A brief history of British radiotherapy

The path to becoming a clinical or radiation oncologist in Nigeria

The number of cancer patients in Nigeria continues to rise; however, global advances in cancer research are making the provision of optimal care possible. Cancer management is globally agreed to be multidisciplinary, with patients now having the right to benefit from progress in systemic cancer therapy and radio-diagnosis by receiving treatment from adequately trained and highly skilled clinical and radiation oncologists. Radiation oncology is part of the three divisions that make up oncology - medical oncology, surgical oncology and radiation oncology. This discipline in recent times has been developed into Clinical Oncology and although both clinical oncologists and medical oncologists continue to deliver non-surgical cancer treatment, only clinical oncologists are qualified to deliver radiotherapy in the management of cancers. Though clinical oncologists continue to provide quality cancer workforce for the country's increasing number of cancer patients, much is still unknown about this discipline in Nigeria. It is hoped that inspiring radio-oncologists will take note of the information provided by this article as a guide. This paper chronicles the multifarious process involved in training to become a clinical and radiation-oncologist in Nigeria, plus the requirements, as well as pertinent information a budding physician seeking to advance in this highly specialised field requires.

In vivo dosimetry; essential or unnecessary?

Introduction: The radiotherapy profession has learned from errors made during treatment planning and delivery. Quality assurance in radiotherapy (QART) procedures are implemented to reduce the risk of an error occuring. The chief medical officer, along with others, has recommended that the QART of all departments includes in vivo dosimetry (IVD) to ensure that the delivered dose equals the planned dose.

Why we need IVD: A lot of effort goes into field verification and it is just as vital that dosimetry is verified. Overdose to normal tissue can cause devastating side effects, even death, whilst tumour underdose may compromise control. Without IVD, there is no way of knowing that a patient is receiving an overdose until it is too late. Underdoses are unlikely to manifest without IVD. IVD allows radiotherapists and physicists to correct for dose errors in a timely manner.

Why IVD is unnecessary: Radiotherapy accidents are rare. Implementing IVD is expensive, time consuming and takes resources away from developing techniques which will improve patient outcomes. Current IVD methods are not suitable for modern techniques such as intensity modulated radiotherapy (IMRT).

Discussion: IVD appears to be a useful QART tool, particularly as dose escalation techniques develop allowing a higher dose to be delivered to the tumour. Departments may be unwilling to spend time and money on an IVD system that is costly and time consuming if it cannot perform IVD on modern techniques. Electronic portal imaging devices (EPIDs) can be utilised to perform IVD on complex techniques, such as IMRT and arc therapy, which current IVD methods cannot, however there is currently no EPID IVD system available commercially.

Conclusion: Ideally, all departments would conduct IVD on all new patients. IVD has proven to be an important QART tool, however, until technology is developed to allow EPID to include IVD, the procedure is not likely to be implemented countrywide.

Enhancement of radiosensitivity of rat rhabdomyosarcoma R1H with normobaric carbogen and hyperbaric oxygen (HBO) using conventionally fractionated irradiation

Hypoxic clonogenic cells are an important contributory factor in tumour radioresistance. The objective of the present study was to evaluate whether hyperbaric oxygen enhances tumour radiosensitivity, using a conventionally fractionated irradiation schedule, and whether the radiosensitizing potential is different from carbogen. Experiments were performed using the rhabdomyosarcoma R1H model transplanted subcutaneously in the flank of WAG/Rij rats. A total of 30 X-ray fractions of 2 Gy were given either in air, normobaric carbogen or high pressure oxygen (HPO) (240 kPa, 2.37 atm) without anaesthesia. The time taken to achieve complete remission was 38.7 +/- 3.6 days, 36.7 +/- 2.7 days and 32.4 +/- 4.1 days for air, normobaric carbogen and HBO, respectively. The differences between air and HBO (p = 0.002) and carbogen and HBO (p = 0.015) were significant. Use of carbogen and HBO produced the same local control probability at 150 days and this was significantly higher than local control under ambient conditions (p < 0.0001). It was concluded that the time to achieve complete remission of the rat rhabdomyosarcoma R1H can be shortened by HBO. Furthermore, both HBO and carbogen give higher local control probabilities than treatment under ambient conditions when used with a conventionally fractionated radiation schedule.