Reporting small bowel dose in cervix cancer high-dose-rate brachytherapy.

Small bowel (SB) is an organ at risk (OAR) that may potentially develop toxicity after radiotherapy for cervix cancer. However, its dose from brachytherapy (BT) is not systematically reported as in other OARs, even with image-guided brachytherapy (IGBT). This study aims to introduce consideration of quantified objectives for SB in BT plan optimization and to evaluate the feasibility of sparing SB while maintaining adequate target coverage. In all, 13 patients were included in this retrospective study. All patients were treated with external beam radiotherapy (EBRT) 45Gy in 25 fractions followed by high dose rate (HDR)-BT boost of 28Gy in 4 fractions using tandem/ring applicator. Magnetic resonance imaging (MRI) and computed tomographic (CT) images were obtained to define the gross tumor volume (GTV), high-risk clinical target volume (HR-CTV) and OARs (rectum, bladder, sigmoid colon, and SB). Treatment plans were generated for each patient using GEC-ESTRO recommendations based on the first CT/MRI. Treatment plans were revised to reduce SB dose when the [Formula: see text] dose to SB was > 5Gy, while maintaining other OAR constraints. For the 7 patients with 2 sets of CT and MRI studies, the interfraction variation of the most exposed SB was analyzed. Plan revisions were done in 6 of 13 cases owing to high [Formula: see text] of SB. An average reduction of 19% in [Formula: see text] was achieved. Meeting SB and other OAR constraints resulted in less than optimal target coverage in 2 patients (D90 of HR-CTV < 77Gyαß10). The highest interfraction variation was observed for SB at 16 ± 59%, as opposed to 28 ± 27% for rectum and 21 ± 16% for bladder. Prospective reporting of SB dose could provide data required to establish a potential correlation with radiation-induced late complication for SB.

Efficacy and Tolerability of Palliative Split-Course Thoracic Chemoradiotherapy for Symptomatic Non-Small Cell Lung Cancer.

INTRODUCTION: To assess the efficacy and tolerability of palliative split-course concurrent thoracic chemoradiotherapy (CRT) in patients with incurable locally advanced and metastatic non-small cell lung cancer. METHODS: All patients with incurable non-small cell lung cancer and symptomatic thoracic disease treated with palliative split-course CRT between March 2006 and February 2013 at a single institution were included in this retrospective study. The primary endpoint was improvement in presenting thoracic symptoms. Secondary endpoints included toxicity, overall survival, and the cumulative incidence of locoregional failure. RESULTS: Fifty-five patients were identified, of whom 89% had distant metastatic disease at the initiation of treatment. The median radiotherapy dose delivered was 40 Gy over 20 fractions. Over 90% of patients were able to complete at least 2 cycles of chemotherapy, and 89% of patients completed the prescribed course of radiotherapy. Forty percent of patients had improvement in all presenting symptoms and 78% experienced improvement in at least 1 symptom. Nine and 2 patients, respectively, experienced grade 1 and 2 esophagitis and 1 patient experienced grade 2 pneumonitis. There were no cases of grade 3 toxicity. With a median follow-up for surviving patients of 4.5 months, the estimated actuarial 6-, 12-, and 24-month overall survival was 56%, 25%, and 13%, respectively. The actuarial 6-, 12-, and 24-month cumulative incidence of locoregional failure was 6%, 14%, and 22%, respectively. DISCUSSION: Split-course CRT allows for early introduction of systemic therapy while providing durable locoregional control with tolerable morbidity and significant improvement in chest symptomatology. This paradigm is a viable model for chest palliation in selected patients with intact performance status.

Patterns-of-failure after helical tomotherapy-based chemoradiotherapy for head and neck cancer: implications for CTV margin, elective nodal dose and bilateral parotid sparing.

OBJECTIVES: There is debate about the optimal clinical target volume (CTV) expansion and prophylactic nodal dose (PND) in head and neck IMRT. We evaluated our patterns-of-failure (POF) after helical tomotherapy-based concurrent chemoradiotherapy (CCRT) to assess the oncologic safety of reducing the CTV, PND, and bilateral parotid sparing (BPS). MATERIALS AND METHODS: All patients with locally advanced squamous cell carcinoma of the head and neck treated with curative intent CCRT between January 2007 and April 2013 at a single institution were included in this retrospective study. Locoregional recurrences (LRR) were overlaid on the treatment plan, and POF was determined relative to planned dose. RESULTS: One hundred and fourteen patients treated with CCRT were evaluated, 74% of whom underwent BPS. The median follow-up for surviving patients was 29.3 months. The 3-year cumulative incidence of locoregional failure, distant metastasis, progression-free and overall survival were 20%, 20%, 56% and 73% respectively. The local failures (n = 12) were either entirely contained within or centered on the original gross tumor volume (GTV), and all but 2 regional recurrences were in GTV. There were no nodal failures in the low-dose or peri-parotid neck (including ipsilateral neck). DISCUSSION: Nearly all LRR were located within the GTV suggesting that minimal-to-zero margin is required for CTV 70. The nodal recurrence pattern suggests the safety of routine bilateral parotid sparing and relatively low biologically equivalent dose (54 Gy in 33fx) to the low-risk neck.

Normal tissue complication probability modeling of acute hematologic toxicity in cervical cancer patients treated with chemoradiotherapy.

PURPOSE: To test the hypothesis that increased pelvic bone marrow (BM) irradiation is associated with increased hematologic toxicity (HT) in cervical cancer patients undergoing chemoradiotherapy and to develop a normal tissue complication probability (NTCP) model for HT. METHODS AND MATERIALS: We tested associations between hematologic nadirs during chemoradiotherapy and the volume of BM receiving≥10 and 20 Gy (V10 and V20) using a previously developed linear regression model. The validation cohort consisted of 44 cervical cancer patients treated with concurrent cisplatin and pelvic radiotherapy. Subsequently, these data were pooled with data from 37 identically treated patients from a previous study, forming a cohort of 81 patients for normal tissue complication probability analysis. Generalized linear modeling was used to test associations between hematologic nadirs and dosimetric parameters, adjusting for body mass index. Receiver operating characteristic curves were used to derive optimal dosimetric planning constraints. RESULTS: In the validation cohort, significant negative correlations were observed between white blood cell count nadir and V10 (regression coefficient (ß)=-0.060, p=0.009) and V20 (ß=-0.044, p=0.010). In the combined cohort, the (adjusted) ß estimates for log (white blood cell) vs. V10 and V20 were as follows: -0.022 (p=0.025) and -0.021 (p=0.002), respectively. Patients with V10≥95% were more likely to experience Grade≥3 leukopenia (68.8% vs. 24.6%, p<0.001) than were patients with V20>76% (57.7% vs. 21.8%, p=0.001). CONCLUSIONS: These findings support the hypothesis that HT increases with increasing pelvic BM volume irradiated. Efforts to maintain V10<95% and V20<76% may reduce HT.

Predictors of competing mortality in advanced head and neck cancer.

PURPOSE Death from noncancer causes (competing mortality) is an important event in head and neck cancer, but studies identifying predictors of this event are lacking. We sought to identify predictors of competing mortality and develop a risk stratification model for competing events. PATIENTS AND METHODS Cohort study of 479 patients with stage III to IV carcinoma of the head and neck diagnosed between August 1993 and November 2004. Patients were treated on consecutive prospective clinical trials involving organ-preserving chemoradiotherapy and surgery. We used multivariable competing risks regression models to analyze factors associated with the cumulative incidence of competing mortality, locoregional and distant failure, and second malignancies as first events. Results Median follow-up was 52 months median for survivors. The 5-year cumulative incidence of competing mortality was 19.6% (95% CI, 15.8 to 23.4). On multivariable analysis, competing mortality was associated with female sex (hazard ratio [HR], 1.72; 95% CI, 1.13 to 2.63), increasing age (HR, 1.30; 95% CI, 1.04 to 1.62), increasing Charlson Comorbidity Index (HR, 1.24; 95% CI, 1.05 to 1.47), decreasing body mass index (HR, 0.33; 95% CI, 0.13 to 0.84), and decreasing distance traveled to the treating center (HR, 0.65; 95% CI, 0.44 to 0.98). Patients with zero, one, two, and > or = three risk factors had 5-year competing mortality of 8.9% (95% CI, 3.0% to 14.8%), 12.4% (95% CI, 7.0% to 17.8%), 22.1% (95% CI, 14.5% to 29.7%), and 39.3% (95% CI, 28.6% to 50.1%), respectively. CONCLUSION Competing mortality in advanced head and neck cancer is associated with several demographic and health status characteristics. Analyses of risk factors for competing mortality may be useful in outcomes reporting and designing clinical trials.