Multimodality Imaging Services

Advanced molecular imaging plays a pivotal role in bridging the gap between benchtop RDC synthesis and clinical translation. Alfa Cytology's comprehensive platform offers an integrated, one-stop solution for real-time visualization of drug distribution, target engagement, and therapeutic efficacy. By combining high-sensitivity PET/SPECT with high-resolution CT or MRI, bespoke imaging protocols are engineered to meet the rigorous demands of preclinical radionuclide drug development, ensuring precise data acquisition for informed decision-making.

Overview of Multimodality Imaging

Multimodality imaging integrates distinct diagnostic technologies to provide a synergistic view of biological processes, capturing both functional and anatomical data simultaneously. In the context of radionuclide drug conjugates (RDCs), this approach is essential for mapping the spatiotemporal distribution of radiopharmaceuticals. By overlaying physiological signals onto detailed structural frameworks, researchers can accurately quantify tracer uptake, evaluate off-target effects, and refine the pharmacokinetic profiles of novel candidates.

Fig.1 CT information from hybrid systems (SPECT/CT, PET/CT) facilitates quantitative emission tomography imaging and patient‑specific voxel‑level dosimetry. (St James, S., et al., 2021)

Types of Imaging Modalities

A full range of preclinical imaging modalities is available, each selected for its unique contribution to RDC characterization. These platforms are not used in isolation but are systematically integrated into multimodality workflows depending on the radionuclide, the biological question, and the required throughput.

Positron Emission Tomography (PET)

Offers ultra‑high sensitivity for positron‑emitting isotopes such as ⁶⁸Ga, ⁶⁴Cu, ⁸⁹Zr, and ¹⁸F. PET is ideal for kinetic modeling, receptor occupancy studies, and longitudinal tracking of RDCs with short to medium half‑lives. Fully quantitative outputs (%ID/g, SUV, Ki) are generated.

Single Photon Emission Computed Tomography (SPECT)

Quantifies gamma‑emitting isotopes (⁹⁹ᵐTc, ¹⁷⁷Lu, ¹¹¹In, ¹²³I) with longer physical half‑lives, enabling multi‑week studies of theranostic RDCs. Advanced multi-pinhole collimators deliver sub‑millimeter resolution, and SPECT/CT is particularly suited for tumor dosimetry in targeted radionuclide therapy (TRT).

Computed Tomography (CT)

Provides rapid, high‑resolution 3D anatomical reference that is essential for co‑registration with PET or SPECT signals. Beyond anatomy, CT offers precise attenuation correction maps for quantitative nuclear imaging, organ volumetry for longitudinal disease monitoring, and skeletal landmarking for accurate multi‑time‑point alignment.

Magnetic Resonance Imaging (MRI)

Delivers superior soft‑tissue contrast without ionizing radiation, making it essential for brain, cardiac, liver, and muscle RDC evaluations. Functional parameters (diffusion, perfusion via DCE‑MRI, T2* mapping for iron‑labeled RDCs) are obtainable. PET/MRI is available upon request for simultaneous acquisition.

Fluorescence / Optical Imaging

Enables rapid, cost‑effective, real‑time tracking of fluorescently labeled RDCs in superficial or intraoperative models. While limited in depth, optical imaging complements nuclear methods for high‑throughput screening of multiple RDC variants, ex vivo organ imaging, and intra‑animal validation using Cherenkov luminescence.

Our Services

Deep, integrated expertise in radiopharmaceutical chemistry, small‑animal imaging physics, and RDC tumor biology drives all multimodality studies. Alfa Cytology provides standardized acquisition protocols, validated reconstruction algorithms, and rigorous quality control to combined with fully customizable study designs, including dosing regimen, anesthesia, time points, and modality sequences. The result is reproducible, publication‑ready quantitative data that directly supports regulatory submissions, delivered with transparent reporting and rapid turnaround.

Workflow of Multimodality Imaging Services for RDC

• Study Consultation & Design: Project-specific endpoints, imaging time points (acute to chronic), dose formulation, and modality combination are defined based on the RDC's mechanism, target biology, and radionuclide half‑life.
• RDC Radiolabeling & Quality Control: Radiolabeling is performed using validated methods (e.g., chelator‑based or direct labeling) for isotopes. Quality control includes radiochemical purity, specific activity, molar activity, and stability in serum or formulation buffer.
• Animal Model Preparation: Tumor‑bearing (xenograft, orthotopic, syngeneic) or disease‑relevant rodent models are prepared according to the study plan. RDC is administered via intravenous, intraperitoneal, subcutaneous, or intratumoral routes under sedation, with careful documentation of injected dose and time zero.
• Multimodality Image Acquisition: Sequential or simultaneous scans (PET/CT, SPECT/CT, PET/MRI, optical) are performed under anesthesia with physiological monitoring (respiration, temperature, heart rate). Bedside isotope decay correction and cross‑calibration for multi‑isotope studies are applied.
• Image Co‑registration & Reconstruction: Multimodal datasets are co‑registered using fiducial markers or automated mutual‑information algorithms. Iterative reconstruction includes attenuation, scatter, randoms, and decay corrections specific to each isotope.
• Quantitative Analysis: Regions of interest (ROIs) are drawn on coregistered anatomical images. Derived metrics include SUVmean/max, %ID/g, tumor‑to‑background ratio (TBR), tumor‑to‑muscle ratio, time‑activity curves (TACs), area under the curve (AUC), and organ‑level absorbed dose.
• Ex Vivo Validation (Optional): Following final imaging, animals are euthanized for ex vivo biodistribution (gamma counting), autoradiography (digital or film), and histology (H&E, IHC) to cross‑validate in vivo imaging findings.

Multi-Isotope Capability

A broad panel of radionuclides is supported for multimodality imaging across different RDC programs. Each isotope can be imaged using its optimal modality and acquisition parameters, allowing flexible study designs tailored to the specific radiolabel, tracer kinetics, and biological question.

Specialized Multimodality Imaging Modalities

The synergy of anatomical and functional datasets allows for a holistic evaluation of RDC performance within the complex biological environment of a living subject. By employing high-performance instrumentation specifically calibrated for small animal research, the platform captures the intricacies of tracer kinetics, vascular permeability, and metabolic activity. Each modality is utilized to address specific biological questions, ensuring that the resulting data provides a definitive assessment of the candidate's therapeutic potential and safety margin.

Why Choose Us?

• Technical Excellence in Radiochemistry: Expertise in complex conjugation and stable labeling of diverse radionuclides ensures the integrity of imaging data.
• Flexible & Tailored Protocols: Customizable imaging time points, isotope pairings, and modality combinations to match any RDC mechanism or project timeline.
• End‑to‑End Integration: From radiolabeling to image analysis and ex vivo validation, the data continuity eliminates inter‑vendor variability and accelerates decision‑making.
• State-of-the-Art Instrumentation: Access to the latest small-animal imaging platforms provides the sensitivity and resolution required for rigorous scientific publication and regulatory filing.

Contact Us

Alfa Cytology's comprehensive multimodality imaging services (PET/CT, SPECT/CT, PET/MRI, optical, and MRI) are available to precisely map RDC biodistribution, target engagement, and therapeutic response. Integrated with radiolabeling, in vitro, and in vivo capabilities, a complete preclinical solution for RDC programs is delivered. For detailed service catalogs, technical consultation, or to initiate a collaborative study, please contact us.

For research use only. Not intended for any clinical use.