Low-dose Involved-field Radiation in the Palliation Of Non-Hodgkin Lymphoma: Predictors of Response and Treatment Failure

Abstract

Purpose/Objective(s)Low-dose involved-field radiation therapy (LD-IFRT) is successful in palliating local sites in patients with advanced indolent non-Hodgkin lymphoma (NHL). We investigated clinical and pathologic factors significant in predicting local response and freedom from further treatment (FFFT) following LD-IFRT for NHL.Materials/MethodsThis was an IRB-approved retrospective review of records. The study cohort consisted of advanced-stage NHL patients treated at a single institution between April, 2004 and September, 2011. LD-IFRT was given as 4 Gy in 2 fractions over two consecutive days. Treatment response and disease control were determined by radiographic studies and/or physical examination.ResultsA total of 187 sites in 127 patients received LD-IFRT. The median age at diagnosis was 54 years. Fifty-four percent of patients were male. Histology of NHL included 66% follicular, 9% CLL, 10%, MALT/marginal zone (MZ), 6% mantle cell, and 8% other. Sites treated included head and neck (HandN) (36%), cutaneous (19%), supradiaphragmatic (non-HandN) (15%), infradiaphragmatic (12%) and pelvic (19%). The median tumor size was 4.0 cm (range, 0.6-35.0 cm). Median follow-up time was 19.1 months (range, 0.03-77.8 months). The complete response (CR), partial response (PR) and overall response rates were 50%, 32%, and 82%, respectively. Median time to CR or PR was 2.3 months. Histology was the only significant predictor of response (CR or PR), with all histologies having a response rate ≥84% except CLL, which had a 52% response rate (p = 0.01). Tumor size, site, age at diagnosis and the use of prior systemic therapy were not associated with response. The median time to local failure leading to re-irradiation or initiation of systemic therapy was not reached. The median time to distant failure requiring irradiation or systemic therapy was 39.1 months. Significantly higher 2-year rates of FFFT (local and/or systemic therapy) were associated with histologies other than CLL/MCL (p = 0.01), no prior systemic therapy (p = 0.01), cutaneous sites (p = 0.03) and having achieved an initial CR or PR (p = 0.03).ConclusionsHigh local response rates were achieved with LD-IFRT across most histologies. Histologies other than CLL/MCL, cutaneous sites, initial response to LD-IFRT and lack of prior systemic therapy were associated with significantly longer freedom from further therapy after LD-IFRT. Purpose/Objective(s)Low-dose involved-field radiation therapy (LD-IFRT) is successful in palliating local sites in patients with advanced indolent non-Hodgkin lymphoma (NHL). We investigated clinical and pathologic factors significant in predicting local response and freedom from further treatment (FFFT) following LD-IFRT for NHL. Low-dose involved-field radiation therapy (LD-IFRT) is successful in palliating local sites in patients with advanced indolent non-Hodgkin lymphoma (NHL). We investigated clinical and pathologic factors significant in predicting local response and freedom from further treatment (FFFT) following LD-IFRT for NHL. Materials/MethodsThis was an IRB-approved retrospective review of records. The study cohort consisted of advanced-stage NHL patients treated at a single institution between April, 2004 and September, 2011. LD-IFRT was given as 4 Gy in 2 fractions over two consecutive days. Treatment response and disease control were determined by radiographic studies and/or physical examination. This was an IRB-approved retrospective review of records. The study cohort consisted of advanced-stage NHL patients treated at a single institution between April, 2004 and September, 2011. LD-IFRT was given as 4 Gy in 2 fractions over two consecutive days. Treatment response and disease control were determined by radiographic studies and/or physical examination. ResultsA total of 187 sites in 127 patients received LD-IFRT. The median age at diagnosis was 54 years. Fifty-four percent of patients were male. Histology of NHL included 66% follicular, 9% CLL, 10%, MALT/marginal zone (MZ), 6% mantle cell, and 8% other. Sites treated included head and neck (HandN) (36%), cutaneous (19%), supradiaphragmatic (non-HandN) (15%), infradiaphragmatic (12%) and pelvic (19%). The median tumor size was 4.0 cm (range, 0.6-35.0 cm). Median follow-up time was 19.1 months (range, 0.03-77.8 months). The complete response (CR), partial response (PR) and overall response rates were 50%, 32%, and 82%, respectively. Median time to CR or PR was 2.3 months. Histology was the only significant predictor of response (CR or PR), with all histologies having a response rate ≥84% except CLL, which had a 52% response rate (p = 0.01). Tumor size, site, age at diagnosis and the use of prior systemic therapy were not associated with response. The median time to local failure leading to re-irradiation or initiation of systemic therapy was not reached. The median time to distant failure requiring irradiation or systemic therapy was 39.1 months. Significantly higher 2-year rates of FFFT (local and/or systemic therapy) were associated with histologies other than CLL/MCL (p = 0.01), no prior systemic therapy (p = 0.01), cutaneous sites (p = 0.03) and having achieved an initial CR or PR (p = 0.03). A total of 187 sites in 127 patients received LD-IFRT. The median age at diagnosis was 54 years. Fifty-four percent of patients were male. Histology of NHL included 66% follicular, 9% CLL, 10%, MALT/marginal zone (MZ), 6% mantle cell, and 8% other. Sites treated included head and neck (HandN) (36%), cutaneous (19%), supradiaphragmatic (non-HandN) (15%), infradiaphragmatic (12%) and pelvic (19%). The median tumor size was 4.0 cm (range, 0.6-35.0 cm). Median follow-up time was 19.1 months (range, 0.03-77.8 months). The complete response (CR), partial response (PR) and overall response rates were 50%, 32%, and 82%, respectively. Median time to CR or PR was 2.3 months. Histology was the only significant predictor of response (CR or PR), with all histologies having a response rate ≥84% except CLL, which had a 52% response rate (p = 0.01). Tumor size, site, age at diagnosis and the use of prior systemic therapy were not associated with response. The median time to local failure leading to re-irradiation or initiation of systemic therapy was not reached. The median time to distant failure requiring irradiation or systemic therapy was 39.1 months. Significantly higher 2-year rates of FFFT (local and/or systemic therapy) were associated with histologies other than CLL/MCL (p = 0.01), no prior systemic therapy (p = 0.01), cutaneous sites (p = 0.03) and having achieved an initial CR or PR (p = 0.03). ConclusionsHigh local response rates were achieved with LD-IFRT across most histologies. Histologies other than CLL/MCL, cutaneous sites, initial response to LD-IFRT and lack of prior systemic therapy were associated with significantly longer freedom from further therapy after LD-IFRT. High local response rates were achieved with LD-IFRT across most histologies. Histologies other than CLL/MCL, cutaneous sites, initial response to LD-IFRT and lack of prior systemic therapy were associated with significantly longer freedom from further therapy after LD-IFRT.