Patterns of practice in the prescription of palliative radiotherapy for the treatment of bone metastases at the Rapid Response Radiotherapy Program between 2005 and 2012

An Analysis of Clinical and Systemic Factors Associated with Palliative Radiotherapy Delivery and Completion at the End of Life in Alberta, Canada

Radiotherapy (RT) is often utilized for symptom control at the end of life. Palliative RT (pRT) may not be taken to completion by patients, thus decreasing clinical benefits and adversely impacting resource allocation. We determined rates of incomplete pRT and examined predictors of non-completion using an electronic questionnaire. Methods: A questionnaire was embedded within the RT electronic prescribing system for all five cancer centers of Alberta, Canada, between 2017 and 2020. Prescribing radiation oncologists (ROs) were tasked with completing the questionnaire. Treatment variables were collected for 2040 patients prescribed pRT. Details on pRT courses delivered and completed were used to determine rates of incomplete RT. Electronic medical records of a subset of 367 patients randomly selected from the 2040 patients were then analyzed to examine for association of non-completion of RT with patient, disease, and therapy-related factors. Results: Overall, 10% of patients did not complete pRT. The rate of single fractions prescribed as a proportion of all RT fractions increased from 18% (pre-2017: pre-study era) to 29% (2017-2020: study era) (p < 0.0001). After conducting multivariate analysis on the overall group, multiple lifetime malignancies (OR:0.64) or increasing the number of pRT fractions (OR:0.08-0.17) were associated with non-completion. Being selected for stereotactic RT (OR:3.75) or survival > 30 days post-RT prescription (OR:2.20-5.02) were associated with greater rates of RT completion. The ROs' estimates of life expectancy at the time of RT prescription were not predictive of RT completion. In the multivariate analysis of the 367-patient subset, the presence of hepatic metastases (OR 2.59), survival 30-59 days (OR 6.61) and survival 90+ days (OR 8.18) post-RT prescription were associated with pRT completion. Only increasing pRT fractionation (OR:0.05-0.2) was associated with non-completion. Conclusion: One in ten patients prescribed pRT did not complete their treatment course. Decreasing pRT fractionation and improving prognostication in patients near the end of life may decrease rates of incomplete RT courses.

Nanoparticle-mediated synergistic drug combination for treating bone metastasis

Bone metastasis at an advanced disease stage is common in most solid tumors and is untreatable. Overexpression of receptor activator of nuclear factor κB ligand (RANKL) in tumor-bone marrow microenvironment drives a vicious cycle of tumor progression and bone resorption. Biodegradable nanoparticles (NPs), designed to localize in the tumor tissue in bone marrow, were evaluated in a prostate cancer model of bone metastasis. The combination treatment, encapsulating docetaxel, an anticancer drug (TXT-NPs), and Denosumab, a monoclonal antibody that binds to RANKL (DNmb-NPs), administered intravenously regressed the tumor completely, preventing bone resorption, without causing any mortality. With TXT-NPs alone treatment, after an initial regression, the tumor relapsed and acquired resistance, whereas DNmb-NPs alone treatment was ineffective. Only in the combination treatment, RANKL was not detected in the tumor tibia, thus negating its role in tumor progression and bone resorption. The combination treatment was determined to be safe as the vital organ tissue showed no increase in inflammatory cytokine or the liver ALT/AST levels, and animals gained weight. Overall, dual drug treatment acted synergistically to modulate the tumor-bone microenvironment with encapsulation enhancing their therapeutic potency to achieve tumor regression.

Efficacy and safety of CT-guided 125I seed implantation by coplanar template as a salvage therapy for vertebral metastases after failure of external beam radiation therapy: a retrospective study

Purpose

To evaluate the efficacy safety of computed tomography (CT)-guided ¹²⁵I seed implantation by coplanar template for vertebral metastases after failure of external beam radiation therapy (EBRT).

Material and methods

Retrospective analysis of the clinical outcomes of 58 patients with vertebral metastases after failure of EBRT, who underwent ¹²⁵I seed implantation as a salvage treatment with a CT-guided coplanar template-assisted technique from January 2015 to January 2017.

Results

The mean post-operative NRS score decreased significantly at T_4w (3.5 ± 0.9, p<0.01), T_8w (2.1 ± 0.9, p<0.01), T_12w (1.5 ± 0.7, p< 0.01) and T_6m (1.2 ± 0.6, p< 0.01) respectively. The local control rates after 3, 6, 9 and 12 months were 100% (58/58), 93.1% (54/58), 87.9% (51/58), and 81% (47/58), respectively. The median overall survival time was 18.52months (95% CI, 16.24-20.8), and 1- and 2-year survival rates were 81% (47/58) and 34.5% (20/58), respectively. By performing a paired t-test analysis, there was no significant difference in D90, V90, D100, V100, V150, V200, GTV volume, CI, EI and HI between preoperative and postoperative (p>0.05).

Conclusions

¹²⁵I seed implantation can be used as a salvage treatment for patients with vertebral metastases after failure of EBRT.

Prognostic Factors Influencing Survival and a Treatment Pattern Analysis of Conventional Palliative Radiotherapy for Patients with Bone Metastases

BACKGROUND

Treatment indication for bone metastases is influenced by patient prognosis. Single-fraction radiotherapy (SFRT) was proven equally effective as multiple fractionation regimens (MFRT) but continues to be underused.

OBJECTIVE

Primary objectives: (a) to identify prognostic factors for overall survival and (b) to analyze treatment patterns of palliative radiotherapy (proportion of SFRT indication and predictive factors of radiotherapy regimen) for bone metastases.

METHODS

582 patients with bone metastases who underwent conventional radiotherapy between January 1st 2014-31 December 2017 were analyzed. The Cox proportional hazard model was used to identify predictors of overall survival. For the treatment pattern analysis, 677 radiotherapy courses were evaluated. The logistic regression model was used to identify potential predictors of radiotherapy regimen.

RESULTS

The 3-year overall survival was 15%. Prognostic factors associated with poor overall survival were multiple bone metastases [hazard ratio (HR = 5.4)], poor performance status (HR = 1.5) and brain metastases (HR = 1.37). SFRT prescription increased from 41% in 2017 to 51% in 2017. Predictors of SFRT prescription were a poor performance status [odds ratio (OR = 0.55)], lung (OR = 0.49) and urologic primaries (OR = 0.33) and the half-body lower site of irradiation (OR = 0.59). Spinal metastases were more likely to receive MFRT (OR = 2.09).

CONCLUSIONS

Based on the prognostic factors we identified, a selection protocol for patients candidates for palliative radiotherapy to bone metastases could be established, in order to further increase SFRT prescription in our institution.

[Ethical stakes in palliative care in radiation oncology]

In 2021, the Ethics Commission of the SFRO has chosen the issue of the practice of palliative care in radiotherapy oncology. Radiation oncology plays a central role in the care of patients with cancer in palliative phase. But behind the broad name of palliative radiotherapy, we actually find a large variety of situations involving diverse ethical issues. Radiation oncologists have the delicate task to take into account multiple factors throughout a complex decision-making process. While the question of the therapeutic indication and the technical choice allowing it to be implemented remains central, reflection cannot be limited to these decision-making and technical aspects alone. It is also a question of being able to create the conditions for a singularity focused care and to build an authentic care relationship, beyond technicity. It is through this daily ethical work, in close collaboration with patients, and under essential conditions of multidisciplinarity and multiprofessionalism, that our fundamental role as caregiver can be deployed.

Synergistic combination treatment to break cross talk between cancer cells and bone cells to inhibit progression of bone metastasis

Advanced-stage cancers often metastasize to bone, and is the major cause of cancer-related morbidity and mortality. Due to poor biodistribution of intravenously administered anticancer drugs within the bone, chemotherapy is not optimally effective in treating bone metastasis. Additionally, overexpression of receptor activator of nuclear factor κB ligand (RANKL) in the bone microenvironment drives the vicious, destructive cycle of progression of bone metastasis and bone resorption. We hypothesized that the combination treatment - with docetaxel (TXT), an anticancer drug encapsulated in sustained release biodegradable nanoparticles (TXT-NPs) that are designed to localize in bone marrow, and denosumab monoclonal antibody (DNmb), which binds to RANKL - could be more effective than either treatment alone. We tested our hypothesis in intraosseous prostate cancer (PC-3) cell-induced osteolytic mouse model of bone metastasis with treatments given intravenously. The results demonstrated better efficacy with TXT-NPs than with TXT-CrEL or saline control in inhibiting progression of metastasis and improving survival. TXT-NPs showed ~3-fold higher drug levels in metastasized bone tissue at 1 wk post-administration than TXT-CrEL, thus explaining their efficacy. However, the combination treatment (TXT-NPs + DNmb) given simultaneously was significantly more effective in inhibiting metastatic progression; it caused early tumor regression and improved survival, and caused no body weight loss or tumor relapse, even when the treatment was discontinued, whereas TXT-NPs or DNmb alone treatments showed tumor relapse after an initial regression. Micro-CT analysis of the bone from the combination treatment showed no bone loss and normal bone mineral content, bone density, and bone volume fraction, whereas TXT-NPs or DNmb alone treatments showed bone loss. Confirming the above results, histochemical analysis of the bone from the combination treatment demonstrated normal bone morphology, and osteoblast and osteoclast cell activities. In conclusion, TXT-NPs and DNmb in combination, because of their complementary roles in breaking the cross talk between cancer cells and bone cells, was significantly effective in treating bone metastasis.

Are radiation oncologists following guidelines? An audit of practice in patients with uncomplicated bone metastases

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At our center single fraction radiotherapy is used in accordance with guidelines.

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Patient age, performance status and tumor histology influence treatment choice.

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We added a quality indicator to our performance dashboard to improve adherence.

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This strategy can be used in other complex practices and improve quality of care.

Background

Best-practice guidelines recommend single-fraction (SFRT) instead of multi-fraction radiation therapy (MFRT) for uncomplicated symptomatic bone metastases. SFRT is comparable to MFRT in relieving pain, convenient for patients, and cost-effective. Patterns of practice in Canada reveal that SFRT is underused, with significant variability across the country. We audited SFRT use and studied factors that may influence treatment decisions at a large academic tertiary care center in Quebec, Canada.

Methods

Patients who received radiotherapy for uncomplicated bone metastases between February 2014 and March 2015 were reviewed. Age, gender, primary histology, site of metastases and performance status were identified as potential factors affecting fractionation. These were explored by Fisher's test on univariate analysis and logistic regression for multivariate analysis. Retreatment rates were analyzed with cumulative incidence and compared with Gray's test.

Results

254 radiotherapy courses were administered to 165 patients, 85.4% of which were delivered using a single fraction of 8 Gy. Patients age less than 70 years and those with breast histology were more likely to receive MFRT (p = 0.04; p = 0.0046). Performance status (ECOG) was a significant predictor of fractionation because of high correlations between young age, breast histology, and ECOG status (p = 0.03). Follow-up was too short in 40% of patients to derive definitive conclusions on retreatment.

Conclusions

In accordance with current guidelines, our audit confirms that use of SFRT in patients with uncomplicated bone metastases at our center is high. We identified that patient age, primary histology, and performance status influenced fractionation. Incorporation of this quality indicator into our performance dashboard will allow assessment of retreatment differences and other criteria that may also influence treatment choice.

CT-Guided 125I Seed Interstitial Brachytherapy as a Salvage Treatment for Recurrent Spinal Metastases after External Beam Radiotherapy

The aim of this study is to evaluate the feasibility, safety, and clinical efficacy of CT-guided ¹²⁵I seed interstitial brachytherapy in patients with recurrent spinal metastases after external beam radiotherapy (EBRT). Between August 2003 and September 2015, 26 spinal metastatic lesions (24 patients) were reirradiated by this salvage therapy modality. Treatment for all patients was preplanned using a three-dimensional treatment planning system 3-5 days before ¹²⁵I seed interstitial brachytherapy; dosimetry verification was performed immediately after seed implantation. Median actual D₉₀ was 99 Gy (range, 90-176), and spinal cord median D_max was 39 Gy (range, 6-110). Median local control (LC) was 12 months (95% CI: 7.0-17.0). The 6- and 12-month LC rates were 52% and 40%, respectively. Median overall survival (OS) was 11 months (95% CI: 7.7-14.3); 6-month and 1-, 2-, and 3-year OS rates were 65%, 37%, 14%, and 9%, respectively. Pain-free survival ranged from 2 to 42 months (median, 6; 95% CI: 4.6-7.4). Treatment was well-tolerated, with no radiation-induced vertebral compression fractures or myelopathy reported. Reirradiation with CT-guided ¹²⁵I seed interstitial brachytherapy appears to be feasible, safe, and effective as pain relief or salvage treatment for patients with recurrent spinal metastases after EBRT.

Assessment of national practice for palliative radiation therapy for bone metastases suggests marked underutilization of single-fraction regimens in the United States

PURPOSE

To characterize temporal trends in the application of various bone metastasis fractionations within the United States during the past decade, using the National Cancer Data Base; the primary aim was to determine whether clinical practice in the United States has changed over time to reflect the published randomized evidence and the growing movement for value-based treatment decisions.

PATIENTS AND METHODS

The National Cancer Data Base was used to identify patients treated to osseous metastases from breast, prostate, and lung cancer. Utilization of single-fraction versus multiple-fraction radiation therapy was compared according to demographic, disease-related, and health care system details.

RESULTS

We included 24,992 patients treated during the period 2005-2011 for bone metastases. Among patients treated to non-spinal/vertebral sites (n=9011), 4.7% received 8 Gy in 1 fraction, whereas 95.3% received multiple-fraction treatment. Over time the proportion of patients receiving a single fraction of 8 Gy increased (from 3.4% in 2005 to 7.5% in 2011). Numerous independent predictors of single-fraction treatment were identified, including older age, farther travel distance for treatment, academic treatment facility, and non-private health insurance (P<.05).

CONCLUSIONS

Single-fraction palliative radiation therapy regimens are significantly underutilized in current practice in the United States. Further efforts are needed to address this issue, such that evidence-based and cost-conscious care becomes more commonplace.

International patterns of practice in radiotherapy for bone metastases: A review of the literature

PURPOSE

Radiation therapy is the standard treatment for symptomatic bone metastases. Several randomized control trials and meta-analyses have concluded a similar efficacy in pain relief when comparing single versus multiple fraction regimes. However, there continues to be reluctance to conform to published guidelines that recommend a single treatment for the palliation of painful bone metastases. The purpose of this literature review is to summarize international patterns of practice, and to determine if guidelines recommending single fraction treatment have been implemented in clinical care.

METHODS

A literature search was conducted in Ovid Medline, Embase, and Cochrane Central. Search words included, 'bone metastases', 'radiation therapy', 'radiotherapy', 'patterns of practice', and 'dose fractionation'. Both prospective and retrospective studies that investigated the prescription of radiotherapy to bone metastases using actual patient databases were included. Articles were excluded if they investigated hypothetical scenarios.

RESULTS

Six hundred and thirteen results were generated from the literature search. Twenty-six articles met the inclusion criteria. Of these, 11 were Canadian, 8 were European, 6 were American, and 1 was Australian. The use of single fraction radiotherapy (SFRT) ranged from 3% to 75%, but was generally lower in American studies. Choice of fractionation depended on a variety of factors, including patient age, prognosis, site of irradiation, and physician experience.

CONCLUSION

Despite the publication of robust randomized control trials, meta-analyses, and clinical practice guidelines recommending the use of a single treatment to palliate uncomplicated bone metastasis, SFRT is internationally underutilized.

Use of single- versus multiple-fraction palliative radiation therapy for bone metastases: population-based analysis of 16,898 courses in a Canadian province

PURPOSE

There is abundant evidence that a single fraction (SF) of palliative radiation therapy (RT) for bone metastases is equivalent to more protracted and costly multiple fraction courses. Despite this, there is low utilization of SFRT internationally. We sought to determine the utilization of SFRT in a population-based, publicly funded health care system.

METHODS AND MATERIALS

All consecutive patients with bone metastases treated with RT during 2007 to 2011 in British Columbia (BC) were identified. Associations between utilization of SFRT and patient and provider characteristics were investigated.

RESULTS

A total of 16,898 courses of RT were delivered to 8601 patients. SFRT was prescribed 49% of the time. There were positive relationships among SFRT utilization and primary tumor group (P<.001; most commonly in prostate cancer), worse prognosis (P<.001), increasing physician experience (P<.001), site of metastases (P<.001; least for spine metastases), and area of training (P<.001; most commonly for oncologists trained in the United Kingdom). There was wide variation in the prescription of SFRT across 5 regional cancer centers, ranging from 25.5% to 73.4%, which persisted after controlling for other, potentially confounding factors (P<.001).

CONCLUSIONS

The large variability in SFRT utilization across BC Cancer Agency (BCCA) cancer centers suggests there is a strong cultural effect, where physicians' use of SFRT is influenced by their colleagues' practice. SFRT use in BC was similar to that in other Canadian and western European reports but strikingly higher than in the United States. Further work is needed to standardize SFRT prescribing practices internationally for this common indication for RT, with the potential for huge health system cost savings and substantial improvements in patients' quality of life.