Pituitary Adenoma

Question 1

SRS Outcomes?

Answer 1

(1) Univ of Virgina (J NSY 2013), RR, 9 centers
GK SRS for nonfx pit adenomas
Median dose 16 Fy
5yr LC 95%
10% of patients had a CN dysfx, 8% required further surgery or RT.

(2) Minniti (Rad Onc 2016), review of 92 SRS pubs
LC 95%
Hypopituitarism in 24% at 5 years
Optic neuropathy 0-3% if Dmax <8-10Gy for nn and chiasm.
Brain necrosis <2%.

Question 2

Fractionated RT vs SRS?

Answer 2

Hormone normalization faster after SRS (usually smaller tumors in SRS cases tho).
Korea study (Cancer 2007) comparing fractionated RT to SRS outcomes.
Median time to response 63 vs 26 months
Similar local control both arms

Question 3

Risk of secondary malignancy with RT?

Answer 3

Royal Marsden RR of 464 pts getting fractionated RT, 3 fields, 45 Gy total
11 developed 2nd brain tumors (5 meningioma, 4 HGG, sarcoma, PNET).
2% risk at 10 yrs and 2.4% risk at 20 years.

Question 4

Adjuvant RT?

Answer 4

If GTR, no RT. If STR…
RT if secretory/functioning, if growth would impact vision, if growth would compromise tx options (SRS now vs EBRT later).
Otherwise, just observe (salvage RT has same LC as immediate PORT).

Question 5

RT vs Surgery?

Answer 5

RT is STR, unresectable, medically inoperable, recurrent after surgery and/or refractory to medical management. LC excellent (90-100%) and similar to surgery. Never compared head to head.

Hypopituitarism happens to 100% of patients who get RT at 5 yrs, most common Growth Hormone (measure IGF-1).

Dose
nonfunctioning = 45-50.4 Gy or 14-16 SRS
functioning = 50.4-54 Gy or 20 Gy SRS
ReRT = 42Gy/21fx