Implementation of 3D conformal radiotherapy technology at the National Cancer Centre Mongolia: A successful Asia-Pacific collaborative initiative.

INTRODUCTION: Mongolia has a population of 3.3 million and is classified by the WHO as a lower middle-income country. Cancer is now a major public health issue and one of the leading causes of mortality. Within the framework of an existing national cancer control plan, the National Cancer Centre of Mongolia (NCCM) aimed to implement 3D conformal radiation planning and linac-based treatment delivery. METHODS: In 2018, an opportunity arose for collaboration between the Mongolia Society for Radiation Oncology (MOSTRO), the National Cancer Centre Mongolia (NCCM), the Asia-Pacific Radiation Oncology Special Interest Group (APROSIG) of the Royal Australian and New Zealand College of Radiologists (RANZCR) and the Asia-Pacific Special Interest Group (APSIG) of the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) and radiation therapists (RTTs) from a range of Australian centres. We describe here the results to date of this collaboration. RESULTS: Despite a number of significant technical and practical barriers, successful linac commissioning was achieved in 2019. Key factors for success included a leadership receptive to change management, stable bureaucracy and health systems, as well as a synchronised effort, regional cooperation and mentorship. CONCLUSION: Future directions for ongoing collaborative efforts include a continued focus on education, practical training in radiotherapy planning and delivery and postgraduate education initiatives. Radiotherapy safety and quality assurance remain an ongoing priority, particularly as technological advances are sequentially implemented.

ACPSEM ROSG Oncology-PACS and OIS working group recommendations for quality assurance.

The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) Radiation Oncology Specialty Group (ROSG) formed a series of working groups in 2011 to develop position papers for guidance of radiation oncology medical physics practice within the Australasian setting. These position papers are intended to provide guidance for safe work practices and a suitable level of quality control without detailed work instructions. It is the responsibility of the medical physicist to ensure that locally available equipment and procedures are sufficiently sensitive to establish compliance to these position papers. The recommendations are endorsed by the ROSG, have been subject to independent expert reviews. For the Australian audience, these recommendations should be read in conjunction with the Tripartite Radiation Oncology Practice Standards [1, 2]. This publication presents the recommendations of the ACPSEM OPACS and OIS Working Group (OISWG) and has been developed in alignment with other international associations. However, these recommendations should be read in conjunction with relevant national, state or territory legislation and local requirements, which take precedence over the ACPSEM position papers. It is hoped that the users of this and other ACPSEM position papers will contribute to the development of future versions through the Radiation Oncology Specialty Group of the ACPSEM.

Variations in daily quality assurance dosimetry from device levelling, feet position and backscatter material.

Daily quality assurance procedures are an essential part of radiotherapy medical physics. Devices such as the Sun Nuclear, DQA3 are effective tools for analysis of daily dosimetry including flatness, symmetry, energy, field size and central axis radiation dose measurement. The DQA3 can be used on the treatment couch of the linear accelerator or on a dedicated table/bed for superficial and orthovoltage x-ray machines. This device is levelled using its dedicated feet. This work has shown that depending on the quantity of backscatter material behind the DQA3 device, the position of the levelling feet can affect the measured central axis dose by up to 1.8 % (250 kVp and 6 MV) and that the introduction of more backscatter material behind the DQA3 can lead to up to 7.2 % (6 MV) variations in measured central axis dose. In conditions where no backscatter material is present, dose measurements can vary up to 1 %. As such this work has highlighted the need to keep the material behind the DQA3 device constant as well as maintaining the accuracy of the feet position on the device to effectively measure the most accurate daily constancy achievable. Results have also shown that variations in symmetry and energy calculations of up to 1 % can occur if the device is not levelled appropriately. As such, we recommend the position of the levelling feet on the device be as close as possible to the device so that a constant distance is kept between the DQA3 and the treatment couch and thus minimal levelling variations also occur. We would also recommend having no extra backscattering material behind the DQA3 device during use to minimise any variations which might occur from these backscattering effects.