Comparative analysis of thermoplastic masks versus vacuum cushions in stereotactic body radiotherapy

Background: To compare thermoplastic masks (TMP) and vacuum cushion system (VCS) to assess differences in interfraction set up accuracy in patients treated with stereotactic radiotherapy (SBRT) for oligometastatic lung cancer. Secondarily, to survey radiotherapy technologists to assess their satisfaction with the two systems. Methods: Retrospective study of patients treated with lung SBRT between 2008 to 2012 at our institution. Immobilization was performed for 73 treatment sessions (VCS = 40; TMP = 33). A total of 246 cone-beams were analysed. Patients considered ineligible for surgery with a life expectancy ≥6 months and performance status > 1 were included. Target lesion location was verified by cone beam computed tomography (CBCT) prior to each session, with displacements assessed by CBCT simulation prior to each treatment session. Couch shifts were registered prospectively in vertical, longitudinal, and latero-lateral directions to obtain Kernel coordinates (3D representation). Technologists were surveyed to assess their satisfaction with indexing, positioning, and learning curve of the two systems. Setup displacements were obtained in all patients for each treatment plan and for each session. To assess differences between the immobilization systems, a t-test (Welch) was performed. Results: Mean displacements for the TMP and VC systems, respectively, were as follows: session one, 0.64 cm vs 1.05 cm (p = 0.0002); session two, 0.49 cm vs 1.02 cm (p < 0.0001), and session three, 0.56 vs 0.97 cm (p = 0.0011). TMP resulted in significantly smaller shifts vs. VCS in all three treatment sessions. Technologists rated the learning curve, set up, and positioning more highly for TMP versus VCS. Conclusions: Due to the high doses and steep gradients in lung SBRT, accurate and reproducible inter-fraction set up is essential. We found that thermoplastic masks offers better reproducibility with significantly less interfractional set up displacement than vacuum cushions. Moreover, radiotherapy technologists rated the TMP system higher. Taken together, these two findings suggest that TMP may be preferable to VCS. However, more research is needed to determine both inter- and intrafraction error to identify the optimal immobilisation system for use in lung SBRT

Smartphones and tablets: Reshaping radiation oncologists’ lives

BackgroundSmartphones and tablets are new handheld devices always connected to an information source and capable of providing instant updates, they allow doctors to access the most updated information and provide decision support at the point of care.AimThe practice of radiation oncology has always been a discipline that relies on advanced technology. Smartphones provide substantial processing power, incorporating innovative user interfaces and applications.Materials and methodsThe most popular smartphone and tablet app stores were searched for “radiation oncology” and “oncology” related apps. A web search was also performed searching for smartphones, tablets, oncology, radiology and radiation oncology.ResultsSmartphones and tablets allow rapid access to information in the form of podcasts, apps, protocols, reference texts, recent research and more.ConclusionWith the rapidly changing advances in radiation oncology, the trend toward accessing resources via smartphones and tablets will only increase, future will show if this technology will improve clinical care

Preliminary Study of the Effect of Stereotactic Body Radiotherapy (SBRT) on the Immune System in Lung Cancer Patients Unfit for Surgery: Immunophenotyping Analysis

An immunophenotyping analysis was performed in peripheral blood samples from seven patients with lung cancer unfit for surgery treated with stereotactic body radiotherapy (SBRT). The objective was to characterize the effect of SBRT on the host immune system. Four patients received 60 Gy (7.5 Gy x 8) and three 50 Gy (12.5 Gy x 4). Analyses were performed before SBRT, 72 h after SBRT, and at one, three, and six months after the end of SBRT. Of note, there was a specific increase of the immunoactive component of the immune system, with elevation of CD56(+high)CD16+ natural killer (NK) cells (0.95% at baseline to 1.38% at six months), and a decrease of the immunosuppressive component of the immune system, with decreases of CD4+CD25+Foxp3+CDA5RA- regulatory T cells (4.97% at baseline to 4.46% at six months), granulocytic myeloid-derived suppressor cells (G-MDSCs) (from 66.1% at baseline to 62.6% at six months) and monocytic (Mo-MDSCs) (8.2% at baseline to 6.2% at six months). These changes were already apparent at 72 h and persisted over six months. SBRT showed an effect on systemic immune cell populations, which is a relevant finding for supporting future combinations of SBRT with immunotherapy for treating lung cancer patients

Detection of risk factors that influence weight loss in patients undergoing radiotherapy

AbstractAimTo identify risk factors that influence weight loss in patients receiving radiotherapy.BackgroundIt is a well-known fact that cancer patients can be affected by malnutrition at the onset of the disease and during treatment due to the toxicity. Pretreatment weight loss alone does not predict those who will need nutritional supplementation. Instead, a variety of nutritional and tumor related factors needs to be taken into account.Material and methodsA retrospective study was conducted on 129 patients with different tumor locations. Weight loss was evaluated during radiotherapy and one month after treatment. The impact of age, ECOG, chemotherapy, pretreatment weight loss, tumor location, previous surgery and TNM were analyzed. We aimed to identify a high-risk group of patients before starting treatment.ResultsThe average net weight loss during radiotherapy and one month after treatment for this group of patients was 0.68kg and 1.6kg, respectively. Median weight loss during radiotherapy was 2.6 kg for head and neck (HN) patients and 0.27 kg for other tumor sites (p=0.028). Median weight loss one month after radiotherapy was 3.7kg for HN patients and 1.1kg for the rest of the patients (p=0.034). The median weight loss one month after treatment was 3.2 kg for patients receiving chemotherapy and 0.5kg for those patients who did not receive chemotherapy (p<0.001). A regression analysis determined that HN tumor location and the use of chemotherapy were independent risk factors.ConclusionsNutritional status must be monitored and managed before, during and after treatment. A variety of nutritional and tumor-related factors must be considered. According to our results, head and neck tumors and the use of chemotherapy are the only two factors considered statistically significant. Because patients continue to lose weight after treatment, we recommend close surveillance after radiotherapy

Role of fluorine-18 fluorodeoxyglucose PET/CT in head and neck oncology: the point of view of the radiation oncologist

Squamous cell carcinoma is the most common malignant tumour of the head and neck. The initial TNM staging, the evaluation of the tumour response during treatment, and the long-term surveillance are crucial moments in the approach to head and neck squamous cell carcinoma (HNSCC). Thus, at each of these moments, the choice of the best diagnostic tool providing the more precise and larger information is crucial. Positron emission tomography with fluorine-18 fludeoxyglucose integrated with CT (F-18-FDG-PET/CT) rapidly gained clinical acceptance, and it has become an important imaging tool in routine clinical oncology. However, controversial data are currently available, for example, on the role of F-18-FDG-PET/CT imaging during radiotherapy planning, the prognostic value or its real clinical impact on treatment decisions. In this article, the role of F-18-FDG-PET/CT imaging in HNSCC during pre-treatment staging, radiotherapy planning, treatment response assessment, prognosis and follow-up is reviewed focusing on current evidence and controversial issues. A proposal on how to integrate F-18-FDG-PET/CT in daily clinical practice is also described

A data mining based clinical decision support system for survival in lung cancer

Background: A clinical decision support system (CDSS) has been designed to predict the outcome (overall survival) by extracting and analyzing information from routine clinical activity as a complement to clinical guidelines in lung cancer patients. Materials and methods: Prospective multicenter data from 543 consecutive (2013–2017) lung cancer patients with 1167 variables were used for development of the CDSS. Data Mining analyses were based on the XGBoost and Generalized Linear Models algorithms. The predictions from guidelines and the CDSS proposed were compared. Results: Overall, the highest (> 0.90) areas under the receiver-operating characteristics curve AUCs for predicting survival were obtained for small cell lung cancer patients. The AUCs for predicting survival using basic items included in the guidelines were mostly below 0.70 while those obtained using the CDSS were mostly above 0.70. The vast majority of comparisons between the guideline and CDSS AUCs were statistically significant (p < 0.05). For instance, using the guidelines, the AUC for predicting survival was 0.60 while the predictive power of the CDSS enhanced the AUC up to 0.84 (p = 0.0009). In terms of histology, there was only a statistically significant difference when comparing the AUCs of small cell lung cancer patients (0.96) and all lung cancer patients with longer (≥ 18 months) follow up (0.80; p < 0.001). Conclusions: The CDSS successfully showed potential for enhancing prediction of survival. The CDSS could assist physicians in formulating evidence-based management advice in patients with lung cancer, guiding an individualized discussion according to prognosis.Instituto de Salud Carlos III PI16/02104Junta de Andalucía PIN-0476-2017Ministerio de Economía y Competitividad FPAP13-1E-242

Evaluation of results and costs of high precision radiotherapy (VMAT) compared with conventional radiotherapy (3D) in the treatment of cancer patients with spinal cord compression of metastatic origin

Background: The aim of this study was to evaluate the results and economic costs of using volumetric modulated arc therapy (VMAT) (5 fr x 5 Gy), compared with other conventional 3D radiotherapy schemes such as “5 x 4 Gy” and “10 x 3 Gy”. Materials and methods: The data about the direct costs for the public health system was obtained from the Economic Information “Management per Patient” System available at the Integrated Health Organization Ezkerraldea Enkarterri Cruces. It is a model of real costs per patient which uses a bottom-up methodology which connects all sources of information generated in clinical practice, integrating healthcare information with economic information. This system presents the real cost per individualized patient, and shows the traceability of all clinical care. The costs of “typical patients” requiring hospital admission were identified for each of the three radiotherapy schemes based on the clinical activity and the material and human resources that were used.  Results: The 5 x 5 Gy scheme has a cost of EUR 4,801.48, which is 1.64% higher (EUR 77) than the “5 x 4 Gy” scheme (EUR 4,724.05). The “10 x 3 Gy” scheme has a cost of EUR 8,394.61, which is 74.8% higher (EUR 3,593) than the “5 x 5 Gy” scheme. The main cost factor in the “10 x 3 Gy” scheme is hospitalization, since patients are at hospital for 2 weeks compared with 1 week in the “5 x 5 Gy” scheme. Conclusions: The cost per patient of the VMAT “5 x 5 Gy” radiotherapy scheme is notably lower than that of the “10 x 3 Gy” scheme (conventional 3D radiotherapy), with the advantage of being administered in half the time. In relation to the scheme with 5 Gy x 4 sessions, the cost is similar to that of the “5 x 5 Gy” scheme

Excellent outcomes after radiotherapy alone for malignant spinal cord compression from myeloma

Uncertainty exists whether patients with spinal cord compression (SCC) from a highly radiosensitive tumor require decompressive spinal surgery in addition to radiotherapy (RT). This study addressed the question by evaluating patients receiving RT alone for SCC from myeloma

Systematic review of educational interventions to improve contouring in radiotherapy

Background and purpose: Contouring is a critical step in the radiotherapy process, but there is limited research on how to teach it and no consensus about the best method. We summarize the current evidence regarding improvement of contouring skills. Methods and materials: Comprehensive literature search of the Pubmed-MEDLINE database, EMBASE database and Cochrane Library to identify relevant studies (independently examined by two investigators) that included baseline contouring followed by a re-contouring assessment after an educational intervention. Results: 598 papers were identified. 16 studies met the inclusion criteria representing 370 participants (average number of participants per study of 23; range (4–141). Regarding the teaching methodology, 5/16 used onsite courses, 8/16 online courses, and 2/16 used blended learning. Study quality was heterogenous. There were only 3 randomized studies and only 3 analyzed the dosimetric impact of improving contouring homogeneity. Dice similarity coefficient was the most common evaluation metric (7/16), and in all these studies at least some contours improved significantly post-intervention. The time frame for evaluating the learning effect of the teaching intervention was almost exclusively short-time, with only one study evaluating the long-term utility of the educational program beyond 6 months. Conclusion: The literature on educational interventions designed to improve contouring performance is limited and heterogenous. Onsite, online and blended learning courses have all been shown to be helpful, however, sample sizes are small and impact assessment is almost exclusively short-term and typically does not take into account the effect on treatment planning. The most effective teaching methodology/format is unknown and impact on daily clinical practice is uncertain.</p