Of all the PET scan prescriptions we see at the front desk, the FDOPA PET scan produces the most puzzled families. It is prescribed by neurologists for tremor patients, by neuro-oncologists for brain tumour patients, and by endocrinologists for rare tumour work-ups — three completely different situations, one unfamiliar scan name, and almost no patient-friendly information about it online in the Indian context.
This guide fixes that. Whether your prescription came from a neurologist, an oncologist, or an endocrine specialist, by the end of this page you will understand what the 18F-FDOPA PET CT scan actually measures, why it was chosen for your situation specifically, how to prepare, and what the report will tell your doctor.
Quick answer: The FDOPA PET scan (18F-FDOPA PET/CT) uses a radioactive form of the amino acid DOPA — an amino acid your body naturally uses to make dopamine — as its tracer. Because different tissues handle amino acids in revealing ways, one tracer serves three distinct clinical roles: mapping dopamine function in the brain for Parkinson’s disease evaluation, imaging brain tumours with far better contrast than FDG, and detecting certain neuroendocrine and endocrine tumours. The FDOPA PET scan is available at Neurad Diagnostic & Healthcare LLP, Paschim Vihar, Delhi — call +91 8368225620 to schedule, as this specialised tracer is arranged per appointment.
What Makes FDOPA Different: An Amino Acid, Not a Sugar
Most people who have heard of PET scans know the standard FDG scan, which uses a radioactive sugar. FDOPA works on an entirely different biological pathway. DOPA is an amino acid — a protein building block — and it sits one step before dopamine in the brain’s neurotransmitter assembly line. Cells that actively transport amino acids and process DOPA take up the tracer; the scanner shows where and how much.
This single difference unlocks the three clinical uses, because three very different cell types happen to handle DOPA distinctively:
- Dopamine-producing neurons in the brain — the cells that degenerate in Parkinson’s disease
- Brain tumour cells, which transport amino acids far more aggressively than normal brain tissue
- Certain neuroendocrine and endocrine tumour cells, which take up and process amine precursors as part of their biology
Let us take the three uses one by one — find the section that matches your prescription.
Use 1: Parkinson’s Disease and Movement Disorder Evaluation
This is the use neurologists prescribe. In Parkinson’s disease, the dopamine-producing neurons of a deep brain region (the substantia nigra, projecting to the striatum) degenerate slowly — usually for years before symptoms appear. The FDOPA PET scan visualises the presynaptic dopamine system directly: healthy striatal neurons take up the tracer strongly; degenerated ones take up less, in a characteristic pattern.
Why this matters clinically: tremor has many causes, and they are treated very differently. Essential tremor, drug-induced parkinsonism, and true Parkinson’s disease can look similar in a clinic room, especially early. On FDOPA PET, essential tremor and drug-induced parkinsonism typically show a preserved dopamine system, while Parkinson’s disease and related degenerative syndromes show characteristic reduction. When the clinical picture is ambiguous, this scan gives the neurologist objective evidence — which can settle years of diagnostic uncertainty in a single study.
Honest boundaries: the scan supports and clarifies the neurologist’s diagnosis; it does not replace clinical assessment, and it does not by itself distinguish every parkinsonian syndrome from every other. Your neurologist interprets it within your full picture — which is exactly how it should be used.
Use 2: Brain Tumour Imaging — Where FDG Struggles Most
Here is a limitation of the standard FDG scan that surprises many families: the normal brain burns glucose constantly and intensely, so on an FDG scan the entire brain glows — and a tumour can hide inside that glow like a candle in daylight. Amino acid tracers like FDOPA solve this elegantly: normal brain takes up relatively little tracer, while tumour tissue, with its aggressive amino acid transport, stands out clearly against a quiet background.
Neuro-oncologists use FDOPA PET particularly for:
- Recurrence vs radiation change — after surgery and radiotherapy, MRI often shows an enhancing area that could be tumour regrowth or treatment-related change (radiation necrosis). The two look alike on MRI but demand opposite responses. Amino acid PET helps separate them: viable tumour typically shows uptake; pure treatment change typically does not.
- Delineating tumour extent for biopsy targeting and radiotherapy planning — identifying the most active region of a glioma so the needle or the beam goes where it matters.
- Assessing gliomas with weak MRI enhancement, where conventional imaging understates the disease.
If your prescription came after an ambiguous post-treatment MRI, this is almost certainly the question your doctor is asking. It pairs naturally with our existing guide on the PET scan for brain for the broader picture of brain PET imaging.
Use 3: Neuroendocrine and Endocrine Tumour Work-Up
The third audience for FDOPA is endocrine and oncology specialists dealing with specific tumour families whose cells process amine precursors — the biology FDOPA images directly:
- Medullary thyroid carcinoma — particularly in recurrence work-ups when calcitonin rises but conventional imaging is unrevealing
- Pheochromocytoma and paraganglioma — as a complementary study in selected cases
- Certain neuroendocrine tumours where somatostatin receptor imaging (DOTANOC/NOTANOC) is equivocal or where the tumour biology favours an amine-precursor tracer
- Congenital hyperinsulinism in infants — a highly specialised application at dedicated paediatric centres, where FDOPA helps distinguish focal from diffuse pancreatic disease before surgery
In this territory, FDOPA is a complementary tool in a toolbox — the choice between DOTANOC, FDG, FDOPA, or a combination is your specialist’s call based on the specific tumour and question. Our comparison guide on which PET tracer suits which situation explains that decision logic in depth.
How to Prepare for an FDOPA PET Scan
Preparation has a few FDOPA-specific points, and the exact protocol depends on which of the three uses your scan is for — the centre confirms your specific instructions at booking. The general framework:
- Fasting for a few hours before the scan is typically advised. Because FDOPA is an amino acid tracer, a recent protein-heavy meal can compete with the tracer for transport — fasting keeps the images clean. Water is fine and encouraged.
- Medication timing matters — especially for Parkinson’s patients. Your Parkinson’s medicines and certain related drugs interact with the very pathway being imaged, and some protocols time the scan relative to doses. Never stop Parkinson’s medication on your own — the scheduling team coordinates timing with your neurologist.
- Premedication in some protocols. Depending on the indication, a premedication tablet may be given before the injection to improve image quality — a routine, protocol-level step the team handles on the day.
- Bring your imaging history. For brain tumour cases, the recent MRI is essential — the PET is read side by side with it. For endocrine cases, bring tumour marker reports (calcitonin, catecholamines/metanephrines) and prior scans.
- Standard nuclear medicine screening applies — inform the team about pregnancy, breastfeeding, and diabetes at booking.
Step-by-Step: The FDOPA Scan Experience
Step 1 — Registration and protocol review (10–15 minutes). Prescription, imaging history and medications are reviewed; any premedication is given per protocol.
Step 2 — Tracer injection. A standard IV injection. FDOPA is labelled with Fluorine-18 (half-life ~110 minutes) and is produced at cyclotron facilities — which is why this scan is scheduled per appointment with tracer arrangement, rather than as a walk-in study. Book a few days ahead where possible.
Step 3 — Uptake period. A quiet rest period follows injection — the duration varies by indication (brain studies and body studies use different timings; your protocol is explained on the day).
Step 4 — Scanning (20–40 minutes depending on protocol). Brain-focused studies image the head; tumour work-ups may cover more of the body. The scanner is open at both ends, and the technologist stays in voice contact throughout.
Step 5 — Report within 24 hours, read by our nuclear medicine physicians — Dr. Swagat Dash (MBBS, DNB – Nuclear Medicine) and Dr. Pradeep Chaurasiya (MBBS, DNB – Nuclear Medicine) — alongside your MRI and clinical history, and written for the specialist who asked the question.
Is the FDOPA PET Scan Safe?
Yes — its safety profile matches other F-18 PET studies. The tracer dose is microscopic in chemical terms, has no drug-like effect at imaging doses, and its radioactivity decays and clears within about a day, mainly through urine. Hydration speeds this along. Elderly patients — a large share of both the Parkinson’s and tumour populations — tolerate the study well; the practical considerations are comfortable positioning and, for tremor patients, our technologists’ experience in acquiring clean images despite involuntary movement. For the complete safety picture — radiation dose comparisons, precautions at home, pregnancy and breastfeeding guidance — see our detailed guide on PET scan side effects and precautions.
FDOPA PET Scan Cost in Delhi
As a specialised, cyclotron-produced tracer study, FDOPA pricing depends on the protocol (brain-focused vs extended coverage), premedication requirements, and tracer logistics for your appointment date. Neurad Diagnostic quotes a single all-inclusive figure for your specific prescription when you call — and that figure holds on scan day, with no additions at billing. For the current rate and the next available tracer date, call +91 8368225620 or +91 7011968879. Our general guide on what affects PET CT scan cost in Delhi explains the pricing logic across scan types.
Frequently Asked Questions About the FDOPA PET Scan
1. Can the FDOPA PET scan diagnose Parkinson’s disease?
It provides objective evidence about the brain’s dopamine system — typically reduced in a characteristic pattern in Parkinson’s disease and preserved in essential tremor or drug-induced parkinsonism. The diagnosis itself remains your neurologist’s, made with the scan as strong supporting evidence within your full clinical picture.
2. My MRI shows something after brain tumour treatment — why FDOPA and not another MRI?
Because MRI can struggle to separate tumour regrowth from radiation-related change — both can enhance similarly. Amino acid PET adds the missing dimension: viable tumour typically takes up FDOPA; pure treatment change typically does not. The two studies together answer what neither answers alone.
3. Why not just use a regular FDG PET scan for a brain tumour?
The normal brain consumes glucose intensely, so tumours hide against the bright FDG background. FDOPA’s quiet normal-brain background makes tumours stand out — which is precisely why amino acid tracers exist for neuro-oncology.
4. Do I need to stop my Parkinson’s medicines before the scan?
Do not stop anything on your own. Some protocols time the scan relative to your medication doses; the scheduling team will coordinate the plan with your neurologist and give you exact, written instructions.
5. Do I need to fast before an FDOPA scan?
A few hours of fasting is typically advised so dietary protein does not compete with the amino acid tracer. Water is allowed. Your exact instructions come with your booking confirmation.
6. Is the FDOPA scan painful or claustrophobic?
The only needle is the IV cannula. The scanner ring is open at both ends — considerably more open than an MRI tunnel — and the technologist remains in contact throughout. Tremor patients are positioned for comfort and imaged with appropriate protocols.
7. How long does the whole appointment take?
Plan for roughly 2 to 3 hours including registration, any premedication, injection, the uptake period, and scanning. The exact flow depends on your indication and is explained when you book.
8. Is FDOPA available every day like the Gallium-68 scans?
FDOPA is a Fluorine-18 tracer produced at cyclotron facilities, so it is arranged per appointment rather than produced on-site daily. Call ahead — the team will align the tracer arrangement with your preferred date.
9. Is the radiation from an FDOPA scan a concern for an elderly patient?
The exposure is a modest, one-time diagnostic dose that decays and clears within about a day. For the clinical decisions it informs — Parkinson’s clarification, recurrence vs necrosis — the benefit balance is strongly favourable. Full details in our safety guide linked above.
10. Where can I get an FDOPA PET scan in Delhi?
Neurad Diagnostic & Healthcare LLP, Paschim Vihar, performs FDOPA PET CT studies for neurology, neuro-oncology and endocrine indications, with reports in 24 hours. Call +91 8368225620 with your prescription — the team will confirm the protocol with your specialist and arrange the tracer for your date.
Conclusion: One Tracer, Three Very Different Answers
The FDOPA PET scan is a beautiful example of how one molecule can serve medicine in three ways — mapping the dopamine system for movement disorder clarity, exposing brain tumours that hide from other scans, and tracing rare endocrine tumours through their own biology. If it has appeared on your prescription, it is because your specialist needs one of those three answers with a precision that other tests cannot provide.
Bring your prescription, your MRI or marker reports, and your medication list — and call Neurad Diagnostic at +91 8368225620. The team will handle the protocol coordination, the tracer arrangement, and every question in between.
Neurad Diagnostic & Healthcare LLP
B-3, opp. Metro Pillar No. 233, Near Paschim Vihar West Metro Station, New Multan Nagar, Paschim Vihar, New Delhi – 110056
Phone: +91 8368225620 | +91 7011968879
Website: https://neuraddiagnostic.com
About the Medical Team
Dr. Swagat Dash — MBBS, DNB (Nuclear Medicine & PET-CT Imaging)
Over a decade of clinical expertise in nuclear medicine and advanced diagnostic PET-CT imaging.
Dr. Pradeep Chaurasiya — MBBS, DNB (Nuclear Medicine, Molecular Imaging)
Several years of expertise in PET-CT scans and nuclear medicine procedures.
Dr. Nishant Thapar — MBBS, MD Radiology (High-End Diagnostic Imaging, MRI, CT)
Extensive experience in diagnostic imaging with advanced radiological equipment.
Practicing at Neurad Diagnostic & Healthcare LLP, B-3, Near Paschim Vihar West Metro Station, New Multan Nagar, Paschim Vihar, New Delhi — 110056.
Clinically reviewed by the nuclear medicine team at Neurad Diagnostic & Healthcare LLP. This content is for general information only and is not a substitute for advice from your treating doctor. Scan protocols, medication timing, and preparation steps vary by indication and individual case — always follow the specific instructions provided by your treating specialist and the nuclear medicine team at your appointment.