Long-Term Bone Marrow Suppression During Postoperative Chemotherapy in Rectal Cancer Patients After Preoperative Chemoradiation Therapy.

PURPOSE/OBJECTIVE(S): To quantify ensuing bone marrow (BM) suppression during postoperative chemotherapy resulting from preoperative chemoradiation (CRT) therapy for rectal cancer. METHODS AND MATERIALS: We retrospectively evaluated 35 patients treated with preoperative CRT followed by postoperative 5-Fluorouracil and oxaliplatin (OxF) chemotherapy for locally advanced rectal cancer. The pelvic bone marrow (PBM) was divided into ilium (IBM), lower pelvis (LPBM), and lumbosacrum (LSBM). Dose volume histograms (DVH) measured the mean doses and percentage of BM volume receiving between 5-40 Gy (i.e.: PBM-V5, LPBM-V5). The Wilcoxon signed rank tests evaluated the differences in absolute hematologic nadirs during neoadjuvant vs. adjuvant treatment. Logistic regressions evaluated the association between dosimetric parameters and ≥ grade 3 hematologic toxicity (HT3) and hematologic event (HE) defined as ≥ grade 2 HT and a dose reduction in OxF. Receiver Operator Characteristic (ROC) curves were constructed to determine optimal threshold values leading to HT3. RESULTS: During OxF chemotherapy, 40.0% (n=14) and 48% (n=17) of rectal cancer patients experienced HT3 and HE, respectively. On multivariable logistic regression, increasing pelvic mean dose (PMD) and lower pelvis mean dose (LPMD) along with increasing PBM-V (25-40), LPBM-V25, and LPBM-V40 were significantly associated with HT3 and/or HE during postoperative chemotherapy. Exceeding ≥36.6 Gy to the PMD and ≥32.6 Gy to the LPMD strongly correlated with causing HT3 during postoperative chemotherapy. CONCLUSIONS: Neoadjuvant RT for rectal cancer has lasting effects on the pelvic BM, which are demonstrable during adjuvant OxF. Sparing of the BM during preoperative CRT can aid in reducing significant hematologic adverse events and aid in tolerance of postoperative chemotherapy.

Modern induction chemotherapy before chemoradiation for bulky locally-advanced nonsmall cell lung cancer improves survival.

BACKGROUND: We seek to investigate whether carboplatin-based induction chemotherapy before modern day concurrent chemoradiotherapy (CCRT) improves survival in patients with bulky, locally advanced nonsmall cell lung cancer (NSCLC). MATERIALS AND METHODS: This analysis included 105 patients with Stage II and III NSCLC treated with definitive CCRT from 2003 to 2013. All patients underwent definitive treatment with weekly platinum-based doublet chemotherapy delivered concurrently with 60-66 Gy of thoracic radiotherapy. Thirty patients who received induction chemotherapy before CCRT had T4 disease, N3 disease, or gross tumor volume (GTV) of >150 cm 3. These patients were compared to those with unresectable disease who received CCRT alone without induction chemotherapy. Statistical analysis included univariate and multivariate methods. RESULTS: Mean follow-up time was 15.6 months. Patients treated with carboplatin based induction chemotherapy demonstrated prolonged overall survival (28.2 vs. 14.2 months, P = 0.04), progression free survival (12.6 vs. 9.0 months, P = 0.02), and distant metastasis free survival (15.8 vs. 10.1months, P = 0.05) compared to those who received CCRT alone without induction chemotherapy. Univariate analysis revealed older age, larger GTV, and squamous pathology as negative prognostic factors. When controlling for these factors, Cox regression analysis indicated a trend toward significantly improved overall survival in the induction cohort (P = 0.10). CONCLUSION: In patients with large tumors or bulky nodal NSCLC, carboplatin-based induction chemotherapy may be an important addition to definitive CCRT in the modern era. Our findings strongly support further investigation induction chemotherapy in this population.

Modern radiotherapy using image guidance for unresectable non-small cell lung cancer can improve outcomes in patients treated with chemoradiation therapy.

BACKGROUND: To investigate the impact of advances in image-guided radiotherapy (IGRT) on the outcomes of patients with non-small cell lung cancer (NSCLC) treated with chemoradiation therapy (CRT). METHODS: We retrospectively reviewed 91 patients with NSCLC treated with definitive CRT using image guidance with daily orthogonal kilovoltage (kV) imaging compared to standard weekly megavoltage (MV) portal verifications. Kaplan-Meier curves for overall survival and locoregional failure were computed and stratified by image guidance techniques. Log-rank tests were used to compare strata. Cox Proportional Hazards models were used to identify risk factors for worse mortality and locoregional control. RESULTS: Fifty-four percent (n=49) of patients received weekly MV portal imaging, while 46% (n=42) underwent IGRT using daily orthogonal kV imaging. kV IGRT was associated with longer median survival (36.4 months) compared to MV imaging (14.9 months; P=0.01). kV imaging was also marginally associated with lower risk of locoregional failure. Median time to local progression in patients imaged with kV was 21.4 months compared to 10.9 months (P=0.065) for those treated with MV portal imaging. CONCLUSIONS: Daily kV imaging appears to be marginally associated with better survival and disease control when compared to MV imaging. Given the small study size and the numerable factors tested, these finding require additional confirmation.