Predictors of the Predominance of NonIndex Pain After Palliative Radiation Therapy for Painful Tumors.

PURPOSE: Even when index pain (pain caused by the irradiated tumor) is palliated after radiation therapy (RT), patients may not derive the full benefits of RT in the presence of another, more intense pain. In this case-control study with prospectively collected data, we sought to identify predictors of the predominance of nonindex pain after palliative RT. METHODS AND MATERIALS: Brief Pain Inventory data were collected from patients who received RT for painful tumors. The treating radiation oncologists prospectively evaluated the intensity and origin of nonindex pain. Patients were diagnosed with predominance of other pain (POP) if nonindex pain of malignant or unknown origin was present and had a greater worst pain score than the index pain at the 1- or 2-month follow-up. Changes in pain interference from baseline to follow-up were compared between the 2 groups using Mann-Whitney U tests. Using variables that were identified as significant in a multivariable logistic regression analysis, we developed a prediction model for POP. RESULTS: Of the 170 patients who were evaluable at the 2-month follow-up, 24 (14%) were diagnosed with POP. At the 2-month follow-up examination of the patients with POP, none of the items of the pain interference scores were reduced from baseline; in contrast, patients without POP experienced significant reductions in all items. Multivariable analysis using the backward elimination method indicated that age ≤65 years, the presence of nonindex pain of malignant or unknown origin at baseline, and no opioid analgesic use at baseline were significant independent predictors of POP. As the number of the risk factors increased, the proportion of patients with POP increased. CONCLUSIONS: We identified three predictors of POP. For patients likely to have POP, careful follow-up is important, and new palliative RT or analgesics should be used when needed.

Spleen Dose-Volume Parameters as a Predictor of Treatment-related Lymphopenia During Definitive Chemoradiotherapy for Esophageal Cancer.

AIM: Our study sought to identify dosimetric predictors of treatment-related lymphopenia during chemoradiotherapy for esophageal cancer. MATERIALS AND METHODS: Patients with esophageal cancer who had received definitive chemoradiotherapy at our Institution were retrospectively assessed. The absolute volume of the spleen, body, and bone marrow that had received 5, 10, 20, and 30 Gy and the mean splenic dose were recorded. RESULTS: Multivariate linear regression analysis revealed that docetaxel use and spleen dose-volume parameters (V5, V10, V20, V30, and mean splenic dose) were significant independent factors negatively influencing the absolute lymphocyte count at nadir. An increase of 1 Gy in mean splenic dose predicted a 2.9% decrease in nadir absolute lymphocyte count. Univariable logistic regression analysis showed that the mean splenic dose was a significant predictor of grade 4 lymphopenia. None of the body or bone marrow dose-volume parameters significantly predicted lymphopenia. CONCLUSION: Higher spleen dose-volume parameters were associated with severe lymphopenia during chemoradiotherapy.

Improvement in pain interference after palliative radiotherapy for solid and hematologic painful tumors: a secondary analysis of a prospective observational study.

BACKGROUND: We previously demonstrated that patients with painful hematologic tumors were more likely to experience pain response after palliative radiotherapy (RT) than those with painful solid tumors. However, it is unknown whether change in pain interference differs between these two tumor types. In the present study, we carried out a secondary analysis of our previous prospective observational study to investigate this matter. METHODS: From patients undergoing palliative RT to treat painful tumors, Brief Pain Inventory data were collected at the start of RT and at the 1-, 2-, and 3- month follow-ups. The Mann-Whitney U test was used to compare changes in pain interference score from baseline between the two groups. RESULTS: Of the 237 patients, 203 (86%) had solid and 34 (14%) had hematologic index tumors planned to receive RT. At baseline, the groups did not differ significantly in terms of pain score, analgesic use, or pain interference score. At the 1-, 2-, and 3-month follow-ups, the changes in pain interference score from baseline did not differ significantly between the two groups. In both groups, all seven pain interference items, other than sleep in patients with hematologic tumors at the 2-month follow-up, were significantly improved (P < 0.05). CONCLUSIONS: The two groups showed comparable benefit from RT in terms of improvement in pain interference. Patients with tumor-related pain should be offered the option of palliative RT, irrespective of whether the painful tumor is solid or hematologic.

A neuropathic pain component as a predictor of improvement in pain interference after radiotherapy for painful tumors: A secondary analysis of a prospective observational study.

BACKGROUND AND PURPOSE: We previously demonstrated that patients with a tumor-related neuropathic pain component were more likely to experience a pain response after radiotherapy (RT) than those without. It is unknown whether the presence of a neuropathic component also favorably influences pain interference. In a secondary analysis of our previous prospective observational study, we investigated if the presence of a neuropathic component of the index pain caused by the irradiated tumors predicts greater reduction in pain interference. MATERIAL AND METHODS: For patients scheduled for RT for painful tumors, Brief Pain Inventory data were collected at initiation of RT and 1, 2, and 3 months thereafter. Multivariable linear regression analyses were performed to investigate the effects of the presence of a neuropathic component on the changes in pain interference scores (i.e., follow-up minus baseline). We used 10 covariates as potential confounders. RESULTS: Of the 302 analyzable patients, 93 (31%) were diagnosed as having a neuropathic component of the index pain. Multivariable linear regression analyses revealed that all the point estimates of regression coefficients at 1-, 2-, and 3-month follow-up were negative values; some were statistically significant. At 2-month follow-up, patients with a neuropathic component experienced greater reductions in their pain interference scores for walking ability (p = 0.048), normal work (p = 0.021), sleep (p = 0.001), and enjoyment of life (p = 0.010) than those without it. CONCLUSIONS: The presence of a neuropathic pain component predicted a greater reduction in pain interference after RT. Patients with neuropathic tumor-related pain should be offered the option of receiving palliative RT.

Predictors of Pain Palliation After Radiation Therapy for Painful Tumors: A Prospective Observational Study.

PURPOSE: Although radiation therapy (RT) is an important part of treatment for cancer pain, prediction of the patient's pain response remains difficult. We evaluated the characteristics of patients, their tumors, and their pain to identify the predictors of pain palliation after RT for painful tumors. METHODS: Our 3-center prospective observational study included patients scheduled for palliative or curative RT for painful tumors. Brief Pain Inventory data were collected at the start of RT and 1, 2, and 3 months thereafter. The pain response was assessed using the International Consensus Endpoint. The Mann-Whitney U-test was used to compare responders and nonresponders based on changes in the BPI scores. Predictors of the pain response were evaluated using the Fine-Gray model, in which death without a pain response was recorded as a competing risk. The independent variables were 11 a priori selected potential predictors with clinical relevance. RESULTS: Of 302 analyzable patients, 262 (87%) had solid and 40 (13%) had hematologic tumors. The median total radiation dose was 30 Gy (range, 6-70.4 Gy). The pain response rate was 52% for 264 (87%) evaluable patients at 1-, 57% for 228 (75%) such patients at 2-, and 58% for 182 (60%) evaluable patients at 3-month follow-up. At 2-month follow-up, responders experienced a greater decrease in all 7 pain interference subscales of the Brief Pain Inventory compared to nonresponders. Multivariable analysis demonstrated that hematologic tumors (hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.15-2.98), a neuropathic component of the index pain (HR, 1.50; 95% CI, 1.05-2.14), and opioid analgesic use before RT (HR, 0.65; 95% CI, 0.47-0.91) were independent significant predictors of pain response. CONCLUSIONS: Patients with hematologic tumors, a neuropathic component of the index pain, and no treatment with opioid analgesics before RT were more likely to experience pain palliation after RT.

Predictors of acute hematologic toxicity attributable to palliative radiotherapy: Analysis of patient characteristics and bone marrow dose-volume parameters.

PURPOSE: As predictors of hematologic toxicity (HT) after palliative radiotherapy (RT) have been studied insufficiently, we explored predictors of leukopenia, neutropenia, and thrombocytopenia attributable to palliative RT. METHODS: We retrospectively assessed patients with various solid tumors who had received palliative RT at our institution. Excluded from our study were patients who had undergone chemotherapy from one month before to one month after the start of RT. To measure the bone marrow dose, all bones were delineated, and the absolute volume of bone marrow that had received 5, 10, 20, and 30 Gy was recorded. Univariate and multivariate logistic regression analysis was performed to identify variables associated with leukopenia, neutropenia, or thrombocytopenia of grade 2 or higher (HT2+). RESULTS: Of 68 patients, 17 (25%) developed HT2+. Grade ≥ 2 leukopenia developed in 13 patients (19%), neutropenia in 8 (12%), and thrombocytopenia in 6 (9%). Only one patient experienced ≥ grade 3 toxicity. The median baseline and nadir white blood cell count (WBC) was 6.950 and 4.650x109/l, respectively; the absolute neutrophil count (ANC) was 5.236 and 3.307x109/l, respectively, and the platelet count was 249 and 177.5x109/l, respectively. Multivariate analysis revealed that female gender and a lower baseline WBC and ANC were significant independent predictors of HT2+. No bone marrow dose-volume parameter was a significant predictor of HT2+. CONCLUSIONS: Overall, HT was relatively mild. Female gender and lower baseline WBC and ANC may be predictors of HT elicited by palliative RT.