A phase III randomized-controlled, single-blind trial to improve quality of life with stereotactic body radiotherapy for patients with painful bone metastases (ROBOMET)

Modelling radiobiology

Radiotherapy has played an essential role in cancer treatment for over a century, and remains one of the best-studied methods of cancer treatment. Because of its close links with the physical sciences, it has been the subject of extensive quantitative mathematical modelling, but a complete understanding of the mechanisms of radiotherapy has remained elusive. In part this is because of the complexity and range of scales involved in radiotherapy-from physical radiation interactions occurring over nanometres to evolution of patient responses over months and years. This review presents the current status and ongoing research in modelling radiotherapy responses across these scales, including basic physical mechanisms of DNA damage, the immediate biological responses this triggers, and genetic- and patient-level determinants of response. Finally, some of the major challenges in this field and potential avenues for future improvements are also discussed.

Radiosurgery Society Case-Based Guide to Stereotactic Body Radiation Therapy for Challenging Cases of Spinal Metastases

PURPOSE

Spinal stereotactic body radiation therapy (SBRT) has become the standard of care in management of patients with limited sites of metastatic disease, radio-resistant histologies, painful vertebral metastases with long life expectancy and cases of reirradiation. Our case-based guidelines aim to assist radiation oncologists in the appropriate utilization of SBRT for common, yet challenging, cases of spinal metastases.

MATERIALS AND METHODS

Cases were selected to include scenarios of large volume sacral disease with nerve entrapment, medically inoperable disease abutting the thecal sac, and local failure after prior SBRT. Relevant literature was reviewed, and areas requiring further investigation were discussed to offer a framework for evidence-based clinical practice.

RESULTS

Spinal SBRT can be effectively delivered in challenging cases following multidisciplinary discussion by utilizing a methodical approach to patient selection, appropriate dose selection, and adherence to evidence-based dose constraints.

CONCLUSIONS

The Radiosurgery Society's case-based practice review offers guidance to practicing physicians treating technically challenging SBRT candidate patients with spinal metastases.

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.

Practice and principles of stereotactic body radiation therapy for spine and non-spine bone metastases

Radiotherapy is the dominant treatment modality for painful spine and non-spine bone metastases (NSBM). Historically, this was achieved with conventional low dose external beam radiotherapy, however, stereotactic body radiotherapy (SBRT) is increasingly applied for these indications. Meta-analyses and randomized clinical trials have demonstrated improved pain response and more durable tumor control with SBRT for spine metastases. However, in the setting of NSBM, there is limited evidence supporting global adoption and large scale randomized clinical trials are in need. SBRT is technically demanding requiring careful consideration of organ at risk tolerance, and strict adherence to technical requirements including immobilization, simulation, contouring and image-guidance procedures. Additional considerations include follow up practices after SBRT, with appropriate imaging playing a critical role in response assessment. Finally, there is renewed research into promising new technologies that may further refine the use of SBRT in both spinal and NSBM in the years to come.

Interobserver variability in gross tumor volume contouring in non-spine bone metastases

BACKGROUND AND AIM

The optimal imaging test for gross tumor volume (GTV) delineation in non-spine bone metastases has not been defined. The use of stereotactic body radiotherapy (SBRT) requires accurate target delineation. Magnetic resonance imaging (MRI) and/or ¹⁸fludesoxyglucose positron emission tomography (18FDG-PET) allow for better visualization of the extent of bone metastases and optimizes the accuracy of tumor delineation for stereotactic radiotherapy compared to computed tomography (CT) alone. We evaluated the interobserver agreement in GTV of non-spine bone metastases in a single center and compared MRI and/or 18FDG-PET and CT in GTV delineation.

METHODS

Anonymous CT and MRI and/or 18FDG-PET obtained from 10 non-spine bone metastases were analyzed by six radiation oncologists at our center. Images acquired by CT and MRI and/or 18FDG-PET were used to delineate 10 GTVs of non-spine bone metastases in the pelvis, extremities, and skull. The cases showed different characteristics: blastic and lytic metastases, and different primary cancers (lung, breast, prostate, rectum, urothelial, and biliary). In both CT and MRI and/or 18FDG-PET, the GTV volumes were compared. The index of agreement was evaluated according to Landis and Koch protocol.

RESULTS

The GTV volume as defined on MRI was in all cases larger or at least as large as the GTV volume on CT (P=0.25). The median GTV volume on MRI was 3.15 cc (0.027-70.64 cc) compared to 2.8 cc on CT (0.075-77.95 cc). Interobserver variance and standard deviation were lower in CT than MRI (576.3 vs. 722.2 and 24.0 vs. 26.9, respectively). The level of agreement was fair (kappa=0.36) between CT and MRI. The median GTV volume on 18FDG-PET in five patients was 5.8 cc (0.46-64.17 cc), compared to 4.1 cc on CT (0.99-54.2 cc) (P=0.236). Interobserver variance and standard deviation in CT, MRI, and 18FDG-PET were 576.3 versus 722.2 versus 730.5 and 24 versus 26.9 versus 27.0, respectively. The level of agreement was slight (kappa=0.08) between CT and 18FDG-PET.

CONCLUSIONS

Interobserver variance in non-spine bone metastases was equal when MRI and PET were compared to CT. CT was associated with the lowest variance and standard deviation. Compared to CT GTVs, the GTVs rendered from MRI images had fair agreement, while the GTVs rendered from 18FDG-PET had only slight agreement.

RELEVANCE FOR PATIENTS

The delimitation of the treatment volume in non-spine bone metastases with SBRT is important for the results determining its efficacy. It is therefore essential to know the variability and to manage it to achieve the highest quality of treatment.

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

PURPOSE

To compare the efficacy and safety of stereotactic body radiation therapy (SBRT) and conventional external beam radiation therapy (cEBRT) in patients with previously unirradiated painful bone metastases (BM).

METHODS

We searched biomedical databases for eligible randomized trials (RCTs). The outcomes of interest were pain response, local progression, overall survival (OS) and adverse events. We used established tools to assess the quality of the individual trials and certainty of the pooled evidence. We performed meta-analyses using random effects models.

RESULTS

Six RCTs were identified. SBRT improved complete pain response rates at 3 months (OR, 3.38; 95% CI, 1.88-6.07; high certainty), reduced local progression rates (OR, 0.19; 95% CI, 0.06-0.62; high certainty) and increase pain flare rates. There were no differences for other outcomes.

CONCLUSION

Among patients with previously unirradiated painful BM, SBRT significantly improved complete pain response rates at 3 months, delayed local progression and increase pain flare rates.

Quality of Life After Stereotactic Body Radiation Therapy Versus Conventional Radiation Therapy in Patients With Bone Metastases

PURPOSE

Painful bone metastases hamper quality of life (QoL). The aim of this prespecified secondary analysis of the PRESENT trial was to compare change in global QoL, physical functioning, emotional functioning, functional interference, and psychosocial aspects after conventional radiation therapy (cRT) versus stereotactic body RT (SBRT).

METHODS AND MATERIALS

A total of 110 patients were enrolled in the phase 2 randomized controlled VERTICAL trial (NCT02364115) following the "trials within cohorts" design and randomized 1:1 to cRT or SBRT. Patient-reported global QoL, physical functioning, emotional functioning, functional interference, and psychosocial aspects were assessed by the European Organization for Research and Treatment of Cancer QoL Questionnaire (QLQ) Core 15 Palliative Care and QLQ Bone Metastases 22 modules. Changes in QoL domains over time were compared between patients treated with cRT and SBRT using intention-to-treat (ITT) and per-protocol (PP) linear mixed model analysis adjusting for baseline scores. Proportions of patients in the cRT versus SBRT arm reporting a clinically relevant change in QoL within 3 months were compared using a χ² test.

RESULTS

QoL scores had improved over time and were comparable between groups for all domains in both the ITT and PP analyses, except for functional interference and psychological aspects in the ITT. Functional interference scores had improved more after 12 weeks in the cRT arm than in the SBRT arm (25.5 vs 14.1 points, respectively; effect size [ES] = 0.49, P = .04). Psychosocial aspects scores had improved more after 8 weeks in the cRT arm than in the SBRT arm (12.2 vs 7.3; ES = 0.56, P = .04). No clinically relevant differences between groups at 12 weeks in terms of global QoL, physical functioning, emotional functioning, functional interference, and psychosocial aspects were observed.

CONCLUSIONS

Palliative RT improves QoL. Both SBRT and cRT have a comparable effect on patient-reported QoL outcomes in patients with painful bone metastases. Functional interference and psychological aspects scores improved more in patients treated with cRT versus patients offered SBRT.

International Multi-institutional Patterns of Contouring Practice and Clinical Target Volume Recommendations for Stereotactic Body Radiation Therapy for Non-Spine Bone Metastases

PURPOSE

Despite the increasing use of stereotactic body radiation therapy for non-spine bone metastases (NSBM), there is no established standard for target delineation. The objective of this study was to provide consensus recommendations on clinical target volume (CTV) delineation based on international expert contours.

METHODS AND MATERIALS

Eleven cases of NSBM were contoured by 9 international radiation oncologists. For each case, the gross tumor volume was provided on the simulation computed tomography scans with accompanying magnetic resonance imaging. Participants contoured the CTV and completed a clinical survey. Agreement between CTV contours were analyzed with simultaneous truth and performance level estimation using the kappa coefficient and the Dice similarity coefficient (DSC) and summarized to establish contouring recommendations. A direction-dependent analysis was applied to the consensus contours to quantify margins.

RESULTS

All CTV contours were completed. Six participants used a single-dose level, whereas 3 used a 2-dose level simultaneous integrated boost (SIB) technique. For the SIB cases, the largest volume receiving a stereotactic body radiation therapy (SBRT) dose was used for contour analysis. There was substantial agreement between contours across cases with a mean kappa of 0.72 (mean sensitivity 0.85, mean specificity 0.97). The mean DSC value was 0.77 (range, 0.67-0.87). Consensus CTV contouring recommendations were (1) an intraosseous CTV margin of 5 to 10 mm should be strongly considered within contiguous bone; (2) an extraosseous margin of 5 to 10 mm should be strongly considered where there is soft tissue disease or cortical bone disruption; (3) CTVs should be manually cropped to respect anatomic barriers to spread (eg, peritoneal cavity, pleura, uninvolved joint space and cortical bone).

CONCLUSIONS

CTV contouring recommendations for NSBM-SBRT were established based on analysis of international expert consensus contours with a high level of agreement. These principles may provide guidance to treating physicians and inform future study until prospective clinical data can provide further refinement.

Stereotactic Ablative Radiation Therapy to All Lesions in Patients With Oligometastatic Cancers: A Phase 1 Dose-Escalation Trial

PURPOSE

Increasing evidence suggests that patients with a limited number of metastases benefit from SABR to all lesions. However, the optimal dose and fractionation remain unknown. This is particularly true for bone and lymph node metastases. Therefore, a prospective, single-center, dose-escalation trial was initiated.

METHODS

Dose-Escalation trial of STereotactic ablative body RadiOtherapY for non-spine bone and lymph node metastases (DESTROY) was an open-label phase 1 trial evaluating SABR to nonspine bone and lymph node lesions in patients with up to 3 metastases. Patients with European Cooperative Oncology Group performance status ≤1, an estimated life expectancy of at least 6 months, and histologically confirmed nonhematological malignancy were eligible. Three SABR fractionation regimens, ie, 5 fractions of 7.0 Gy versus 3 fractions of 10.0 Gy versus a single fraction of 20.0 Gy, were applied in 3 consecutive patient cohorts. The rate of ≥grade 3 toxicity, scored according to the Common Toxicity Criteria for Adverse Events v. 4.03, up to 6 months after SABR, was the primary endpoint. The trial was registered on clinicaltrials.gov (NCT03486431).

RESULTS

Between July 2017 and December 2018, 90 patients were enrolled. In total 101 metastases were treated. No ≥grade 3 toxicity was observed in any of the enrolled patients (95% CI 0.0%-12.3% for the first cohort with 28 analyzable patients; 95% CI 0.0%-11.6% for the second and third cohort with 30 analyzable patients each). Treatment-related grade 2 toxicities occurred in 4 out of 30 versus 2 out of 30 versus 2 out of 30 patients for the 5, 3 and 1 fraction schedule, respectively. Actuarial local control rate at 12 months was 94.5%.

CONCLUSION

All 3 treatment schedules were feasible and effective with remarkably low toxicity rates and high local control rates. From a patient and resource point of view, the single-fraction schedule is undoubtedly most convenient.

Using a Chinese time trade-off approach to explore the health utility level and quality of life of cancer patients in urban China: a multicentre cross-sectional study

PURPOSE

A quality of life assessment is useful in identifying a specific health impact on patients who are suffering from various medical conditions. This study estimated the quality of life among patients with cancers of the lungs, breast, colorectum, oesophagus, liver, and stomach in urban China and evaluates the associated factors.

METHODS

This study employed a random cluster sampling strategy to recruit patients with lung, breast, colorectal, oesophageal, liver, or stomach cancer from eleven third-grade class-A (the highest level) hospitals in Beijing between October 2013 and May 2014. We performed a quality of life survey that included solicitation of sociodemographic and clinical information and the use of a EuroQoL five-dimension three-level questionnaire. We applied the Chinese time trade-off method to calculate the health utility values, which were transformed into binary variables (using the median as the cut-off). In addition, multivariable logistic regression analysis was used to examine the factors associated with the quality of life.

RESULTS

A total of 637 patients (91 with lung cancer, 152 with breast cancer, 60 with colorectal cancer, 108 with oesophageal cancer, 154 with liver cancer, and 72 with stomach cancer) were included in this study; the medians of the health utility values were 0.780, 0.800, 0.800, 0.860, 0.800, and 0.870, respectively. The most common concerns for patients of all six cancer types were pain/discomfort and anxiety/depression. The reported health status of patients was associated with various demographic and clinical variables.

CONCLUSION

This study highlighted that pain relief and psychological support are important aspects of patient management for those with these types of cancer. Individuals with factors associated with a poorer quality of life should be targets for additional support.

Patient-Reported Outcomes of Oligometastatic Patients After Conventional or Stereotactic Radiation Therapy to Bone Metastases: An Analysis of the PRESENT Cohort

PURPOSE

Stereotactic body radiation therapy (SBRT) has become a widely adopted treatment for patients with oligometastatic disease, despite limited evidence of superiority. We compared pain response and quality of life (QoL) in patients with oligometastatic disease treated with conventionally fractionated 3-dimensional radiation therapy (3DCRT) or SBRT to bone metastases.

METHODS AND MATERIALS

We included patients with oligometastatic disease (≤5 lesions within ≤3 organs) treated within the prospective PRESENT cohort. Main outcomes were pain response, clinical local control, and QoL 2, 4, and 8 weeks and 3, 6, and 12 months after treatment. Pain response was assessed only in patients who reported pain at baseline and was defined according to international consensus criteria.

RESULTS

Of 131 patients with oligometastatic disease, 66 patients were treated with 3DCRT and 65 patients with SBRT. A pain response was achieved in 81% (3DCRT) versus 84% (SBRT) with a median duration of 23 weeks (range, 1-58) and 24 weeks (range, 0-50), respectively. Reirradiation was needed in 33% versus 5% of the patients, respectively. None of the QoL subscales were significantly different between both groups.

CONCLUSIONS

In patients with oligometastatic disease, SBRT to bone metastases did not improve pain response or QoL compared with 3DCRT. Reirradiation was less often needed in the SBRT group.