Cervicothoracic Junction Tumors

Presentation and Treatment

The most common presenting symptoms of CTJ lesions include pain, weakness, and neurological deficits such as myelopathy from cord compression. In a case series of 46 patients with CTJ lesions, Le and colleagues found that 93% of patients noted impaired sensation, 83% presented with upper thoracic back pain, 58% experienced lower extremity weakness, and 58% presented with a positive Babinski sign. Less common symptoms included ataxia (25%), radicular pain (33%), hand weakness (35%), and bowel/bladder dysfunction (17%). Lesions in this region, which can arise from several etiologies, including trauma, degeneration, infection, vascular malformations, pathological fractures, and neoplasms, can exacerbate the preexisting biomechanical burden on the CTJ and lead to instability of this junction. ^, Tumors previously described to involve the CTJ include spinal metastasis, primary spine tumor, primary lymphoma, chordoma, schwannoma, angiosarcoma, giant cell tumor, chondrosarcoma, and myeloma. The most common type of CTJ neoplasm is metastatic disease, often from lung cancer or renal cell carcinoma. In addition to the symptoms noted, CTJ tumors often present with neck and back pain that are most prominent at night. One proposed mechanism for this characteristic temporal pain pattern is the decrease in endogenous steroid secretion at night. This biological pain in combination with the aforementioned symptoms should alert physicians to the possibility of a CTJ tumor because it is often an early indication of bony metastases caused by tumor infiltration of the vertebral body. Patients may also develop mechanical instability owing to the compressive lesion and present with movement-related pain that can arise from either compression or bone and ligament destruction. Mechanical instability pain is exacerbated with weightbearing and relieved with rest. In cases of epidural disease that compresses the neural foramen, radiculopathy is often present, along with weakness from spinal cord compression.

Once detected, acute CTJ lesions should be addressed promptly and appropriately to minimize the neurological sequalae associated with CTJ instability. Without treatment, progressive instability of the CTJ often results in kyphosis and cord compression. The narrow spinal canal of the CTJ, paired with tenuous blood supply to this region, renders the CTJ particularly susceptible to neurological and vascular damage from compressive lesions. Indeed, rates of neural injury from CTJ instability have been documented to reach over 80%. In a case series of 90 patients with CTJ tumors reported by Placantonakis and colleagues, 71% of patients experienced high-grade spinal cord compression.

The goals of treatment for CTJ tumors include biomechanical stabilization, decompression of neural elements, tumor excision, and restoration of anatomical alignment in the spine. Various treatment modalities are used to achieve these ends, including radiation therapy, chemotherapy, stereotactic radiosurgery, and surgery.

Radiation and Stereotactic Radiosurgery

Radiation therapy is the treatment of choice for many patients with CTJ tumors, especially those with metastatic disease. Because radiation is less invasive and has a lower morbidity compared with surgery, it is often preferred over surgical intervention in many cases. The landmark study by Gilbert and colleagues in 1978 is credited with shifting the treatment for metastatic lesions of the spine from laminectomy to radiation therapy. In this retrospective review of 235 patients, the rate of ambulation following treatment was 46% in the surgical group and 49% in the radiation therapy group. Patients with radiosensitive tumors, such as breast cancer, myeloma, and lymphoma, experienced significantly better functional outcomes than patients with radioresistant tumors, including lung, colon, and renal cell carcinoma. In the following decades, advances in surgical technique and instrumentation systems led to a large number of surgical case series reporting improved rates of maintenance (95%) and recovery of ambulation (60%). One of the most influential studies on radiation therapy in the treatment of spinal cord lesions was presented in a landmark paper by Patchell and colleagues in 2005. In this study, patients with solid tumors were randomized to either surgery with adjuvant radiotherapy or radiotherapy alone. The authors found clear improvements in maintenance of ambulation, recovery of ambulation, and survival in patients who received both surgery and radiation therapy compared with those who only received radiation.

The dosage and type of radiotherapy a given patient receives depends on the extent of epidural spinal cord compression (ESCC), which is graded from 0 to 3. Grade 0 describe lesions without any epidural impingement. Grade 1 describes subarachnoid space impingement with no cord deformation, whereas grade 2 describes spinal cord deformation with a partially obliterated subarachnoid space. Lastly, grade 3 describes spinal cord deformation to the extent that no cerebrospinal fluid (CSF) is seen. Grades 2 and 3 are considered high-grade compression. The current treatment paradigm for spinal lesions undergoing radiotherapy is to treat patients with grade 0 or 1 ESCC with single-dose stereotactic radiation. ^, Patients with high-grade compression of the spinal cord should explore surgical options, with possible adjuvant radiotherapy following resection.

Developments such as IGIMRT have significantly improved the chance of local tumor control of radiotherapy-resistant tumors. ^, Patients with radiotherapy-resistant tumors should be offered surgical resection in combination with IGIMRT to improve the chances of postoperative tumor control. ^,

Surgical Treatment

Surgical access to and treatment of CTJ tumors are challenging because of the anatomical complexity of this region, the unique biomechanical burden associated with this transitional zone, and the presence of critical neurovascular and soft tissue structures. ^, To optimize outcomes, careful patient selection and meticulous preoperative planning are imperative. Advances in surgical approaches, along with a more robust understanding of the biomechanical dynamics of this region, have allowed improved access to this intricate area.

Surgical Indications

Appropriate patient selection is of paramount importance for management of CTJ tumors. To this end, the NOMS framework is used to guide the treatment of spinal tumors and to determine the necessity of surgical intervention. This treatment algorithm is based on assessments in four broad categories: (1) neurological (N), which includes the degree of myelopathy, radiculopathy, and radiographic evidence of spinal cord compression; (2) oncological (O), which consists of the predicted response to various treatment modalities based on tumor histology; (3) mechanical instability (M), which reflects movement-associated pain, and (4) systemic disease (S), which accounts for patient comorbidity burden and extent of disease. Under the current NOMS framework, the primary indications for surgical intervention include compression of the epidural spinal cord by radioresistant tumors, malignant primary spinal cord tumors, and tumors causing mechanical instability in patients who can tolerate the operation from a systemic perspective. ^, Indeed, Le and colleagues found myelopathy to be the surgical indication in all 19 patients with CTJ neoplasms in their cohort. There is an increasing body of evidence to support the role of surgical resection in patients with epidural spinal cord compression. In this patient population, resection is associated with postoperative improvement in terms of neurological function, recovery, ambulation, and survival. All patients being considered for surgical intervention will receive standard preoperative evaluation to promote optimal outcomes.

Preoperative Evaluation

All patients undergoing preoperative workup for CTJ lesions will receive anteroposterior and lateral plain films, which provide important information regarding the presence and possible etiology of disease processes. Red flags consistent with pathology include collapse of the vertebrae, pedicle widening, and malalignment on plain radiographs. Furthermore, key features on plain films can also narrow the differential diagnosis and point toward a particular etiology. For instance, infections such as osteomyelitis often present with disc space narrowing (present in 74% of patients) during the early stages, and vertebral body destruction, which can manifest as lytic lesions in the anterior vertebral body, and sclerosis in the later stages.

In contrast, hallmark characteristics of bony metastases include pedicle erosion, osteoblastic changes, and vertebral body collapse, although these signs are often only late in the disease course, as these changes are only visible on x-ray after significant bony destruction (30%–70%). Another imaging modality used in the workup of a metastatic lesion is myelography: by assessing patency of the subarachnoid space, myelography can identify both the level of the lesion and the presence of intradural tumors, vascular malformations, and disc herniations.

Computed tomography (CT) is also indispensable for tumor staging, surgical planning, and diagnosis. Not only does CT help differentiate between tumor and osteoporosis as the responsible agent in vertebral body collapse, it also sheds light on the extent of bone destruction, and is the most commonly used modality for image-guided biopsy. Finally, no preoperative evaluation of CTJ lesions would be complete without magnetic resonance imaging (MRI) of the cervicothoracic spine, which allows evaluation of the extent of disease and provides superior anatomical detail of neurovascular structures and soft tissue critical to surgical planning. Indeed, MRI has been documented to have a sensitivity and accuracy on par with concomitant gallium and bone scanning in the workup of metastatic disease.

An important preoperative consideration is the vascularity of the target tumor, as patients with hypervascular tumors may benefit from preoperative arterial embolization to minimize the risk of intraoperative bleeding, which in turn will allow the surgeon to achieve maximal tumor excision and spinal cord decompression. In cases where aggressive tumor resection in the vicinity of a vertebral artery is projected to occur, preoperative angiography for sacrifice of the corresponding vertebral artery may be necessary. At baseline, embolization procedures are correlated with a 2% risk for neurological complications and a 4% to 10% risk of local or systemic complications. ^, However, it is important to note that the risks associated with preoperative embolization are much higher for tumors of the cervical spine, as this procedure can increase the risk for stroke. Thus, the benefits of decreased intraoperative bleeding must be weighed against the risks for stroke when considering preoperative embolization of a tumor in the cervical spine.

In addition to preoperative imaging, patients should also undergo metabolic and systemic evaluation to ensure fitness for surgery. Standard labs include a complete blood count, liver function tests and profile, and renal panel, including blood urea nitrogen, creatinine, and electrolytes. The presence of inflammatory conditions should be screened for by obtaining levels of inflammatory markers, such as the erythrocyte sedimentation rate and C-reactive protein levels. Lastly, a hematological evaluation, including levels of antinuclear antibody and rheumatoid factor, should also be performed before the operation.