[Imaging of side effects after radiation therapy]

Area of Science:

• Radiology
• Oncology
• Pathology

Background:

• Radiotherapy inevitably irradiates peritumoral normal tissues, leading to acute, subacute, or chronic alterations.
• These radiation-induced changes can be transient or persistent, depending on the dose and time post-irradiation.
• Imaging plays a key role in detecting these alterations in various organ systems.

Purpose of the Study:

• To provide a comprehensive overview of imaging findings for radiation-induced radiogenic alterations in normal tissues.
• To highlight common signs across different organ systems affected by radiotherapy.
• To emphasize the importance of recognizing these changes for accurate diagnosis.

Main Methods:

• Review of imaging findings associated with radiation-induced tissue damage.
• Discussion of common radiogenic alterations in various organ systems.
• Comparison with differential diagnoses, particularly tumor recurrence.

Main Results:

• Frequent imaging findings include pneumonitis, blood-brain barrier disturbance, brain radionecrosis, liver damage, mucositis, colitis, osteitis, osteoradionecrosis, and myositis.
• Combined therapies (chemotherapy, immunotherapy) can exacerbate radiogenic reactions.
• Distinguishing radiation effects from tumor recurrence requires consideration of latency periods, location, and radiation field matching.

Conclusions:

• Radiologists must be familiar with the imaging morphology of radiogenic tissue changes to avoid misinterpretation.
• Accurate follow-up requires adherence to guidelines, patient condition assessment, and understanding of radiation-induced changes.
• Differentiating radiogenic alterations from tumor recurrence is critical for effective patient management.