Criteria of Pain Response to Radiotherapy in Advanced Cancer Patients

Abstract

External radiotherapy is the treatment of choice for metastatic localized bone pain without adequate response to analgesic drugs. 1 Previous clinical studies that measure analgesic response to radiation therapy in advanced cancer patients accepted both an improvement in the intensity of pain or a reduction in the dose of analgesic drugs (morphine equivalent) as response criteria. 2 Recently, we developed a prospective study in advanced cancer patients with painful bone metastases: 29 palliative radiotherapy treatments were administered to 25 patients to alleviate malignant bone pain secondary to clinically evident bone metastases. Four episodes were not included in the analysis because three patients died and one developed symptomatic brain metastases before evaluation. Pain intensity was measured on a scale of 0 (no pain) to 10 (maximum pain). We found a reduction of 3.5 points (95% confidence interval [CI]: 2.5 to 4.8; P Ͻ 0.001, Wilcoxon test) in median pain intensity after radiotherapy. However, this pain reduction was associated only to a slight decrease of 6.0 mg (95% CI: Ϫ 12.0 to 30.0; P ϭ 0.53, Wilcoxon test) in median daily dose of oral morphine equivalent. In only two episodes (8%), the threshold of significant dose reduction of 50% or more in opioid consumption was exceeded; in both of them a parallel reduction of basal pain was achieved as well. No significant differences were observed in the proportion of patients receiving nonsteroidal anti-inflammatory drugs or adjuvant analgesics before and after radiotherapy (Table 1).Palliative radiotherapy for painful bone metastases decreases pain intensity 3 but, according to our data, does not reduce overall analgesic needs in advanced cancer patients. We suppose that overwhelming progressing disease in advanced cancer patients does not allow a reduction in analgesic therapy even when an adequate local bone pain control is achieved with palliative radiotherapy. Thus, decrease in opioid intake is not a good independent criteria of response to palliative radiotherapy for bone metastases related pain in advanced cancer patients.

Scoring the effect of radiotherapy for painful bone metastases

“…Thus, this integrated score may be helpful in quantifying the general clinical effect in time. Analyzing data from a previous report, for example, and using the EAS score, a clear improvement from 21 (7×3) to 8.4 (3.5×2.4) would be evident, although these data are only presumed and simulated because only changes from basal values and not raw data were reported [11]. From a recent report, morphine doses were doubled 1 week after radiotherapy.…”

Managing Breakthrough Pain

“…The Alberta Breakthrough Pain Assessment Tool recently has been developed and used in research settings, but it has not yet been validated for use in clinical practice [10]. A comprehensive pain assessment including frequency and duration of each episode, intensity, precipitating factors, previous and current pain treatments for baseline (persistent) pain, and their effectiveness is recommended.…”

“…Radiotherapy, radionuclides, and bisphosphonates have been reported to reduce pain and the occurrence of fracture, as well as the development of new osteolytic lesions, and, as a consequence, to improve the quality of life [8][9][10][11][12]. In observational studies, a reduction in intensity of pain at rest and in movementrelated pain after treatment with up to six infusions of zoledronate, 4 mg every 28 days, or infusion of a single dose of samarium, 1.0 mCi/kg [11,13].…”