Side effects of radiotherapy (RT) are unwanted effects in normal tissue within and adjacent to the RT treatment volume.
Side effects of RT are classified as acute (usually occurring within 30 days of treatment) or late (occurring months to years after treatment).
Side effects of RT depend on the site treated, the radiotherapy modality, the overall total dose, the daily dose per fraction and the rate at which it is delivered.
Overview of evidence (non-systematic literature review)
Acute radiation effects
Acute side effects arise 2–3 weeks after starting RT and last some weeks before completely resolving. The radiobiology of acute side effects is well understood.
The most common side effect is skin inflammation. This increases as more radiation dose is given over days of the prescribed treatment course. The inflammation is first seen as erythema (skin redness), then dry desquamation (skin peeling) and finally, moist desquamation (patchy or confluent superficial ulceration). Temporary epilation occurs at low doses around 6 Gy, while permanent alopecia occurs at 16 Gy.
Treatment close to the eye may cause conjunctivitis, while treatment over the nose may cause increased nasal vestibule crusting and mucosal bleeding; these are treated as symptoms arise with topical therapies. Systemic pain relief is rarely needed.
Acute radiation reactions are transient and generally resolve within 6 weeks. A meta-analysis and a systematic review concluded that no treatment could be recommended to reduce acute effects. Both studies also found that the use of deodorants did not increase acute effects.
A randomised controlled trial (RCT) comparing a new non-woven dressing with silicon (Mepitel film) with standard care in the treatment of radiation dermatitis in patients with head-and-neck cancer has been registered.
Late radiation effects
Late side effects occur months to years after treatment, are irreversible, and can be progressive. The long-term features of radiation damage to the skin may include atrophy (thinning), loss of skin appendages (alopecia, loss of sweating), variable change in colour (pallor or pigmentation), development of variable telangiectasia (fine blood vessels), subcutaneous fibrosis and, rarely, skin breakdown (radionecrotic ulcer <2–5% risk).
The visible features of late radiation skin damage can change with time if RT is given in large fractions. An initial highly favourable cosmetic result can potentially deteriorate over subsequent years.
The late sequelae of radiotherapy can be minimised by reducing the daily dose per fraction (i.e. by delivering smaller daily doses over a greater number of treatments). The trade-off is that this increases the overall treatment time. When advanced basal cell carcinoma and squamous cell carcinoma invade cartilage (classically the pinna) or bone (e.g. mandible) there is a higher risk of chondroradionecrosis or osteoradionecrosis.
Radiotherapy rarely damages nerves or muscle and does not cause major tissue deficit.
A previous course of radiotherapy may influence future surgery and wound healing at the site due to the resulting late effects that may occur over time.
PP 8.8.1. When treating a patient who has undergone previous radiotherapy, the clinician (e.g. general practitioner or skin cancer specialist) should consult the radiation oncologist on the patient’s history to ascertain the dose and location of prior radiation.
- Radiotherapy – Introduction
- Radiotherapy with or without surgical treatment for keratinocyte cancer
- Radiotherapy for basal cell carcinoma
- Radiotherapy for cutaneous squamous cell carcinoma
- Radiotherapy for regional (nodal) metastatic disease (non-distant)
- Radiotherapy for actinic keratosis and cutaneous squamous cell carcinoma in situ
- Radiotherapy for keratoacanthoma
- Recent advances in the radiotherapy of skin cancer
- Radiotherapy – health system implications and discussion
- Bostock S, Bryan J. Radiotherapy-induced skin reactions: assessment and management. Br J Nurs 2016 Feb;25(4):S18, S20-4 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/26911177.
- Trueman E. Management of radiotherapy-induced skin reactions. Int J Palliat Nurs 2015 Apr;21(4):187-92 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/25901591.
- Bradford CD, Morabito B, Shearer DR, Norén G, Chougule P. Radiation-induced epilation due to couch transit dose for the Leksell gamma knife model C. Int J Radiat Oncol Biol Phys 2002 Nov 15;54(4):1134-9 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/12419440.
- Severs GA, Griffin T, Werner-Wasik M. Cicatricial alopecia secondary to radiation therapy: case report and review of the literature. Cutis 2008 Feb;81(2):147-53 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/18441767.
- Chan RJ, Webster J, Chung B, Marquart L, Ahmed M, Garantziotis S. Prevention and treatment of acute radiation-induced skin reactions: a systematic review and meta-analysis of randomized controlled trials. BMC Cancer 2014 Jan 31;14:53 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/24484999.
- Salvo N, Barnes E, van Draanen J, Stacey E, Mitera G, Breen D, et al. Prophylaxis and management of acute radiation-induced skin reactions: a systematic review of the literature. Curr Oncol 2010 Aug;17(4):94-112 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/20697521.
- Narvaez C, Doemer C, Idel C, Setter C, Olbrich D, Ujmajuridze Z, et al. Radiotherapy related skin toxicity (RAREST-01): Mepitel® film versus standard care in patients with locally advanced head-and-neck cancer. BMC Cancer 2018 Feb 17;18(1):197 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/29454311.
- Caccialanza M, Piccinno R, Cuka E, Alberti Violetti S, Rozza M. Radiotherapy of morphea-type basal cell carcinoma: results in 127 cases. J Eur Acad Dermatol Venereol 2014 Dec;28(12):1751-5 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/25564683.