What imaging scans are needed in oncology and what are their indications?

From the Guidelines

In oncology, the choice of imaging scan depends on the type of cancer, suspected location, staging requirements, and the need to monitor treatment response, with considerations for radiation exposure, cost, and availability influencing the choice of imaging technique. The most recent and highest quality study 1 provides guidance on the appropriate use of imaging modalities in oncology.

• Computed Tomography (CT) scans are commonly used for initial cancer detection and staging, particularly useful for lung, liver, and pancreatic cancers.
• Magnetic Resonance Imaging (MRI) offers superior soft tissue contrast without radiation exposure, making it ideal for brain, spinal cord, liver, and pelvic tumors.
• Positron Emission Tomography (PET) scans, often combined with CT (PET-CT), use radioactive tracers like fluorodeoxyglucose (FDG) to detect metabolically active cancer cells, helping distinguish between benign and malignant lesions and identifying metastases.
• Bone scans are indicated for detecting bone metastases, particularly in breast, prostate, and lung cancers.
• Ultrasound provides real-time imaging without radiation and is useful for breast, thyroid, liver, and kidney tumors, as well as guiding biopsies.
• Single-Photon Emission Computed Tomography (SPECT) helps evaluate functional aspects of tumors and is valuable for neuroendocrine tumors. For example, in breast cancer, FDG-PET/CT whole body is usually appropriate for staging or assessment of response to neoadjuvant chemotherapy, especially in specific settings where it is preferable to conventional CT chest, abdomen, and pelvis imaging 1. Similarly, in lung cancer, PET/CT is recommended by NCCN for initial staging, and it can play a role in the evaluation and more accurate staging of non-small cell lung cancer (NSCLC) 1. It is essential to consider the clinical context and the specific cancer type when selecting an imaging modality, as the choice of scan can significantly impact patient outcomes.

From the Research

Scans Needed in Oncology and Their Indications

• The following scans are commonly used in oncology:
  • Computed Tomography (CT) scans: used for diagnosing and staging various types of cancer, including lung, breast, and pancreatic cancer 2, 3, 4
  • Magnetic Resonance Imaging (MRI) scans: used for diagnosing and staging cancer, particularly in the breast, prostate, and pancreas 2, 3, 5, 6, 4
  • Positron Emission Tomography (PET) scans: used for diagnosing and staging cancer, as well as monitoring treatment response and detecting distant metastases 2, 3, 5, 6, 4
  • PET/CT scans: used for diagnosing and staging cancer, particularly in the breast, prostate, and lung 2, 3, 5, 6
  • PET/MRI scans: used for diagnosing and staging cancer, particularly in the breast and prostate 3, 5, 6

Indications for Each Scan

• CT scans:
  • Lung cancer staging 2
  • Breast cancer staging 3
  • Pancreatic cancer diagnosis and staging 4
• MRI scans:
  • Breast cancer staging 3
  • Prostate cancer staging 5, 6
  • Pancreatic cancer diagnosis and staging 4
• PET scans:
  • Cancer diagnosis and staging 2, 3, 5, 6, 4
  • Monitoring treatment response and detecting distant metastases 2, 3, 5, 6, 4
• PET/CT scans:
  • Breast cancer staging 3
  • Prostate cancer staging 5, 6
  • Lung cancer staging 2
• PET/MRI scans:
  • Breast cancer staging 3
  • Prostate cancer staging 5, 6

Specific Tracers Used in PET Scans

• FDG (fluorodeoxyglucose): used for diagnosing and staging various types of cancer, including lung, breast, and pancreatic cancer 2, 3, 4
• Choline: used for diagnosing and staging prostate cancer 5
• PSMA (prostate-specific membrane antigen): used for diagnosing and staging prostate cancer 5, 6
• NaF (sodium fluoride): used for diagnosing and staging bone metastases in prostate cancer 5