38 HOW TO TREAT: RADIATION ONCOLOGY
38 HOW TO TREAT: RADIATION ONCOLOGY
20 JUNE 2025 ausdoc. com. au
Figure 13. A cT2N0M0 squamous cell carcinoma of the left cheek. a defunctioning stoma and discussed at the MDT meeting. The recommendation is for neoadjuvant long course chemoradiotherapy prior to resection. The surgery and post-treatment MRI is shown in figure 12B.
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Case study five
Jurgen, a 69-year-old male, presents
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with a lesion on his left cheek and a healing ulcer following 5-fluorouracil treatment( see figure 13A). He has a history of end-stage renal disease, infective endocarditis, aortic valve repair, atrial fibrillation, cardiomyopathy, cataract replacements, chronic obstructive pulmonary disease, gout and previous septic arthritis.
A biopsy demonstrates a welldifferentiated squamous cell carcinoma. FDG PET demonstrates a left face lesion invading into the masseter without obvious bone involvement( see figure 13C). His case is discussed at the MDT and he is deemed unsuitable for operative management. Jurgen is treated with definitive radiotherapy( see figures 13B and 13D).
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Clinical photo before treatment. |
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FDG PET before definitive radiotherapy( 60Gy / 30f). |
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Clinical photo after treatment.
How to Treat Quiz.
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1. Which THREE statements regarding radiotherapy therapy are correct? a Radiotherapy uses high energy radiation to damage the DNA of cancer cells and destroy them. b Radiotherapy is a local treatment modality. c Treatment is always palliative. d Electrons spare deeper tissues from a radiation dose.
2. Which TWO statements regarding radiotherapy therapy are correct? a Brachytherapy has the same radiation safety risk as external beam radiotherapy. b DNA damage from radiotherapy is greater in less oxygenated tumours. c Fractionation describes dividing up the total course of radiotherapy over a number of days / weeks. d Treatment breaks are generally avoided unless the patient experiences significant toxicities.
3. Which THREE benign processes may be treated with radiotherapy? a Arteriovenous malformations. b Pituitary carcinoma. c Plantar fasciitis. d Dupuytren’ s contracture.
D
4. Which TWO genitourinary tumours are commonly treated with radiotherapy? a Prostate. b Ovarian. c Bladder. d Uterine.
5. Which THREE statements are correct? a In the palliative setting, lower doses of radiotherapy are delivered per fraction to decrease the overall treatment time burden for the patient. b Higher doses and more treatments are prescribed over several weeks in the curative setting. c Lower doses and shorter courses of treatment are recommen ded in the palliative setting. d Head / neck cancer requires a relatively higher dose of radiotherapy compared with other tumour sites.
6. Which THREE may occur before
FDG PET after definitive radiotherapy.
a patient starts radiotherapy? a Dosimetric checking of a radiotherapy plan. b Initial consultation with the radiation oncologist. c A planning scan. d Small tattoo dots may be applied.
7. Which TWO statements regarding the outcomes of radiotherapy are correct? a Primary brain tumours have very high cure rates. b The stage of the cancer is a significant determinant of the outcome. c Most haematological malignancies respond poorly to radiotherapy. d In the palliative setting, follow-up allows for confirmation of whether the treatment has aided in symptom management.
8. Which THREE statements regarding the side effects of radiation therapy are correct? a Carcinogenesis is an important potential late effect of
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RADIATION ONCOLOGY
radiotherapy. b Late side effects can occur months to years following the completion of radiotherapy. c Vascular or neuronal cells may become scarred many months to years following treatment. d Patients may develop an acute skin or mucosal reaction months to years after being treated.
9. Which TWO are appropriate modalities for the treatment of radiation therapy side effects? a Mouth washes and analgesia for mucosal ulceration. b Skin grafting for severe radiation erythema. c Pelvic floor exercises for radiation cystitis. d Simple antiemetics for nausea and vomiting.
10. Which THREE statements regarding malignant spinal cord compression are correct? a Impingement may occur at the level of the spinal cord or cauda equina. b Radiotherapy is favoured in malignant solid tumour metastases where surgical decompression is feasible. c The condition requires urgent management. d Treatment aims to alleviate pain and prevent progression of any neurological deficit.
CONCLUSION
RADIOTHERAPY is a safe and effective cancer treatment that is currently underused. High energy radiation( usually X-rays) targets tumour tissue to destroy it via DNA damage. A wide variety of tumour types can be treated with radiotherapy either on its own or in conjunction with surgery and / or systemic therapy.
A patient can expect a stepwise consultation, and planning and treatment process together with a high level of quality assurance. Different modalities of treatment are chosen to optimise patient outcomes. The delivered dose and overall treatment time for a patient is dependent on patient, tumour and treatment factors. A curative course of radiotherapy is usually delivered as a fraction of radiotherapy once per day over several weeks. Palliative intent radiotherapy is usually delivered over a much shorter time frame, sometimes as a single fraction.
Radiotherapy-related acute toxicities are usually transient, although in rare cases late-term toxicities can occur. The location of potential side effects is intuitive as they occur within irradiated volume.
Urgently refer patients with MSCC to a radiation oncologist, because neurological outcomes are better with earlier treatment.
The role of the GP is important for patients receiving radiotherapy. This may be during the initial diagnosis, during treatment or as part of post-treatment care, including surveillance and survivorship.
RESOURCES
• Radiation Oncology: Targeting Cancer targetingcancer. com. au
• Cancer Institute NSW eviQ: Radiation oncology bit. ly / 40Ed2aw
• Cancer Council: Radiation therapy bit. ly / 40A5Axa
References Available on request from howtotreat @ adg. com. au