From the Guidelines
The assessment of a patient with prolactinoma involves a comprehensive evaluation of clinical presentation, laboratory results, and imaging studies.
Key Components of Assessment
- Clinical evaluation: includes assessment of growth, puberty, galactorrhoea, menstrual history, gynaecomastia or loss of libido in puberty 1
- Laboratory results: measurement of serum prolactin levels, with consideration of serial dilutions to avoid the "high-dose hook effect" 1
- Imaging studies: MRI to evaluate tumor size and location, with repeat imaging as needed to monitor response to treatment 1
Initial Treatment and Monitoring
Initial treatment typically involves dopamine agonist therapy, such as cabergoline (0.5-2 mg twice weekly) or bromocriptine (2.5-10 mg three times daily), with the goal of normalizing prolactin levels and reducing tumor size.
- Patients should be monitored for symptoms, prolactin levels, and tumor size every 3-6 months, with dose adjustments as needed to achieve and maintain therapeutic efficacy 1
- Echocardiogram should be offered at the start of treatment with a dopamine agonist, with yearly surveillance echocardiography for patients receiving >2 mg per week cabergoline and every 5 years if on ≤2 mg per week 1
Special Considerations
- Cardiac valve regurgitation: high-dose and long-term use of dopamine agonists may pose a risk, although the doses used in treating prolactinomas are notably lower 1
- Bone mineral density: assessment of BMD 2 years after diagnosis may be important in patients with prolactinoma, particularly in the context of delayed growth and puberty 1
From the FDA Drug Label
Patients with rapidly progressive visual field loss should be evaluated by a neurosurgeon to help decide on the most appropriate therapy Monitoring of visual fields in patients with macroprolactinoma is therefore recommended for an early recognition of secondary field loss due to chiasmal herniation and adaptation of drug dosage Since pregnancy may occur prior to reinitiation of menses, a pregnancy test is recommended at least every four weeks during the amenorrheic period, and, once menses are reinitiated, every time a patient misses a menstrual period. Patients must be monitored closely throughout pregnancy for signs and symptoms that may signal the enlargement of a previously undetected or existing prolactin-secreting tumor.
The assessment for a patient with Prolactinoma includes:
- Monitoring of visual fields to recognize secondary field loss due to chiasmal herniation
- Pregnancy testing at least every four weeks during the amenorrheic period
- Close monitoring throughout pregnancy for signs and symptoms of tumor enlargement
- Evaluation by a neurosurgeon for patients with rapidly progressive visual field loss 2
From the Research
Assessment of Prolactinoma
The assessment of a patient with prolactinoma involves several steps, including:
- Measurement of serum prolactin concentrations to confirm the diagnosis of hyperprolactinemia 3, 4, 5
- Morphological evaluation of the pituitary gland by magnetic resonance imaging (MRI) to determine the size and extent of the tumor 3, 4, 5
- Evaluation of clinical symptoms, such as menstrual irregularities, galactorrhea, and visual field defects 3, 4, 5
Treatment Options
Treatment options for prolactinoma include:
- Dopamine agonists, such as cabergoline, which are considered the first-line treatment for prolactinoma 3, 4, 5
- Transsphenoidal adenomectomy, which may be indicated for patients who are resistant or intolerant to dopamine agonists 5, 6
- External radiation therapy, which may be used in patients with poor response to medical and surgical procedures 5
Response to Treatment
The response to treatment with dopamine agonists, such as cabergoline, can be significant, with:
- Normalization of serum prolactin concentrations in up to 76.5% of patients 3
- Reduction in tumor size in up to 90% of patients 4
- Improvement in clinical symptoms, such as menstrual irregularities and visual field defects 3, 4
Pre-operative Treatment
Pre-operative treatment with dopamine agonists may improve post-operative tumor control following prolactinoma resection, with:
- Greater reductions in prolactin levels 6
- Lower prolactin levels at long-term follow-up 6
- Improved tumor control and reduced need for additional therapy 6
Resistance to Treatment
Resistance to standard doses of cabergoline is an infrequent phenomenon, but can occur in up to 8.7% of patients, and may require: