20 Intensity-modulatedradiotherapyKCE reports 62 Key points • Weak to moderate quality of evidence exists demonstrating a reduction in toxicity after IMRT compared with 2D radiotherapy or 3DCRT for head and neck cancer, prostate cancer and breast cancer. Current reports do no allow for a good comparison of relapse or survival data between IMRT and conventional techniques. • As IMRT for head and neck cancer is more difficult to plan and deliver, and still an area of investigation, it has been suggested restrict to this treatment to centres with the necessary expertise. • IMRT or (3D) conformal radiation therapy (3DCRT) can be used to deliver high doses for prostate cancer. The challenge is to precisely target the prostate with or without the pelvic nodes each session. Frequent image-based adjustments help to achieve this. • Use of IMRT may reduce skin complications in breast cancer radiotherapy, primarily in heavy breasted women. Long term studies are required to assess the risk of induction of a secondary tumour in the contralateral breast after IMRT before introduction into common practice. • The induction of fatal secondary malignancies is considered the greatest risk associated with treatment radiation. Total body irradiation is higher using IMRT and, in theory, may overall double the incidence of fatal secondary malignancies compared with standard external radiotherapy techniques. Especially younger patients are at risk. • Large variations exist in total body irradiation between various IMRT techniques. Also use of daily radiation-based imaging for treatment setup verification adds to the overall exposure. Manufacturers and users of IMRT hardware and software should be aware of this. Further product improvement should be stimulated in an effort to reduce the risk for secondary malignancies.
KCE reports 62 Intensity-modulatedradiotherapy 21 4 LOCAL SITUATION 4.1 INCIDENCE OF SPECIFIC MALIGNANCIES IN BELGIUM Cancers are the second cause of mortality in Europe and in Belgium, after the cardiovascular diseases. In the Belgian Cancer Register, Walloon and Brussels figures are underestimated. The cancer incidence rates in Belgium were extrapolated from the Flemish figures, standardized by age and gender. About 56 000 new cases of malignant cancer were diagnosed in Belgium in 2001, which represents 547 cases per 100 000 inhabitants. The five most common localisations accounting for those cases were: breast (C50), prostate (C61), bronchus and lung (C34), colon (C18) and malignant neoplasms of skin (C44). HEAD AND NECK CANCER Based on the Flanders Cancer Registry, 1973 cases of head and neck cancer were estimated in Belgium for 2001. This is similar to other European countries or regions. In women, the incidence was almost five times lower than in men. Tobacco and alcohol use are the most important risk factors. In Flanders, as for chronic liver disease, the incidence of head and neck cancer is somewhat lower in the eastern parts of Flanders. PROSTATE CANCER Based on the Flemish Cancer Registry, prostate cancer was the most frequently diagnosed tumour in males and accounted for 8884 new diagnoses (29.1% of the male tumours) for 2001. In Belgium, the cumulative incidence of prostate cancer up to the age of 75 increased from 2% to 6% between 1990 and 1998. 37 This trend was also seen in other regions where PSA tests are frequently used for screening of prostate cancer. The cumulative mortality of prostate cancer to the age of 75 has remained stable at approximately 1.1% in Belgium. BREAST CANCER Over 9500 patients in Belgium are diagnosed with breast cancer each year. In 80% of these patients the treatment regimen will include radiotherapy. 59 4.2 EXTERNAL RADIOTHERAPY AND IMRT IN BELGIUM 4.2.1 Local Regulations Radiotherapy facility approvals are determined by the Royal Decree of 5 April 1991 that imposes minimal requirements to general hospitals in terms of infrastructure, equipment and staff in function of the activity. The Royal Decree of 9 July 2000 restricted the number of radiotherapy centres to existing facilities at that time; except in provinces that had no facility. New facilities could open if located at more than 50 km of existing centres. There are now 25 radiotherapy facilities in Belgium, listed in appendix 1. The installation of IMRT equipment in itself is not legally limited in Belgium. Nevertheless, the devices used for IMRT fall under the Royal Decree of 18 March 1999, that translate the European directive 93/42 concerning medical devices. According to this decree, the producer, the authorized representative, the distributors, the notified bodies, the physicians and the persons responsible for the reception and the distribution of devices have to report any incident to the Ministry of Health (federal public service of health, food chain safety and environment). In the case of radiotherapy devices, each reported incident transmitted to the federal public service is automatically transferred also to the federal Agency for Nuclear Control. Information on incidents and failures of devices is currently not publicly accessible.