dromlakhani Indicate growth hormone therapy for confirmed GHD
STEP 1 — Gather Information
Confirm growth hormone deficiency via provocative testing (insulin tolerance test, glucagon, or arginine) per guideline, avoiding reliance on serum IGF‑I alone; document cancer treatment details (HP axis radiation dose, TBI, spinal radiation), assess for other pituitary hormone deficiencies, verify disease‑free status (≥1 year off therapy) or note stable disease, and review current medications (e.g., tyrosine kinase inhibitors).
Action: If GHD is confirmed by appropriate provocative testing and not solely by IGF‑I, proceed to Step 2; otherwise, do not offer GH.
STEP 2 — Rule In / Rule Out
Rule out active malignancy unless the patient has been disease‑free for ≥1 year or has stable disease discussed with an oncologist; rule out concurrent tyrosine kinase inhibitor therapy (suggest against GH); rule out uncorrected central hypothyroidism or adrenal insufficiency as prerequisites.
Action: If no contraindications are present, proceed to Step 3; otherwise, do not offer GH.
STEP 3 — Classify or Stratify
Classify the patient as a candidate for GH when GHD is confirmed, disease‑free ≥1 year (or stable disease with oncologist discussion), and no contraindications from Step 2 exist.
Action: Proceed to Step 4 to decide on GH offering.
STEP 4 — Decide
Offer growth hormone therapy using regimens similar to those for non‑cancer‑population GHD, initiate after confirming baseline assessments (thyroid, adrenal, IGF‑I), and schedule monitoring per guideline.
Action: Initiate GH therapy.
Clinical Guardrails / Mimics / Pitfalls
Monitor serum IGF‑I to keep within age‑ and sex‑specific normal range; assess for slipped capital femoral epiphysis, metabolic changes, and intracranial hypertension; avoid GH in patients on active tyrosine kinase inhibitors; consider reduced spinal growth benefit after spinal radiation; discuss timing with oncologist for patients with stable disease; ensure adequate thyroid and adrenal function before starting GH; do not rely on spontaneous GH secretion or GHRH‑arginine alone for diagnosis.
Concrete Clinical Example
A 12‑year‑old survivor of medulloblastoma treated with cranial radiation 18 Gy is now 2 years off therapy, has confirmed GHD by insulin tolerance test (peak GH < 5 ng/mL), no other hormone deficits, and is disease‑free.
Decision: Offer GH therapy per standard regimen.
Source: Hypothalamic Pituitary and Growth Disorders in Survivors of Childhood Cancer, Sklar et al., Endocrine Society Clinical Practice Guideline, 2018, doi:10.1210/jc.2018-01175