Analysis of Local Control and Pain Control After Spine Stereotactic Radiosurgery Reveals Inferior Outcomes for Hepatocellular Carcinoma Compared With Other Radioresistant Histologies

Efficacy and safety of SBRT for spine metastases: A systematic review and meta-analysis for preparation of an ESTRO practice guideline

BACKGROUND AND PURPOSE

Advances in characterizing cancer biology and the growing availability of novel targeted agents and immune therapeutics have significantly changed the prognosis of many patients with metastatic disease. Palliative radiotherapy needs to adapt to these developments. In this study, we summarize the available evidence for stereotactic body radiotherapy (SBRT) in the treatment of spinal metastases.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed using PRISMA methodology, including publications from January 2005 to September 2021, with the exception of the randomized phase III trial RTOG-0631 which was added in April 2023. Re-irradiation was excluded. For meta-analysis, a random-effects model was used to pool the data. Heterogeneity was assessed with the I2-test, assuming substantial and considerable as I2 > 50 % and I2 > 75 %, respectively. A p-value < 0.05 was considered statistically significant.

RESULTS

A total of 69 studies assessing the outcomes of 7236 metastases in 5736 patients were analyzed. SBRT for spine metastases showed high efficacy, with a pooled overall pain response rate of 83 % (95 % confidence interval [CI] 68 %-94 %), pooled complete pain response of 36 % (95 % CI: 20 %-53 %), and 1-year local control rate of 94 % (95 % CI: 86 %-99 %), although with high levels of heterogeneity among studies (I2 = 93 %, I2 = 86 %, and 86 %, respectively). Furthermore, SBRT was safe, with a pooled vertebral fracture rate of 9 % (95 % CI: 4 %-16 %), pooled radiation induced myelopathy rate of 0 % (95 % CI 0-2 %), and pooled pain flare rate of 6 % (95 % CI: 3 %-17 %), although with mixed levels of heterogeneity among the studies (I2 = 92 %, I2 = 0 %, and 95 %, respectively). Only 1.7 % of vertebral fractures required surgical stabilization.

CONCLUSION

Spine SBRT is characterized by a favorable efficacy and safety profile, providing durable results for pain control and disease control, which is particularly relevant for oligometastatic patients.

The role of radiation therapy in the treatment of spine metastases from hepatocellular carcinoma: a systematic review and meta-analysis

OBJECTIVE

Spine hepatocellular carcinoma (HCC) metastases severely worsen quality of life and prognosis, with the role of radiotherapy being controversial. The authors systematically reviewed the literature on radiotherapy for spine metastatic HCCs.

METHODS

The PubMed, Scopus, Web of Science, and Cochrane databases were searched according to the PRISMA guidelines to include studies of radiotherapy for spine metastatic HCCs. Outcomes, complications, and local control were analyzed with indirect random-effect meta-analyses.

RESULTS

The authors included 12 studies comprising 713 patients. The median time interval from diagnosis of HCC to spine metastases was 12 months (range 0–105 months). Most lesions were thoracic (35.9%) or lumbar (24.7%). Radiotherapy was delivered with conventional external-beam (67.3%) or stereotactic (31.7%) techniques. The median dose was 30.3 Gy (range 12.5–52 Gy) in a median of 5 fractions (range 1–20 fractions). The median biologically effective dose was 44.8 Gy10 (range 14.4–112.5 Gy10). Actuarial rates of postradiotherapy pain relief and radiological response were 87% (95% CI 84%–90%) and 70% (95% CI 65%–75%), respectively. Radiation-related adverse events and vertebral fractures had actuarial rates of 8% (95% CI 5%–11%) and 16% (95% CI 10%–23%), respectively, with fracture rates significantly higher after stereotactic radiotherapy (p = 0.033). Fifty-eight patients (27.6%) had local recurrences after a median of 6.8 months (range 0.1–59 months), with pooled local control rates of 61.6% at 6 months and 40.8% at 12 months, and there were no significant differences based on radiotherapy type (p = 0.068). The median survival was 6 months (range 0.1–62 months), with pooled rates of 52.5% at 6 months and 23.4% at 12 months.

CONCLUSIONS

Radiotherapy in spine metastatic HCCs shows favorable rates of pain relief, radiological responses, and local control. Rates of postradiotherapy vertebral fractures are higher after high-dose stereotactic radiotherapy.

Local control of bone metastases treated with external beam radiotherapy in recent years: a multicenter retrospective study

BACKGROUND

Over the past decades, remarkable advancements in systemic drug therapy have improved the prognosis of patients with bone metastases. Individualization is required in external beam radiotherapy (EBRT) for bone metastases according to the patient's prognosis. To establish individualized EBRT for bone metastases, we investigated factors that affect the local control (LC) of bone metastases.

METHODS

Between January 2010 and December 2019, 536 patients received EBRT for 751 predominantly osteolytic bone metastases. LC at EBRT sites was evaluated with a follow-up computed tomography. The median EBRT dose was biologically effective dose (BED10) (39.0) (range of BED10: 14.4-71.7 Gy).

RESULTS

The median follow-up time and median time of computed tomography follow-up were 11 (range 1-123) months and 6 (range 1-119) months, respectively. The 0.5- and 1-year overall survival rates were 73% and 54%, respectively. The 0.5- and 1-year LC rates were 83% and 79%, respectively. In multivariate analysis, higher age (≥ 70 years), non-vertebral bone metastases, unfavorable primary tumor sites (esophageal cancer, colorectal cancer, hepatobiliary/pancreatic cancer, renal/ureter cancer, sarcoma, melanoma, and mesothelioma), lower EBRT dose (BED10 < 39.0 Gy), and non-administration of bone-modifying agents (BMAs)/antineoplastic agents after EBRT were significantly unfavorable factors for LC of bone metastases. There was no statistically significant difference in the LC between BED10 = 39.0 and BED10 > 39.0 Gy.

CONCLUSIONS

Regarding tumor-related factors, primary tumor sites and the sites of bone metastases were significant for the LC. As for treatment-related factors, lower EBRT doses (BED10 < 39.0 Gy) and non-administration of BMAs/antineoplastic agents after EBRT were associated with poor LC. Dose escalation from BED10 = 39.0 Gy did not necessarily improve LC.

Advances in radiotherapy in bone metastases in the context of new target therapies and ablative alternatives: A critical review

In patients with bone metastases (BM), radiotherapy (RT) is used to alleviate symptoms, reduce the risk of fracture, and improve quality of life (QoL). However, with the emergence of concepts like oligometastases, minimal invasive surgery, ablative therapies such as stereotactic ablative RT (SABR), radiosurgery (SRS), thermal ablation, and new systemic anticancer therapies, there have been a paradigm shift in the multidisciplinary approach to BM with the aim of preserving mobility and function survival. Despite guidelines on using single-dose RT in uncomplicated BM, its use remains relatively low. In uncomplicated BM, single-fraction RT produces similar overall and complete response rates to RT with multiple fractions, although it is associated with a higher retreatment rate of 20% versus 8%. Complicated BM can be characterised as the presence of impending or existing pathologic fracture, a major soft tissue component, existing spinal cord or cauda equina compression and neuropathic pain. The rate of complicated BM is around 35%. Unfortunately, there is a lack of prospective trials on RT in complicated BM and the best dose/fractionation regimen is not yet established. There are contradictory outcomes in studies reporting BM pain control rates and time to pain reduction when comparing SABR with Conventional RT. While some studies showed that SABR produces a faster reduction in pain and higher pain control rates than conventional RT, other studies did not show differences. Moreover, the local control rate for BM treated with SABR is higher than 80% in most studies, and the rate of grade 3 or 4 toxicity is very low. The use of SABR may be preferred in three circumstances: reirradiation, oligometastatic disease, and radioresistant tumours. Local ablative therapies like SABR can delay change or use of systemic therapy, preserve patients' Qol, and improve disease-free survival, progression-free survival and overall survival. Moreover, despite the potential benefit of SABR in oligometastatic disease, there is a need to establish the optial indication, RT dose fractionation, prognostic factors and optimal timing in combination with systemic therapies for SABR. This review evaluates the role of RT in BM considering these recent treatment advances. We consider the definition of complicated BM, use of single and multiple fractions RT for both complicated and uncomplicated BM, reirradiation, new treatment paradigms including local ablative treatments, oligometastatic disease, systemic therapy, physical activity and rehabilitation.

Multidisciplinary management of metastatic spine disease: initial symptom-directed management

In the past 2 decades, a deeper understanding of the cancer molecular signature has resulted in longer longevity of cancer patients, hence a greater population, who potentially can develop metastatic disease. Spine metastases (SM) occur in up to 70% of cancer patients. Familiarizing ourselves with the key aspects of initial symptom-directed management is important to provide SM patients with the best patient-specific options. We will review key components of initial symptoms assessment such as pain, neurological symptoms, and spine stability. Radiographic evaluation of SM and its role in management will be reviewed. Nonsurgical treatment options are also presented and discussed, including percutaneous procedures, radiation, radiosurgery, and spine stereotactic body radiotherapy. The efforts of a multidisciplinary team will continue to ensure the best patient care as the landscape of cancer is constantly changing.

Bone Metastases: Mechanisms of the Metastatic Process, Imaging and Therapy

The mechanisms by which tumors metastasize to bone are complex. Upon the successful establishment of metastatic deposits in the skeleton, detection of the disease becomes essential for therapeutic planning. The roles of CT, skeletal scintigraphy, SPECT/CT, MRI, PET/CT and PET/MRI will be reviewed. Therapeutic response criteria specifically designed to evaluate bone metastases (MD Anderson/MDA criteria) can guide image interpretation. Knowledge of therapeutic strategies such as systemic therapy with bisphosphonates or radiopharmaceuticals, radiation therapy, surgery, and percutaneous interventions such as vertebroplasty and radiofrequency ablation can help the radiologist produce reports that will provide maximum benefit to clinicians and patients.

Local control and toxicity outcomes of stereotactic radiosurgery for spinal metastases of gastrointestinal origin

OBJECTIVE

Colorectal cancer (CRC) and other gastrointestinal (GI) cancers are believed to have greater radioresistance than other histologies. The authors report local control and toxicity outcomes of stereotactic radiosurgery (SRS) to spinal metastases from GI primary cancers.

METHODS

A retrospective single-center review was conducted of patients with spinal metastases from GI primary cancers treated with SRS from 2004 to 2017. Patient demographics and lesion characteristics were summarized using medians, interquartile ranges (IQRs), and proportions. Local failure (LF) was estimated using the cumulative incidence function adjusted for the competing risk of death and compared using Gray's test for equality. Multivariable analyses were conducted using Cox proportional hazard models, adjusting for death as a competing risk, on a per-lesion basis. Patients were stratified in the Cox model to account for repeated measures for clustered outcomes. Median survival was calculated using the Kaplan-Meier method.

RESULTS

A total of 74 patients with 114 spine lesions were included in our analysis. The median age of the cohort was 62 years (IQR 53-70 years). Histologies included CRC (46%), hepatocellular carcinoma (19%), neuroendocrine carcinoma (13%), pancreatic carcinoma (12%), and other (10%). The 1- and 2-year cumulative incidence rates of LF were 24% (95% confidence interval [CI] 16%-33%) and 32% (95% CI 23%-42%), respectively. Univariable analysis revealed that older age (p = 0.015), right-sided primary CRCs (p = 0.038), and single fraction equivalent dose (SFED; α/β = 10) < 20 Gy (p = 0.004) were associated with higher rates of LF. The 1-year cumulative incidence rates of LF for SFED < 20 Gy10 versus SFED ≥ 20 Gy10 were 35% and 7%, respectively. After controlling for gross tumor volume and prior radiation therapy to the lesion, SFED < 20 Gy10 remained independently associated with worse LF (hazard ratio 2.92, 95% CI 1.24-6.89, p = 0.014). Toxicities were minimal, with pain flare observed in 6 patients (8%) and 15 vertebral compression fractures (13%).

CONCLUSIONS

Spinal metastases from GI primary cancers have high rates of LF with SRS at a lower dose. This study found that SRS dose is a significant predictor of failure and that prescribed SFED ≥ 20 Gy10 (biological equivalent dose ≥ 60 Gy10) is associated with superior local control.

Single fraction radiosurgery, fractionated radiosurgery, and conventional radiotherapy for spinal oligometastasis (SAFFRON): A systematic review and meta-analysis

BACKGROUND AND PURPOSE

To perform a systematic review/meta-analysis of outcomes for patients with spinal metastases treated with stereotactic radiosurgery (SRS) (either single-fraction (SF-SRS) or multiple-fraction (MF-SRS)) or conventional radiotherapy (RT).

MATERIALS AND METHODS

Thirty-seven studies were identified. Primary outcomes were 1-year local control (LC) and acute/late grade 3-5 toxicities (including vertebral compression fractures (VCF)). Weighted random effects meta-analyses using the DerSimonian and Laird methods and meta-regressions were conducted to characterize and compare effect sizes. Mixed effects regression models were used in dose analyses.

RESULTS

A total of 3237 patients with 4911 lesions were included; 43.8%, 19.7%, and 36.5% of lesions received SF-SRS, MF-SRS, or RT, respectively. SF-SRS resulted in improved 1-year LC (92.9% (95% CI: 86.4-97.4%); p = 0.007) compared to RT (81.0% (95% CI: 69.2-90.5%)) with no difference between MF-SRS (82.1%; p = 0.86) and RT. On subgroup analysis of de novo metastases, superior 1-year LC following SF-SRS (95.5% (95% CI: 87.4-99.6%)) was maintained compared to RT (83.6% (95% CI: 70.4-93.5%); p = 0.007). A 4.7% increase in LC was noted for each 10 Gy₁₀ increase in biologically effective dose (BED₁₀, assuming an alpha/beta = 10) with SRS (p < 0.001). No difference in toxicities were found between SF-SRS (0.4%), MF-SRS (0.2%), or RT (0%). Higher VCF rates were noted following SF-SRS (19.5%) vs. MF-SRS (9.6%; p = 0.039)) with no correlation between dose and VCF rates.

CONCLUSION

SF-SRS resulted in superior LC with a roughly 5% LC benefit for every 10 Gy₁₀ increase in BED₁₀ with higher VCF rates compared to MF-SRS. If LC is the goal of treatment, then SRS may be a preferred treatment modality. However, these results are hypothesis-generating, and prospective randomized clinical trials are indicated to definitively address the question of whether SRS results in improved LC compared to RT.

Evolving Role of Stereotactic Body Radiation Therapy in the Management of Spine Metastases: Defining Dose and Dose Constraints

When treating solid tumor spine metastases, stereotactic high-dose-per-fraction radiation, given in a single fraction or in a hypofractionated approach, has proved to be a highly effective and safe therapeutic option for any tumor histology, in the setting of de novo therapy, as salvage treatment of local progression after previous radiation, and in the postoperative setting. There are variations in practice based on the clinical presentation, goals of therapy, as well as institutional preferences. As a biologically potent therapy, a thoughtful and careful attention to detail with patient selection, treatment planning, and delivery is crucial for treatment success.

Single-Fraction Radiotherapy (SFRT) For Bone Metastases: Patient Selection And Perspectives

Bone metastases are a frequent and important source of morbidity in cancer patients. Stereotactic body radiation therapy (SBRT) is an established treatment option for local control and pain relief of bone metastases, and it is increasingly used as upfront treatment, postoperative consolidation or salvage treatment after prior RT. However, heterogeneity of dose schedules described in literature represents a severe limitation in the definition of the role of SBRT as a standard of care. No consensus is available on the use of single versus multiple fraction SBRT for bone metastases. Advantages of single-fraction SBRT include shorter overall duration of treatment, absence of inter-fraction uncertainty, improved compliance, theoretical increased efficacy, and lower costs. However, caution has been advised due to reports of severe late toxicities, in particular, vertebral collapse fracture (VCF). The aim of this paper is to review dose fractionation and indications for the management of bone metastases using SBRT.

Personalized Radiation Therapy in Cancer Pain Management

The majority of advanced cancer patients suffer from pain, which severely deteriorates their quality of life. Apart from analgesics, bisphosphonates, and invasive methods of analgesic treatment (e.g., intraspinal and epidural analgesics or neurolytic blockades), radiation therapy plays an important role in pain alleviation. It is delivered to a growing primary tumour, lymph nodes, or distant metastatic sites, producing pain of various intensity. Currently, different regiments of radiation therapy methods and techniques and various radiation dose fractionations are incorporated into the clinical practice. These include palliative radiation therapy, conventional external beam radiation therapy, as well as modern techniques of intensity modulated radiation therapy, volumetrically modulated arch therapy, stereotactic radiosurgery or stereotactic body radiation therapy, and brachytherapy or radionuclide treatment (e.g., radium-223, strontium-89 for multiple painful osseous metastases). The review describes the possibilities and effectiveness of individual patient-tailored conventional and innovative radiation therapy approaches aiming at pain relief in cancer patients.