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DIAGNOSIS AND TREATMENT OF LOCAL RADIATION INJURIES DIAGNOSIS AND TREATMENT OF LOCAL RADIATION INJURIES Module XIII.

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Presentation on theme: "DIAGNOSIS AND TREATMENT OF LOCAL RADIATION INJURIES DIAGNOSIS AND TREATMENT OF LOCAL RADIATION INJURIES Module XIII."— Presentation transcript:

1 DIAGNOSIS AND TREATMENT OF LOCAL RADIATION INJURIES DIAGNOSIS AND TREATMENT OF LOCAL RADIATION INJURIES Module XIII

2 Module Medical XIII. 2 Significance of local radiation injuries l In over 90% of radiation accidents only local injuries occur mainly due to direct contact with source l Most frequent complicating factor of acute radiation sickness (ARS)

3 Module Medical XIII. 3 Common sources inducing radiation injury l 192 Ir l 60 Co l 137 Cs l Fission products (beta exposure) l 90 Sr l X-ray machines l X-ray fluorescence l Cyclotron products

4 Module Medical XIII. 4 Typical scenarios leading to partial body radiation injuries finding lost unshielded sources

5 Module Medical XIII. 5 Common features of local radiation injuries l Occurrence of extremely high local radiation doses causing very severe tissue damages (often result of direct contact with sealed source) l Very steep dose gradient in all directions from centre (“inverse square law”)

6 Module Medical XIII. 6 Severe radiation injury of hand - Algerian accident with lost 925 GBq (25 Ci) 192 Ir source, 1978

7 Module Medical XIII. 7 Common features of local radiation injuries l Clinical symptoms may appear relatively late after exposure, or successively from moment of irradiation, following typical clinical course l The earlier the onset of symptoms, the more severe the intensity of exposure l Range of manifestations - erythema, swelling, blisters, ulceration, necrosis and sclerosis.

8 Module Medical XIII. 8 Factors determining severity of local radiation injuries

9 Module Medical XIII. 9 Penetration of radiation I I I I I ı Cell nucleus Cell diameter 100 cell diameter Auger 5.3 MeV alpha 0.15 MeV beta 1.7 MeV beta mm beta alpha

10 Module Medical XIII. 10 Human skin structure

11 Module Medical XIII. 11 Penetration of radiation through skin stuctures Alpha radiation is absorbed in superficial layers of dead cells within the stratum corneum Beta radiation damages epithelial basal stratum. High energy ß- radiation may affect vascular layer of derma, with lesion like thermal burn l Gamma radiation damages underlying tissues and organs

12 Module Medical XIII. 12 Normal Irradiated

13 Module Medical XIII. 13 Clinical course of local radiation injuries l Response of skin to ionizing radiation - radiation dermatitis or cutaneous radiation syndrome (CRS) l Types of skin responses - depending on dose: 1. Initial erythema 2. Dry desquamation 3. Erythema proper 4. Moist desquamation 5. Ulceration and necrosis 6. Late effects: dermal atrophy, hyperpigmentation, fibrosis

14 Module Medical XIII. 14 Blister formation

15 Module Medical XIII. 15 On right hand severe blisters developed after irradiation; on left hand epidermis has sloughed. Presence of hyaline fluid gives blisters translucent appearance Moist desquamation

16 Module Medical XIII. 16 Ulceration and necrosis

17 Module Medical XIII. 17 Hyperpigmentation

18 Module Medical XIII. 18 Section of normal skin (left) and of healed lesion (right) from same bovine hide.

19 Module Medical XIII. 19 Diagnosis of local radiation injuries in early phase Goals: Establishment of origin of observed local injuries Consider radiation as a possibility! Assessment of severity and clinical consequences Be careful with the early prognosis! Early dose estimation

20 Module Medical XIII. 20 Time of onset of clinical signs of skin injury depending on dose of radiation exposure

21 Module Medical XIII. 21 Differential diagnosis T hermal vs r adiation burns l Thermal injury l Thermal injury prompt pain, severe inflamatory response, death of affected cells and destruction of tissue l All types of cells and tissue components damaged l Radiation injury initially painless, and evidence of cell death is not apparent until epidermal surface layers are shed and local cell renewal systems have failed l Types of cells found in skin vary in their sensitivity to ionizing radiation

22 Module Medical XIII. 22 Skin response curves as diagnostic and prognostic means of local radiation injury Hand (70 Gy  ) Foot (18 Gy  -n) amputation on day 62 Amputation 4.5 years later

23 Module Medical XIII. 23 Diagnosis of late radiation induced injuries Goals  Determining extent of damage (especially lesions that become irreversible)  Decision on therapy (conservative/surgical)  Choosing most suitable moment for surgery  Dosimetry

24 Module Medical XIII. 24 Contact liquid crystal thermography

25 Module Medical XIII. 25 Thermography

26 Module Medical XIII. 26 Thermography

27 Module Medical XIII. 27 Perfusion scintigraphy Phase 1: Blood flow Phase 2: Blood pool

28 Module Medical XIII. 28 Thermography Normal hand thermography

29 Module Medical XIII. 29 thermography Later phase of clinical course: thermography

30 Module Medical XIII. 30 Determination of radiation induced tissue oedema l MR and CT images: Useful to show early oedema associated with radiation induced inflamatory reaction and deep swelling especially when affecting muscles

31 Module Medical XIII. 31 Accident reconstruction

32 Module Medical XIII. 32 Principals of treatment local radiation injuries – I l Standardized therapeutical protocols (treatment schemes) do not exist Conservative treatment l Pain management At all stages, especially during blistering (systemic analgesics and local cooling) l Reduction of inflammatory reaction antihistamines, NSAID, corticosteroids, aloe vera extracts

33 Module Medical XIII. 33 Principals of treatment-II Conservative treatment l Healing acceleration occlusive dressings tetrachlorodecaoxide (TCDO) induces granulation and re-epithelization in erosive skin conditions l Wound cleaning and prevention of infection antiseptic solutions (boric acid), for ruptured blisters and vesicles neomycin- coated dressing local and systemic antibiotics only for secondary infections

34 Module Medical XIII. 34 Principals of treatment-III Conservative treatment l Improvement of local microcirculation use of systemic vasodilators questionable  pentoxifylline-trental  hyperbaric oxygen therapy l Late phase: lesions are susceptible to reopening due to progressive vasculitis avoidance of trauma, rehabilitation,skin hydration use of drugs to reduce fibrosis  interferon-gamma  superoxide dismutase

35 Module Medical XIII. 35 Surgical treatment-I l O pening overstretching blisters and vesicles if necessary, but increases pain and risk of secondary infection l Reconstructive and plastic surgery excision of necrosis full thickness grafting myocutenous flap or pedicle flap

36 Module Medical XIII. 36 Surgical treatment-II l Indications for amputation very severe lesions with destruction of underlying tissue, including vascular damage intractable pain lack of infection control

37 Module Medical XIII. 37 Conclusion l Local radiation injury (or CRS) is a complex pathological syndrome that follows a typical clinical course characterized by excessively prolonged or incomplete healing l Long term and careful clinical observation and evaluation of perfusion and tissue necrosis by scintigraphy, thermography, cutenous laser doppler, CT and MR is essential


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