Faculty Bibliography

Background: Combined chemoradiotherapy (CRT) has been successful in both tumor eradication and colostomy prevention in patients with squamous-cell carcinoma of the anal canal. Unfortunately, CRT can be toxic with high rates of acute gastrointestinal and skin toxicity. This can necessitate treatment interruptions, prolonging therapy, possibly leading to loss of local control. In RTOG 0529, intensity modulated radiation therapy (IMRT) decreased the rate of treatment interruption compared to historical controls. We aim to compare toxicity and outcomes in patients treated with CRT based on radiation technique. Methods: We retrospectively reviewed 107 consecutive patients, 39 HIV+, 68 HIV-, who underwent definitive CRT for anal cancer at a single institution between 2004 and 2013. Overall survival (OS), colostomy-free survival (CFS), local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) were analyzed. Chi-square test was used to compare frequencies and t-test was used to compare means. Kaplan-Meier survival was calculated and differences were evaluated by Log-rank statistic. Results: Median follow-up was 15 months. Radiation technique was IMRT in 60% of patients with the remainder treated with 3-dimensional conformal radiation therapy (3D). Dose to the draining lymph nodes was higher in patients treated with IMRT (mean dose 40 Gy vs. 32 Gy, p < 0.001). Fewer patients had a greater than 10 day treatment break in IMRT cohort than the 3D cohort (21% vs. 43%, p = 0.028). Three-year OS (91% vs. 47%, p < 0.001) and DMFS (88% vs 64%, p= 0.033) were improved in patients treated with IMRT. There was no significant difference in acute GI or skin toxicity. There was no difference in stage, number of chemotherapy cycles and dose reductions, growth factor support, transfusion necessity, hospital admission, LRFS, sphincter function preservation, or CFS. Conclusions: In this cohort, patients treated with IMRT had better OS and DMFS than patients treated with 3D. Higher radiation doses to the draining lymph nodes and fewer prolonged treatment breaks may contribute to improved outcomes in patients treated with IMRT. Further studies are necessary to establish the etiology of this difference in outcomes

INTRODUCTION: Evaluate use of novel multi-channel applicator (MC) Capri to improve vaginal disease coverage achievable by single-channel applicator (SC) and comparable to Syed plan simulation. MATERIALS AND METHODS: Twenty-eight plans were evaluated from four patients with primary or recurrent gynecologic cancer in the vagina. Each received whole pelvis radiation, followed by three weekly treatments using HDR brachytherapy with a 13-channel MC. Upper vagina was treated to 5 mm depth to 1500 cGy/3 fractions with a simultaneous integrated boost totaling 2100 cGy/3 fractions to tumor. Modeling of SC and Syed plans was performed using MC scans for each patient. Dosimetry for MC and SC plans was evaluated for PTV700 cGy coverage, maximum dose to 2 cm(3) to bladder, rectum, as well as mucosal surface points. Dosimetry for Syed plans was calculated for PTV700 cGy coverage. Patients were followed for treatment response and toxicity. RESULTS: Dosimetric analysis between MC and SC plans demonstrated increased tumor coverage (PTV700 cGy), with decreased rectal, bladder, and contralateral vaginal mucosa dose in favor of MC. These differences were significant (p < 0.05). Comparison of MC and Syed plans demonstrated increased tumor coverage in favor of Syed plans which were not significant (p = 0.71). Patients treated with MC had no cancer recurrence or >/=grade 3 toxicity. CONCLUSION: Use of MC was efficacious and safe, providing superior coverage of tumor volumes