33
Table 4. Endocrine Toxicities
4.3 Pituitary — Hypophysitis
Workup/Evaluation:
• Evaluate ACTH (AM), cortisol (AM), TSH, free T4, electrolytes.
• Consider standard dose ACTH stimulation testing for indeterminate results (AM
cortisol >3 ug/dL and <15 ug/dL).
• Consider evaluating LH and testosterone in males, FSH, and estrogen in
premenopausal females with fatigue, loss of libido and mood changes, or
oligomenorrhea.
• Consider magnetic resonance imaging (MRI) brain w/wo contrast with pituitary/
sellar cuts in all patients with new hormonal deficiencies and particularly those with
multiple endocrine abnormalities +/- new severe headaches or complaints of vision
changes.
• Perform MRI brain w/wo contrast with pituitary/sellar cuts for all patients
presenting with diabetes insipidus (DI is most commonly from metastatic disease).
Grading Management
All Grades • Referral to endocrinolog y
• Education on steroid stress dosing, emergency
injections, and a medical alert bracelet/necklace,
accessory, or system.
G1: Asymptomatic or mild
symptoms
• Consider holding ICPi until patient is stabilized on
replacement hormones.
• Endocrine consultation.
• Corticosteroid replacement for adrenal
insufficiency with preference for hydrocortisone
(15–20 mg in divided doses — see additional
considerations section 4.2).
• Initiate other hormone replacement only after any
needed adrenal replacement to avoid precipitating
adrenal crisis.
▶ Thyroid hormone replacement if needed using
dosing as above for primary hypothyroidism,
with a goal FT4 in the upper half of the
reference range (TSH is not accurate in central
hypothyroidism).
▶ Testosterone or estrogen therapy if needed in
those without contraindications (e.g., prostate
cancer, breast cancer, or history of deep vein
thrombosis (DVT)).
• Recommend education on stress dosing, emergency
injectable, and a medical alert /necklace accessory
or system.
(cont'd)
