Breast intraoperative radiotherapy (IORT) is a partial irradiation technique that delivers a single fraction of radiation dose to the tumour bed during surgery. The use of this technique is increasing (especially in the Middle East), and therefore, it is essential to have a comprehensive approach to this treatment modality. The aim of this study is to conduct a literature review on available IORT modalities during breast irradiation as well as dedicated IORT machines and associated treatment procedures. The main IORT trials and corresponding clinical outcomes are also studied.

A computerised search was performed through MEDLINE, PubMed, PubMed Central, ISI web of knowledge and reference list of related articles.

IORT is now feasible through using two main modalities, including low-kilovolt IORT and intraoperative electron radiotherapy (IOERT). The dedicated machines employed and treatment procedure for mentioned modalities are quite different. The outcomes of implemented clinical trials showed that IORT is not inferior to external beam radiotherapy (EBRT) in specifically selected and well-informed patients and can be considered as an alternative to EBRT.

Although the clinical outcomes of introduced IORT methods are comparable, but based on the review results, it could be said that IOERT is the most effective technical method, in view of the treatment time and dose uniformity concepts. The popularity of IORT is mainly due to the distinguished obtained results during breast cancer treatment. Despite the presence of some technical challenges, it is expected that the IORT technique will become more widespread in the immediate future.

Safety is a mandatory issue during the operation of a nuclear power plant. A nuclear reactor can have some atmospheric dispersion due to any errors in the safety system.

The aim of this study is to estimate the cancer risk incidence for different body organs due to accidentally released radionuclides from Bushehr Nuclear Power Plant (BNPP).

The assumed hypothesis was atmospheric dispersion of radionuclide into the environment due to the safety failure of BNPP. Total effective dose equivalent (TEDE) from radionuclide diffusion in the medium was calculated using HOTSPOT code at two different wind speeds. Finally, the risk of cancer incidence for different organs of male and female sex has been estimated by Biologic Effects of Ionizing Radiation (BEIR) VII model.

The results showed that with increasing the exposure age and attained age, the risk of cancer incidence for different organs is decreased. The value of TEDE was increased at lower wind speed. The most probable organ for cancer incidence at different levels of TEDE in male and female sex was colon and bladder, respectively. On the other hand, prostate and uterus had the lowest radiation sensitivity and cancer risk incidence in male and female sex, respectively. Increasing the wind speed reduces the risk of cancer incidence for all of organs understudy.

Based on the obtained results, it can be concluded that the younger persons are more subject to the cancer risk incidence because of both the intrinsically greater radio-sensitivity of their organs and their longer remaining life expectancy during which a cancer may develop. The overall risk of cancer incidence as well as the site specific solid cancer incidence were highly dependent to the sex of exposed person, so that the female sex was more exposed to the cancer risk incidence at all of the irradiation levels understudy.

The effective source to surface distance (SSDeff) for different combinations of energy/applicator size of the electron beam produced by the light intraoperative accelerator, a mobile dedicated intraoperative radiotherapy accelerator, has been calculated in this study.

Both ionometric dosimetry and Monte Carlo (MC) simulation were followed to obtain the SSDeff for different combinations of electron energy/applicator size. Simulations were performed using Monte Carlo Nuclear Particles (MCNP) MC code. Measurements were performed by Advance Markus chamber and inside a polymethyl methacrylate slab phantom. Inverse square law method was employed to determine the SSDeff from acquired dosimetry data.

With increasing the applicator diameter at a given energy, SSDeff is also increased. The same result is obtained with increasing the electron beam energy for a given applicator size. The results of MC-based SSDeff for 10 cm diameter reference applicator at different energies were in a good accordance with those obtained by ionometric dosimetry. The maximum and mean differences between the results were 1·1 and 0·6%, respectively.

The results of this study showed that SSDeff of intraoperative electron beam is highly dependent on the applicator size and is a mild function of electron beam energy. These facts are in accordance with those reported for conventional electron beam. The good agreement between the results of MC simulation and ionometric dosimetry confirms the application of MCNP code in modelling of intraoperative electron beam and obtaining the intended parameters.

Intraoperative radiotherapy is a method of choice to deliver a critical radiation dose to the tumour bed immediately after surgical excision.

The purpose of this work is to check the dose delivered to the patients during intraoperative electron beam radiation therapy (IOERT) in the conservative treatment of breast cancer, by means of reference dose measurement using radiochromic (EBT-2) films.

Ninety patients with early-stage breast cancer underwent exclusive IOERT to the tumour bed using a LIAC linear accelerator. Absolute dose measurements were done with film pieces. After irradiation, the pixel values of the films were obtained via MATLAB and ImageJ softwares. Calibration curve was also used for calculating net optical density. Expected dose was compared to the patient delivered dose.

The mean deviation of the delivered dose from the expected one was 2·56% that is well in the accepted criteria. Only in one case, there was a larger deviation due to barometer miscalibration.

EBT-2 film response is independent from dose-per-pulse and as it was shown in this study it can be robustly used during breast IOERT for dosimetric and also positioning verifications.