Table 3.

Target volume constraints

Dose constraints	Optimal	Mandatory
PTV D98%	≥95% of prescribed dose	≥90% of prescribed dose
PTV D50%	±1% of prescribed dose	–
PTV D2%	≤105% of prescribed dose	≤107% of prescribed dose
Normal tissue D1cc	–	≤110% of prescribed dose

PTV D_98% is the dose received by 98% of planning target volume (PTV).

PTV D_50% is the dose received by 50% of PTV.

PTV D_2% is the dose received by 2% of PTV.

Normal tissue D_1cc is the dose received by 1 cm³ of normal tissue outside the PTV.