SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Clinical oncology (Royal College of Radiologists (Great Britain))

37

The accident at the Fukushima Daiichi Nuclear Power Plant occurred after the Great East Japan Earthquake on 11 March 2011, releasing a large amount of radioactive materials into the atmosphere. Questions were raised regarding the health effects of radiation exposure, which led to increased anxiety among the Fukushima residents about the possible development of thyroid cancer. Thus, thyroid ultrasound examinations began for those who were from the areas where the radiation doses were highest, and will continue for the long term. In total, 300 476 subjects aged 18 years or younger at the time of the disaster were screened from 9 October 2011 to 31 March 2014. The participation rate was 81.7% of the total population of this age and in the affected area. Among them, the proportions of those who fell into the categories A1 (no nodules or cysts present), A2 (nodule ≤ 5 mm or cyst ≤ 20 mm diameter), B (nodule > 5 mm or cyst > 20 mm diameter) and C (immediate need for further investigation) were 51.5, 47.8, 0.8 and 0%, respectively; 2294 subjects in categories B and C were recommended to undergo a confirmatory examination; 113 were subsequently diagnosed with malignancy or suspected malignancy by fine needle aspiration cytology. The full-scale survey (second round survey) began in April 2014, and was completed by 30 June 2015, and comprised 169 455 subjects (participation rate; 44.7%). The proportions of those who fell into the categories A1, A2, B and C were 41.6, 57.6, 0.8 and 0% (no case), respectively; 1223 subjects in category B were recommended to undergo a confirmatory examination, 25 of these were subsequently diagnosed with malignancy or suspected malignancy by fine needle aspiration cytology. The thyroid cancers identified in this survey so far are unlikely to be due to radiation exposure, and are more likely to be the result of screening using highly sophisticated ultrasound techniques. However, it would be advisable to continue long-term screening to determine whether the risk of childhood and adolescent thyroid cancer due to radiation exposure increases or not.

Concepts: Cancer, Ionizing radiation, Biopsy, Chernobyl disaster, Radioactive decay, Needle aspiration biopsy, Nuclear power, Nuclear safety

26

Advanced radiotherapy techniques, such as intensity-modulated radiotherapy (IMRT), may significantly benefit cervical cancer patients, in terms of reducing late toxicity and potentiating dose escalation. Given the steep dose gradients around the planning target volume (PTV) with IMRT planning, internal movement of organs during treatment may cause geographical miss of the target and unnecessary organs at risk (OAR) inclusion into high dose regions. It is therefore important to consider the extent and patterns of organ motion and to investigate potential image-guided radiotherapy (IGRT) solutions before implementing IMRT for cervical cancer. A systematic literature search was carried out using Medline, Embase, Cochrane Library, Web of Science, Cinahl and Pubmed. Database-appropriate search strategies were developed based upon terms for uterine neoplasms, IGRT, organ motion and target volume. In total, 448 studies were identified and screened to find 39 relevant studies, 12 of which were abstracts. These studies show that within the target volume for cervical cancer radiotherapy, uterine motion is greater than cervical. Uterine motion is predominantly influenced by bladder filling, cervical motion by rectal filling. Organ motion patterns are patient specific, with some having very little (5 mm) and others having much larger shifts (40 mm) of the target volume. Population-based clinical target volume (CTV)-PTV margins would be large (up to 4 cm around the uterus), resulting in unnecessary OAR inclusion within the PTV, reducing the benefits of IMRT. Potential solutions include anisotropic margins with increased margins in the anteroposterior and superoinferior directions, or greater PTV margins around the uterine fundus than the cervix. As pelvic organ motion seems to be patient specific, individualised PTV margins and adaptive IGRT strategies have also been recommended to ensure target volume coverage while increasing OAR sparing. Although these strategies are promising, they need significant validation before they can be adopted into clinical practice.

Concepts: Cancer, Oncology, Cervical cancer, Carcinoma in situ, Uterus, Radiation therapy, Endometrial cancer, Image-guided radiation therapy

13

Five years have passed since the Great East Japan Earthquake and the subsequent Fukushima Daiichi Nuclear Power Plant accident on 11 March 2011. Countermeasures aimed at human protection during the emergency period, including evacuation, sheltering and control of the food chain were implemented in a timely manner by the Japanese Government. However, there is an apparent need for improvement, especially in the areas of nuclear safety and protection, and also in the management of radiation health risk during and even after the accident. Continuous monitoring and characterisation of the levels of radioactivity in the environment and foods in Fukushima are now essential for obtaining informed consent to the decisions on living in the radio-contaminated areas and also on returning back to the evacuated areas once re-entry is allowed; it is also important to carry out a realistic assessment of the radiation doses on the basis of measurements. Until now, various types of radiation health risk management projects and research have been implemented in Fukushima, among which the Fukushima Health Management Survey is the largest health monitoring project. It includes the Basic Survey for the estimation of external radiation doses received during the first 4 months after the accident and four detailed surveys: thyroid ultrasound examination, comprehensive health check-up, mental health and lifestyle survey, and survey on pregnant women and nursing mothers, with the aim to prospectively take care of the health of all the residents of Fukushima Prefecture for a long time. In particular, among evacuees of the Fukushima Nuclear Power Plant accident, concern about radiation risk is associated with psychological stresses. Here, ongoing health risk management will be reviewed, focusing on the difficult challenge of post-disaster recovery and resilience in Fukushima.

Concepts: Chernobyl disaster, Management, Coal, Nuclear power, Nuclear safety, Prefectures of Japan, Government of Japan, Three Mile Island accident

8

In locally advanced cervical cancer, the dose delivered results from the sum of external beam radiotherapy and brachytherapy, and is limited by the surrounding organs at risk. The balance between both techniques influences the total dose delivered to the high-risk clinical target volume (HR-CTV). The aim of the present study was to compare the ability of reaching different planning aims after external beam radiotherapy pelvic doses of 45 Gy in 25 fractions or 50.4 Gy in 28 fractions, both considered as standard prescriptions.

Concepts: Metastasis, Human papillomavirus, Cervical cancer, Prostate cancer, Radiation therapy, Endometrial cancer, Brachytherapy, External beam radiotherapy

7

The National Prostate Cancer Audit (NPCA) started in April 2013 with the aim of assessing the process of care and its outcomes in men diagnosed with prostate cancer in England and Wales. One of the key aims of the audit was to assess the configuration and availability of specialist prostate cancer services in England.

Concepts: Health care, Cancer, Metastasis, Prostate cancer, United Kingdom, England, Scotland, English people

6

Breast cancer and prostate cancer are the most common cancers diagnosed in women and men, respectively, in the UK, and radiotherapy is used extensively in the treatment of both. In vitro data suggest that tumours in the breast and prostate have unique properties that make a hypofractionated radiotherapy treatment schedule advantageous in terms of therapeutic index. Many clinical trials of hypofractionated radiotherapy treatment schedules have been completed to establish the extent to which hypofractionation can improve patient outcome. Here we present a concise description of hypofractionation, the mathematical description of converting between conventional and hypofractionated schedules, and the motivation for using hypofractionation in the treatment of breast and prostate cancer. Furthermore, we summarise the results of important recent hypofractionation trials and highlight the limitations of a hypofractionated treatment regimen.

Concepts: Cancer, Breast cancer, Metastasis, Oncology, Chemotherapy, Prostate cancer, Radiation therapy, BRCA2

5

Patients with locally advanced rectal cancer receive preoperative chemoradiation as the standard of care, producing a pathological complete response in 10-20% and a complete clinical response (CCR) in 20-30%. Small observational studies suggest a selective non-operative management with rigorous surveillance is an option and is increasingly being advocated in many parts of the world for patients who achieve a CCR or near CCR. The assumption is that oncological outcomes for good responders, who are observed, compare favourably with patients subjected to radical surgery. Late regrowth of the primary is rare, almost invariably endoluminal and, hence, can be salvaged. However, concerns remain among some surgeons and oncologists regarding the reproducibility of published results in routine practice. We have previously reviewed this topic. The aim of this brief overview was to re-assess the feasibility and safety of a non-operative approach based on the currently available literature. We make recommendations as to the quality of care required to undertake this management. Significant heterogeneity remains in the initial inclusion criteria, staging and restaging methods, study design, timing of assessment, duration and rigour of follow-up of the trials reviewed - all of which obscure the validity of the results.

Concepts: Scientific method, Medicine, Cancer, Oncology, Chemotherapy, Tumor, Observation, Philosophy of science

4

Although pelvic radiotherapy is an effective treatment for various malignancies, around half of patients develop significant gastrointestinal problems. These symptoms often remain undetected, despite the existence of effective treatments. This study developed and refined a simple screening tool to detect common gastrointestinal symptoms in outpatient clinics. These symptoms have a significant effect on quality of life. This tool will increase detection rates and so enable access to specialist gastroenterologists, which will in turn lead to improved symptom control and quality of life after treatment.

Concepts: Cancer, Ionizing radiation, Disease, Oncology, Medical terms, Life, Prostate cancer, Fatigue

4

Radiotherapy is an important treatment modality in the multidisciplinary management of rectal cancer. It is delivered both in the neoadjuvant setting and postoperatively, but, although it reduces local recurrence, it does not influence overall survival and increases the risk of long-term complications. This has led to a variety of international practice patterns. These variations can have a significant effect on commissioning, but also future clinical research. This study explores its use within the large English National Health Service (NHS).

Concepts: Health care, Medicine, Clinical trial, Cancer, Ionizing radiation, Radiation therapy, Clinical research, National Health Service

4

About 57% of the total number of cancer cases occur in low and middle income countries. Radiotherapy is one of the main components of cancer treatment and requires substantial initial investment in infrastructure and training. Many departments continue to have basic facilities and to use simple techniques, while modern technologies have only been installed in big cities in upper-middle income countries. More than 50% of cancer patients requiring radiotherapy in low and middle income countries lack access to treatment. The situation is dramatic in low income countries, where the proportion is higher than 90%. The overall number of additional teletherapy units needed corresponds to about twice the installed capacity in Europe. The figures for different income level groups clearly show the correlation between gross national income per capita and the availability of services. The range of radiotherapy needs currently covered varies from 0% and 3-4% in low income countries in Latin America and Africa up to 59-79% in upper-middle income countries in Europe and Central Asia. The number of additional radiation oncologists, medical physicist, dosimetrists and radiation therapists (RTTs) required to operate additional radiotherapy departments needed is 43 200 professionals. Training and education programmes are not available in every developing country and in many cases the only option is sending trainees abroad, which is not a cost-effective solution. The implementation of adequate local training should be the following step after establishing the first radiotherapy facility in any country. Joint efforts should be made to establish at least one radiotherapy facility in countries where they do not exist, in order to create radiotherapy communities that could be the base for future expansion.

Concepts: Cancer, Oncology, Chemotherapy, Radiation therapy, Radiation oncologist, Radiation oncology, Income, Household income in the United States