Advanced Radiotherapy Consulting Mammosite
- Mammosite is a catheter balloon used as a HDR brachy breast applicator
- Rx Dose = 10 fx at 340 cGy/fx for a total dose of 34 Gy delivered BID
- Rx Point is 1 cm from balloon
- Used for early stage breast cancer (preferably node negative)
- Protocol allows for 3 (+) nodes
- Physics Notes
o Total Dose = 34 Gy
o Symmetry of Balloon 2mm asymmetric
o Min distance to skin is (should be 7mm; shall be 5mm)
o PTV_Eval 95% Volume covering 90% Dose
o Max skin dose: 145%
o Tissue Volume V150 50cc
o Tissue Volume V200 10cc
o Uninvolved Normal Breast: 60% receives 50% Rx Dose
- Contouring Notes
o Subtract balloon volume from breast volume
o PTV_eval = PTV – 5mm from skin – pectoral muscle
o Breast Volume based on external tangential fields
o Evaluate Air Pockets vs Volume
Advanced Radiotherapy Consulting 3D PBI
- 3D Partial Breast Irradiation used in leau of Mammosite
- Rx Dose = 10 fx at 385 cGy/fx for a total dose of 38.5 Gy delivered BID
- Rx Point Volume is PTV_eval
- Used for early stage breast cancer (preferably node negative)
- Protocol allows for 3 (+) nodes
- Physics Notes
o Total Dose = 38.5 Gy
o PTV_Eval 90% Volume covering 90% Dose
o Max Dose in Plan: 120%
o Heart Dose: 5%V 5% Dose (right sided lesions)
o Heart Dose: 40%V 5% Dose (left sided lesions)
o Thyroid Max: 3%
o Ipsilateral Lung Dose: 15%V 30% Rx Dose
o Contralateral Lung Dose: 15%V 5% Rx Dose
o Whole Breast Reference Volume
§ 60%V at 50% Rx Dose
§ 35%V at Rx Dose
- Contouring Notes
o Subtract balloon volume from breast volume
o PTV_eval = PTV – 5mm from skin – pectoral muscle
o Breast Volume based on external tangential fields