Stereotactic Body Radiation Therapy versus Conventional External Beam Radiation Therapy for Painful Bone Metastases: A Systematic Review and Meta-analysis of Randomized Trials

Comparative Analysis of Stereotactic Radiation Therapy and Conventional Radiation Therapy in Cancer Pain Control: A Systematic Review and Meta-Analysis

AIMS

Approximately 55% of patients diagnosed with primary or metastatic cancer endure pain directly attributable to the disease. Consequently, it becomes imperative to address pain management through a comparative analysis of stereotactic radiotherapy (SRT) and conventional radiation therapy (CRT), especially in light of the less efficacious improvement achieved solely through pharmacological interventions.

MATERIALS AND METHODS

A systematic exploration was undertaken on PubMed, the Cochrane Library, and Elsevier's ScienceDirect databases to identify studies that compare Stereotactic Radiotherapy to Conventional radiation therapy for pain management in individuals with metastatic bone cancer. The analyses were executed utilizing the random-effects model.

RESULTS

A cohort of 1152 participants with metastatic bone cancer was analyzed, demonstrating significantly higher complete pain relief in the Stereotactic Radiotherapy group during both early and late follow-up (RR: 1.61; 95% CI: 1.17, 2.23, p-value: 0.004; I2: 0%). Stereotactic Radiotherapy also showed a non-significant increase in the incidence of partial pain relief (RR: 1.07; 95% CI: 0.85, 1.34, p-value: 0.56; I2: 18%). Furthermore, Stereotactic Radiotherapy was associated with a significantly reduced risk of stationary pain throughout follow-up (RR: 0.61; 95%CI: 0.48, 0.76, p-value: <0.0001; I2: 0. The incidence of progressive pain was non-significantly reduced with Stereotactic Radiotherapy during both early and late follow-up (RR: 0.77; 95% CI: 0.50, 1.17, p-value: 0.22; I2: 0%). Secondary outcomes exhibited a non-significant trend favoring Stereotactic Radiotherapy for dysphagia, esophagitis, pain, and radiodermatitis, while a non-significant increase was observed for nausea, fatigue, and vertebral compression fracture.

CONCLUSION

In summary, stereotactic radiation therapy (SRT) has improved in achieving complete pain relief while exhibiting a decreased probability of delivering stationary pain compared to conventional radiation therapy (CRT). Nevertheless, it is crucial in future research to address a noteworthy limitation, specifically, the risk of vertebral compression fracture.

An Update on the Management of Bone Metastases

PURPOSE OF REVIEW

Increasing life expectancy among patients with advanced cancer has placed a greater emphasis on optimizing pain control and quality of life. Concurrently, significant advancements in radiotherapy for bone metastases have permitted for dose escalation strategies such as stereotactic radiotherapy. This review aims to provide updated information on the management of bone metastases in light of these developments.

RECENT FINDINGS

We reviewed recent studies regarding the role and details of external beam radiotherapy for bone metastases, with emphasis on differences by treatment site as well as intention (palliative versus ablative for oligometastases). Conventional palliative radiotherapy remains a mainstay of management. While stereotactic radiotherapy may augment durability of pain relief and even survival time, there are significant questions remaining regarding optimal dosing and patient selection. Radiotherapy for bone metastases continues to evolve, particularly with increasing use of stereotactic radiotherapy. Future studies are needed to clarify optimal dose, fractionation, modality, and patient selection criteria among different radiotherapy approaches.

Stereotactic Body and Conventional Radiotherapy for Painful Bone Metastases: A Systematic Review and Meta-Analysis

Importance

Conventional external beam radiotherapy (cEBRT) and stereotactic body radiotherapy (SBRT) are commonly used treatment options for relieving metastatic bone pain. The effectiveness of SBRT compared with cEBRT in pain relief has been a subject of debate, and conflicting results have been reported.

Objective

To compare the effectiveness associated with SBRT vs cEBRT for relieving metastatic bone pain.

Data Sources

A structured search was performed in the PubMed, Embase, and Cochrane databases on June 5, 2023. Additionally, results were added from a new randomized clinical trial (RCT) and additional unpublished data from an already published RCT.

Study Selection

Comparative studies reporting pain response after SBRT vs cEBRT in patients with painful bone metastases.

Data Extraction and Synthesis

Two independent reviewers extracted data from eligible studies. Data were extracted for the intention-to-treat (ITT) and per-protocol (PP) populations. The study is reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

Overall and complete pain response at 1, 3, and 6 months after radiotherapy, according to the study's definition. Relative risk ratios (RRs) with 95% CIs were calculated for each study. A random-effects model using a restricted maximum likelihood estimator was applied for meta-analysis.

Results

There were 18 studies with 1685 patients included in the systematic review and 8 RCTs with 1090 patients were included in the meta-analysis. In 7 RCTs, overall pain response was defined according to the International Consensus on Palliative Radiotherapy Endpoints in clinical trials (ICPRE). The complete pain response was reported in 6 RCTs, all defined according to the ICPRE. The ITT meta-analyses showed that the overall pain response rates did not differ between cEBRT and SBRT at 1 (RR, 1.14; 95% CI, 0.99-1.30), 3 (RR, 1.19; 95% CI, 0.96-1.47), or 6 (RR, 1.22; 95% CI, 0.96-1.54) months. However, SBRT was associated with a higher complete pain response at 1 (RR, 1.43; 95% CI, 1.02-2.01), 3 (RR, 1.80; 95% CI, 1.16-2.78), and 6 (RR, 2.47; 95% CI, 1.24-4.91) months after radiotherapy. The PP meta-analyses showed comparable results.

Conclusions and Relevance

In this systematic review and meta-analysis, patients with painful bone metastases experienced similar overall pain response after SBRT compared with cEBRT. More patients had complete pain alleviation after SBRT, suggesting that selected subgroups will benefit from SBRT.

Stereotactic body radiation therapy versus conventional external beam radiotherapy for spinal metastases: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

This study aimed to compare SBRT and cEBRT for treating spinal metastases through a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

PubMed, EMBASE and Cochrane Library were searched up to 6 May 2023 for RCTs comparing SBRT and cEBRT for spinal metastases. Overall and complete pain response, local progression, overall survival, quality of life and adverse events were extracted. Data were pooled using random-effects models. Results were reported as risk ratios (RRs) for dichotomous outcomes, and hazard ratios (HRs) for time-to-event outcomes, along with their 95% confidence intervals (CIs). Heterogeneity was evaluated using the I2 statistic.

RESULTS

Three RCTs were identified involving 642 patients. No differences were seen in overall pain response comparing SBRT and cEBRT (RR at 3 months: 1.12, 95% CI, 0.74-1.70, p = 0.59; RR at 6 months: 1.29, 95% CI, 0.97-1.72, p = 0.08). Only two of three studies presented complete pain response data. SBRT demonstrated a statistically significant improvement in complete pain response compared to cEBRT (RR at 3 months: 2.52; 95% CI, 1.58-4.01; P < 0.0001; RR at 6 months: 2.48; 95% CI, 1.23-4.99; P = 0.01). There were no significant differences in local progression and overall survival. Adverse events were similar, except for any grade radiation dermatitis, which was significantly lower in SBRT arm (RR 0.17, 95% CI 0.03-0.96, P = 0.04).

CONCLUSION

SBRT is a safe treatment option for spine metastases. It may provide better complete pain response compared to cEBRT. Additional trials are needed to determine the potential benefits of SBRT in specific patient subsets.

Considerations on surgery invasiveness and response and toxicity patterns in classic palliative radiotherapy for acrometastases of the hand: a hint for a potential role of stereotactic body radiation therapy? A case report and literature review

Background

The rarity of hand acrometastases hampers the consensus-building for their optimal management among the involved oncology professionals. In the current literature, demolitive surgery overcomes the use of palliative radiotherapy, which proved to be ineffective in more than 30% of cases treated with classic palliative dose schemes, carrying also a not negligible radiation-related adverse event rate. Against this background, stereotactic body radiation therapy (SBRT) could emerge as a well-balanced therapeutic option.

Case summary

Here we describe the methods and outcomes of a SBRT treatment of a painful and function-limiting hand acrometastasis in a patient with a history of stage IIIB lung adenocarcinoma. We delivered a total dose of 30 Gy in five daily fractions to a soft-tissue metastasis abutting the fifth metacarpal bone through the SBRT protocol generally used for intracranial treatments. A few weeks later, the patient reported a clinical complete response with acrometastasis and pain disappearance, function recovery, and no significant toxicity. The acrometastasis was the first sign of an atypical cancer progression.

Conclusions

SBRT for hand acrometastases is feasible and might have the best therapeutic profile among the currently available treatment options for this rare clinical scenario. Larger investigations are needed to confirm the present single-case experience.