Stereotactic body radiation therapy for stage I non-small cell lung cancer: a small academic hospital experience.

PURPOSE/OBJECTIVE(S): Stereotactic body radiation therapy (SBRT) has been shown to have increased local control and overall survival relative to conventional external beam radiation therapy in patients with medically inoperable stage I non-small cell lung cancer (NSCLC). Excellent rates of local control have been demonstrated both in clinical trials and in single-center studies at large academic institutions. However, there is limited data on the experiences of small academic hospitals with SBRT for stage I NSCLC. The purpose of this study is to report the local control and overall survival rates in patients treated with SBRT for stage I NSCLC at Winthrop-University Hospital (WUH), a small academic hospital. MATERIALS/METHODS: This is a retrospective review of 78 stage I central and peripheral NSCLC tumors treated between December 2006 and July 2012 with SBRT at WUH. Treatment was given utilizing fiducials and a respiratory tracking system. If the fiducials were not trackable, a spine tracking system was used for tumor localization. CT-based planning was performed using the ray trace algorithm. Treatment was delivered over consecutive days to a median dose of 4800 cGy delivered in four fractions. The Kaplan-Meier method was used to calculate local control and overall survival. RESULTS: The median age was 78.5 years. Fifty-four percent of the patient population was female. Sixty seven percent of the tumors were stage IA, and 33% of the tumors were stage IB. Fifty-three percent of the tumors were adenocarcinomas and 29% were squamous cell carcinomas, with the remainder being of unknown histology or NSCLC, not otherwise specified The 2-year local control rate was 87%, and the 2-year overall survival was 68%. CONCLUSION: Our findings support that local control and overall survival at a small academic hospital are comparable to that of larger academic institutions' published experiences with SBRT for stage I NSCLC.

Intensity modulated radiation therapy versus three-dimensional conformal radiation therapy for the treatment of high grade glioma: a dosimetric comparison.

The present study compared the dosimetry of intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3D-CRT) techniques in patients treated for high-grade glioma. A total of 20 patients underwent computed tomography treatment planning in conjunction with magnetic resonance imaging fusion. Prescription dose and normal-tissue constraints were identical for the 3D-CRT and IMRT plans. The prescribed dose was 59.4 Gy delivered at 1.8 Gy per fraction using 4-10 MV photons. Normal-tissue dose constraints were 50-54 Gy for the optic chiasm and nerves, and 55-60 Gy for the brainstem. The IMRT plan yielded superior target coverage as compared with the 3D-CRT plan. Specifically, minimum and mean planning target volume cone down doses were 54.52 Gy and 61.74 Gy for IMRT and 50.56 Gy and 60.06 Gy for 3D-CRT (p < or = 0.01). The IMRT plan reduced the percent volume of brainstem receiving a dose greater than 45 Gy by 31% (p = 0.004) and the percent volume of brain receiving a dose greater than 18 Gy, 24 Gy, and 45 Gy by 10% (p = 0.059), 14% (p = 0.015), and 40% (p < or = 0.0001) respectively. With IMRT, the percent volume of optic chiasm receiving more than 45 Gy was also reduced by 30.40% (p = 0.047). As compared with 3D-CRT, IMRT significantly increased the tumor control probability (p < or = 0.005) and lowered the normal-tissue complication probability for brain and brainstem (p < 0.033). Intensity-modulated radiation therapy improved target coverage and reduced radiation dose to the brain, brainstem, and optic chiasm. With the availability of new cancer imaging tools and more effective systemic agents, IMRT may be used to intensify tumor doses while minimizing toxicity, therefore potentially improving outcomes in patients with high-grade glioma.

Rate of pathologic complete response with increased interval between preoperative combined modality therapy and rectal cancer resection.

INTRODUCTION: Recent data suggest a favorable prognosis for rectal cancer patients with a pathologic complete response to preoperative combined modality therapy. Prolongation of the interval between preoperative combined modality therapy and surgery (RT-surgery interval) as a means of increasing pathologic complete response rate has not been fully examined. METHODS: One hundred and fifty-five rectal cancer patients undergoing preoperative pelvic external beam radiation therapy and 5-fluorouracil-based chemotherapy followed by rectal resection were identified. All patients had endorectal ultrasound prior to combined modality therapy. Final pathology reports were reviewed for ypT and ypN stage and margin status. Medical records were reviewed for sphincter preservation, operative time, estimated blood loss, hospital stay, and morbidity (overall, anastomotic, and perineal). RESULTS: A pathologic complete response (ypT0N0) occurred in 24 patients (15 percent). Median RT-surgery interval was 44 (range, 15-206) days. A pathologic complete response occurred in 19 percent of patients with an interval >44 days, vs. 12 percent in those with an interval < or =44 days ( P = 0.27). Downstaging by three stages occurred more frequently in the long-interval group (15 percent vs. 6 percent, P = 0.11). The rates of sphincter preservation, positive margins, estimated blood loss, and operative time were not significantly different. Overall morbidity was similar between groups. CONCLUSIONS: Our results demonstrate a trend toward increased pathologic complete response rate and downstaging with increased RT-surgery interval. However, sphincter preservation is not increased. Until prospective analyses are conducted assessing the impact of prolonged RT-surgery interval on long-term outcome, the benefit of a prolonged interval between the completion of preoperative combined modality therapy and surgery remains unclear.