[18F]FES PET/CT in PAH

This is a feasibility study of serial FES scanning in female patients with Pulmonary Arterial
Hypertension (PAH) to determine whether patients have detectable changes in FES SUV following
treatment with fulvestrant on the separate therapeutic protocol IRB# 824861 "Estrogen
Receptor Antagonist in Patients with Pulmonary Arterial Hypertension (ERA PAH)". Subjects
will undergo up to 2 [18F]FES PET/CT scans for this protocol. A baseline FES PET/CT will
occur on Day 0 (-2 days) of the companion treatment trial prior to initiation of fulvestrant.
The second FES PET/CT scan will occur on week 9 (63 ± 7 days) after initiation of
fulvestrant. We will compare SUV values after fulvestrant to pre-treatment values.

Inclusion Criteria:

- 1. Women who are post-menopausal, defined as one of the following

1. > 50 years old and a) have not menstruated during the preceding 12 months per
medical record review or self-report or b) have follicle-stimulating hormone
levels > 40 IU/L at screening OR

2. < 50 years and follicle-stimulating hormone levels > 40 IU/L at screening OR

3. history of bilateral oophorectomy per medical record review or self-report.

2. Diagnosis of Pulmonary Arterial Hypertension (PAH) per medical record review.

3. Patients must be candidates to receive treatment on the companion therapeutic trial
"Estrogen Receptor-α Inhibitor in Patients with Pulmonary Arterial Hypertension (ERA
PAH)" (IRB# 824861 "ERA PAH")

4. Participants must be informed of the investigational nature of this study and be
willing to provide written informed consent and participate in this study in
accordance with institutional and federal guidelines prior to study-specific
procedures.

Exclusion Criteria:

- 1. Inability to tolerate imaging procedures in the opinion of an investigator or
treating physician

2. Serious or unstable medical or psychological conditions that, in the opinion of the
investigator, would compromise the subject's safety or successful participation in the
study.

3. Ineligible for the therapeutic trial IRB# 824861 "ERA PAH" entitled "Estrogen
Receptor Antagonist in Patients with Pulmonary Arterial Hypertension (ERA PAH)" (IRB#
824861 "ERA PAH")