I. Membrive

Accelerated hypofractionated radiation therapy (AHRT) for non-small-cell lung cancer: can we leave standard fractionation?

PurposeTo report interim results from a single-institution study conducted to assess accelerated hypofractionated radiotherapy (AHRT) delivered with 3D conformal radiotherapy in two groups of patients with non-small cell lung cancer: (1) patients with early stage disease unable to tolerate surgery and ineligible for stereotactic body radiation therapy, and (2) patients with locally advanced disease unsuitable for concurrent chemoradiotherapy.Methods/patientsA total of 83 patients (51 stage I–II, 32 stage III) were included. Radiotherapy targets included the primary tumor and positive mediastinal areas identified on the pre-treatment PET–CT. Mean age was 77.8xa0±xa07.8xa0years. ECOG performance status (PS) was ≥2 in 50.6xa0% of cases. Radiotherapy was delivered in daily fractions of 2.75xa0Gy to a total dose of 66xa0Gy (BED10 84xa0Gy). Acute and late toxicities were evaluated according to NCI CTC criteria.ResultsAt a median follow-up of 42xa0months, median overall survival (OS) and cause-specific survival (CSS) were 23 and 36xa0months, respectively. On the multivariate analysis, PS [HR 4.14, pxa0=xa00.0001)], stage [HR 2.51, pxa0=xa00.005)], and maximum standardized uptake values (SUVmax) [HR 1.04, pxa0=xa00.04)] were independent risk factors for OS. PS [HR 5.2, pxa0=xa00.0001)] and stage [HR 6.3, pxa0=xa00.0001)] were also associated with CSS. No cases of severe acute or late treatment-related toxicities were observed.ConclusionsOS and CSS rates in patients treated with AHRT for stage I–II and stage III NSCLC were good. Treatment was well tolerated with no grade three or higher treatment-related toxicity. PS, stage, and SUV max were predictive for OS and CSS.

Predictive factors for survival in neoadjuvant radiochemotherapy for advanced rectal cancer

IntroductionNeoadjuvant radiochemotherapy followed by radical surgery is the standard approach in advanced rectal carcinoma. Tumor response is determined in histological specimen.ObjectiveTo assess predictive factors for survival in 115 patients.Patients and Method115 patients treated with neoadjuvant radiochemotherapy followed by radical surgery with total mesorectal excision, in our hospital from January 2007 to December 2014. All patients received pelvic radiotherapy with concomitant chemotherapy, followed by radical surgery and in some adjuvant chemotherapy.ResultsIn univariate analysis, distance to anal verge, radial margin, perineural invasion, and good grade regression are predictive factors for both, specific and disease free survival; and in multivariant, only radial margin and perineural invasion were predictive factors for survival. We found distance to anal verge (<5xa0cm) as the only clinical factor to predict a positive margin in the histologic specimen.ConclusionsPerineural invasion and positive radial margin are predictive factors for both specific and disease free survival.

EP-1221: Accelerated hypofractionated three-dimensional conformal radiation therapy (AHRT) for NSCLC

Results: The main result was the reduction in primary and nodal volumes due to better definition of lung mass and nearby lung Collapse , the latter could be easily defined in 14 cases on the DW-MRI vs. 7 cases only by CT scans (P=0.016). Median GTV total (sum of 1ry and nodal GTV), on MRI Diffusion compared to that on the CT scan was 354 and 386 cm3 respectively (P= 0.009). In 15 cases, a mean decrease in the GTV total of 34% ±56% (median, 9%; range, 0.232.5%) by using DW-MRI. only in three other cases a mean increase in the GTV total of 12.7% ±14.9% (median, 9.7%; range, 0.4221%). was found. The median PTVs on the CT scans vs. the MRI Diffusion were 1623 (range, 493–2965 cm3) & 1419 (range, 542–3158 cm3) respectively which was statistically non significant (P= 0.391).