PET/CT (positron emission tomography/computed tomography) and Gallium-68 (Ga-68) PET are among the most advanced imaging techniques in modern medicine, playing a crucial role particularly in cancer diagnosis, staging, and treatment follow-up. These methods shed light on treatment planning and are decisive in achieving an accurate diagnosis by enabling the evaluation of diseases not only at an anatomical level but also at biological and metabolic levels.
How Does PET/CT Work?
PET/CT is a combination of PET and CT scans. PET is an imaging technique used to examine biological processes in the body. A radioactive tracer, such as FDG (fluorodeoxyglucose), is administered, and this substance is used to measure metabolic activity in the body. Cancer cells consume more glucose compared to normal cells; FDG accumulates in these cells, making lesions prominent in PET images. The CT scan, on the other hand, provides a detailed anatomical image of the body's internal structure. PET/CT scanning helps determine the localization, size, and spread of cancerous tumors by using the combined PET and CT images of FDG.
This combined imaging provides physicians with highly valuable data by presenting anatomical and metabolic information in a single session. While PET shows biological activity, CT reveals the exact location of the lesion and its relationship with adjacent structures. As a result, both small lesions can be detected early, and the response to treatment can be evaluated objectively.
What is Gallium-68 PET (Ga-68 PET)?
Gallium-68 is a radiopharmaceutical used for the diagnosis and follow-up of neuroendocrine tumors and certain other tumors. Ga-68 is highly effective, particularly in identifying neuroendocrine tumors (NETs). These types of tumors can cause hormonal imbalances in the body and can occur in various organs such as the pancreas, lungs, and digestive system. A Ga-68 PET scan can determine the localization of these tumors, evaluate their spread, and guide treatment planning.
Furthermore, Ga-68 PSMA PET, used in prostate cancer, provides highly sensitive results in evaluating the spread of prostate cancer. This method, which allows for the detection of even small metastatic foci where conventional imaging methods fall short, has become the gold standard in evaluating biochemical recurrence. Ga-68 DOTATATE targets somatostatin receptors found on the surface of neuroendocrine tumor cells and is used both in diagnosis and for patient selection for targeted therapy (PRRT).
In Which Diseases Is It Used?
- Oncological diseases: Many types of cancer, primarily lung, breast, colorectal, lymphoma, melanoma, head and neck, and esophageal cancers
- Neuroendocrine tumors: Ga-68 DOTATATE PET for pancreatic, digestive system, and lung NETs
- Prostate cancer: Ga-68 PSMA PET for spread, recurrence, and treatment follow-up
- Cancer staging and restaging
- Evaluation of treatment response
- Early detection of recurrence and metastases
- Investigation of unknown primary foci
- Neurological diseases: Selected cases of Alzheimer's, dementia, and epilepsy
- Cardiac evaluations: Myocardial viability and perfusion assessment
- Investigation of infection and inflammation foci
- Surgery and radiotherapy planning
Advantages of PET/CT
- Combining anatomical and metabolic information in a single session
- Whole-body imaging capability
- Early-stage tumor detection and accurate staging
- Objective evaluation of treatment efficacy
- Early detection of recurrence and metastases
- Guidance for surgery and radiotherapy planning
- High sensitivity in investigating unknown primary cancer foci
- Patient selection for receptor-targeted therapy (PRRT) with Ga-68 PET
- Prevention of unnecessary treatments by reducing misstaging rates
- Providing baseline data for personalized treatment planning
- Use in prognosis estimation and follow-up
Procedure Process
Patients are required to fast for a certain period before PET/CT; this ensures high image quality. Generally, 4-6 hours of fasting is recommended; blood sugar control is of special importance in diabetic patients. An intravenous line is opened, and the radioactive substance is injected. For FDG, a resting period of approximately 60 minutes is required; during this time, the substance distributes throughout the body and reaches the target tissues. During this period, the patient is rested in a quiet and calm environment; muscle activity is reduced to improve image quality. Afterward, the patient is placed in the scanner, and the imaging, which usually lasts 20-30 minutes, is performed.
Waiting times and scanning protocols for Ga-68 PET may vary. The procedure is painless; there may only be minor discomfort such as the insertion of an intravenous line and lying still for a long time. The images are evaluated and reported by a nuclear medicine specialist. Results are usually ready within a few business days and are evaluated together with the relevant branch physicians to create a treatment plan.
Points to Consider
PET/CT imaging techniques carry some risks due to the use of radioactive substances and must be requested and interpreted by a healthcare professional. Although the radioactive doses used are low, different approaches may be required during pregnancy and breastfeeding; these situations must be reported to the physician in advance. Blood sugar control in diabetic patients is important for image quality; the use of insulin and diabetes medications before the examination should be planned in consultation with the team. Drinking plenty of water after the procedure helps the body eliminate the radioactive substance. It is recommended that patients avoid close contact with small children and pregnant women for a short time after the procedure; this period can be considered as 24 hours. All medication use, allergies, and chronic diseases must be reported to the physician before the examination. Additionally, avoiding intense physical activity, smoking, and caffeine in the 24 hours prior to the examination improves image quality.
PET/CT at Koru Hospital
As Koru Hospital, we offer all current imaging protocols such as FDG PET, Ga-68 DOTATATE, and Ga-68 PSMA to our patients in our nuclear medicine unit with our modern PET/CT device and experienced expert staff. Thanks to our multidisciplinary approach carried out with oncology, urology, endocrinology, cardiology, and other relevant departments, imaging results are quickly reflected in the treatment plan, ensuring that our patients reach the right diagnosis and the right treatment. We offer our patients a safe examination experience with our comfortable patient-oriented design, experienced technicians, and high-standard radiation safety practices. Detailed information before the examination, professional support during the preparation phase, and the rapid sharing of results are the fundamental principles of our processes. With the individual evaluation of each case in our tumor board, the most appropriate treatment plan is determined, and a personalized medical approach is offered to our patients. As Koru Hospital, our goal is to increase treatment success by detecting diseases at the earliest stage and with the highest accuracy, and to maintain our patients' quality of life at the highest level.
