Dr. Swagat - Nuclear Theranostic Specialist

04/12/2025

FAPI PET: Precision Beyond FDG

Welcome to our latest video where we dive deep into the fascinating world of FAPI PET Scan. In this comprehensive guide, we will explore everything you need ...

01/12/2025

Ga-68 FAPI PET to Lu-177 FAPI Therapy: The Complete Theranostic Journey

One molecule. Two missions. Transformative outcomes.

Theranostics—the marriage of diagnostics and therapeutics—has found its most elegant expression in FAPI-based radioligands. The journey from scan to treatment using the same molecular target represents precision oncology at its finest.

The Diagnostic Phase: Ga-68 FAPI PET

Gallium-68 labelled FAPI tracers illuminate tumors by binding to fibroblast activation protein in cancer-associated fibroblasts. This diagnostic scan:
• Identifies FAP-positive tumors with exceptional clarity
• Maps disease burden across primary and metastatic sites
• Predicts therapeutic response potential
• Guides patient selection for targeted therapy

The Therapeutic Phase: Lu-177 FAPI
By replacing Gallium-68 with Lutetium-177—a therapeutic radionuclide—the same FAPI molecule transforms into a precision weapon. The beta-emitting Lu-177 delivers targeted radiation directly to tumor stroma, sparing healthy tissue.

Why This Matters
Lu-177 FAPI has demonstrated considerable promise as an effective and safe theranostic agent, particularly for:

→ Pancreatic adenocarcinomas
→ Metastatic breast cancers
→ Radioiodine-refractory thyroid cancers
→ Advanced sarcomas

Recent breakthroughs show Lu-177 FAPI enhances immunogenicity, creating synergistic effects when combined with immunotherapy—opening doors to combination protocols.

The Paradigm Shift
Traditional oncology separates imaging from treatment. FAPI theranostics unifies them—the same target, seamless transition, personalised precision. From visualisation to eradication, all guided by molecular fingerprints.

This isn't just treatment evolution. It's a treatment revolution.

28/11/2025

Is FAPI Therapy Right for You? The 5 Eligibility Criteria

Not every patient qualifies for FAPI therapy—and that's by design.

Precision medicine demands precise patient selection. Here's what determines eligibility:

1. Positive FAPI-PET Uptake
→ Must show significant FAP expression on Ga-68 FAPI-PET scan
→ No uptake = No therapy
→ The diagnostic scan predicts therapeutic response

2. Exhausted Conventional Options
→ Surgery, chemotherapy, or radiotherapy already attempted
→ Designed for advanced, treatment-refractory malignancies
→ Standard approaches have failed

3. Adequate Bone Marrow Reserve
→ Sufficient platelet and white blood cell counts are essential
→ Primary side effect: bone marrow toxicity
→ Risk: anemia, leukopenia, thrombocytopenia

4. Preserved Kidney Function
→ Renal clearance demands healthy kidneys
→ Compromised function increases radiation to healthy tissue
→ Safety depends on adequate renal capacity

5. Performance Status
→ Reasonable functional capacity required
→ Must tolerate multiple treatment cycles
→ Ability to manage potential side effects

The Bottom Line
FAPI therapy's favourable dosimetry ensures safe absorbed doses for critical organs when criteria align. Success isn't treating everyone—it's treating the right patients precisely.
Selection matters. Precision delivers.

25/11/2025

Ga-68 vs F-18: The Isotope Choice That Changes Everything

Ordering "a PET scan" isn't enough anymore. The isotope you choose determines what you'll see—and miss.

Here's what most clinicians don't realise:
F-18 FDG: The Workhorse

What it sees: Glucose-avid tumors (most cancers)
Best for: Lymphoma, lung cancer, colorectal, melanoma, head-neck malignancies

Limitations:
- Poor for low-grade/neuroendocrine tumors
- High physiologic brain and urinary activity
- Less effective for prostate cancer
- Inflammation creates false positives

Think: High metabolic rate = high FDG uptake
Ga-68 DOTATATE/PSMA: The Game Changers

DOTATATE targets somatostatin receptors:
- Neuroendocrine tumors (carcinoid, gastrinoma, pheochromocytoma)
- Superior to FDG for well-differentiated NETs
- Guides peptide receptor radionuclide therapy eligibility

PSMA targets prostate-specific membrane antigen:
- Revolutionary for prostate cancer staging
- Detects biochemical recurrence earlier than conventional imaging
- Identifies oligometastatic disease for targeted therapy

Advantages over FDG:
- Tumor-specific targeting
- Minimal physiologic uptake
- Better lesion-to-background ratio
- Lower false positive rates

The Clinical Decision
- Order FDG for: Aggressive, metabolically active tumors
- Order Ga-68 DOTATATE for: Known/suspected neuroendocrine tumors
- Order Ga-68 PSMA for: Prostate cancer staging or recurrence

Wrong isotope = missed diagnosis.
A neuroendocrine tumor might be FDG-negative but DOTATATE-avid. Prostate mets invisible on FDG light up on PSMA.

The Bottom Line
PET imaging evolved beyond FDG. Precision oncology requires precision imaging—starting with the right radiotracer.

Question: What's your experience with Ga-68 tracers versus traditional FDG?

21/11/2025

What Makes a 'Good' PET Scan Centre? 10 Red Flags to Watch For?

Not all PET scans are created equal. The centre you choose affects diagnostic accuracy.

Here are the red flags:

1. No Pre-Scan Fasting Protocol
Patients should fast 4-6 hours. High blood glucose falsely lowers SUV values and image quality.

2. Inadequate Uptake Time
FDG needs 60-90 minutes post-injection to distribute. Rushing compromises accuracy.

3. No Blood Glucose Monitoring
Glucose >200 mg/dL? Reschedule. Proceeding anyway = suboptimal imaging.

4. Poor Patient Preparation Instructions
No guidance on avoiding exercise, staying warm, or medication timing indicates lack of quality control.

5. Non-Subspecialised Reporting
General radiologists interpreting PET miss nuances. Look for nuclear medicine or PET-trained specialists.

6. No Multidisciplinary Tumor Board Participation
Quality centres integrate with oncology teams, not just generate reports.

7. Older Scanner Technology
Time-of-flight (TOF) PET/CT significantly improves image quality. Non-TOF scanners = suboptimal detection.

8. High Patient Volume, Low Quality
Rushing patients through compromises preparation, uptake time, and acquisition quality.

9. No Quality Assurance Program
ACR accreditation or equivalent certification ensures standardised protocols.

10. Reports Without Clinical Context
Good reports integrate clinical history, prior imaging, and provide differential diagnoses—not just describe uptake patterns.

What to Look For Instead
✓ ACR/IAEA accreditation
✓ Dedicated nuclear medicine physicians
✓ Modern TOF PET/CT systems
✓ Standardised preparation protocols
✓ Detailed, clinically integrated reports

Quality imaging isn't expensive. Bad imaging that misses the disease is.
Where you send patients matters as much as what you order.

Question: What quality markers do you prioritise when referring for PET?

19/11/2025

Lymphoma Response Assessment: Deauville Score Explained Simply

Your lymphoma patient finished chemotherapy. The PET report says "Deauville 3."

What does that actually mean for prognosis?

The Deauville 5-Point Scale
This visual scoring system compares residual lymphoma uptake to reference organs:
Score 1: No uptake (complete metabolic response)
Score 2: Uptake ≤ mediastinum (liver background)
→ Essentially complete response
Score 3: Uptake > mediastinum but ≤ liver
→ The grey zone—minimal residual uptake
Score 4: Uptake moderately > liver
→ Residual disease likely
Score 5: Uptake markedly > liver and/or new lesions
→ Progressive disease

The Clinical Translation
Deauville 1-3: Favourable response—complete remission likely
Deauville 4-5: Unfavourable response—consider treatment modification

The Score 3 dilemma: Interpretation depends on:
Timing (interim vs. end-of-treatment)
Lymphoma subtype (Hodgkin vs. Non-Hodgkin)

Clinical context
Most protocols treat Deauville 1-3 as negative at end-of-treatment PET.

Why It Matters:
Before Deauville, Radiologists used subjective descriptors. "Minimal residual uptake"—what does that mean?

After Deauville: Standardised, reproducible, prognostically validated scoring that guides treatment decisions.

Real impact:
Deauville 1-2 after 2 cycles → Continue current regimen
Deauville 4-5 after 2 cycles → Escalate therapy
Deauville guides stem cell transplant decisions

For Your Patients
"The Deauville score compares any remaining activity to normal organs. Scores 1-3 indicate excellent response. Your score suggests the treatment is working effectively."

Simple comparison = better understanding.
Deauville transformed lymphoma management from guesswork to precision. Know the score, know the prognosis.

Fellow oncologists: How has Deauville changed your treatment decisions?

15/11/2025

Beyond Prostate and NETs: FAPI Opens Doors for 'Untreatable' Cancers

The diagnostic blind spots in oncology are shrinking.
For years, FDG-PET imaging has struggled with cancers that don't consume glucose aggressively—pancreatic tumors, cholangiocarcinomas, and certain sarcomas often evade detection until advanced stages.

Enter FAPI: A New Approach
Fibroblast Activation Protein Inhibitors target cancer-associated fibroblasts—the structural scaffolding in 90% of tumors. Unlike FDG's metabolic tracking, FAPI illuminates the tumor microenvironment itself.

Why It Matters
• Superior visualisation across 28 cancer types
• Exceptional contrast in gastrointestinal, breast, and esophageal cancers
• Game-changing results where traditional imaging fails: sarcomas and cholangiocarcinomas
• Higher tumour-to-background ratio enables precise surgical planning

Beyond Diagnosis
The same targeting mechanism opens therapeutic doors. FAPI's theranostic potential means delivering radiation directly to tumors—turning imaging into treatment.

The Bottom Line
Patients with "invisible" cancers now gain access to:
→ Earlier detection
→ Accurate staging
→ Real-time treatment monitoring
→ Personalised therapy strategies

FAPI represents a fundamental shift—from metabolic imaging to stromal targeting. We're not just improving detection; we're redefining what "untreatable" means in modern oncology.

The transformation is tangible. The possibilities are unprecedented.

12/11/2025

The SUV Number Everyone Obsesses Over? It's Misleading.

"Doctor, my SUV is 8.5. Is that cancer?"

Here's the uncomfortable truth: That number is almost meaningless in isolation.

The SUV Illusion
Standardised Uptake Value sounds precise. Scientific. Diagnostic.
It's none of those things.
SUV measures FDG concentration at a single point in time. But it's wildly variable based on:
→ Blood glucose levels (high glucose = falsely low SUV)
→ Time between injection and scanning
→ Patient weight and body composition
→ Scanner calibration
→ Breathing artefacts during acquisition

The same lesion scanned twice in one day can show different SUVs.

Why We Can't Stop Using It
Despite limitations, SUV provides a relative context. An SUV of 15 is concerning. An SUV of 2.3 in the liver? Often physiologic.
But there's no magic cutoff.

Inflammation can hit SUV 10+. Some indolent lymphomas barely reach 3. Aggressive neuroendocrine tumors often show minimal uptake.

Clinical context trumps numbers every time.

What Matters More Than SUV
→ Pattern of uptake (focal vs. diffuse)
→ Anatomic location (expected vs. unexpected)
→ Change over time (stable vs. progressive)
→ Correlation with CT findings
→ Patient's clinical picture

An SUV of 4 in a new lung nodule in a smoker? Biopsy it.
An SUV of 8 in the axillary nodes post-vaccination? Watch it.

The Real Conversation
"Your SUV indicates metabolic activity. What matters more is the pattern, location, and your clinical context—not the number itself."

Stop letting a single value drive binary decisions.

SUV is a data point, not a diagnosis. Treat the patient, not the number.

Question: Have you seen low-SUV malignancies fool everyone? Share below.

07/11/2025

Theranostic Toolkit: PSMA, DOTATATE, FAPI, Exendin - When to Use Which

The right radioligand at the right time changes everything.

Modern theranostics offers multiple precision tools—each designed for specific molecular targets. Success lies in matching the molecule to the malignancy.

PSMA: The Prostate Cancer Specialist
→ Target: Prostate-specific membrane antigen
→ Indication: Metastatic castration-resistant prostate cancer
→ FDA-approved Lu-177 PSMA improves progression-free and overall survival

DOTATATE: The NET Navigator
→ Target: Somatostatin receptors (SSTR)
→ Indication: Gastroenteropancreatic neuroendocrine tumors
→ Gold standard for well-differentiated, SSTR-positive NETs
→ FDA-approved since 2018

FAPI: The Versatile Newcomer
→ Target: Fibroblast activation protein in tumor stroma
→ Indication: Multiple solid malignancies
→ Best for: Pancreatic, gastric, breast, sarcomas—when other theranostics fail
→ Broad applicability across 28+ cancer types

Exendin: The Insulinoma Tracker
→ Target: GLP-1 receptors
→ Indication: Benign insulinomas
→ Highly specific for insulin-secreting pancreatic lesions

Clinical Decision Framework
Diagnostic scans dictate therapeutic paths. High target expression predicts response. When one radioligand fails, another molecular pathway may succeed—particularly with FAPI's versatility.

Precision isn't choosing one tool. It's knowing which tool, when.

05/11/2025

Why 30% of Indian Women Need More Than Standard Screening

Mammograms save lives—except when breast tissue is too dense.
The Problem: Dense tissue appears white. Tumors appear white. Finding cancer becomes impossible.

30-40% of Indian women have this issue.

Why Indian Women Are Different
Younger diagnosis age. Premenopausal breast composition. Denser tissue naturally.
Aggressive cancers like inflammatory breast cancer? Mammography misses them entirely.

The PET Advantage
FDG-PET doesn't care about density. It tracks glucose metabolism—cancer cells' signature behaviour.

Inflammatory breast cancer? Visible on PET.
Accurate axillary staging? PET delivers.
Dense breasts obscuring tumors? Not metabolically.

What This Means
Dense breasts aren't just an imaging challenge—they're a risk factor demanding better screening.

Know your breast density. Advocate for supplemental imaging when needed.
Because early detection only works if we're actually detecting.
Breast Cancer Awareness Month: Don't assume normal mammogram = no cancer.

02/11/2025

Without reflection, experience becomes repetition

01/11/2025

From Physics Lab to Cancer Detection: 70 Years of Metabolic Imaging

1930s: The Foundation Positron was discovered. Radioactive tracers were born. Nobody had imagined medical applications yet.

1950s: The Concept Scientists realised: inject radioactive glucose, track where it goes. Cancer cells eat more glucose. Physics meets biology.

1970s: First PET Scanner Crude. Expensive. Research-only. A ring of detectors capturing annihilation photons when positrons meet electrons. Revolutionary physics, limited clinical use.

1980s: FDG Synthesis F-18 Fluorodeoxyglucose—the game-changer. A glucose molecule tagged with radioactive fluorine. Cancer cells consume it but can't metabolise it fully. They light up.

1990s: Clinical Breakthrough PET proves superior for cancer staging, especially lung, lymphoma, and melanoma. Problem? Anatomical context missing. Where exactly is that hot spot?

2000s: PET-CT Fusion: The marriage of metabolism and anatomy. One scan, complete picture. Oncology transformed overnight. Staging accuracy jumps 30-40%.

2010s: Beyond FDG PSMA for prostate. DOTATATE for neuroendocrine. FAPI for diverse tumors. Theranostics emerges—same molecule diagnoses and treats.

2020s: AI Integration, Automated detection. Radiomics. Predictive modeling. PET evolves from a diagnostic tool to a precision medicine platform.

2025: Advanced Integration and Standardisation. The focus shifts to widespread standardisation and clinical trial validation of new tracers (like FAPI and PSMA). AI moves from assisting diagnosis to predicting therapy response and personalising dosimetry (radiation dose calculation) for theranostic treatments (e.g., Lu-177 PSMA, Lu-177 FAPI), making these treatments routine for more cancer types.

Today: From physics experiment to standard-of-care. PET democratises cancer detection—seeing disease at the molecular level before morphology changes. The invisible made visible.

The future made present.