Metastatic spinal cord compression. Influence of time between onset of motoric deficits and start of irradiation on therapeutic effect

Metastatic spinal cord compression: review of the evidence for a radiotherapy dose fractionation schedule

Metastatic spinal cord compression is a frequent medical emergency, and the most common treatment offered is radiotherapy. The routine treatment prescription for spinal cord compression in the UK is 20 Gy in five daily fractions delivered over 1 week. Here, we evaluate the evidence base for the radiotherapy dose for spinal cord compression. Evidence from the four prospective studies conducted so far and retrospective studies does not support a uniform dose of 20 Gy for all patients with spinal cord compression. Available evidence suggests that the radiotherapy dose should be tailored to the individual patient, depending on the subtype of the tumour, the extent of metastatic disease and expected survival. A risk stratification for the optimum dose prescription for patients with spinal cord compression is recommended.

The effect of early surgical treatment on recovery in patients with metastatic compression of the spinal cord

We analysed the influence of the timing of surgery (< 48 hours, group 1, 21 patients vs > 48 hours, group 2, 14 patients) on the neurological outcome and restoration of mobility in 35 incomplete tetra- and paraplegic patients with metastatic spinal-cord compression.

Pain and neurological symptoms were assessed using the American Spinal Injury Association impairment scale. More improvement was found in group 1 than in group 2 when comparing the pre-operative findings with those both immediately post-operatively (p = 0.021) and those at follow-up at four to six weeks (p = 0.010). In group 1 the number of pre-operatively mobile patients increased from 17 (81%) to 19 patients (90%) whereas the number of mobile patients in group 2 changed from nine (64%) to ten (71%).

These results suggest that early surgical treatment in patients with metastatic spinal-cord compression gives a better neurological outcome even in a palliative situation.

Solitary vertebral metastasis

As survival time increases for many cancers, it is likely that the incidence and prevalence of spinal metastases will increase also. Given that most patients first present with solitary lesions in the spine, proper initial diagnosis and management are of paramount importance in minimizing pain, improving neurologic function, and potentially lengthening survival. Although pain control and standard radiation are still used, spinal stereotactic radiosurgery, vertebroplasty and kyphoplasty, and spinal cord decompression and fusion are now consistently used in aggressive management and offer exciting preliminary results.

The role of external beam radiotherapy in the management of bone metastases

External beam radiotherapy is effective in the management of bone metastases for both local and more widespread pain. It is effective in spinal canal compression and pathological fracture where it also may have a prophylactic role. Single dose radiotherapy for bone metastases is a highly cost effective palliative treatment.

Metastatic disease of the spine

Metastatic spine disease accounts for 10% to 30% of new cancer diagnoses annually. The most frequent presentation is axial pain. A thorough spinal examination includes assessment of local tenderness, deformity, limitation of motion, and signs of nerve root or cord compression. Plain radiographs are obtained routinely; for a suspected or known malignancy, radionuclide studies are essential. Magnetic resonance imaging is more specific than bone scans. Computed tomography-guided biopsy is considered to be safe and accurate for evaluating spinal lesions. Treatment is multidisciplinary, and virtually all treatment is palliative. Management is guided by three key issues: neurologic compromise, spinal instability, and individual patient factors. Site-directed radiation, with or without chemotherapy, is the mainstay of treating painful lesions that are not impinging on neural elements. New data documenting the benefit of surgical decompression using improved techniques such as anterior approaches have amplified the role of the spine surgeon in the care of these patients.

Epidural spinal cord compression

Spinal cord compression from epidural metastases (epidural spinal cord compression, ESCC) is the most common neurological complication of cancer after brain metastases. Extradural compression represents 97% of spinal cord metastatic lesions. ESCC usually occurs in patients with disseminated disease. The most common tumours associated with ESCC are lung and breast cancers, followed by lymphoma, myeloma, prostate cancer and sarcoma. ESCC represents a medical emergency because delayed treatment can be responsible for irreversible deficits, such as paralysis and loss of sphincter control. Patients with ESCC require a multidisciplinary diagnostic and therapeutic approach. Clinical suspect is radiologically detected for confirmation. The median expected survival time from diagnosis usually ranges from 3 to 6 months. The nature of the primary tumour and the degree of the neurological deficit are the most important factors affecting survival. The lack of prospective randomized trials makes the optimal treatment of ESCC controversial and the decision is to be tailored to the individual. Treatment options include: bed rest, administration of corticosteroids, surgery followed by radiation therapy, radiotherapy alone and, to a limited extent, chemotherapy and hormonal therapy.

Spinal reirradiation after short-course RT for metastatic spinal cord compression

PURPOSE

To investigate the feasibility and effectiveness of reirradiation (re-RT) for in-field recurrence of metastatic spinal cord compression after primary RT with 1 x 8 Gy or 5 x 4 Gy.

METHODS AND MATERIALS

A total of 62 patients, treated with 1 x 8 Gy (n = 34) or 5 x 4 Gy (n = 28) between January 1995 and August 2003, received re-RT for in-field recurrence of metastatic spinal cord compression. The median time to recurrence was 6 months (range, 2-40 months). Re-RT was performed with 1 x 8 Gy (after 1 x 8 Gy or 5 x 4 Gy, n = 34), 5 x 3 Gy (after 1 x 8 Gy or 5 x 4 Gy, n = 15), or 5 x 4 Gy (after 1 x 8 Gy, n = 13). The cumulative biologically effective dose (primary RT plus re-RT) was 80-100 Gy2. The median follow-up after re-RT was 8 months (range, 2-42 months). Motor function was evaluated up to 6 months after re-RT.

RESULTS

After re-RT, 25 patients (40%) showed improvement of motor function, 28 (45%) had no change, and 9 (15%) had deterioration. Of the 16 previously nonambulatory patients, 6 (38%) regained the ability to walk. No second in-field recurrence in the same spinal region was observed after re-RT. The outcome was not significantly influenced by the radiation schedule. Radiation myelopathy was not observed.

CONCLUSIONS

Spinal re-RT with 1 x 8 Gy, 5 x 3 Gy, or 5 x 4 Gy for in-field recurrence of metastatic spinal cord compression appears safe and effective. Myelopathy seems unlikely, if the cumulative biologically effective dose is < or = 100 Gy2.

The effect of biological effective dose on time to symptom progression in metastatic renal cell carcinoma

AIMS

Renal cell carcinoma is commonly thought to be a radioresistant malignancy. Retrospective studies report conflicting results on the effect of radiotherapy dose escalation on response and time to progression in symptomatic metastatic disease; studies using the linear quadratic model have used alpha/beta ratios that are inappropriate for slow growing tumours. We aim to describe our experience with palliative radiotherapy in this context, relating Biological Effective Dose to outcome.

MATERIALS AND METHODS

From December 1995 to April 2001, 143 independent palliative radiotherapy treatments were delivered to 78 patients in a single institution. Retrospective data was obtained on the radiotherapy schedule used, symptom response and time to symptom progression. The biological effective dose (BED) was calculated using alpha/beta ratios of 3 and 7 Gy (BED3 and BED7). The Log-Rank test was used to assess any differences in time to progression, and the Cox Proportional Hazards analysis to determine prognostic factors of time to progression.

RESULTS

Overall symptomatic response rate was 73%, with most responses being partial (67%). Forty-three (38%) patients had symptomatic progression after a median follow-up of 425 days. BED (BED3 or BED7) was not significantly different across response types (complete, partial or no response; P=0.90 and 0.88, respectively) and was not predictive for time to symptomatic progression (P=0.99 for BED3 and P=0.70 for BED7). Patients with bone metastases received less total dose (P=0.001), less BED (BED3, P=0.0013, and BED7, P=0.0005) and had a significantly longer time to progression than other sites of metastases (hazard ratio (HR) 0.4; 95% confidence interval (CI) 0.2-0.7; P=0.004). Initial treatment with interferon-alpha alone in patients presenting with metastatic disease, before palliative radiotherapy, was also associated with a shorter time to symptom progression (HR 4.6; 95% CI 1.5-14.1; P=0.007). On removal of these criteria, brain metastases became a significant predictor of progression time, with an HR of 2.5 (95% CI 1.0-5.9; P=0.05), showing an increased risk of progression with brain metastases compared with metastases elsewhere. Time from primary diagnosis to development of metastatic disease was not predictive of time to symptom progression (P=0.29).

CONCLUSION

Despite the widespread assumption that renal cell carcinoma is radioresistant, retrospective assessment showed high response rates to palliative radiotherapy. On the basis of our data, higher BED does not seem to be a predictor of response or of duration of response in the palliative treatment of renal cell carcinoma. Palliation of bone pain seems to be particularly durable compared with the palliation of symptoms at other sites of metastases. A trend for shorter duration of palliative effect of whole-brain radiotherapy was noted.

Prognostic factors for survival in metastatic spinal cord compression: a retrospective study in a rehabilitation setting

OBJECTIVE

Metastatic spinal cord compression (MSCC) occurs in 5-10% of all patients with cancer, and it is associated with short survival durations. Patients with MSCC may also have functional loss and require rehabilitation before discharge from the hospital. The purposes of this retrospective study were to identify clinical and social variables that had a significant impact on survival of patients with MSCC who underwent inpatient rehabilitation.

DESIGN

A total of 60 consecutive patients with MSCC who were admitted to the inpatient rehabilitation unit at our tertiary care cancer center between 1996 and 1998 were included. Age, discharge destination, primary tumor site, metastasis, comorbidity, hemoglobin and albumin levels, treatment rendered for MSCC, opioids used, and psychological symptoms were examined as variables, and the Kaplan-Meier survival analysis was used.

RESULTS

Our study showed that most of the variables we examined had no significant influence on survival time (median, 4.1 mo), with the exception of gastrointestinal cancer; patients with gastrointestinal cancer had a poorer prognosis (median survival durations, 0.6 mo; P < 0.0001). We also found a 1-mo gap between the time of diagnosis and the time of transfer to the rehabilitation unit.

CONCLUSION

This study suggests that rehabilitation programs for patients with MSCC should be of short duration and that early referral (i.e., when the patient is diagnosed of MSCC) to the rehabilitation service should be encouraged.

Spondylodiscitis in patients with spinal cord compression: a possible pitfall in radiation oncology

PURPOSE

In patients presented for spinal irradiation it may be difficult to distinguish between malignant and benign lesions if only plain X-rays and computed tomography (CT)-scans are available. Spinal magnetic resonance imaging (MRI) can be of great diagnostic value.

METHODS

From 11/1995 to 05/2000 447 patients were presented for spinal irradiation, 264 beyond regular operating hours. At presentation no spinal MRI was available in 170/447 and 132/264 patients.

RESULTS

After spinal MRI, diagnosis was changed from vertebral metastases to spondylodiscitis in 10/170 and 8/132 patients. Six of these patients were already known as cancer patients.

CONCLUSION

In patients presented for spinal irradiation spondylodiscitis is not very uncommon. If there is any doubt about metastatic disease as the cause for spinal cord compression a spinal MRI has to be demanded, even beyond regular operating hours.

Prognostic significance of the time of developing motor deficits before radiation therapy in metastatic spinal cord compression: one-year results of a prospective trial

PURPOSE

To investigate prospectively the prognostic value of the time of developing motor deficits before radiation therapy (RT) for post-treatment functional outcome in metastatic spinal cord compression.

METHODS AND MATERIALS

From November 1998 until October 1999, 57 patients were included. Two subgroups were formed according to the time of developing motor deficits before RT: 1-14 days (n = 29) and > 14 days (n = 28). Therapeutic effect on motor function was evaluated by an 8-point scale directly, 6, 12, and 24 weeks after RT. Patients with rapid deterioration of motor function within 48 h before RT (n = 14) were evaluated separately.

RESULTS

Directly after RT, 26/28 patients (93%) of the group developing motor deficits > 14 days showed improvement of motor function, in comparison to 3/29 patients (10%) of the group 1-14 days (p < 0.001). Deterioration rates were 0% (> 14 days) and 45% (1-14 days). In patients with rapid deterioration of motor function within 48 h before RT, prognosis was poor (improvement 0%, no change 43%, deterioration 57%). Results were comparable 6, 12, and 24 weeks after RT.

CONCLUSION

A slower development of motor deficits before RT predicts a better post-treatment functional outcome. In patients with rapid deterioration of motor function within 48 h before RT, prognosis was extraordinarily poor. These results support the findings of our preceding retrospective analysis.