. Author manuscript; available in PMC: 2023 Jan 1.

Published in final edited form as: Int J Radiat Oncol Biol Phys. 2021 Aug 15;112(1):222–236. doi: 10.1016/j.ijrobp.2021.08.015

Table 2.

Published values for (α/β)_x for selected early and late normal tissue endpoints. Shaded rows indicate endpoints with potentially high relative biological effectiveness due to low (α/β)_x

Tissue endpoints	(α/β)_x [Gy]
Capillarics¹⁵⁸	3
Connective tissue fibrosis¹⁵⁸	2
Skin nccrosis/fibrosis^159,160	1.9–2.3
Skin (dermatitis [erythema, desquamation])^66,158	8.8–12.3
Skin desquamation⁶⁶	18–35
Skin telangiectasis^66,159	3.9–5.7
Ncrve (brachial plexopathy)^160,161	2; < 5.3
Nerve (cauda equina)¹⁶⁰	2–3
Breast (atrophy, fibrosis)¹⁵⁸	2–3
Heart (peri card i ti s)^158,160	2–3
Chiasm (loss of visión)^158,160	2–3
Optic nerve (ncuropathy)¹⁵⁸	2
Larynx (chronic edema, fibrosis)^158,160	2–4
Larynx: cartilage necrosis and edema^66,160	3.4–4.4
Salivary glands (xerostomia)¹⁵⁸	3
Oral museositis¹⁵⁸	10
Hairloss¹⁵⁸	7
Oropharynx: late effects⁶⁶	4.5
Brain/brainstcm necrosis^160,162	2.1
Spinal cord myelopathy/necrosis^66,160	2; <3.3
Livcr fibrosis¹⁵⁸	1
Liver failure¹⁶⁰	1.5
Esophagus (stricturc/pcrforation)¹⁶⁰	3
Kidney ncphritis/ncphropathy^158,160	2–3.5
Stomach (ulccration/pcrforation)^158,160	4; 7–10
Colon (obstruction/ulccration/pcrforation)¹⁶⁰	3.1–5
Rcctum (stcnosis/proctitis/necrosis)¹⁶⁰	3.9
Rectum (chronic inflammation, ulcer)¹⁶⁰	5
Small intestinc (obstruction/pcrforation)¹⁶⁰	6–8.3
Bowel (stricture/perforation)⁶⁶	2.2–8
Bladder¹⁶⁰	3.4–6
Urinary bladder cystitis¹⁵⁸	10
Ccrvical/thoracic/lumbar myelopathy¹⁵⁸	2
Lung perfusion¹⁶³	1.3
Lung fibrosis^158,159	3–3.6; 4
Lung pneumonitis^66,159,160	< 3.8; 4.4–6.9
Lung pneumonitis (early)^66,158	> 8.8; 5
Rib fractures^159,160	1.8–2.5
Bone (osteoradionecrosis)¹⁵⁸	60