Background and recommendations Flashcards
What dose do you provide when giving larynx only RT?
- T1 N0 = 63 Gy at 2.25 Gy/fx (28)
2. T2 N0 = 65.25 at 2.25 Gy/fx (29)
What are the indications for treating glottic CIS?
- Recurrence
- Involvement of anterior commisure
- Patient is unreliable for close follow up
- Medically high risk for surgery
What are the borders of larynx only fields for glottic cancer?
Sup: Midthryoid notch
Ant: flash by 2 cm
Inf: bottom of cricoid or 1 cm below if subglottic extension is noted
Posterior: ant edge of VB
T1 glottic
a. Tumor involves glottis only, 1 cord
b. Tumor involves glottis only, 2 cords
T2 glottic
- Tumor involves supra or subglottis
2. impaired cord mobility
T3 glottic
Fixed cord
Paraglottic space invasion
Only inner cortex T-cartilage invasion
T4 glottic
Full thickness T-cartilage invasion Deep tongue invasion Trachea invasion Soft tissues of neck invasion Esophageal invasions Thyroid invasion
What are the indications for ENI for larynx cancer?
- All supraglottic cancers
2. All cancers with > 5 mm subglottic or supraglottic extension
What nodes should be covered with ENI?
Unilateral
- RS in node positive neck
- RP in node positive neck or if tumor involves PPW (bilaterally)
- Level 5 in node positive neck
Always bilateral
2, 3, 4, 6, 7
When do you use a LAN?
Never. Just use whole neck IMRT.
What beam energy is preferred?
4 MV but 6 MV can be just as good but close attention must be paid to isodose lines
How do you weight the beams for larynx only RT with unilateral tumor?
3:2
What tumor volume do you use for supraglottic cancers when deciding surgery vs. RT?
12 cc
What equation approximates tumor volume?
4/3 x Pi x r^3 = Volume of sphere
T1 supraglottic
Limited to one subsite of supraglottis
