Radiation therapy for bone-only metastases in breast cancer patients: A GOCO survey of current clinical practice.

INTRODUCTION: The role of radiation therapy (RT) for patients with bone-only metastatic (BOM) breast cancer has not been investigated sufficiently. The aim of this survey was to evaluate current clinical practice in treating breast cancer patients with BOM in Radiation Therapy Departments in Catalonia and Occitania within the scope of the GOCO group. MATERIALS AND METHODS: An electronic questionnaire was completed by experienced radiation oncologists from fourteen RT centers. The items surveyed the professional experience, therapeutic approach, technique, dose stereotactic body RT (SBRT) availability. RESULTS: All Radiation Oncology Departments (ROD) in Catalonia (12) and Occitania (2) responded to the survey. Eleven (78.5%) of the RODs advise RT for BOM as initial treatment in the oligometastatic setting. RT to asymptomatic bone oligometastases is more often restricted for "risky lesions". The most inconsistent approaches were the treatment for asymptomatic lesions, when to treat bone metastases with respect to systemic treatment (ST) and the indication for RT after a complete response to ST. CONCLUSION: While BOM breast cancer patients have a relatively good prognosis, there is a lack of consistency in their approach with RT. This can be explained by the absence of evidence-based guidelines and an incomplete availability of SBRT.

Evidence-based guidelines for hypofractionated radiation in breast cancer: conclusions of the Catalan expert working group.

INTRODUCTION: Daily, moderate hypofractionation has become standard treatment for breast cancer following breast-conserving surgery, although substantial variation exists in its use. This paper describes the generation of consensus-based recommendations for the utilisation of this therapy at the healthcare system level and compares these to American Society for Radiation Oncology (ASTRO) guidelines. MATERIALS AND METHODS: Consensus-based guidelines were developed in three steps, including a systematic literature review and involvement of radiation oncologists specialising in breast cancer in Catalonia: (a) creation of a working group and evidence review; (b) consideration of the levels of evidence and agreement on the formulation of survey questions; and (c) performance of survey and development of consensus-based recommendations. Results were compared to the ASTRO recommendations. RESULTS: Consensus was above 80% for 10 of the 14 survey items. Experts supported hypofractionated radiotherapy for all breast cancer patients aged 40 years or more; with invasive carcinoma and breast-conserving surgery; without radiation of lymph nodes; and regardless of the tumour size, histological grade, molecular subtype, breast size, laterality, other treatment characteristics, or need for a boost. Over half favoured its use in all situations, even where available scientific evidence is insufficient. The resulting recommendations and the quality of the evidence are comparable to those from ASTRO, despite some differences in the degree of consensus. CONCLUSION: Specialists agree that hypofractionation is the standard treatment for breast cancer following breast-conserving surgery, but some specific areas require a higher level of evidence before unequivocally extending indications.

Publication of interventional phase 3 and 4 clinical trials in radiation oncology: an observational study.

OBJECTIVES: Clinical trials produce the best data available for decision-making in modern evidence-based medicine. We aimed to determine the rate of non-publication of interventional phase 3 and 4 clinical trials involving patients with cancer undergoing radiotherapy. SETTING: The ClinicalTrials.gov database was searched for interventional phase 3 and 4 trials in radiotherapy with a primary completion date before 1 January 2013. We determined how many of these registry entries have not published the compulsory deposition of their results in the database and performed a systematic search for published studies in peer-reviewed journals. RESULTS: Of 576 trials, 484 (84.0%) did not deposit a summary result in the registry. In addition, 44.9% of them did not publish their results in a peer-reviewed journal. Similar percentages were found for most cancer subtypes: brain (41%), breast (38%), cervical (66%), colorectal (38%), lung (48%), prostate (45%), bladder (56%), head and neck (56%) and lymphoma (33%). CONCLUSION: Our results show that most trials in radiation oncology did not report the results in the registry. Almost half of these trials have not been published in the biomedical literature. This means that a large number of study participants were exposed to the risks of trial participation without the supposed benefits that sharing and publishing of results would offer to future generations of patients.

Evidence-based guidelines for hypofractionated radiation in breast cancer: conclusions of the Catalan expert working group

IntroductionDaily, moderate hypofractionation has become standard treatment for breast cancer following breast-conserving surgery, although substantial variation exists in its use. This paper describes the generation of consensus-based recommendations for the utilisation of this therapy at the healthcare system level and compares these to American Society for Radiation Oncology (ASTRO) guidelines.Materials and methodsConsensus-based guidelines were developed in three steps, including a systematic literature review and involvement of radiation oncologists specialising in breast cancer in Catalonia: (a) creation of a working group and evidence review; (b) consideration of the levels of evidence and agreement on the formulation of survey questions; and (c) performance of survey and development of consensus-based recommendations. Results were compared to the ASTRO recommendations.ResultsConsensus was above 80% for 10 of the 14 survey items. Experts supported hypofractionated radiotherapy for all breast cancer patients aged 40 years or more; with invasive carcinoma and breast-conserving surgery; without radiation of lymph nodes; and regardless of the tumour size, histological grade, molecular subtype, breast size, laterality, other treatment characteristics, or need for a boost. Over half favoured its use in all situations, even where available scientific evidence is insufficient. The resulting recommendations and the quality of the evidence are comparable to those from ASTRO, despite some differences in the degree of consensus.ConclusionSpecialists agree that hypofractionation is the standard treatment for breast cancer following breast-conserving surgery, but some specific areas require a higher level of evidence before unequivocally extending indications. (AU)

Understanding variations in the use of hypofractionated radiotherapy and its specific indications for breast cancer: A mixed-methods study.

BACKGROUND AND PURPOSE: Radiation oncology guidelines favour hypofractionated whole-breast radiotherapy (HWBRT) over more conventional schemes in the conservative treatment of breast cancer, but its adoption still varies in clinical practice. This study assessed the patterns of HWBRT adoption in Catalonia (Spain). MATERIAL AND METHODS: We used a mixed-methods approach based on an explanatory sequential design, first collecting and analysing quantitative data on HWBRT use (>2.5Gy per fraction) in 11 public radiotherapy centres (2005-2015) and then performing 25 semi-structured interviews with all department heads and reference radiation oncologist/s. RESULTS: Of the 34,859 patients fulfiling the study criteria over the study period, just 12% were hypofractionated, reaching a percentage of 29% in 2015 (p<0.001). Our analysis showed a narrowing age gap between patients receiving conventional fractionation and hypofractionation in centres leading adoption. However, there were important differences in clinicians' interpretation of evidence (e.g. regarding the perceived risk of long-term toxicity) and selection of patients for specific indications, both within and between departments. CONCLUSIONS: Differences observed in the rate of adoption of HWBRT could not be tackled only using a rational, evidence-based approach. Factors related to the management of radiotherapy departments play a major role in the diffusion of therapeutic strategies.

Comparison of positron emission tomography (PET) and computed tomography (CT) for better target volume definition in radiation therapy planning.

BACKGROUND: In cancer patients, positron emission tomography/ computed tomography (PET/CT) fused images present less variability in target contouring, respect to use only CT images, respectively. However, the gold standard has not yet been clearly established between radiation oncologists with regard to PET images and the methodology of contouring targets with confidence using PET/CT fused images. The aim of this study was to determine whether integrated PET/CT fused images provide advantages in virtual simulation compared with morphological contouring only with CT. MATERIAL AND METHODS: Thirty cancer patients were evaluated in an adapted PET/CT hybrid in radiotherapy (RT) setup position, with 20 of them being suitable for RT: 17 were suitable for curative intent, which was the group of interest in this study. All image series were sent to the RT work station (WS) where CT and PET series were automatically fused by Digital Imaging and Communications in Medicine (DICOM) in each case. PET series were threshold and were subjected to source-to-background contrast algorithms to fi nally redefine the original tumour description. Three different radiotherapy plans (RTP) for each patient were compared after targets were contoured: [1] planning over metabolic (PET) contoured targets, [2] planning over only morphologic (CT) targets, and [3] planning over targets obtained for treatment based on fused PET/CT images. RESULTS: PET/CT findings altered initial-stage planning in four patients (23.5%) because they had been undergoing chemotherapy. Gross target volume (GTV) and planning target volume (PTV) based only on PET showed more homogeneity to obtain mean doses (p = 0.025) with respect to those based on PET/CT, respectively. However, no percentage differences were observed in median PTV doses between the planning methods, although there was higher variability in PET/CT planning. Morphological (CT) and PET/ CT target volumes were more voluminous than metabolic (PET) volumes. On the other hand, 20% of metabolic (PET) PTV were out of those defined by PET/CT. Thoracic RT plans based on PET preserved better bilateral lung [percentage volume of lung irradiated with a dose of 20 Gy (V20); significance, R(2) = 0.559, p = 0.006]. CONCLUSIONS: For our physicians, PET/CT fused images allowed better contouring of primary tumours in 40% of head and neck cancers and 34% of thoracic cancers. PET/CT provides useful information for virtual simulation therapy. Image treatment and planning in an RT workstation is mandatory.

Use of an electron spoiler for radiation treatment of surface skin diseases.

OBJECTIVES: Low-energy electron beams are characterised by low surface doses with a pronounced dose build-up and penetration of several centimetres, but often a higher surface dose and a lower penetration range is desired. The purpose of this study was to investigate the use of an electron spoiler to modify these beams for treating surface skin diseases and evaluate the feasibility of this method. MATERIALS AND METHODS: An aluminium foil 4-mm thick covering the end of the electron applicator was used as a spoiler for a 6 MeV electron beam. The dosimetric characteristics of this beam were measured, and Monte Carlo simulations were performed. RESULTS: The spoiler reduced the practical range and increased surface and build-up doses, but it also significantly broadened the penumbra and increased peripheral doses. Nevertheless, the beam was clinically acceptable when skin collimation with lead was employed. Monte Carlo simulations agreed well with all the experimental measurements. CONCLUSIONS: The feasibility of using a low-energy electron beam with a spoiler for treating surface skin diseases was demonstrated. The method is hygienic and avoids some of the disadvantages associated with the bolus technique, but it is valid only for flat surfaces and perpendicular incidence. As a consequence, it can be an alternative to bolus and other reported methods in certain cases, especially when a particular sterility assurance level is required.