Skin Flashcards
What is the risk of PNI, LN, DM for BCC
very low
What is the risk of PNI, LN, DM for SCC
PNI is 2-15%
Well diff SCC LN+ 1%
Risk factors for greater LN+ for SCC
>3 cm
>4 mm depth
Lips
Temporal lesions
SCC from burn scars or osteomyelitis
What syndrome increases risk of BCC and medulloblastoma
Gorlin syndrome
What is etiology of Merkel cell
Merkel polyoma virus
What imaging is needed for Merkel cell
PET CT
When should MRI be ordered for skin cancers
Concern for PNI
T1 SCC/BCC
<2 cm
T2 skin
2-4 cm
T3 skin
>4 cm and/or
PNI and/or
Deep invasion or minor bone erosion
T4a skin
cortical bone or marrow invasion
T4b skin
BOS or foramen involvement
What is preferred managment of BCC or SCC
Moh’s surgery
What are the indications for post-op RT for SCC or BCC
- Positive margin
- Extensive PNI or large nerve involvement
- Skeletal muscle, bone/cartilage invasion or other high risk features
What is large nerve involvement for skin cancer
>0.1 mm
What are indicates for RT to nodes for SCC/BCC
N+ disease or ECE
What levels are treated for skin cancers
IB to III
Which skin lesions should be offered definitive RT
Central lesions > 5 mm
eyelids, tip of nose, lip commissure
Large lesions with poor comesis after Moh’s
If incurable skin cancer, what is another treatment option
cemiplimab
PD1 inhibitor
What is the preferred RT approach for SCC/BCC
Electron beam therapy
Doses of SC for definitive SCC
70 Gy in 2 fractions
55 Gy in 20 fractions
Prescribe electrons to 90%IDL
Dose of RT for postop SCC
60 Gy in 30 fractions
What is electron setup for SCC
custom electron cutout with bolus and 1-2 cm margin on lesion
Specific steps for periorbital treatment
Lead sheild
Place anesthetic drops prior to placement of lead shield and then do eye patch afterward due to impaired corneal reflex
Specific steps for nose
Wax bolus over node to convert to box like contour
Lead plugs in nostrils
Special steps for lips
Lead shield between gingiva and lips
When to start RT if skin graft
6-8 weeks
If there is a graft what should be in the field?
FUll graft
What is 90% electron range
E/4
What is 80% electron range
E/3
What is preferred treatment for Merkel cell
WLE + LND if cN+ or SLNB+
Then typically adjuvant RT for MOST PATIENTS
RT target for Merkel if WLE and neg SLNB
Primary site itself
tumor bed + 5 cm margins (scalp but non HN)
tumor bed + 2 cm margins (HN primary)
What is Merkel adjuvant RT plan if N+
Adjuvant RT to primary and nodal basin
Dose for Merkel if R0
50 Gy
Dose for Merkel cell if R1
56 Gy
Dose for Merkel if R2 or definitive
60 Gy
Most common form of melanoma
Superficial spreading
Imaging needed for melanoma
CT CAP or PET for stage III/IV
How is T stage determined for melanoma
Thickness
T2 melanoma is what thickness
1-2 mm
T3 melanoma
2-4 mm
T4 melanoma
>4 mm
What is stage I/II melanoma
T1-T4N0
What is preferred treatment for stage I or II melanoma
WLE and LN evaluation
What is the required surgical margin for melanoma
1 cm if superficial T1
2 cm margin if T3+
Which melanoma patients need SLNB
cN0 and >0.8 mm
If melanoma patient is cN+, next step
LND
Indications for postop RT to primary for melanoma
Close or + margin (though re-excision preferred)
Desmoplastic
Thickeness > 4 mm
Recurrence
Extensive PNI
What are the indications for postop RT to nodes for melanoma
1+ parotid nodes, 2+ cervical or axillary, 3+ groin
ECE
LN>3 cm
WHat is the adjuvant RT dose for melanoma
48 in 20 fractions (2.4 per fraction)
