio [sHR] 0.78, [95% CI, 0.63-0.97]; P = .03) or with EBRT alone (sHR, 0.70 [95% CI, 0.53-0.92]; P = .01) was associated with significantly improved prostate cancer-specific mortality; there was no difference in prostate cancer-specific mortality between EBRT with BT and EBRT alone (sHR, 0.89 [95% CI, 0.67-1.18]; P = .43). No significant differences in prostate cancer-specific mortality were found across treatment cohorts among 2940 patients who received guideline-concordant multimodality treatment (eg, optimal EBRT alone vs optimal RP: sHR, 0.76 [95% CI, 0.52-1.09]; P = .14). However, treatment with EBRT alone or EBRT with BT was consistently associated with lower rates of distant metastasis compared with treatment with RP (eg, EBRT vs RP: sHR, 0.50 [95% CI, 0.44-0.58]; P < .001). Conclusions and Relevance: These findings suggest that among patients with high-risk prostate cancer and additional unfavorable clinicopathologic features receiving guideline-concordant multimodal therapy, prostate cancer-specific mortality outcomes were equivalent among those treated with RP, EBRT, and EBRT with BT, although distant metastasis outcomes were more favorable among patients treated with EBRT and EBRT with BT. Optimal multimodality treatment is critical for improving outcomes in patients with high-risk prostate cancer.

Variación de dosis de radioyodo en pacientes con cáncer diferenciado de tiroides post implementación de guías ATA 2015 / Variation of radioiodine dose in patients with differentiated thyroid cancer after implementation of the ATA 2015 guidelines

Introducción: El cáncer diferenciado de tiroides (CDT), es actualmente la neoplasia endocrina más frecuente. Su tratamiento estándar es la resolución quirúrgica, asociado a ablación con radioyodo (RI) según la clasificación propuesta por la American Thyroid Association (ATA). Las indicaciones y dosis de este último, han ido variando en los últimos años según avanzan las investigaciones en este ámbito. Objetivo: En el siguiente estudio se compararon las dosis de RI utilizadas previo y posterior a la implementación de las últimas guías de la ATA. Materiales y métodos: Estudio retrospectivo observacional de 70 pacientes con diagnóstico de CDT del Hospital Clínico de la Universidad de Chile entre 2012 y 2017. Se agruparon los pacientes en dos cohortes, los operados entre los años 2012-2015 y los 2016-2017 clasificándolos según riesgo ATA, TNM y riesgo de recurrencia. Se consignaron las dosis de RI utilizadas y se compararon entre las cohortes. Análisis estadístico: Mann Whithney. Resultados: Al comparar la dosis de RI entre ambas cohortes, según TNM y riesgo ATA, se obtuvo los siguientes resultados: los pacientes T1b de la cohorte 2012-2015 presentaron dosis de RI significativamente mayores que los de la cohorte 2016-2017; también se evidenció que en pacientes N0 hubo una diferencia estadísticamente significativa, mostrando una tendencia a disminuir la dosis de RI; además, en los pacientes de la cohorte 2012-2015 con riesgo ATA intermedio, se obtuvo que las dosis de RI fueron significativamente mayores que las utilizadas en la cohorte 2016-2017. Conclusión: Se concluye que las variaciones de las dosis de RI utilizadas en pacientes con CDT en un hospital universitario van acorde a las recomendaciones internacionales actuales, particularmente la publicación de la guía ATA 2015, aplicándose radioablación con menor dosis de RI. Dado este cambio, se ha evidenciado igualdad de efectos con dosis menores de RI y consecuentemente menos efectos adversos.

Introduction: Differentiated thyroid cancer (CDT) is currently the most frequent endocrine neoplasia. Its standard of care is surgical treatment, associated with radioiodine ablation (IR) according to the classification proposed by the American Thyroid Association (ATA). The indications and doses of the latter have changed in recent years as research in this area advances. Objective: In the following study, the doses of IR used before and after the implementation of the latest ATA guidelines were compared. Materials and methods: Retrospective observational study of 70 patients with a diagnosis of CDT from the Clinical Hospital of the University of Chile between 2012 and 2017. Patients were grouped into two cohorts, those surgically intervened between the years 2012-2015 and 2016-2017, classifying them according to ATA risk, TNM and recurrence risk. The IR doses used were reported and compared between the cohorts. Statistical analysis: Mann Whithney. Results: When comparing the IR dose between both cohorts, according to TNM and ATA risk, the following results were obtained: T1b patients in the 2012-2015 cohort had significantly higher IR doses than those in the 2016-2017 cohort; It was also evidenced that N0 patients showed a statistically significant tendency to decrease the IR dose; In addition, the 2012-2015 cohort with intermediate ATA risk, revealed IR doses significantly higher than those used in the 2016-2017 cohort. Conclusion: It is concluded that the variations in IR doses, used in patients with CDT in a university hospital, are in accordance with current international recommendations, particularly the publication of the ATA 2015 guidelines, applying radioablation with a lower dose of IR. Given this change, equality of effects has been evidenced with lower doses of IR and consequently fewer adverse effects.

Utilizing Quality Improvement Methods to Examine the Radiation Therapy Pathway for Patients Requiring Palliative Radiation Therapy at a Community Cancer Center.

BACKGROUND: At a community cancer center, during weekly quality improvement huddles, the radiation therapy team expressed stress and frustration with the pretreatment pathway for patients requiring palliative radiotherapy. As the department was meeting provincial targets with respect to wait times, it was unknown why the consensus around the department reflected discomfort and stress. METHODS: Four radiation therapists formed a quality improvement project team, intent on utilizing a data-driven improvement cycle to investigate and address opportunities to improve the discomfort around this pretreatment pathway. After defining the process and identifying the customers (the health care providers operating in this pathway), the team conducted interviews with each person, transcribing answers verbatim, and grouping results by discipline. Utilizing the interview themes, each discipline identified one or two priorities to measure, as well as metrics to capture the magnitude and prevalence of these priorities. RESULTS: Each discipline's priorities were measured and analyzed. The identified issues brought forward at the weekly quality improvement huddles were not as prevalent as expected. Minor changes were implemented for priority issues. CONCLUSION: The team focused on the four principles of quality improvement: the patient, team, process, and data to address the expressed discomfort around this specific radiation therapy pathway. The results dispelled some of the myths among teams and provided solutions to areas where minor improvements were required. Utilizing the data, an evidence-informed timeline was validated, encouraging task deadlines to be more evenly distributed across the pathway. Plans to monitor this pathway are being established. The team was successful in contributing to a growing culture of continuous improvement at this community cancer center.

Approved Treatments for Patients with Recurrent High-grade Gliomas.

OBJECTIVES: To review the existing glioma literature and National Comprehensive Cancer Network current standard-of care guidelines for recurrent high-grade glioma, which includes surgery, radiation, and systemic therapies. DATA SOURCES: PubMed, MedlinePlus, Science Direct, National Comprehensive Cancer Network, and Google Scholar were searched. Key words for databases were high-grade glioma, glioblastoma, recurrent, surgery, radiation, and systemic therapy. CONCLUSION: Approved treatments for patients with recurrent high-grade glioma are limited and do not significantly impact progression-free survival rates, nor do they offer long-term benefit in symptom improvement or quality of life. Particular consideration for progression versus pseudoprogression should be evaluated before pursuing recurrent therapies. IMPLICATIONS FOR NURSING PRACTICE: Given the limited availability of standard-of-care treatments, clinical trials should be prioritized to maximize future treatment options. Individual performance status, genetic and molecular profiles, as well as goals of care and quality of life are important considerations in the context of treatment plans.

Current Standard and Future Perspectives in Non-Surgical Therapy for Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is an aggressive liver tumor with a poor 5-year survival rate. Many HCCs are not amenable to surgical resection, because of tumor size, location, or because of the patient's poor liver function, a common obstacle to HCC therapy, because HCCs almost always develop in chronically inflamed livers. SUMMARY: In recent years, many efforts have been made to improve patient survival by conducting clinical trials investigating local and systemic treatment options for patients with unresectable tumors. These treatment options include radiofrequency ablation (RFA), transarterial chemoembolization (TACE), selective internal radiotherapy with yttrium-90 (SIRT), stereotactic body radiation therapy (SBRT), proton beam therapy, molecular targeted therapy, and checkpoint inhibition. In this "to-the-point" article, we review the current standard and summarize the most recent findings in unresectable HCC treatment. KEY POINTS: (1) RFA is currently the preferred treatment for patients with tumor burden restricted to the liver and not eligible for surgical resection; (2) TACE is utilized in patients who are not eligible for RFA because of tumor location and/or number of tumor lesions; (3) SIRT might improve treatment responses achieved by TACE and is feasible in patients with portal vein thrombosis; (4) new radiation therapy treatment modalities such as SBRT and proton beam therapy show promising results for local tumor control; and (5) sorafenib remains the first-line systemic treatment option after several large clinical trials have failed to show superiority of other molecular targeted therapies in HCC patients.

Differentiated Thyroid Cancer-Treatment: State of the Art.

Differentiated thyroid cancer (DTC) is a rare malignant disease, although its incidence has increased over the last few decades. It derives from follicular thyroid cells. Generally speaking, the prognosis is excellent. If treatment according to the current guidelines is given, cases of recurrence or persistence are rare. DTC requires special expertise by the treating physician. In recent years, new therapeutic options for these patients have become available. For this article we performed a systematic literature review with special focus on the guidelines of the American Thyroid Association, the European Association of Nuclear Medicine, and the German Society of Nuclear Medicine. For DTC, surgery and radioiodine therapy followed by levothyroxine substitution remain the established therapeutic procedures. Even metastasized tumors can be cured this way. However, in rare cases of radioiodine-refractory tumors, additional options are to be discussed. These include strict suppression of thyroid-stimulating hormone (also known as thyrotropin, TSH) and external local radiotherapy. Systemic cytostatic chemotherapy does not play a significant role. Recently, multikinase or tyrosine kinase inhibitors have been approved for the treatment of radioiodine-refractory DTC. Although a benefit for overall survival has not been shown yet, these new drugs can slow down tumor progression. However, they are frequently associated with severe side effects and should be reserved for patients with threatening symptoms only.

Association of Hospital Volume With Racial and Ethnic Disparities in Locally Advanced Cervical Cancer Treatment.

OBJECTIVE: To evaluate racial-ethnic disparities in guideline-based care in locally advanced cervical cancer and their relationship to hospital case volume. METHODS: Using the National Cancer Database, we performed a retrospective cohort study of women diagnosed between 2004 and 2012 with locally advanced squamous or adenocarcinoma of the cervix undergoing definitive primary radiation therapy. The primary outcome was the race-ethnicity-based rates of adherence to the National Comprehensive Cancer Network guideline-based care. The secondary outcome was the effect of guideline-based care on overall survival. Multivariable models and propensity matching were used to compare the hospital risk-adjusted rates of guideline-based adherence and overall survival based on hospital case volume. RESULTS: The final cohort consisted of 16,195 patients. The rate of guideline-based care was 58.4% (95% confidence interval [CI] 57.4-59.4%) for non-Hispanic white, 53% (95% CI 51.4-54.9%) for non-Hispanic black, and 51.5% (95% CI 49.4-53.7%) for Hispanic women (P<.001). From 2004 to 2012, the rate of guideline-based care increased from 49.5% (95% CI 47.1-51.9%) to 59.1% (95% CI 56.9-61.2%) (Ptrend<.001). Based on a propensity score-matched analysis, patients receiving guideline-based care had a lower risk of mortality (adjusted hazard ratio 0.65, 95% CI 0.62-0.68). Compared with low-volume hospitals, the increase in adherence to guideline-based care in high-volume hospitals was 48-63% for non-Hispanic white, 47-53% for non-Hispanic black, and 41-54% for Hispanic women. CONCLUSION: Racial and ethnic disparities in the delivery of guideline-based care are the highest in high-volume hospitals. Guideline-based care in locally advanced cervical cancer is associated with improved survival.

Current patterns of care for patients with extensive stage small cell lung cancer: Survey of US radiation oncologists on their recommendations regarding thoracic consolidation radiotherapy.

OBJECTIVES: Current National Comprehensive Cancer Network (NCCN) guidelines recommend thoracic consolidation radiation therapy (TCRT) for patients with Extensive Stage Small Cell Lung Cancer (ES-SCLC) with response to systemic chemotherapy, based on two randomized clinical trials, which varied in patient selection and radiation therapy doses administered. The current pattern of practice among US radiation oncologists is unknown. MATERIALS AND METHODS: We have surveyed practicing US radiation oncologist via a short online questionnaire. Respondents' characteristics and their self-rated knowledge base were analyzed for association with their treatment recommendations. RESULTS: We received 473 responses from practicing US radiation oncologists. Over half of respondents were practicing for over 10 years after completing residency training and 70% treated more than 10 lung cancer patients per year. 96% of respondents recommend TCRT for patients with ES-SCLC after systemic chemotherapy. Patient selection and radiation therapy doses vary greatly. High self-rated knowledge of individual clinical trials is associated with lower TCRT recommended doses. Patients treated at academic centers are less likely to receive TCRT than patients treated in private clinics (p=0.0101). CONCLUSION: Our analysis revealed that among the respondents, there was a very high adherence to current NCCN guidelines, which recommend TCRT for ES-SCLC patients with clinical response to systemic chemotherapy. The great variability in patient selection and radiation therapy doses is concerning and calls for future clinical trials to standardize treatment approaches and improve treatment outcomes among patients with ES-SCLC. Until such data exists and in light of poor long-term survival of patients with ES-SCLC, the shorter and less toxic regimen of 30Gy in 10 fractions should be used as the standard of care and the more aggressive regimens studied on clinical protocols.

Fox Chase Cancer Center's Genitourinary Division: a national resource for research, innovation and patient care.

Founded in 1904, Fox Chase Cancer Center remains committed to its mission. It is one of 41 centers in the country designated as a Comprehensive Cancer Center by the National Cancer Institute, is a founding member of the National Comprehensive Cancer Network, holds the magnet designation for nursing excellence, is one of the first to establish a family cancer risk assessment program, and has achieved national distinction because of the scientific discoveries made there that have advanced clinical care. Two of its researchers have won Nobel prizes. The Genitourinary Division is nationally recognized and viewed as one of the top driving forces behind the growth of Fox Chase due to its commitment to initiating and participating in clinical trials, its prolific contributions to peer-reviewed publications and presentations at scientific meetings, its innovations in therapies and treatment strategies, and its commitment to bringing cutting-edge therapies to patients.

Quality indicators for prostate radiotherapy: are patients disadvantaged by receiving treatment in a 'generalist' centre?

INTRODUCTION: The purpose of this retrospective review was to evaluate concordance with evidence-based quality indicator guidelines for prostate cancer patients treated radically in a 'generalist' (as distinct from 'sub-specialist') centre. We were concerned that the quality of treatment may be lower in a generalist centre. If so, the findings could have relevance for many radiotherapy departments that treat prostate cancer. METHODS: Two hundred fifteen consecutive patients received external beam radiotherapy (EBRT) and/or brachytherapy between 1.10.11 and 30.9.12. Treatment was deemed to be in line with evidence-based guidelines if the dose was: (i) 73.8-81 Gy at 1.8-2.0 Gy/fraction for EBRT alone (eviQ guidelines); (ii) 40-50 Gy (EBRT) for EBRT plus high-dose rate (HDR) brachytherapy boost (National Comprehensive Cancer Network (NCCN) guidelines); and (iii) 145 Gy for low dose rate (LDR) I-125 monotherapy (NCCN). Additionally, EBRT beam energy should be ≥6 MV using three-dimensional conformal RT (3D-CRT) or intensity-modulated RT (IMRT), and high-risk patients should receive neo-adjuvant androgen-deprivation therapy (ADT) (eviQ/NCCN). Treatment of pelvic nodes was also assessed. RESULTS: One hundred four high-risk, 84 intermediate-risk and 27 low-risk patients (NCCN criteria) were managed by eight of nine radiation oncologists. Concordance with guideline doses was confirmed in: (i) 125 of 136 patients (92%) treated with EBRT alone; (ii) 32 of 34 patients (94%) treated with EBRT + HDR BRT boost; and (iii) 45 of 45 patients (100%) treated with LDR BRT alone. All EBRT patients were treated with ≥6 MV beams using 3D-CRT (78%) or IMRT (22%). 84%, 21% and 0% of high-risk, intermediate-risk and low-risk patients received ADT, respectively. Overall treatment modality choice (including ADT use and duration where assessable) was concordant with guidelines for 176/207 (85%) of patients. CONCLUSION: The vast majority of patients were treated concordant with evidence-based guidelines suggesting that, within the limits of the selected criteria, prostate cancer patients are unlikely to be disadvantaged by receiving radiotherapy in this 'generalist' centre.

The QUIRO Study (assurance of quality and innovation in radiooncology): methodology, instruments and practices.

PURPOSE: The QUIRO study aimed to establish a secure level of quality and innovation in radiation oncology. Over 6 years, 27 specific surveys were conducted at 24 radiooncological departments. In all, 36 renowned experts from the field of radiation oncology (mostly head physicians and full professors) supported the realization of the study. METHODS: A salient feature of the chosen methodological approach is the "process" as a means of systematizing diversified medical-technical procedures according to standardized criteria. On the one hand, "processes" as a tool of translation are adapted for creating and transforming standards into concrete clinical and medical actions; on the other hand, they provide the basis for standardized instruments and methods to determine the required needs of physicians, staff, and equipment. In the foreground of the collection and measurement of resource requirements were the processes of direct service provision which were subdivided into modules for reasons of clarity and comprehensibility. Overhead tasks (i.e., participation in quality management) were excluded from the main study and examined in a separate survey with appropriate methods. RESULTS: After the exploration of guidelines, tumor- or indication-specific examination and treatment processes were developed in expert workshops. Moreover, those specific modules were defined which characterize these entities and indications in a special degree. Afterwards, these modules were compiled according to their time and resources required in the "reference institution", i.e., in specialized and as competent recognized departments (mostly from the university area), by various suitable survey methods. CONCLUSION: The significance of the QUIRO study and the validity of the results were optimized in a process of constant improvements and comprehensive checks. As a consequence, the QUIRO study yields representative results concerning the resource requirement for specialized, qualitatively and technologically highly sophisticated radiooncologic treatment in Germany.

Consistency in reference radiotherapy dosimetry: resolution of an apparent conundrum when (60)Co is the reference quality for charged-particle and photon beams.

Substantial changes in ion chamber perturbation correction factors in (60)Co γ-rays, suggested by recent Monte Carlo (MC) calculations, would cause a decrease of about 1.5% in the reference dosimetry of all types of charged particles (electrons, protons and heavier ions) based on calculated kQ values. It has gone largely unnoticed that the ratio of calibration coefficients ND, w, Co60 and NK, air, Co60 yields an experimental value of Fch, Co60 = (sw-air pch)Co60 through ND, air, Co60. Coefficients provided by the IAEA and traceable to the BIPM for 91 NE-2571 chambers result in an average Fch, Co60 which is compared with published (and new) MC simulations and with the value in IAEA TRS-398. It is shown that TRS-398 agrees within 0.12% with the experimental Fch, Co60. The 1.5% difference resulting from MC calculations (1.1% for the new simulations) cannot be justified using current fundamental data and BIPM standards if consistency in the entire dosimetry chain is sought. For photons, MC kQ factors are compared with TRS-398. Using the same uncertainty for Wair, the two sets of data overlap considerably. Experimental kQ values from standards laboratories lie between the two sets of calculated values, showing no preference for one set over the other. Observed chamber-to-chamber differences, that include the effect of waterproof sleeves (also seen for (60)Co), justify the recommendation in TRS-398 for kQ values specifically measured for the user chamber. Current developments on I-values for the stopping powers of water and graphite are presented. A weighted average Iwater = 78 ± 2 eV is obtained from published experimental and DRF-based values; this would decrease sw-air for all types of radiotherapy beams between 0.3% and 0.6%, and would consequently decrease the MC derived Fch, Co60. The implications of a recent proposal for Igraphite = 81 eV are analysed, resulting in a potential decrease of 0.7% in NK, air, Co60 which would raise the experimental Fch, Co60; this would result in an increase of about 0.8% in the current TRS-398 value when referred to the BIPM standards. MC derived Fch, Co60 using new stopping powers would then agree at a level of 0.1% with the experimental value, confirming the need for consistency in the dosimetry chain data. Should world average standards be used as reference, the figures would become +0.4% for TRS-398 and -0.3% for the MC calculation. Fch, Q calculated for megavoltage photons using new stopping powers would decrease by between 0.2% and 0.5%. When they enter as a ratios in kQ, differences with MC values based on current key data would be within 0.2% but their discrepancy with kQ experimental photon values remains unresolved. For protons the new data would require an increase in Wair, Q of about 0.6%, as this is inferred from a combination of calorimetry and ionometry. This consistent scenario would leave unchanged the current TRS-398 kQ (NE-2571) data for protons, as well as for ions heavier than protons unless new independent Wair, Q values become available. Also in these advanced radiotherapy modalities, the need for maintaining data consistency in an analysis that unavoidably must include the complete dosimetry chain is demonstrated.

Imaging of moving fiducial markers during radiotherapy using a fast, efficient active pixel sensor based EPID.

PURPOSE: The purpose of this work was to investigate the use of an experimental complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) for tracking of moving fiducial markers during radiotherapy. METHODS: The APS has an active area of 5.4 × 5.4 cm and maximum full frame read-out rate of 20 frame s(-1), with the option to read out a region-of-interest (ROI) at an increased rate. It was coupled to a 4 mm thick ZnWO4 scintillator which provided a quantum efficiency (QE) of 8% for a 6 MV x-ray treatment beam. The APS was compared with a standard iViewGT flat panel amorphous Silicon (a-Si) electronic portal imaging device (EPID), with a QE of 0.34% and a frame-rate of 2.5 frame s(-1). To investigate the ability of the two systems to image markers, four gold cylinders of length 8 mm and diameter 0.8, 1.2, 1.6, and 2 mm were placed on a motion-platform. Images of the stationary markers were acquired using the APS at a frame-rate of 20 frame s(-1), and a dose-rate of 143 MU min(-1) to avoid saturation. EPID images were acquired at the maximum frame-rate of 2.5 frame s(-1), and a reduced dose-rate of 19 MU min(-1) to provide a similar dose per frame to the APS. Signal-to-noise ratio (SNR) of the background signal and contrast-to-noise ratio (CNR) of the marker signal relative to the background were evaluated for both imagers at doses of 0.125 to 2 MU. RESULTS: Image quality and marker visibility was found to be greater in the APS with SNR ∼5 times greater than in the EPID and CNR up to an order of magnitude greater for all four markers. To investigate the ability to image and track moving markers the motion-platform was moved to simulate a breathing cycle with period 6 s, amplitude 20 mm and maximum speed 13.2 mm s(-1). At the minimum integration time of 50 ms a tracking algorithm applied to the APS data found all four markers with a success rate of ≥92% and positional error ≤90 µm. At an integration time of 400 ms the smallest marker became difficult to detect when moving. The detection of moving markers using the a-Si EPID was difficult even at the maximum dose-rate of 592 MU min(-1) due to the lower QE and longer integration time of 400 ms. CONCLUSIONS: This work demonstrates that a fast read-out, high QE APS may be useful in the tracking of moving fiducial markers during radiotherapy. Further study is required to investigate the tracking of markers moving in 3D in a treatment beam attenuated by moving patient anatomy. This will require a larger sensor with ROI read-out to maintain speed and a manageable data-rate.

ACR-ASTRO practice guideline for the performance of therapy with unsealed radiopharmaceutical sources.

This guideline is intended to guide appropriately trained and licensed physicians performing therapy with unsealed radiopharmaceutical sources. Adherence to this guideline should help to maximize the efficacious use of these procedures, maintain safe conditions, and ensure compliance with applicable regulations. The topics dealt with in this guideline include indications for the use of iodine-131, both for the treatment of hyperthyroidism and thyroid carcinoma. In addition, indications for other less common procedures include those for the use of phosphorous-32 in its liquid and colloidal forms, strontium-89, samarium-153, and the use of Y-90 antibodies.

Treatment guideline of radiotherapy for Chinese esophageal carcinoma (draft).

Esophageal carcinoma is one of the most common human cancers in China. Radiotherapy plays an important role in combination therapy of esophageal carcinoma. With regret, there is still no unified standard for the treatment of esophageal carcinoma in China, and there are many controversies in the treatment regimens, indications, methods and efficacy. Clinically, the clinical practice guidelines of the National Comprehensive Cancer Network (NCCN) of the United States were often consulted, but the data of them were mainly from the patients from Europe and America, and they might not be applicable for Chinese patients. In order to standardize clinical process of radiotherapy for esophageal carcinoma in China, the Esophageal Carcinoma Cooperative Group of Radiation Oncology Society of Chinese Medical Association wrote a consensus and controversies on the radiotherapy for esophageal carcinoma (draft) after years of research and discussion. We hope it be tried out and discussed with advice and valuable suggestions, in order to accelerate the process of standardization of esophageal carcinoma treatment in China.

[Quality assurance in radiotherapy]. / Assurance de la qualité en radiothérapie.

Quality assurance in radiotherapy affects the radiotherapy department organization, management, patient follow-up, distribution of responsibilities, training and equipment management. The development of innovative techniques for radiotherapy and associated radiotherapy equipment requires an adaptation of the concepts of quality assurance and quality control as practiced last 30 years. A new paradigm and new methods adapted from industry, including patient safety and quality care in a more holistic approach to quality assurance and quality control.

Establishment of technical prerequisites for cell irradiation experiments with laser-accelerated electrons.

PURPOSE: In recent years, laser-based acceleration of charged particles has rapidly progressed and medical applications, e.g., in radiotherapy, might become feasible in the coming decade. Requirements are monoenergetic particle beams with long-term stable and reproducible properties as well as sufficient particle intensities and a controlled delivery of prescribed doses at the treatment site. Although conventional and laser-based particle accelerators will administer the same dose to the patient, their different time structures could result in different radiobiological properties. Therefore, the biological response to the ultrashort pulse durations and the resulting high peak dose rates of these particle beams have to be investigated. The technical prerequisites, i.e., a suitable cell irradiation setup and the precise dosimetric characterization of a laser-based particle accelerator, have to be realized in order to prepare systematic cell irradiation experiments. METHODS: The Jena titanium:sapphire laser system (JETI) was customized in preparation for cell irradiation experiments with laser-accelerated electrons. The delivered electron beam was optimized with regard to its spectrum, diameter, dose rate, and dose homogeneity. A custom-designed beam and dose monitoring system, consisting of a Roos ionization chamber, a Faraday cup, and EBT-1 dosimetry films, enables real-time monitoring of irradiation experiments and precise determination of the dose delivered to the cells. Finally, as proof-of-principle experiment cell samples were irradiated using this setup. RESULTS: Laser-accelerated electron beams, appropriate for in vitro radiobiological experiments, were generated with a laser shot frequency of 2.5 Hz and a pulse length of 80 fs. After laser acceleration in the helium gas jet, the electrons were filtered by a magnet, released from the vacuum target chamber, and propagated in air for a distance of 220 mm. Within this distance a lead collimator (aperture of 35 mm) was introduced, leading, along with the optimized setup, to a beam diameter of 35 mm, sufficient for the irradiation of common cell culture vessels. The corresponding maximum dose inhomogeneity over the beam spot was less than 10% for all irradiated samples. At cell position, the electrons posses a mean kinetic energy of 13.6 MeV, a bunch length of about 5 ps (FWHM), and a mean pulse dose of 1.6 mGy/bunch. Cross correlations show clear linear dependencies for the online recorded accumulated bunch charges, pulse doses, and pulse numbers on absolute doses determined with EBT-1 films. Hence, the established monitoring system is suitable for beam control and a dedicated dose delivery. Additionally, reasonable day-to-day stable and reproducible properties of the electron beam were achieved. CONCLUSIONS: Basic technical prerequisites for future cell irradiation experiments with ultrashort pulsed laser-accelerated electrons were established at the JETI laser system. The implemented online control system is suitable to compensate beam intensity fluctuations and the achieved accuracy of dose delivery to the cells is sufficient for radiobiological cell experiments. Hence, systematic in vitro cell irradiation experiments can be performed, being the first step toward clinical application of laser-accelerated particles. Further steps, including the transfer of the established methods to experiments on higher biological systems or to other laser-based particle accelerators, will be prepared.

Report of AAPM Therapy Physics Committee Task Group 74: in-air output ratio, Sc, for megavoltage photon beams.

The concept of in-air output ratio (Sc) was introduced to characterize how the incident photon fluence per monitor unit (or unit time for a Co-60 unit) varies with collimator settings. However, there has been much confusion regarding the measurement technique to be used that has prevented the accurate and consistent determination of Sc. The main thrust of the report is to devise a theoretical and measurement formalism that ensures interinstitutional consistency of Sc. The in-air output ratio, Sc, is defined as the ratio of primary collision water kerma in free-space, Kp, per monitor unit between an arbitrary collimator setting and the reference collimator setting at the same location. Miniphantoms with sufficient lateral and longitudinal thicknesses to eliminate electron contamination and maintain transient electron equilibrium are recommended for the measurement of Sc. The authors present a correction formalism to extrapolate the correct Sc from the measured values using high-Z miniphantom. Miniphantoms made of high-Z material are used to measure Sc for small fields (e.g., IMRT or stereotactic radiosurgery). This report presents a review of the components of Sc, including headscatter, source-obscuring, and monitor-backscattering effects. A review of calculation methods (Monte Carlo and empirical) used to calculate Sc for arbitrary shaped fields is presented. The authors discussed the use of Sc in photon dose calculation algorithms, in particular, monitor unit calculation. Finally, a summary of Sc data (from RPC and other institutions) is included for QA purposes.