Treatment Paradigm

Question 1

What is the Tx paradigm for craniopharyngioma?

Answer 1

Tx paradigm: max safe resection

Question 2

While controversial, what is the favored Tx approach?

Answer 2

Conservative/STR + RT. The morbidity of a GTR can be detrimental. An STR spares some morbidity and has better QOL (e.g., St. Jude’s data [2002] showed that the Sg group lost an avg of 9.8 IQ points; the more limited Sg + RT group lost an avg of 1.25 points).

Question 3

What surgical approach is typically employed for craniopharyngioma resection?

Answer 3

Lat pterional approach (temporal craniotomy). Approach depends on location of tumor relative to 3rdventricle and optic nerves.

Question 4

What is the rate of GTR?

Answer 4

Large referral centers report GTR rates in 50%–79% of pts.

Question 5

What % of attempted craniopharyngioma GTRs result in STR?

Answer 5

Depends on location, but overall, 20%–30%. (Tomita T et al., Childs Nerv Syst 2005)

Question 6

Is observation ever appropriate after incomplete resection for craniopharyngioma?

Answer 6

Yes. Observation is especially appropriate in young pts. Adj and salvage therapy may have similar LC in closely followed pts. However, more surgical procedures often lead to higher morbidity.

Question 7

What are the RT doses used for craniopharyngioma?

Answer 7

50.4–54 Gy with EBRT in 1.8 Gy/fx

Question 8

What volumes are typically irradiated for craniopharyngioma?

Answer 8

GTV is residual tumor and cyst volume. CTV includes GTV + 0.5–1-cm margin and postop tumor bed. PTV is 3–5 mm expansion on CTV. Be aware of cyst(s) and monitor during RT for possible adaptive RT planning.

Question 9

With what methods can craniopharyngioma cysts be managed?

Answer 9

Aspiration of fluid; injection of radioactive isotope, bleomycin, or IFN. (Cavalheiro S et al., Neurosurg Focus 2010)

Question 10

What isotopes have been used for intracystic RT and what do they deliver?

Answer 10

a-emitting isotopes (yttrium-90, P-32, Rh-186); 200–250 Gy to the cyst wall, be aware of location of chiasm relative to cyst wall.

Question 11

What is the energy and half-life of P-32 and to what depth is it effective?

Answer 11

0.7 MeV, 2 wks. The effective depth is 3–4 mm.

Question 12

What are the indications for intralesional cyst Tx (vs. cyst aspiration)?

Answer 12

Intralesional Tx is an option if the cyst is >50% of total tumor bulk and the number of cysts is ≤3 (ideal if there is a solitary cyst) or for those with recurrent cysts after prior resection.

Question 13

What intracystic chemo has been used?

Answer 13

Bleomycin typically has been used for intralesional cyst management.

Question 14

If a pt has worsening visual Sx while getting adj RT, is this likely d/t an acute side effect from RT?

Answer 14

No. Acute Sx during RT are likely d/t a rapidly enlarging cystic component; therefore, urgent surgical intervention for decompression should be considered. Radiographic cyst monitoring during RT is recommended to allow for smaller PTV. 15% of cysts increase in size during RT.

Question 15

What is the significance of cyst regrowth after RT?

Answer 15

Cyst regrowth may occur after definitive Tx (does not mean failure, as RT can take a long time to exert its ablative effects). Repeat aspirations are in order if the pt is symptomatic.

Question 16

What is the mortality and morbidity rate from Sg for craniopharyngioma?

Answer 16

In modern series, mortality is <4%. Morbidity ranges b/t 8% and 14%.

Question 17

What are the most common/serious side effects of Sg?

Answer 17

DI, hypothalamic obesity, vision loss (<2%), and other hypothalamic injury (defective short-term memory, sleep disturbances)

Question 18

What are the potential long-term side effects of RT?

Answer 18

Hypopituitarism (short stature, delayed puberty in 14%–50% depending on age), cognitive dysfunction or ↓IQ (10%), 2nd malignancy, and vasculopathy

Question 19

The hypothalamus should be kept at or below what total RT dose?

Answer 19

If possible, the hypothalamus dose should not exceed 45 Gy.

Question 20

How long does it usually take for tumors to regrow? What f/u is needed?

Answer 20

2 yrs on avg. However, there is a wide range, and regrowth can take up to 9 yrs. Thus, the pt requires long-term f/u with serial MRIs and neuro-ophthalmology or endocrinology exams.

Question 21

What is the role for radiosurgery (SRS), and what is the recommended dose in the management of craniopharyngioma?

Answer 21

The role for SRS in craniopharyngioma is primarily for postoperative residual disease, or in the setting of recurrent disease, where tumors should be at least 5 mm away from the optic apparatus and hypothalamus. Dose for SRS is 12 to 14 Gy.

Plowman, PN, Wraith, C, Royle, N, et al. Stereotactic radiosurgery. IX. Craniopharyngioma: durable complete imaging responses and indications for treatment. Br J Neurosurg. 1999;13:352-358.

Question 22

What is the consensus on initial primary management of craniopharyngioma?

Answer 22

The two primary approaches for craniopharyngioma management include GTR or maximal safe resection followed by adjuvant radiotherapy (54–55 Gy with 1.8 Gy/fx). In a recent study, the 10-year local control with surgery (GTR or STR) alone versus surgery and radiation was found to be 42% versus 84%, respectively. Additionally, St. Jude data revealed that the IQ deficit for aggressive surgical management was 8.8 points compared to the limited surgery with radiation group, where average IQ loss was 1.25 points.

Merchant, TE, Kiehna, EN, Sanford, RA, et al. Craniopharyngioma: the St. Jude Children’s Research Hospital experience 1984–2001. Int J Radiat Oncol Biol Phys. 2002;53:533-542.