Predictors of Hematologic Toxicity and Chemotherapy Dose Intensity in Patients Undergoing Chemoradiation for Pancreatic Cancer.

OBJECTIVES: Intensity-modulated radiation therapy (IMRT) has been shown to decrease abdominal toxicity in patients undergoing chemoradiation (CRT) for pancreatic cancer. We evaluated whether IMRT impacts the rates of hematologic toxicity and chemotherapy dose intensity in patients undergoing CRT. METHODS: We retrospectively reviewed patients with borderline resectable or locally advanced pancreatic cancer undergoing CRT between 2006 and 2012. Exclusion criteria included receipt of non-gemcitabine therapy, chemotherapy before CRT, or abnormal baseline hematologic indices. Endpoints included total gemcitabine dose received, dose intensity, unplanned dose reductions, and hematologic toxicity (WBC, ANC, platelet, and hemoglobin). Patient/treatment factors were evaluated for their relationship to the above endpoints during CRT and within the first 3 months post-CRT. Statistical analysis was performed using the Fisher exact test and regression models. Because of the multiple comparisons in the presented analysis, a false discovery rate adjustment was performed at the 5% false discovery rate level. RESULTS: Eighty-five patients met the inclusion criteria. Fifty-eight (68.2%) patients received treatment with IMRT, and 27 (31.8%) patients were treated with 3D-conformal radiation. During CRT, there was no relationship between radiation technique and gemcitabine dose received, dose intensity, or hematologic grade 3+ toxicity. Post-CRT, there was no relationship between radiation technique and total gemcitabine dose received, dose intensity, or dose reduction. Patients receiving IMRT were more likely to have ANC grade 3+ toxicity (P=0.007) post-CRT, although this was no longer statistically significant after correction. There were no other relationships between treatment technique and hematologic toxicity. CONCLUSIONS: IMRT technique may be associated with higher hematologic toxicity in patients undergoing CRT for pancreatic cancer. Given the expanding use of CRT, additional study is needed to identify the impact of IMRT on myelosuppression in these patients.

Dosimetric predictors of hematologic toxicity in patients undergoing concurrent gemcitabine-based chemoradiation for localized pancreatic cancer.

PURPOSE: This study was undertaken to identify parameters associated with hematologic toxicity or chemotherapy dose modification in patients undergoing concurrent chemoradiation (CRT) with gemcitabine for localized pancreatic cancer. METHODS AND MATERIALS: We reviewed patients with localized pancreatic cancer undergoing CRT between 2006 and 2012. Exclusion criteria included receipt of nongemcitabine therapy, chemotherapy before CRT, or abnormal baseline hematologic indices. The T11-L3 vertebrae were contoured as bone marrow region at risk. Linear and logistic regression models were used to test associations between dosimetric parameters and gemcitabine dose modification or hematologic toxicity during or within 3 months following CRT. Receiver operator curves were generated to identify threshold doses for hematologic toxicity. RESULTS: Forty-nine patients were included. During CRT, the maximum thoracolumbar dose was associated with grade 2+ neutropenia during CRT (P = .017) and the volume receiving 5 Gy (V5) was associated with grade 2+ leukopenia (P = .041). Post-CRT, thoracolumbar mean dose (P = .015), V5 (P = .01), and V10 (P = .012) were associated with increased grade 2+ neutropenia. On multivariable analysis, the thoracolumbar maximum dose (P = .045) and V5 (P = .045) were associated with grade 2+ neutropenia and grade 2+ leukopenia during CRT, respectively. Post-CRT, the mean dose (P = .046), V5 (P = .019), and V10 (P = .037) were associated with increased grade 2+ neutropenia. A maximum dose of 48.02 Gy and V5 of 57.6% were identified as predictors of toxicity during CRT. A V5 of 56.6%, V10 of 47.05%, and mean dose of 11.67 Gy were identified as predictors of post-CRT hematologic toxicity. Post-CRT, there was a trend toward increased dose modifications with increased V5 (P = .065). CONCLUSIONS: In our dataset, the thoracolumbar mean dose, maximum dose, V5, and V10 correlated with hematologic toxicity during CRT and post-CRT in patients with localized pancreatic cancer. Because of the high rates of distant failure and importance of systemic therapy in these patients, this may be an important consideration during treatment planning.

Peripheral T-cell lymphomas: a review of current approaches and hopes for the future.

Peripheral T-cell lymphomas (PTCL) are a diverse group of lymphoproliferative disorders, which share a common denominator of overall poor prognosis, with few exceptions. In this article, the authors review current standard of care approaches for the treatment of PTCLs, the role of stem-cell/bone marrow transplantation, and current developments in novel targeted therapies.