أجهزة العلاج الإشعاعي Clinical Radiation Generator إعـداد  م. أنور صلاح عطاالله September 19, 2018 Clinical Radiation Generator

المعالجة الإشعاعية Radiotherapy استخدام الإشعاع المؤين في معالجة السرطان Using the ionizing Radiation to treat cancer معالجة خارجية (عن بعد) External Beam Therapy (EBT) معالجة داخلية (عن قرب) Brachytherapy September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator Radiotherapy One of the main treatment modalities for cancer (often in combination with chemotherapy and surgery) It is generally assumed that 50 to 60% of cancer patients will benefit from radiotherapy Minor role in other diseases Siemens Oncology September 19, 2018 Clinical Radiation Generator

External Beam Radiotherapy tumor patient September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator September 19, 2018 Clinical Radiation Generator

External Beam Radiotherapy More than 90% of all radiotherapy patients are treated using EBT Most of these are treated using X-rays ranging from 20keV to 20MeV in peak-energy Other EBT treatment options include telecurie units (60-Co and 137-Cs), electrons from linear accelerators and accelerators for heavy charged particles such as protons September 19, 2018 Clinical Radiation Generator

Cancer incidence (WHO) September 19, 2018 Clinical Radiation Generator

Major indications for radiotherapy Head and neck cancers Gynaecological cancers (eg. Cervix) Prostate cancer Other pelvic malignancies (rectum, bladder) Adjuvant breast treatment Brain cancers Palliation September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator Approaches Palliative radiotherapy to reduce pain and address acute symptoms - eg bone metastasis, spinal cord compression, ... Radical radiotherapy as primary modality for cure - eg head and neck Adjuvant treatment in conjunction with surgery - eg breast cancer September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator Aim Patient Critical organs To kill ALL viable cancer cells To deliver as much dose as possible to the target while minimising the dose to surrounding healthy tissues target Beam directions September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator Prognostic Factors Cancer type and stage Patient performance Radiation dose ... Good prognosis survival Bad prognosis time September 19, 2018 Clinical Radiation Generator

Accurate dose delivery Clinical Radiation Generator Prognostic Factors Cancer type and stage Patient performance Radiation dose ... Accurate dose delivery matters! September 19, 2018 Clinical Radiation Generator

Dose should be accurate To target: 5% too low - may result in clinically detectable reduction in tumour control (eg. Head and neck cancer: 15%) To normal tissues: 5% too high - significant increase in normal tissue complication probability = morbidity = unacceptable side effects September 19, 2018 Clinical Radiation Generator

External beam radiotherapy (EBT) treatment approaches Superficial X-rays Orthovoltage X-rays Telecurie units Megavoltage X-rays Electrons Heavy charged particles Others September 19, 2018 Clinical Radiation Generator

External beam radiotherapy (EBT) treatment approaches Superficial X-rays Orthovoltage X-rays Telecurie units Megavoltage X-rays Electrons Heavy charged particles Others 40 to 120kVp 150 to 400kVp 137-Cs and 60-Co Linear accelerators Protons from cyclotron, C, Ar, ... Neutrons, pions September 19, 2018 Clinical Radiation Generator

Superficial radiotherapy 50 to 120kVp - similar to diagnostic X-ray qualities Low penetration Limited to skin lesions treated with single beam Typically small field sizes Applicators required to collimate beam on patient’s skin Short distance between X-ray focus and skin September 19, 2018 Clinical Radiation Generator

Superficial radiotherapy Philips RT 100 September 19, 2018 Clinical Radiation Generator

Superficial radiotherapy issues Due to short FSD high output and large influence of inverse square law Calibration difficult (strong dose gradient, electron contamination) Dose determined by a timer - on/off effects must be considered Photon beams may be contaminated with electrons from the applicator September 19, 2018 Clinical Radiation Generator

Orthovoltage radiotherapy 150 - 400kVp Penetration sufficient for palliative treatment of bone lesions relatively close to the surface (ribs, spinal cord) Largely replaced by other treatment modalities September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator September 19, 2018 Clinical Radiation Generator

Kilovoltage Equipment (150 - 400 kVp) Depth dose dramatically affected by the FSD FSD 6cm, HVL 6.8mm Cu FSD 30cm, HVL 4.4mm Cu September 19, 2018 Clinical Radiation Generator

Orthovoltage patient set-up Like for superficial irradiation units the beam is set-up with cones directly on the patient’s skin September 19, 2018 Clinical Radiation Generator

Megavoltage radiotherapy 60-Cobalt (energy 1.25MeV) Linear accelerators (4 to 25MVp) Skin sparing in photon beams Typical focus to skin distance 80 to 100cm Isocentrically mounted September 19, 2018 Clinical Radiation Generator

Clinical Radiation Generator مع أطيب الأمنيات September 19, 2018 Clinical Radiation Generator