Department Of Nuclear Medicine & Theranostics

Department Overview

Nuclear medicine is a branch of medical imaging and therapy that uses small, carefully measured amounts of radioactive tracers to visualise how organs and tissues are functioning at a molecular level — rather than relying only on structural imaging such as Xray or CT.

Molecular imaging techniques such as PET/CT and SPECT/CT allow physicians to detect disease activity, assess how a condition is behaving biologically, and identify specific molecular targets within a tumour or organ system, often before structural changes become apparent on other scans.

Theranostics combines this diagnostic capability with targeted therapy. The underlying principle is straightforward: image the target, identify the right patient, treat the target, and assess response. A molecular imaging scan first confirms whether a specific biological target — a receptor or protein expressed by the disease — is present in sufficient amount. If confirmed, a matched radioactive therapeutic agent is then used to deliver treatment directly to those same cells, and follow-up imaging is used to assess how the disease has responded.

This integration allows the department to support more individualised treatment decisions, made in collaboration with a patient’s treating oncologist, surgeon, or physician, and reviewed through multidisciplinary discussion where appropriate.

Our Core Services (Overview)

The department’s services are organised into four areas:

• Diagnostic Molecular Imaging — PET/CT, SPECT/CT, and organ-specific scintigraphy studies
• Oncology Imaging — cancer detection, staging, restaging, and response assessment
• Theranostics — radionuclide therapies matched to molecular imaging findings
• Personalised Radionuclide Therapy Planning — dosimetry and multidisciplinary treatment planning, where available

Molecular Imaging (Diagnostic Services)

PET/CT (Positron Emission Tomography–Computed Tomography)

What it is: A combined scan that overlays functional (molecular) information from a PET tracer onto detailed anatomical images from CT, in a single imaging session. What it helps detect: Areas of abnormal metabolic or receptor activity, which may represent tumour tissue, infection, or inflammation. Common indications: Cancer diagnosis, staging, restaging, treatment response assessment; selected infection and inflammation work-up.
Clinical value: Helps guide treatment decisions by distinguishing active disease from scar tissue or treated areas, and by identifying disease not visible on structural imaging alone.

PET/MRI

Available as a separate, dedicated modality alongside PET/CT — combines PET’s molecular information with MRI’s superior soft-tissue contrast, useful in selected neurological, pelvic, and hepatic indications.

SPECT/CT (Single Photon Emission Computed Tomography–CT)

What it is: A functional imaging technique using gamma-emitting tracers, fused with CT for precise anatomical localisation. Indications: Bone scintigraphy, thyroid and parathyroid imaging, renal imaging, cardiac perfusion, and more.

Whole-Body Bone Scintigraphy

Detects areas of abnormal bone turnover, commonly used to evaluate suspected bone metastases, unexplained bone pain, or selected orthopaedic and infective conditions.

Renal Scintigraphy (Dynamic and Static)

Assesses individual kidney function, drainage, and structural integrity — used in evaluating obstruction, renal function before or after surgery, and paediatric urological conditions. Performed using DTPA (filtration-based) and EC — Ethylenedicysteine (tubular-functionbased) renography, selected according to clinical indication.

Lung Perfusion Scan (MAA)

Uses Tc-99m MAA (Macroaggregated Albumin) to assess pulmonary blood flow, commonly used in evaluating suspected pulmonary embolism and in pre-procedure planning for selected liver-directed therapies.

Hepatobiliary Scintigraphy

Evaluates gallbladder function and bile flow, useful in suspected acute cholecystitis, bile leak, or biliary atresia in infants.

Thyroid Scintigraphy

Assesses thyroid gland function and nodule activity, supporting evaluation of hyperthyroidism and thyroid nodules.

Parathyroid Imaging

Localises overactive parathyroid tissue prior to surgery in patients with hyperparathyroidism.

Myocardial Perfusion Imaging (MPI)

Assesses blood flow to the heart muscle at rest and stress, supporting evaluation of coronary artery disease and myocardial viability. Both exercise (treadmill) stress and pharmacological stress protocols are available, selected based on the patient’s fitness for exercise and clinical suitability.

Infection/Inflammation Imaging

Supports localisation of occult infection, fever of unknown origin, and selected prosthetic or device-related infections.

Sentinel Lymph Node and Lymphatic Imaging

Maps the lymphatic drainage pathway of a tumour, most commonly used in breast cancer and melanoma surgical planning.

Oncology Imaging

Molecular imaging plays a role across the full cancer care pathway:

• Detection — identifying disease not always visible on structural imaging
• Initial staging — assessing the true extent of disease before treatment planning
• Restaging — reassessing disease extent after treatment
• Recurrence detection — identifying suspected relapse
• Treatment planning — informing surgical, radiation, or systemic therapy decisions
• Response assessment — evaluating how a tumour is responding to treatment
• Prognostic assessment — supporting risk stratification in selected cancers

Tracers used, depending on clinical indication and availability:

• ¹⁸F-FDG — the most widely used PET tracer, reflecting glucose metabolism, applicable across many cancer types
• ⁶⁸Ga/¹⁸F-PSMA — targets prostate-specific membrane antigen, used in prostate cancer
• ⁶⁸Ga-DOTATATE — targets somatostatin receptors, used in neuroendocrine tumours
• ¹⁸F-FDOPA — used in selected neuroendocrine and neurological indications

Tracer availability varies by clinical indication and institutional resources; not all tracers listed are necessarily available for routine use at all times. Please confirm current availability with the department.

Theranostics

Theranostics applies the “image, select, treat, assess” principle to deliver radionuclide therapy matched to a confirmed molecular target, in appropriately selected patients following multidisciplinary evaluation. For eligible patients, this offers a targeted, surgeryless treatment option delivered through the bloodstream or direct administration, rather than an operative procedure.

Radioiodine (I-131) Therapy

• Target: Iodine-avid thyroid tissue.
• Indication: Differentiated thyroid cancer (post-surgical ablation or treatment of recurrent/metastatic disease) and selected benign hyperthyroid conditions.
• Mechanism: Thyroid cells selectively absorb iodine; radioactive iodine delivers targeted radiation to these cells.
• Patient selection: Guided by histopathology, surgical findings, and thyroid function/imaging assessment.

Lu-177 PSMA Therapy

• Target: Prostate-specific membrane antigen (PSMA).
• Indication: Appropriately selected patients with metastatic castration-resistant prostate cancer, typically after standard hormonal therapy and chemotherapy.
• Mechanism: A PSMA-targeting molecule carrying Lutetium-177 binds to PSMA-expressing cancer cells, delivering localised radiation.
• Patient selection: Confirmed via pre-therapy PSMA PET/CT to verify adequate target expression.
• Role of imaging: Both to confirm eligibility and to monitor response over subsequent cycles.

Lu-177 DOTATATE / DOTATOC Therapy (PRRT-Peptide Receptor Radionuclide Therapy)

• Target: Somatostatin receptors.
• Indication: Neuroendocrine tumours of the gastrointestinal tract, pancreas, and lung, in appropriately selected patients.
• Mechanism: A somatostatinreceptor-targeting peptide carrying Lutetium-177 binds to receptor-expressing tumour cells.
• Patient selection: Confirmed via pre-therapy DOTATATE PET/CT.
• Treatment concept: Typically delivered as a course of cycles at defined intervals, with imaging and biochemical monitoring between cycles.

Yttrium-90 Radioembolisation (SIRT) / SIR-Spheres

• Target: Liver tumour vasculature.
• Indication: Primary liver cancer or liver-dominant metastatic disease not amenable to surgery.
• Mechanism: Yttrium-90 microspheres are delivered via the hepatic artery, concentrating radiation within the tumour-supplying vessels.
• Role of imaging: A pre-procedure hepatic angiogram and Tc-99m MAA mapping scan assess feasibility, calculate dosimetry, and screen for unsafe extrahepatic shunting.

Y-90 Hydroxyapatite Radiosynovectomy

• Target: Inflamed synovial lining of affected joints.
• Indication: Chronic, recurrent joint synovitis (e.g., in haemophilic arthropathy, rheumatoid arthritis, or pigmented villonodular synovitis) not adequately controlled by conservative treatment.
• Mechanism: Yttrium-90 hydroxyapatite particles are injected directly into the affected joint space, delivering localised radiation to ablate the inflamed synovium and reduce recurrent joint bleeding/inflammation.
• Patient selection: Confirmed by orthopaedic/rheumatology assessment together with the nuclear medicine team.

I-131 MIBG Therapy

• Target: Neuroendocrine tissue with noradrenaline-transporter uptake.
• Indication: Neuroblastoma, pheochromocytoma, paraganglioma, and other MIBG-avid neuroendocrine disorders, in appropriately selected patients.
• Mechanism: MIBG (metaiodobenzylguanidine) labelled with I-131 is taken up selectively by these tumour cells, delivering targeted radiation.
• Role of imaging: Confirmed by pre-therapy diagnostic MIBG scintigraphy.

Lu-177 EDTMP (Bone Pain Palliation)

• Target: Areas of active bone metastasis.
• Indication: Painful, widespread skeletal metastases (commonly from prostate or breast cancer) where pain is not adequately controlled by standard analgesia.
• Mechanism: Lu-177 EDTMP localises to areas of increased bone turnover at metastatic sites, delivering targeted radiation to relieve pain.
• Patient selection: Confirmed via bone scintigraphy demonstrating tracer-avid metastatic disease.

Ac-225 PSMA Therapy (Targeted Alpha Therapy)

• Target: Prostate-specific membrane antigen (PSMA).
• Indication: Appropriately selected patients with metastatic castration-resistant prostate cancer, including selected patients with inadequate response to Lu-177 PSMA therapy.
• Mechanism: An alpha-emitting radionuclide, Actinium-225, is carried by a PSMA-targeting molecule, delivering highenergy, short-range alpha radiation directly to PSMA-expressing cancer cells.
• Patient selection: Confirmed via pre-therapy PSMA PET/CT and multidisciplinary review, particularly for patients previously treated with beta-emitter (Lu-177) PSMA therapy.

Personalised Radionuclide Therapy Planning

Radionuclide therapy at the department is approached as an individualised process:

• Target identification — confirming the relevant molecular target through diagnostic imaging
• Patient selection — assessed jointly by nuclear medicine and the referring specialist
• Dosimetry — where appropriate and available, estimating radiation dose to tumour and critical organs to guide treatment planning
• Personalised treatment planning — determined through multidisciplinary discussion
• Targeted radiation delivery — administered under radiation safety protocols
• Response assessment — via follow-up imaging and relevant biomarkers
• Repeat treatment decisions — based on documented response and tolerability

All therapy decisions are made following appropriate multidisciplinary clinical evaluation, not by the Nuclear Medicine department in isolation.

Multidisciplinary Care

The department works closely with medical oncology, surgical oncology, radiation oncology, urology, endocrinology, gastroenterology, hepatobiliary surgery, cardiology, neurology, radiology, pathology, and radiation safety/medical physics teams.

This collaborative structure supports more informed patient selection, coordinated treatment planning, and consistent follow-up — particularly for patients being considered for theranostic therapy, where imaging findings, histopathology, and clinical status are reviewed together before a treatment decision is made.

Patient Information

Before your visit: You will receive personalised preparation instructions specific to your scan or therapy, which may include fasting, medication adjustments, or hydration guidance.

Radiation safety: All procedures follow institutional and regulatory radiation safety protocols. Radiation exposure from diagnostic scans is carefully controlled and considered acceptable relative to the clinical benefit; therapy procedures involve additional precautions explained to you in advance.

During therapy: Our team provides support throughout your time in the department, including guidance for accompanying family members.

Pregnancy and breastfeeding: Please inform our team if you are, or could be, pregnant, or if you are breastfeeding, as this may affect scheduling or the type of procedure recommended.

After therapy: You will be given clear, individualised instructions on hydration, hygiene, and any temporary precautions around family members, along with a written radiation safety card where relevant.

Follow-up: Structured follow-up imaging and clinical review are scheduled to assess your response and plan next steps.

Why Choose Our Nuclear Medicine & Theranostics Centre?

• Integrated diagnostics and therapy within a single department, supporting continuity of care
• Multidisciplinary clinical decision-making for therapy candidacy and planning
• Access to a range of molecular imaging modalities, subject to institutional availability Radionuclide therapies matched to confirmed molecular targets, not offered as one-size-fits-all treatment
• A surgery-less, targeted treatment option for appropriately selected patients, delivered without an operative procedure
• Radiation safety protocols aligned with regulatory requirements
• Coordinated patient support throughout diagnosis, therapy, and follow-up
• Collaboration with specialist oncology, endocrinology, urology, and other clinical teams

For Referring Physicians

The Department of Nuclear Medicine and Theranostics welcomes referrals for diagnostic molecular imaging and theranostic evaluation.

Consider referral when:

• Structural imaging is inconclusive or additional functional/molecular information is required
• Cancer staging, restaging, or recurrence assessment is needed
• A patient may be a candidate for radionuclide therapy (e.g., confirmed PSMA-avid metastatic prostate cancer, or neuroendocrine tumours being considered for PRRT)
• Evaluation of thyroid, parathyroid, renal, hepatobiliary, or cardiac function is clinically indicated

Please provide at referral, where available:

• Relevant clinical history and current treatment status
• Prior imaging (with reports, ideally with images for comparison)
• Relevant histopathology
• Renal and haematological parameters, where therapy is being considered

Multidisciplinary discussion: Cases being considered for radionuclide therapy are typically reviewed through multidisciplinary discussion; referring physicians are welcome to participate in or request this discussion for their patients.

To refer a patient or discuss a case: Phone: +91 9840059268 | Email: nuclearmedicine@relainstitute.com