Skin

Question 1

Risk factors for Nodal involvement

Answer 1

Poorly differentiated, >3cm, >4mm depth, lips and temporal lesions – LN+ 10-15%

•SCC from burn scar (Marjolins) or osteomyelitic sites: LN+ 10-30%

Gorlin syndrome: inc risk of BCC and medullo; high sensitivy to IR

Otherwise risk is <1%

Question 2

Cut. SCC H&N Staging:

Answer 2

Cut. SCC H&N Staging:
T1 – < 2 cm 
T2 – > 2 - 4 cm
T3 – > 4 cm and/or PNI and/or deep invasion or minor bone erosion 
T4a – cortical bone/marrow invasion
T4b – BOS, foramen invasion

Question 3

BCC Low risk criteria

Answer 3

Truck/extremity <2cm
Well-defined borders
No immunosuppression or prior RT
Nodular/superficial subtype
No PNI

Must have all or it’s high risk

Question 4

BCC or SCCa treatment paradigm

Answer 4

MOH’s surgery or definitive RT if not candidate

Definitive RT for central lesions > 5 mm (eyelids, tip nose), lip commissure, and large lesions with poor cosmesis after Mohs

CI for RT: area w poor blood supply or high trauma (dorsum of hand, belt line, shin), previous RT to area, exposed cartilage/bone, Gorlins syndrome

Question 5

Indications for post-op RT to primary

Answer 5

Indications for post-op RT to primary:

1. • margin
2. Extensive PNI or large-nerve involvement
3. Skeletal muscle, bone/cartilage invasion or other high-risk factors

Question 6

Indications for post-op RT to nodes:

Answer 6

Indications for RT to nodes: include ipsi IB-III

1. N+ (especially if multiple nodes)
2. Large nodes (>3 cm)
3. ECE

Question 7

Merkel cell initial treatment

Answer 7

Merkel cell: WLE + LND if cN+ or SLNB+

Question 8

Merkel cell adjuvant RT indications

Answer 8

-adjuvant RT: size > 2 cm, positive/close margins, LVI, LN+ or no LN eval, immunocompromised

• Adj RT to primary if pN0
• Adj RT to primary and nodes if N+

R0 and ENI: 50 Gy
R1: 60 Gy
R2/definitive: 66 Gy

Question 9

Merkel treatment volume

Answer 9

Treat tumor bed + 5cm margins
Can be 2 cm if H&N primary site

Bolus!

Treat nodes if 2+ nodes or ECE

Question 10

Electrons Depth

Answer 10

Electrons
Depth   --    % Isodose
Surf.     --    75-95%
E/4       --    100%
E/3.2    --     90%
E/2.8    --     80%
E/2.3    --     50%
E/2       --     0% (range)

90% isodose line
6MeV = 1.8
9MeV = 2.8
12MeV = 3.8
15MeV = 4.8

Question 11

BCC or SCC dose

Answer 11

electrons

• dose: definitive 55/2.5 or 64-70/2 or 30/6 (64 if <2 cm); -post op 50/2.5 Gy to 90% IDL
• for H&N, use 60/2

Question 12

SCC LC rates

Answer 12

SCC Local control w RT:
T1 – 95%
T2 – 80%
T3 – 50%

5-10% higher for BCC

Tox:
Lymphedema rates can be high

Question 13

Melanoma Workup

Answer 13

For melanoma:
- CT c/a/p or PET/CT and MRI brain for stage III/IV

• Melanoma stains S-100, melan-A

- Path report need to know:
•Breslow thickness
•# of mitosis
•Ulceration
•Margin status
•Microsatellitosis
•PNI
•Desmoplasia

Question 14

Melanoma staging

Answer 14

Melanoma staging:
T1a – < 0.8 mm thick
T1b – <0.8 mm w/ ulcer or 0.8-1 mm
T2 – 1-2 mm thick
T3 – 2-4 mm thick
T4 – > 4 mm thick
(for T2-4, a/b are w/o or w/ ulceration)

N1: 1
N2: 2-3
N3: ≥ 4
(slightly more complicated than this)

M1a – skin, muscle, nonregional node
M1b – lung
M1c – non-lung visceral
M1d – CNS

Stage Ia: T1a 
Stage Ib: T1b-T2a
Stage IIA: T2b-T3a
Stage IIB: T3b-T4a
Stage IIC: T4b
Stage III: N+
Stage IV: M1

Question 15

Melanoma Stage I-II treatment

Answer 15

Stage I-II: WLE + LN evaluation

• 1 cm margin for T1
• 2 cm margin for T3+
• SLNB for cN0 and 1mm or greater thickness
• LND for cN+ or SLNB+

Indications for RT to primary: sorta dont really do RT

1. Close or + margin (re-resection preferred)
2. Recurrent disease
3. Breslow > 4 mm with ulceration (T4b)
4. Desmoplastic
5. Extensive PNI

Question 16

Melanoma dose

Answer 16

Adjuvant RT dose:
48/ (20 fx)

Definitive 55/20

Question 17

Merkel treatment algorithm

Answer 17

Wide excision + SLNB > adjv RT

Note: unlike SCC, BCC, and melanoma, nearly all MCC get adjuvant RT (except <1 cm tumors w/ wide neg margins)

Excision: want 1-2 cm margins.
SLNB: If neg, then observe nodal basin. If SLNB pos or clinically evidence nodes, then nodal dissection (preferred) or RT to the basin.

RT details:
RT for all. Can consider observation for small (<1 cm) with widely neg margins without LVSI and in immunocompetent patient. Start RT within 4-6 weeks of surgery