Upper Cervical Spine Diseases

Radiation therapy is the main treatment for nasopharyngeal carcinoma (NPC), a cancer type commonly found in southern Asia. However, a complication known as osteoradionecrosis (ORN) frequently arises in patients undergoing radiation therapy for NPC or other head and neck cancers. ORN can present in different ways on magnetic resonance (MR) images and must be distinguished from recurrent or metastatic tumors.

Depending on the severity, patients with ORN may require additional interventions such as antibiotic administration, sequestrectomy or surgical fusion, or hyperbaric oxygen therapy. If the disease recurs, further chemotherapy or radiation therapy becomes mandatory.

ORN is a condition that can impact different regions of the head and neck, although it is uncommon in the cervical spine. Due to limited research, diagnosing cervical ORN early can be challenging. Proposed MR imaging features for diagnosis are often not typical. Distinguishing ORN from recurrent tumors poses difficulties. Biopsies are infrequently performed due to the associated risks, further complicating accurate diagnosis.

Differentiating between osteoradionecrosis (ORN) and recurrent malignant disease in the upper cervical spine after radiation therapy for head and neck cancer is aided by MR imaging findings. ORN manifests as contiguous bone involvement, bilateral presence, and early deterioration of facet joints and subchondral bone.

Conversely, recurrent or metastatic lesions often exhibit isolated involvement, less preservation of joint space, cortical destruction at the lateral border, and an adjacent solid mass. These distinctions can be attributed to the vascular supply of the cervical vertebral body and direct invasion of tumors from adjacent spaces.

In addition to adjacent soft-tissue changes and epidural involvement, other imaging features provide valuable assistance in distinguishing between recurrent tumor and cervical osteoradionecrosis (ORN).

Soft-tissue masses associated with ORN tend to be less voluminous, resulting in minimal to mild mass effect. Notably, the involvement of soft tissues demonstrates a symmetric pattern, which may be indicative of underlying inflammatory and infectious processes. Furthermore, alterations in the bone structure can potentially indicate the presence of osteomyelitis.

During the follow-up period, the resolution of soft-tissue lesions and the enhancement of bone marrow are typically observed concurrently in cases of ORN. In contrast, soft-tissue masses in recurrent disease typically exhibit a tendency to enlarge over time.

According to a study reported by literature, the occurrence of osteoradionecrosis (ORN) was limited to patients who had received additional radiation therapy. However, a different study revealed that almost half of the patients with ORN had undergone radiation therapy only once, and there were no significant disparities in radiation dosage or treatment duration between the groups.

These findings suggest that cervical ORN can develop in any patient who has undergone radiation therapy for head and neck cancer. Laser nasopharyngectomy, a local treatment, may also contribute to an increased risk of expedited ORN development, potentially due to the infiltration of infectious sources through nasopharyngeal defects into the upper cervical spine.

Another study reported by literature presented several limitations. Firstly, due to the high risks associated with biopsies in the area, such as potential damage to the vertebral artery or cervical spinal cord, pathologic evidence was unavailable for all patients.

Consequently, noninvasive methods were preferred for follow-up by both clinicians and patients. Secondly, it is possible that recurrent tumor occurs within the osteoradionecrosis (ORN) site, leading to a combined imaging appearance. Without a comprehensive pathological examination of the entire lesion, it is challenging to differentiate between the regional variations and their corresponding imaging features, which may contribute to the overlapping characteristics of ORN and recurrence.

Lastly, the small sample size limited the ability to adjust comparisons for potential confounding factors. Nevertheless, the identified imaging findings in the study have practical implications for guiding patient treatment.