A validated scoring system to identify long-term survivors after radiotherapy for metastatic spinal cord compression

PURPOSE

This study aimed to develop and validate a scoring system to identify long-term survivors after conventional radiotherapy (RT) for metastatic spinal cord compression (MSCC).

PATIENTS AND METHODS

Data from 1,125 patients who had received long-course RT for MSCC were included in this study. Of these patients, 344 survived for over 12 months and 781 died within a year following RT. Based on differences between the distributions of patient characteristics in the two groups, a scoring system was developed. Scores ranged from 0 to 18 points and 15 points was selected as the cutoff for identifying long-term survivors. Data from the 1,125 long-course RT patients (test group) were compared to data from 773 patients receiving short-course RT (validation group).

RESULTS

A score of ≥ 15 points was associated with a 94 % proportion of long-term survivors. The 15-point cutoff resulted in a specificity of 98 % and a positive predictive value of 94 % for identification of long-term surviving patients. The proportions of long-term survivors for each scoring point in the validation group were very similar to those in the test group.

CONCLUSION

This new scoring system enabled identification of long-term survivors after RT for MSCC with very high specificity and positive predictive value. The score proved to be valid and reproducible.

Impact of zoledronic acid on control of metastatic spinal cord compression

BACKGROUND

Zoledronic acid was demonstrated to reduce the rate of skeletal-related events, a hypernym including various outcomes, in patients with bone metastases. In contrast to other studies, this matched-pair analysis focused solely on the impact of zoledronic acid on metastatic spinal cord compression (MSCC).

PATIENTS AND METHODS

Data from 98 patients with MSCC receiving radiotherapy plus zoledronic acid were matched 1:2 to 196 patients receiving radiotherapy alone for ten potential prognostic factors. Both groups were compared for local control of MSCC within the irradiated region, overall control of MSCC (local and distant MSCC control), and survival.

RESULTS

The 1-year local control rates were 90% after radiotherapy plus zoledronic acid and 81%, after radiotherapy alone (p = 0.042). The 1-year overall control rates were 87% and 75%, respectively (p = 0.016), and the 1-year survival rates were 60% and 52%, respectively (p = 0.17). Results were significant in the Cox proportional hazards model regarding local control (p = 0.024) and overall control (p = 0.008).

CONCLUSION

According to the results of this study, zoledronic acid was associated with improved control of MSCC in irradiated patients.

A survival score for patients with metastatic spinal cord compression from prostate cancer

BACKGROUND

This study aimed to develop and validate a survival scoring system for patients with metastatic spinal cord compression (MSCC) from prostate cancer.

PATIENTS AND METHODS

Of 436 patients, 218 patients were assigned to the test group and 218 patients to the validation group. Eight potential prognostic factors (age, performance status, number of involved vertebrae, ambulatory status, other bone metastases, visceral metastases, interval from cancer diagnosis to radiotherapy of MSCC, time developing motor deficits) plus the fractionation regimen were retrospectively investigated for associations with survival. Factors significant in the multivariate analysis were included in the survival score. The score for each significant prognostic factor was determined by dividing the 6-month survival rate (%) by 10. The total score represented the sum of the scores for each factor. The prognostic groups of the test group were compared to the validation group.

RESULTS

In the multivariate analysis of the test group, performance status, ambulatory status, other bone metastases, visceral metastases, and interval from cancer diagnosis to radiotherapy were significantly associated with survival. Total scores including these factors were 20, 21, 22, 24, 26, 28, 29, 30, 31, 32, 33, 35, 37, or 39 points. In the test group, the 6-month survival rates were 6.5% for 20-24 points, 44.6% for 26-33 points, and 95.8% for 35-39 points (p < 0.0001). In the validation group, the 6-month survival rates were 7.4%, 45.4%, and 94.7%, respectively (p < 0.0001).

CONCLUSIONS

Because the survival rates of the validation group were almost identical to the test group, this score can be considered valid and reproducible.

Prognostic factors in a series of 504 breast cancer patients with metastatic spinal cord compression

BACKGROUND

This study was performed to identify new significant prognostic factors in breast cancer patients irradiated for metastatic spinal cord compression (MSCC).

PATIENTS AND METHODS

The data of 504 patients with breast cancer patients with MSCC were retrospectively analyzed with respect to posttreatment motor function, local control of MSCC, and survival. The investigated potential prognostic factors included age, Eastern Cooperative Oncology Group (ECOG) performance score, number of involved vertebrae, other bone metastases, visceral metastases, pretreatment ambulatory status, interval from cancer diagnosis to radiotherapy of MSCC, time developing motor deficits before radiotherapy, and the radiation schedule.

RESULTS

On multivariate analysis, better functional outcome was associated with ambulatory status prior to RT (estimate - 1.29, p < 0.001), no visceral metastases (estimate - 0.52, p = 0.020), and slower development of motor deficits (estimate + 2.47, p < 0.001). Improved local control was significantly associated with no other bone metastases (risk ratio (RR) 4.33, 95% confidence interval (CI) 1.36-14.02, p = 0.013) and no visceral metastases (RR 3.02, 95% CI 1.42-6.40, p = 0.005). Improved survival was significantly associated with involvement of only 1-2 vertebrae (RR 1.27, 95% CI 1.01-1.60, p = 0.044), ambulatory status before radiotherapy (RR 1.75, 95% CI 1.23-2.50, p = 0.002), no other bone metastases (RR 1.93, 95% CI 1.18-3.13, p = 0.009), no visceral metastases (RR 7.60, 95% CI 5.39-10.84, p < 0.001), and time developing motor deficits before radiotherapy (RR 1.55, 95% CI 1.30-1.86, p < 0.001).

CONCLUSION

Several new independent prognostic factors were identified for treatment outcomes. These prognostic factors should be considered in future trials and may be used to develop prognostic scores for breast cancer patients with MSCC.

Resection plus whole-brain irradiation versus resection plus whole-brain irradiation plus boost for the treatment of single brain metastasis

BACKGROUND

The optimal treatment for patients with a single brain metastasis is controversial. This study investigated the value of a radiation boost given in addition to neurosurgerical resection and whole-brain irradiation (WBI).

PATIENTS AND METHODS

In this retrospective study, outcome data of 105 patients with a single brain metastasis receiving metastatic surgery plus WBI (S + WBI) were compared to 90 patients receiving the same treatment plus a boost to the metastatic site (S + WBI + B). The outcomes that were compared included local control of the resected metastasis (LC) and overall survival (OS). In addition to the treatment regimen, eight potential prognostic factors were evaluated including age, gender, performance status, extent of metastatic resection, primary tumor type, extracerebral metastases, recursive partitioning analysis (RPA) class, and interval from first diagnosis of cancer to metastatic surgery.

RESULTS

The LC rates at 1 year, 2 years, and 3 years were 38%, 20%, and 9%, respectively, after S + WBI, and 67%, 51%, and 33%, respectively, after S + WBI + B (p = 0.002). The OS rates at 1 year, 2 years, and 3 years were 52%, 25%, and 19%, respectively, after S + WBI, and 60%, 40%, and 26%, respectively, after S + WBI + B (p = 0.11). On multivariate analyses, improved LC was significantly associated with OP + WBI + B (p = 0.006) and total resection of the metastasis (p = 0.014). Improved OS was significantly associated with age ≤ 60 years (p = 0.028), Karnofsky Performance Score > 70 (p = 0.015), breast cancer (p = 0.041), RPA class 1 (p = 0.012), and almost with the absence of extracerebral metastases (p = 0.05).

CONCLUSION

A boost in addition to WBI significantly improved LC but not OS following resection of a single brain metastasis.

Final results of a study comparing short-course and long-course radiotherapy (RT) for local control of metastatic spinal cord compression (MSCC)

9522

Background: Many MSCC patients live long enough to develop a recurrence in the irradiated spinal area. This is the first prospective study comparing different RT schedules for local control (LC) of MSCC. Methods: 265 patients treated with RT alone (1/06–12/07) were included in this prospective non-randomized study. The primary goal was to compare short-course (1×8 Gy/5×4 Gy, N=131) and long-course RT (10×3 Gy/15×2.5 Gy/20×2 Gy, N=134) for 1-year LC. Secondary endpoints were motor function and 1-year survival (OS). Dutch patients received short-course, and German patients long-course RT. The analysis of LC (no MSCC recurrence in the irradiated spinal area) included the 224 patients with improvement or no change of motor deficits during RT. The difference in 1-year LC was previously reported to be 14% between short- and long-course RT. For a statistical power of 90 % (significance level 5%), ≥218 patients were required to detect this difference. Univariate analyses (UVA) for LC and OS were performed with Kaplan-Meier-method and log-rank test, multivariate analyses (MVA) with the Cox proportional hazards model. UVA and MVA for motor function were performed with the ordered-logit-model. Eleven additional factors were evaluated. Results: 1-year LC was 61% after short-course RT and 81% after long-course RT (P=0.005). On MVA, improved LC was only associated with long-course RT (P=0.018). Motor function improved in 37% after short- and 39% after long-course RT (P=0.95). Improved motor function was associated with better performance status (P=0.015), favorable tumor (P=0.034), and slower development of motor deficits (P<0.001). 1-year OS was 23% after short- and 30% after long-course RT (P=0.28). On MVA, improved OS was associated with better performance status (P<0.001), no visceral metastases (P<0.001), involvement of 1–3 vertebrae (P=0.040), ambulatory status (P=0.038), and bisphosphonates (P<0.001). Conclusions: Long-course RT was associated with better LC, similar functional outcome, and similar OS compared to short-course RT. Patients with a favorable OS prognosis should receive long-course RT, and those with a poor OS prognosis should receive short-course RT.

[Table: see text]

Scoring systems predictive of survival and local control of patients irradiated for brain metastases

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Background: This study was performed to create and validate scoring systems to estimate survival and intracerebral local control at 6 months of patients irradiated for brain metastases. Methods: Data of 1,797 patients irradiated for brain metastases (1,346 whole-brain radiotherapy [WBRT], 131 radiosurgery [RS], 61 WBRT + RS, 259 resection + WBRT) were retrospectively analyzed. Patients were randomly assigned to the test group (N = 1,198) or the validation group (N = 599). In the test group, multivariate analyses (MVA, Cox proportional hazards model) were performed for survival (OS) and local control (LC). Based on the MVA results, two scoring systems were developed, one for OS and another for LC. The scores included the prognostic factors found significant on MVA. Age, performance status, extracranial metastases, interval from tumor diagnosis to RT, and number of brain metastases were significant for OS. Tumor type, performance status, interval from tumor diagnosis to RT, and number of brain metastases were significant for LC. The score for each factor was determined by dividing the 6-month OS or LC rate (%) by 10. The total score represented the sum of the scores for each factor. For OS, total scores ranged from 15–30 points, and patients were divided into three groups (15–19, 20–25, and 26–30 points). For LC, total scores ranged from 14–27 points, and patients were divided into three groups (14–18, 19–23, and 24–27 points). Results: In the test group, the 6-month OS rates were 9 ± 1% for patients with scores of 15–19 points, 41 ± 2% for those with 20–25 points, and 78 ± 2% for those with 26–30 points (p < 0.0001). The corresponding OS rates in the validation group were 7 ± 2%, 39 ± 3%, and 79 ± 3%, respectively (p < 0.0001).In the test group, the 6-month LC rates were 17 ± 3% for patients with 14–18 points, 49 ± 3% for those with 19–23 points, and 77 ± 2% for those with 24–27 points (p < 0.0001). The corresponding LC rates in the validation group were 19 ± 4%, 52 ± 4%, and 77 ± 3%, respectively (p < 0.0001). Conclusions: Patients irradiated for brain metastases can be grouped with these scores to estimate OS and LC. The OS and LC rates of the validation group were almost identical to the test group, which demonstrates the high validity and reproducibility of both scores.

No significant financial relationships to disclose.

Reirradiation of primary brain tumours: survival, clinical response and prognostic factors

BACKGROUND AND PURPOSE

First, the aim was to determine the survival and quality of life after reirradiation of relapsing primary malignant brain tumours. The second aim was to assess the influence of a set of potentially prognostic factors on survival.

MATERIALS AND METHODS

Forty-two patients received reirradiation for recurring primary brain tumours. The interval between the two consecutive treatments was at least 1 year. External beam irradiation for the initial and recurrent tumour was usually delivered with two opposing lateral fields or two wedged fields in orthogonal directions. The median physical doses of the first and second radiation course were 50 and 46 Gy, respectively. The median cumulative biological equivalent doses (BED) were 200.4 (alpha/beta = 2 Gy) and 115.2 Gy (alpha/beta = 10 Gy). During follow-up, corticosteroid medication and the WHO-performance were registered at regular intervals. The radiological response was assessed by reviewing all available CT- and MRI-films. Potentially prognostic factors with respect to survival were evaluated by both univariate and multivariate analyses.

RESULTS

A clinical response (i.e. clinical improvement) was seen in 24% of the patients. Of the evaluable patients, nearly one-third showed a complete (8%) or partial (22%) radiological response. The median overall survival (OS) and progression-free survival (PFS) after retreatment were 10.9 and 8.6 months, respectively. By multivariate analysis, four independent prognostic factors for survival were identified: (1), the WHO-score before retreatment (P = 0.002); (2), the length of the interval between treatments (P = 0.008); (3), the tumour histology; and (4), the response to initial treatment (P values, 0.04). The median survival times for patients with WHO-scores of 0-1 and > or = 2 were 14.0 and 7.4 months, respectively. Patients with oligodendrogliomas had a median OS of 27.5 months, whereas patients with astrocytomas had a median OS of 6.9 months after retreatment. Long-term complications of retreatment were seen in three patients, all of whom had a cumulative BED(2) of > 204 Gy (with alpha/beta = 2 Gy). The quality of life after retreatment, however, was well preserved in the majority of patients. They remained ambulant and capable of self-care until the time of progression which occurred after 8.6 months (median PFS).

CONCLUSIONS

After an initial treatment with radiation up to tolerance levels of normal brain tissue, reirradiation of recurring primary brain tumours seems feasible. During the time until clinical progression, patients remained independent with a reasonable quality of life.

Equivalence of hyperfractionated and continuous brachytherapy in a rat tumor model and remarkable effectiveness when preceded by external irradiation

PURPOSE

In clinical brachytherapy, there is a tendency to replace continuous low-dose-rate (LDR) irradiation by either single-dose or fractionated high-dose-rate (HDR) irradiation. In this study, the equivalence of LDR treatments and fractionated HDR (2 fractions/day) or pulsed-dose-rate (PDR, 4 fractions/day) schedules in terms of tumor cure was investigated in an experimental tumor model.

METHODS AND MATERIALS

Tumors (rat rhabdomyosarcoma R1M) were grown s.c. in the flank of rats and implanted with 4 catheters guided by a template. All interstitial radiation treatment (IRT) schedules were given in the same geometry. HDR was given using an (192)Ir single-stepping source. To investigate small fraction sizes, part of the fractionated HDR and PDR schedules were applied after an external irradiation (ERT) top-up dose. The endpoint was the probability of tumor control at 150 days after treatment. Cell survival was estimated by excision assay.

RESULTS

Although there was no fractionation effect for fractionated HDR given in 1 or 2 fractions per day, TCD(50)-values were substantially lower than that for LDR. A PDR schedule with an interfraction interval of 3 h (4 fractions/day), however, was equivalent to LDR. The combination of ERT and IRT resulted in a remarkably increased tumor control probability in all top-up regimens, but no difference was found between 2 or 4 fractions/day. Catheter implantation alone decreased the TCD(50) for single-dose ERT already by 17.4 Gy. Cell viability assessed at 24 h after treatment demonstrated an increased effectiveness of interstitial treatment, but, after 10 Gy ERT followed by 10 Gy IRT (24-h interval), it was not less than that calculated for the combined effect of these treatments given separately.

CONCLUSION

In full fractionation schedules employing large fractions and long intervals, the sparing effect of sublethal damage repair may be significantly counteracted by reoxygenation. During 3-h intervals, however, repair may be largely completed with only partial reoxygenation causing PDR schedules to be less effective than fractionated HDR, and equivalent to LDR. Brachytherapy with clinically sized fractions after a large external top-up dose showed a remarkable increase in tumor control rate with no effect of fractionation (up to 4 fractions/day), which could not be fully explained by differences in dose distribution or in the cell viability assessed after treatment. This suggests a longer lasting effect on cell survival or radiosensitivity associated with catheter implantation shortly after the top-up dose.

Non-effectivity of roentgen irradiation in an in vivo rapidly growing murine lymphosarcoma

The survival time of mice bearing a rapidly growing murine lymphosarcoma (cell doubling time 9.6 h) is hardly influenced by roentgen irradiation with fractions of 2 Gy, not even if delivered according to superfractionated schedules. Growth kinetic measurements reveal an almost complete mitotic block 6 h after exposure, followed by a large overshoot in cell proliferative activity. The dose-response curve for in vivo irradiated cells has a D0 of 1.9 and lacks a shoulder. Hence, repair of sublethal damage must be of restricted significance. The extremely strong proliferative capability appears to lead to rapid repopulation of the tumour. Typically, surviving cells show a high content of RNA and protein.

Kinetics of cell proliferation in a rapidly growing murine lymphosarcoma

The growth kinetics of a murine lymphosarcoma were investigated the spleen and liver of mice by means of quantitative flow-cytofluorometric DNA measurements in individual cells in combination with 3H-thymidine incorporation into the DNA. The amount of DNA in the S-phase cells was calculated from the resulting DNA histograms. From the 3H-thymidine incorporation, related to the amount of S-phase DNA, the relative changes in the duration of the S-phase during the growth of the lymphosarcoma were estimated. A marked prolongation of the duration of the S-phase was observed in the course of the growth of the lymphosarcoma. The disappearance of cells of higher ploidy normally found in the liver indicates the elimination of those normal cells in the course of the tumour growth.

Uptake of serotonin liberated by irradiation of rabbits and mice

The radiation-induced release of serotonin (5-HT) in rabbits and mice has a linear dose-response relationship over a short range of approximately 0.75 Gy. In both animal species a threshold value is present, which is 1 Gy for rabbits and 5 Gy for mice. Doses higher than those falling in the linear range give rise to lower plasma 5-HT values. These lower values occur concurrent with increased splenic 5-HT levels. Stimulated 5-HT uptake of the spleen may be responsible for the diminished increase in plasma 5-HT.