Palliation of bone metastases: a survey of patterns of practice among Canadian radiation oncologists

Review of patterns of practice and patients’ preferences in the treatment of bone metastases with palliative radiotherapy

INTRODUCTION

Since the 1980s, randomized clinical trials showed that single fraction radiotherapy (RT) provided equal pain relief as multiple fractions of RT in the treatment of bone metastases.

MATERIALS AND METHODS

Using Medline, a literature search was conducted on patterns of practice among radiation oncologists and patients' preferences of dose fractionations for the treatment of bone metastases.

RESULTS AND DISCUSSION

Fifteen studies on international patterns of practice published between 1966 and May 2006 were identified. Surveys of Canadian radiation oncologists indicated approximately 85% preferred multiple fractions, most often as 20 Gray in five fractions (20 Gy/5). Surveys in the United States indicated that 30 Gy/10 was most commonly used, and 90-100% of these oncologists preferred multiple over single fraction RT. Multiple fractions were most commonly used in the United Kingdom, Western Europe, Australia and New Zealand, and India; however, more radiation oncologists in these countries would prescribe a single fraction than in North America. Three studies investigated patients' preferences of dose fractionations. In the Australian study, most patients favored single fraction RT as long as long-term outcomes were not compromised. Durability of pain relief was considered more important than short-term convenience factors. In the Singapore study, 85% of patients would choose extended courses of RT (24 Gy/6) compared to a single 8 Gy. In the Canadian study, most patients (76%) would choose a single 8 Gy over 20 Gy/5 of palliative RT due to greater convenience.

CONCLUSION

Despite strong evidence supporting the use of single fraction RT, current practices and preferences favor multiple fractions for the treatment of bone metastases. This has significant implications for the overall quality of life, RT department workload, costs to healthcare systems, and patient convenience.

Advancing prostate cancer: treatment options for the urologist

Today's urologists often face the dilemma of how to treat patients who have advancing prostate cancer. The diversity of this patient population makes treatment decisions challenging. For over 60 years the mainstay of treatment for patients who have advancing prostate cancer has been androgen deprivation therapy. Now there are new chemotherapeutic options, novel hormone manipulations, and other adjunctive therapies available. Based on a case presentation, the authors have attempted to outline for the practicing urologist, a logical progression of treatment options for advancing prostate cancer.

Radiation Therapy and Radio-nuclides for Palliation of Bone Pain

Bone pain from metastatic prostate cancer can be effectively palliated by a single fraction of 8 Gy with no increase in toxicity, which can occur with more protracted fractionation schemes. Re-treatment, if required, is simple and effective. For multiple painful sites on the same side of the diaphragm, hemi-body radiotherapy is rapidly effective; pre-medication with odanstetron and steroids has markedly improved tolerance. For multiple painful sites on both sides of the diaphragm, radiopharmaceuticals can be considered but will not treat adjacent soft tissue disease or neurologic compromise.

In vitro evaluation of no carrier added, carrier added and cross-complexed [90Y]-EDTMP provides evidence for a novel “foreign carrier theory”

The present study focused on the preparation of novel bone tracers containing yttrium as radionuclide or carrier. Moreover, these preparations were comparatively evaluated in vitro on the basis of a recently presented pre vivo model comprising binding studies on synthetic and human bone powder. It was shown that among the therapeutic radionuclides, no carrier added [(90)Y]-EDTMP exceeded [(188)Re]-EDTMP while yielding lower binding values than [(153)Sm]-EDTMP. Furthermore, the authors investigated the influence of "foreign" carriers added to [(90)Y]-EDTMP, [(99m)Tc]-EDTMP and [(111)In]-EDTMP by the method of cross-complexation. The findings reveal a new paradigm: a carrier more foreign to the complexed radionuclide causes a higher binding increase on human bone matrices in vitro than a more "related" carrier.

Factors Influencing the Use of Single vs Multiple Fractions of Palliative Radiotherapy for Bone Metastases: A 5-Year Review

AIMS

Evidence from a number of randomised trials and meta-analyses supports the use of single-fraction radiotherapy for the palliation of painful bone metastases. This study explores patient and treatment factors that influence the choice of single compared with multiple-fraction radiotherapy for the treatment of bone metastases in clinical practice.

MATERIALS AND METHODS

The Princess Margaret Hospital Palliative Radiation Oncology Program Database served as the basis for our report. All courses of treatment delivered for bone metastases were extracted. Courses were classified into single or multiple fractions. Clinical characteristics were compared between the two groups.

RESULTS

Between 1998 and 2002, 882 courses of radiotherapy were delivered for the treatment of bone metastases, of which 283 (32%) were a single fraction. The proportion of single-fraction treatments was 37% in 1998, 30% in 1999 and 43% in 2000, but dropped to 26% and 28% in 2001 and 2002, respectively (P = 0.02). Patients treated with single fractions were significantly older (68 +/- 12 years vs 64 +/- 12 years), and had more weight loss and poor performance status. Single fractions included 20% of treatments in palliative irradiation of the spine, 36% in the pelvis and long bones, and 59% in the chest wall (P < 0.001). There was no significant difference in patients' gender, primary cancers, number of metastatic sites, treating physicians, enrollment in a clinical trial and general radiotherapy waiting time in our department. Multivariate analysis indicated age (P = 0.001), performance status (P < 0.001), anatomical site (P < 0.001) and year of radiotherapy (P = 0.006) as significant.

CONCLUSION

One-third of palliative radiotherapy courses for bone metastases in our programme were given as single fractions. Performance status, age and anatomical site were significant factors affecting single compared with multiple fractionation. The variation in the use of single fractions over time may reflect the dynamic process of interpretation and application of evidence from clinical trials to practice.

Synergistic cytotoxic effects of zoledronic acid and radiation in human prostate cancer and myeloma cell lines

PURPOSE

The clinical use of the potent bisphosphonate zoledronic acid has increased recently, especially for the treatment of bone metastases. Synergistic effects with chemotherapeutic agents (e.g., doxorubicin, paclitaxel) have been shown. It is not known whether similar synergistic effects exist with radiation.

METHODS AND MATERIALS

IM-9 myeloma cells and C4-2 prostate cancer cells were treated with up to 200 microM concentrations of zoledronic acid, irradiated with single doses of up to 1,000 cGy, or exposed to combinations of both treatments. Cell viability was then determined via yellow dye 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide assay and the affected fractions analyzed using the median effect principal, a method developed and validated by Chou and Talalay.

RESULTS

A statistically significant synergistic cytotoxic effect of the combination of zoledronic acid and radiation was documented. The extent of the effect was cell type-dependent, with the C4-2 cells showing a greater synergistic effect than the IM-9 cells.

CONCLUSIONS

The combined use of zoledronic acid and radiotherapy shows enhanced in vitro cytotoxicity for two human prostate and myeloma cancer cell lines over that expected for a simple additive effect from each treatment alone. A clinical trial is under way to test this combination therapy.

Radiotherapy fractionation for the palliation of uncomplicated painful bone metastases - an evidence-based practice guideline

BACKGROUND

This practice guideline was developed to provide recommendations to clinicians in Ontario on the preferred standard radiotherapy fractionation schedule for the treatment of painful bone metastases.

METHODS

A systematic review and meta-analysis was performed and published elsewhere. The Supportive Care Guidelines Group, a multidisciplinary guideline development panel, formulated clinical recommendations based on their interpretation of the evidence. In addition to evidence from clinical trials, the panel also considered patient convenience and ease of administration of palliative radiotherapy. External review of the draft report by Ontario practitioners was obtained through a mailed survey, and final approval was obtained from the Practice Guidelines Coordinating Committee.

RESULTS

Meta-analysis did not detect a significant difference in complete or overall pain relief between single treatment and multifraction palliative radiotherapy for bone metastases. Fifty-nine Ontario practitioners responded to the mailed survey (return rate 62%). Forty-two percent also returned written comments. Eighty-three percent of respondents agreed with the interpretation of the evidence and 75% agreed that the report should be approved as a practice guideline. Minor revisions were made based on feedback from the external reviewers and the Practice Guidelines Coordinating Committee. The Practice Guidelines Coordinating Committee approved the final practice guideline report.

CONCLUSION

For adult patients with single or multiple radiographically confirmed bone metastases of any histology corresponding to painful areas in previously non-irradiated areas without pathologic fractures or spinal cord/cauda equine compression, we conclude that: Where the treatment objective is pain relief, a single 8 Gy treatment, prescribed to the appropriate target volume, is recommended as the standard dose-fractionation schedule for the treatment of symptomatic and uncomplicated bone metastases. Several factors frequently considered in clinical practice when applying this evidence such as the effect of primary histology, anatomical site of treatment, risk of pathological fracture, soft tissue disease and cord compression, use of antiemetics, and the role of retreatment are discussed as qualifying statements.Our systematic review and meta-analysis provided high quality evidence for the key recommendation in this clinical practice guideline. Qualifying statements addressing factors that should be considered when applying this recommendation in clinical practice facilitate its clinical application. The rigorous development and approval process result in a final document that is strongly endorsed by practitioners as a practice guideline.

Palliation of metastatic bone pain: single fraction versus multifraction radiotherapy--a systematic review of randomised trials

Recent randomised studies have reported that single fraction radiotherapy is as effective as multifraction radiotherapy in relieving pain caused by bone metastasis. However, there are concerns about the higher re-treatment rates and the efficacy of preventing future complications, such as pathological fracture and spinal cord compression, by single fraction radiotherapy. A systematic review of randomised studies, examining the effectiveness of single fraction radiotherapy versus multiple fraction radiotherapy for metastatic bone pain relief and prevention of bone complications, was conducted to help answer this controversy. Randomised studies comparing single fraction radiotherapy with multifraction radiotherapy on metastatic bone pain were identified. The analyses were performed using intention-to-treat principle. The results were pooled using meta-analysis to estimate the effect of treatment on pain response, re-treatment rate, pathological fracture rate and spinal cord compression rate. Twelve trials involving 3621 sites were included in the meta-analysis. The overall pain-response rates for single fraction radiotherapy and multifraction radiotherapy were 60% (1080/1814) and 59% (1060/1807), respectively, giving an odds ratio (OR) of 1.03 (95% confidence interval [CI] 0.90-1.19), indicating no difference between the two radiotherapy schedules. There was also no difference in complete pain response rates for single fraction radiotherapy (34% [508/1476]) and multifraction radiotherapy (32% [475/1473]), with an OR of 1.10 (950% CI 0.94-1.30). Patients treated by single fraction radiotherapy had a higher re-treatment rate, with 21.5% (267/1240) requiring re-treatment compared with 7.4% (91/1236) of patients in the multifraction radiotherapy arm (OR 3.44 [95% CI 2.67-4.43]). The pathological fracture rate was also higher in single fraction radiotherapy arm patients. Three per cent (37/1240) of patients treated by single fraction radiotherapy developed pathological fracture compared with 1.6% (20/1236) for those treated by multifraction radiotherapy (OR 1.82 [95% CI 1.06-3.11]). The spinal cord compression rates were similar for both arms (OR 1.41 [95% CI 0.72-2.75]). Single fraction radiotherapy was as effective as multifraction radiotherapy in relieving metastatic bone pain. However, the re-treatment rate and pathological fracture rate were higher after single fraction radiotherapy. Studies with quality of life and health economic end points are warranted to find out the optimal treatment option.

Society of Urologic Oncology position statement: Redefining the management of hormone-refractory prostate carcinoma

Because patients with hormone-refractory prostate carcinoma are a very diverse group, management of these patients represents a unique challenge. Despite much research, to the authors' knowledge few studies published to date have provided definitive treatment answers. The Society of Urologic Oncology (SUO) convened a multidisciplinary panel of urologists, oncologists, and radiation oncologists to develop a treatment algorithm for patients with hormone-refractory prostate carcinoma. The resulting treatment outline was based on a review of the literature review and on the expert opinions of the panelists. The current article provided a logical progression of treatment choices that included hormonal manipulations, chemotherapeutic options, and adjunctive therapies. Future clinical trials and therapies were also discussed by the authors. Management strategies should be targeted toward the individual patient. Although significant progress has been made in understanding and treating hormone-refractory prostate carcinoma, earlier interventions would be ideal and better therapeutic approaches to prolong survival are necessary.

Palliation of metastatic bone pain: single fraction versus multifraction radiotherapy - a systematic review of the randomised trials

BACKGROUND

Recent randomised studies reported that single fraction radiotherapy was as effective as multifraction radiotherapy in relieving pain due to bone metastasis. However, there are concerns about the higher re-treatment rates and the efficacy of preventing future complications such as pathological fracture and spinal cord compression by single fraction radiotherapy.

OBJECTIVES

To undertake a systematic review and meta-analysis of single fraction radiotherapy versus multifraction radiotherapy for metastatic bone pain relief and prevention of bone complications.

SEARCH STRATEGY

Trials were identified through MEDLINE, EMBASE, Cancerlit, reference lists of relevant articles and conference proceedings. Relevant data was extracted.

SELECTION CRITERIA

Randomised studies comparing single fraction radiotherapy with multifraction radiotherapy on metastatic bone pain

DATA COLLECTION AND ANALYSIS

The analyses were performed using intention-to-treat principle. The results were pooled using meta-analysis to estimate the effect of treatment on pain response, re-treatment rate, pathological fracture rate and spinal cord compression rate.

MAIN RESULTS

Eleven trials that involved 3435 patients were identified. Of 3435 patients, 52 patients were randomised more than once for different painful bone metastasis sites. Altogether, 3487 painful sites were randomised. The trials included patients with painful bone metastases of any primary sites, but were mainly prostate, breast and lung. The overall pain response rates for single fraction radiotherapy and multifraction radiotherapy were 60% (1059/1779) and 59% (1038/1769) respectively, giving an odds ratio of 1.03 (95% confidence interval [CI], 0.89 - 1.19) indicating no difference between the two radiotherapy schedules. There was also no difference in complete pain response rates for single fraction radiotherapy (34% [497/1441]) and multifraction radiotherapy (32% [463/1435]) with an odds ratio of 1.11 (95%CI 0.94-1.30). Patients treated by single fraction radiotherapy had a higher re-treatment rate with 21.5% (267/1240) requiring re-treatment compared to 7.4% (91/1236) of patients in the multifraction radiotherapy arm (odds ratio 3.44 [95%CI 2.67-4.43]). The pathological fracture rate was also higher in single fraction radiotherapy arm patients. Three percent (37/1240) of patients treated by single fraction radiotherapy developed pathological fracture compared to 1.6% (20/1236) for those treated by multifraction radiotherapy (odds ratio 1.82 [95%CI 1.06-3.11]). The spinal cord compression rates were similar for both arms (odds ratio 1.41 [95%CI 0.72-2.75]). Repeated analyses excluding dropout patients gave similar results.

REVIEWERS' CONCLUSIONS

Single fraction radiotherapy was as effective as multifraction radiotherapy in relieving metastatic bone pain. However, the re-treatment rate and pathological fracture rates were higher after single fraction radiotherapy. Studies with quality of life and health economic end points are warranted to find out the optimal treatment option.

Patient preference for radiotherapy fractionation schedule in the palliation of painful bone metastases

PURPOSE

The radiotherapeutic management of painful bone metastases is controversial, with several institutional and national guidelines advocating use of single-fraction radiotherapy. We aimed to determine patient choice of fractionation schedule after involvement in the decision-making process by use of a decision board.

PATIENTS AND METHODS

Advantages and disadvantages of two fractionation schedules (24 Gy in six fractions v 8 Gy in one fraction) used in the randomized Dutch Bone Metastasis Study were discussed with patients using a decision board. Patients were asked to choose a fractionation schedule, to give reasons for their choice, and to indicate level of satisfaction with being involved in decision making.

RESULTS

Sixty-two patients were entered. Eighty-five percent (95% confidence interval, 74% to 93%) chose 24 Gy in six fractions over 8 Gy in one fraction (P <.0005). Variables including age, sex, performance status, tumor type, pain score, and paying class were not significantly related to patient choice. Multiple fractionation was chosen for lower re-treatment rates (92%) and fewer fractures (32%). Single-fraction treatment was chosen for cost (11%) and convenience (89%). Eighty-four percent of patients expressed positive opinions about being involved in the decision-making process.

CONCLUSION

Decision board instruments are feasible and acceptable in an Asian population. The vast majority of patients preferred 24 Gy fractionated radiotherapy compared with a single fraction of 8 Gy. These results indicate the need for further research in this important area and serve to remind both clinicians and national or institutional policy makers of the importance of individual patient preference in treatment decision making.

Meta-analysis of dose-fractionation radiotherapy trials for the palliation of painful bone metastases

PURPOSE

To compare pain relief among various dose-fractionation schedules of localized radiotherapy (RT) in the treatment of painful bone metastases.

METHODS AND MATERIALS

A systematic search for randomized trials of localized RT on bone metastases using different dose fractionations was performed using Medline (1966 to February 2001) and other sources. The primary outcomes of interest were complete and overall pain relief. The studies were divided into three groups: comparisons of doses given as a single fraction, single vs. multiple fractions, and comparisons of doses given as multiple fractions. The complete and overall pain responses for studies comparing single vs. multiple fractions were pooled. Exploratory analyses of the dose-response relationship, using the biologic effective dose (alpha/beta = 10), were performed using results from all three groups of trials.

RESULTS

Two trials comparing single vs. single, eight trials comparing single vs. multiple, and six trials comparing multiple vs. multiple fractions were included. The complete and overall response rates from studies comparing single-fraction RT (median 8 Gy, range 8-10 Gy) against multifraction RT (median 20 Gy in 5 fractions, range 20 Gy in 5 fractions to 30 Gy in 10 fractions) were homogeneous and allowed pooling of data. Of 3260 randomized patients in seven studies, 539 (33.4%) of 1613 and 523 (32.3%) of 1618 patients achieved a complete response after single and multifraction RT, respectively, giving a risk ratio of 1.03 (95% confidence interval 0.94-1.14; p = 0.5). The overall response rate was in favor of single-fraction RT (1011 [62.1%] of 1629) compared with multifraction (958 [58.7%] of 1631; risk ratio 1.05, 95% confidence interval 1.00-1.11, p = 0.04), reaching statistical significance. However, when the analysis was restricted to evaluated patients alone, the overall response rates were similar for single fraction and multifraction RT, at 1011 (72.7%) of 1391 and 958 (72.5%) of 1321, respectively (risk ratio 1.00; p = 0.9). Exploratory analyses by biologic effective dose did not reveal any dose-response relationship among the fractionation schedules used (single 8 Gy to 40 Gy in 15 fractions). Of the other results and observations reported in the trials, only the re-irradiation rates were consistently different between the treatment arms (more frequent re-irradiation in lower dose arms among trials reporting re-irradiation rates).

CONCLUSION

Meta-analysis of reported randomized trials shows no significant difference in complete and overall pain relief between single and multifraction palliative RT for bone metastases. No dose-response relationship could be detected by including data from the multifraction vs. multifraction trials. Additional data are needed to evaluate the role of re-irradiation and the impact of RT on other treatment end points such as quality of life.

National Comprehensive Cancer Network guidelines for the management of prostate cancer

Guidelines for the management of prostate cancer issued by the National Comprehensive Cancer Network provide a basis for rational treatment decisions. These guidelines represent consensus recommendations by a panel of experts that are evidence based and are designated according to the degree of consensus within the expert panel. The initial stratification point is the patient's life expectancy (>5 or <5 years). If life expectancy is >5 years, the recommended intervention is based on clinical stage, prostate-specific antigen (PSA) level, and Gleason score, as well as the presence of symptoms. These assessments establish the patient's risk of recurrence after therapy. Specific initial therapies are then recommended according to whether the risk category is low, intermediate, high, or very high. The guidelines also describe the appropriate use of observation ("watchful waiting") versus active intervention in certain patients. After definitive therapy, patients should be monitored with PSA determinations, digital rectal examination, and bone scans, as outlined in the guidelines. Patients who exhibit increasing PSA levels after prostatectomy are candidates for salvage therapy with androgen ablation, radiotherapy, or observation. If PSA levels begin to increase after radiotherapy, surgery may then be an additional option. Systemic salvage therapy generally consists of androgen ablation; the benefit of total androgen blockade versus initial monotherapy remains controversial. Relapse after initial androgen ablation is treated with an antiandrogen, if none had been administered previously. Patients refractory to further hormonal manipulations are observed or receive palliative therapy, including chemotherapy. The treatment of prostate cancer is complex. Optimal treatment is risk-adapted to the specific characteristics of the cancer and the expected longevity and personal preferences of the patient.

Six gray single dose radiotherapy in the treatment of metastatic bone pain

Bone metastases are observed in approximately 50% of patients with cancer and these are essential to influence the quality of life. As one of the most effective means of therapy for patients with bone metastases, radiotherapy can be applied as fractional and single dose. In this prospective study, we analyzed the pain relief after 6 Gy single dose irradiation in 62 patients with painful bone metastases. This was assessed by an 11-point scale questionnaire. In 88.7% of the treatments response was obtained after the single-dose radiotherapy (37.1% complete response, 51.6% partial response, 11.3% no response). In approximately 53% of the treatments the response initiated within one week. We concluded that a single dose of 6 Gy was very effective in the palliation of painful bone metastases.

Primary treatment endpoint following palliative radiotherapy for painful bone metastases: need for a consensus definition?

OBJECTIVES

To compare and contrast the definitions of primary treatment endpoints in randomized studies of dose-fractionation schedules for treating bone metastases and to identify basic characteristics of treatment endpoint that may require consensus among investigators.

METHODS

Randomized controlled trials (RCTs) of various dose-fractionation schedules for painful bone metastases, published between 1980 and 1999, and on-going trials whose protocols were available, were systematically reviewed based on the following features of the primary treatment endpoint: (i) degree of pain relief; (ii) timing of the pain response assessment; (iii) effect of co-interventions on pain relief; (iv) the reduction of analgesic as a treatment response; and (v) quantification of response duration.

RESULTS

Ten published RCTs (each sampled over 100 patients), plus two current trial protocols were reviewed. Five of the 12 studies defined any reduction in pain score as the primary endpoint. Three trials defined response at pre-determined time points, whereas eight studies attributed pain improvement at any time during follow-up to the effect of radiotherapy. No trial incorporated effect of systemic treatments on response. Only two trials incorporated analgesic scores into the primary endpoint criteria, although several trials reported results of combined pain and analgesic relief. Eight trials reported duration of response. Three provided some estimation of duration with respect to survival: two of them employing actuarial time to pain progression, and one calculated the ratio of pain response to median survival duration (percent net relief). Quality of life was measured in four of 12 studies, as secondary endpoint.

CONCLUSION

Although available data suggest similarity in pain relief among various dose-fractionation schedules, accurate and consistent description of the degree of benefit from radiotherapy is lacking. While pain relief is a consistent primary treatment goal among randomized trials, a consensus on several important features of treatment endpoint is needed in order to establish common grounds for future trials in palliative radiotherapy.

Prospective patient-based assessment of effectiveness of palliative radiotherapy for bone metastases

PURPOSE

The primary objective of this report is to prospectively evaluate pain control provided by palliative radiotherapy for all irradiated patients with bone metastases by using their own assessments.

MATERIALS AND METHODS

A prospective database was set up for all patients referred for palliative radiotherapy for bone metastases. Patients were asked to rate their pain intensity using an 11 categorical point scale (0=lack of pain, 10=worst pain imaginable). Analgesic consumption during the preceding 24 h was recorded and converted into equivalent total daily dose of oral morphine. For those who received radiotherapy, follow-up was conducted via telephone interviews at week 1, 2, 4, 8 and 12 post treatment using the same pain scale and analgesic diary. Radiotherapy outcome was initially assessed by pain score alone. Complete response (CR) was defined as a pain score of 0. Partial response (PR) was defined as a reduction of score > or =2 or a> or =50% reduction of the pre-treatment pain score. We further analyzed outcomes using integrated pain and analgesic scores. Response was defined as either a reduction of pain score > or =2 with at least no increase in analgesics or at least stable pain score with a > or =50% reduction in analgesic intake.

RESULTS

One hundred and five patients were treated with palliative radiotherapy. When response evaluation was by pain score alone, the PR rates at 2, 4, 8 and 12 weeks were 44, 42, 30 and 38%, respectively; while the CR rates were 24, 32, 31 and 29%, respectively. The overall response rate at 12 weeks was 67%. When assessed by the integrated pain and analgesic scores, the response rates were 50, 46, 43 and 43%, respectively.

CONCLUSION

The response rate in our patient population is comparable with those reported in clinical trials. This is important when counselling our patients on the expected effectiveness of radiotherapy outside of clinical trials. Our observations confirm the generalizability of the trials conducted to date. While randomized trials still remain the gold standard of research, observational studies can serve as useful adjuncts to randomized trials to confirm the efficacy and guide the design of new controlled trials.

[Gross tumor volume and clinical target volume in radiotherapy: bone metastasis]

Bone is one of the three most favored sites of solid tumor metastasis. Skeletal metastasis may be identified by four clinical imaging methods: plain film radiography, computed tomography scanning, radioisotope scanning, and magnetic resonance imaging. The dose per fraction, total dose, and anatomic distribution of the radiation (dosimetry) are important factors in determining the efficacy and normal tissue tolerance to radiotherapy. Controversies about fractionation of palliative radiotherapy for bone metastasis are steel ongoing. The most commonly used schedules are a single treatment of 8 Gy, 30 Gy in 10 fractions and 20 Gy in 5 fractions. Treatment volumes and safety margins depend on the location and the extent of the bone metastasis, and are also determined by the symptoms felt by the patient.

Continuing reluctance to use single fractions of radiotherapy for metastatic bone pain: an Australian and New Zealand practice survey and literature review

PURPOSE

To survey Australian and New Zealand (ANZ) radiation oncologists on their preferred fractionation regimens for pain due to bone metastases in the context of similar overseas surveys and the large body of evidence from randomized trials.

METHODS

Delegates to the October 1998 Royal ANZ College of Radiologists Annual Scientific Meeting were asked to state their fractionation for four hypothetical cases viz. local bone pain from metastatic breast, prostate and lung cancer and neuropathic (radicular) pain from metastatic lung cancer. In addition to demographic data, respondents were asked to select reasons for their choices and indicate what factors would influence a change in their recommended fractionation.

RESULTS

Twelve of 32 trainees and 41 of 82 specialists completed the survey, giving an overall response rate of 46%. There was decreasing use of shorter fractionation schedules from lung through prostate to breast cancer with, in particular, single fractions recommended by, respectively, 42, 28 and 15% of respondents for local bone pain (P=0.013). However, the presence of neuropathic pain from metastatic lung cancer led to lower use of single fractions (15%, P=0.0046). There were no statistically significant differences in preferred fractionation with respect to other variables assessed in this survey. The commonest reasons cited for fractionating were desire to minimize recurrent pain and the influence of training, with desire to minimize the risk of neurological progression and optimize tumour regression also important for neuropathic pain. By contrast, use of single fractions was most commonly based upon literature results and patient convenience. Changing from multiple to single fractions was most influenced by poor performance status, while the presence of neurological signs/symptoms had the reverse effect.

CONCLUSIONS

The findings from this ANZ survey largely reflect the results from other surveys performed in the UK, Europe, Canada and USA. Although debate continues in the literature, the continuing preference of radiation oncologists to fractionate for local bone pain is contrary to the 16 randomized trials published to date which give little support for a dose-response relationship above a single 6-8 Gy in this setting. This practice has significant implications for departmental workload, costs to the healthcare system and patient convenience. There is no objective evidence on the influence of fractionation for neuropathic bone pain in the literature at present, although an ANZ randomized trial addressing this problem is under way (TROG 96.05).