HyTEC Dose Constraints

This page contains the normal tissue dose constraints from the HyTEC publications, with organ names labeled according to the AAPM TG 263 naming convention. A few notes on the structure names:

HyTEC expresses some constraints as ranges; this data separates the ranges into two constraints: an upper limit and a lower limit.
The Optic pathway constraints were duplicated into 3 constraints: Optic Chiasm, Optic Nerve Left, and Optic Nerve Right.
The Carotid artery constraints were duplicated into left and right organs.

HyTEC Constraints (1 Fraction)

Organ	Constraint	Notes
Brain	V12Gy < 5 cc	Symptomatic necrosis (10%)
Brain	V12Gy < 10 cc	Symptomatic necrosis (15%)
Brain	V12Gy < 15 cc	Symptomatic necrosis (20%)
Optic Chaism	Max < 10 Gy	Neuropathy (1%). Lower limit
Optic Chaism	Max < 12 Gy	Neuropathy (1%). Upper limit
Optic Nerve Left	Max < 10 Gy	Neuropathy (1%). Lower limit
Optic Nerve Left	Max < 12 Gy	Neuropathy (1%). Upper limit
Optic Nerve Right	Max < 10 Gy	Neuropathy (1%). Lower limit
Optic Nerve Right	Max < 12 Gy	Neuropathy (1%). Upper limit
Spinal Cord	Max < 12.4 Gy	Myelopathy (1-5%). No prior RT. Lower limit
Spinal Cord	Max < 14 Gy	Myelopathy (1-5%). No prior RT. Upper limit

HyTEC Constraints (2 Fractions)

Organ	Constraint	Notes
Spinal Cord	Max < 17 Gy	Myelopathy (1-5%). No prior RT. Lower limit
Spinal Cord	Max < 19.3 Gy	Myelopathy (1-5%). No prior RT. Upper limit

HyTEC Constraints (3 Fractions)

Organ	Constraint	Notes
Brain	V20Gy < 20 cc	Edema or necrosis (10%)
Brain	V20Gy < 30 cc	Edema or necrosis (20%)
Optic Chaism	Max < 20 Gy	Neuropathy (1%)
Optic Nerve Left	Max < 20 Gy	Neuropathy (1%)
Optic Nerve Right	Max < 20 Gy	Neuropathy (1%)
Liver	Mean < 13 Gy	Grade 3+ liver enzyme change (< 20%). Liver primary. Excludes GTV
Liver	Mean < 15 Gy	Grade 3+ liver enzyme change (< 20%). Liver mets. Excludes GTV
Liver	D700cc < 15 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Lower limit
Liver	D700cc < 17 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Upper limit
Lungs	Mean < 8 Gy	Grade 2+ toxicity (10-15%). Excludes target
Lungs	V20Gy < 10 %	Grade 2+ toxicity (10-15%). Excludes target. Lower limit
Lungs	V20Gy < 15 %	Grade 2+ toxicity (10-15%). Excludes target. Upper limit
Spinal Cord	Max < 20.3 Gy	Myelopathy (1-5%). No prior RT. Lower limit
Spinal Cord	Max < 23.1 Gy	Myelopathy (1-5%). No prior RT. Upper limit

HyTEC Constraints (4 Fractions)

Organ	Constraint	Notes
Bladder	V100% < 5 cc	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Lower limit
Bladder	V100% < 10 cc	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Upper limit
Liver	D700cc < 15 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Lower limit
Liver	D700cc < 17 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Upper limit
Lungs	Mean < 8 Gy	Grade 2+ toxicity (10-15%). Excludes target
Lungs	V20Gy < 10 %	Grade 2+ toxicity (10-15%). Excludes target. Lower limit
Lungs	V20Gy < 15 %	Grade 2+ toxicity (10-15%). Excludes target. Upper limit
Rectum	Max < 35 Gy	Late grade 3+ bowel toxicity (< 3%). Prostate SBRT. Lower limit
Rectum	Max < 38 Gy	Late grade 3+ bowel toxicity (< 3%). Prostate SBRT. Upper limit
Spinal Cord	Max < 23 Gy	Myelopathy (1-5%). No prior RT. Lower limit
Spinal Cord	Max < 26.2 Gy	Myelopathy (1-5%). No prior RT. Upper limit
Urethra	Max < 38 Gy	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Lower limit
Urethra	Max < 42 Gy	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Upper limit

HyTEC Constraints (5 Fractions)

Organ	Constraint	Notes
Bladder	V100% < 5 cc	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Lower limit
Bladder	V100% < 10 cc	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Upper limit
Brain	V24Gy < 20 cc	Edema or necrosis (10%)
Brain	V24Gy < 30 cc	Edema or necrosis (20%)
Carotid Artery Left	Max < 20 Gy	Grade 3-5 bleeding (2-12%). No prior RT. Lower limit
Carotid Artery Left	Max < 30 Gy	Grade 3-5 bleeding (2-12%). No prior RT. Upper limit
Carotid Artery Left	D0.5cc < 20 Gy	Grade 3-5 bleeding (2-12%). No prior RT
Carotid Artery Right	Max < 20 Gy	Grade 3-5 bleeding (2-12%). No prior RT. Lower limit
Carotid Artery Right	Max < 30 Gy	Grade 3-5 bleeding (2-12%). No prior RT. Upper limit
Carotid Artery Right	D0.5cc < 20 Gy	Grade 3-5 bleeding (2-12%). No prior RT
Optic Chaism	Max < 25 Gy	Neuropathy (1%)
Optic Nerve Left	Max < 25 Gy	Neuropathy (1%)
Optic Nerve Right	Max < 25 Gy	Neuropathy (1%)
Liver	D700cc < 15 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Lower limit
Liver	D700cc < 17 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Upper limit
Lungs	Mean < 8 Gy	Grade 2+ toxicity (10-15%). Excludes target
Lungs	V20Gy < 10 %	Grade 2+ toxicity (10-15%). Excludes target. Lower limit
Lungs	V20Gy < 15 %	Grade 2+ toxicity (10-15%). Excludes target. Upper limit
Rectum	Max < 35 Gy	Late grade 3+ bowel toxicity (< 3%). Prostate SBRT. Lower limit
Rectum	Max < 38 Gy	Late grade 3+ bowel toxicity (< 3%). Prostate SBRT. Upper limit
Spinal Cord	Max < 25.3 Gy	Myelopathy (1-5%). No prior RT. Lower limit
Spinal Cord	Max < 28.8 Gy	Myelopathy (1-5%). No prior RT. Upper limit
Urethra	Max < 38 Gy	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Lower limit
Urethra	Max < 42 Gy	Late grade 2+ urinary toxicity (< 20%). Prostate SBRT. Upper limit

HyTEC Constraints (6 Fractions)

Organ	Constraint	Notes
Liver	Mean < 18 Gy	Grade 3+ liver enzyme change (< 20%). Liver primary. Excludes GTV
Liver	Mean < 20 Gy	Grade 3+ liver enzyme change (< 20%). Liver mets. Excludes GTV
Liver	D700cc < 15 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Lower limit
Liver	D700cc < 17 Gy	Liver dysfunction and grade 3-5 GI toxicity (< 13%). Excludes GTV. Upper limit