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Purpose: To assess the correlation of radiation-induced apoptosis in vitro of CD4 and CD8 T lymphocytes with late toxicity of prostate cancer patients treated with radiation therapy., Methods and Materials: 214 patients were prospectively included in the study. Peripheral blood was drawn from patients before treatment and irradiated with 8 Gy. The percentage of CD4+ and CD8+ T lymphocytes that underwent radiation-induced apoptosis was assessed by flow cytometry. Toxicity and mortality were correlated in 198 cases with pretreatment apoptosis and clinical and biological variables by use of a Cox proportional hazards model., Results: The mean percentage of CD4+ and CD8+ T lymphocyte radiation-induced apoptosis was 28.58% (±14.23) and 50.76% (±18.9), respectively. Genitourinary (GU) toxicity was experienced by 39.9% of patients, while gastrointestinal (GI) toxicity was experienced by 19.7%. The probability of development of GU toxicity was nearly doubled (hazard ratio [HR] 1.99, P=.014) in those patients in whom the percentage of in vitro radiation-induced apoptosis of CD4+ T-lymphocytes was ≤28.58%. It was also almost double in patients who received doses ≥50 Gy in 65% of the bladder volume (V65 ≥50) (HR 1.92, P=.048). No correlation was found between GI toxicity and any of the variables studied. The probability of death during follow-up, after adjustment for different variables, was 2.7 times higher in patients with a percentage of CD8+ T lymphocyte apoptosis ≤50.76% (P=.022)., Conclusions: In conclusion, our study shows, in the largest prospective cohort of prostate cancer patients undergoing radiation therapy, that in vitro radiation-induced apoptosis of CD4+ T lymphocytes assessed before radiation therapy was associated with the probability of developing chronic GU toxicity. In addition, the radiation dose received in the urinary bladder (V65 ≥50) affected the occurrence of GU toxicity. Finally, we also demonstrate that radiation-induced apoptosis of CD8+ T lymphocytes was associated with overall survival, although larger series are needed to confirm this finding., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Purpose: To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT)., Methods and Materials: 102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor., Results: The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (P<.01). Late skin toxicity was no worse than grade 2 in either group, without significant differences between the 2 groups. In the ipsilateral breast, the areas that received the highest doses (ie, the boost or quadrant) showed the greatest loss of elasticity. WBI resulted in a greater loss of elasticity in the high-dose area compared with APBI (P<.05). Physician assessment showed that >75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups., Conclusions: APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: Positron emission tomography (PET) with the glucose analogue [18F] fluoro-2-deoxy-D-glucose ((18)F-FDG-PET) has been used in radiation treatment planning for non-small-cell carcinoma. To date, lymph nodes have been contoured according to the uptake of the tumor. This prospective study was performed to evaluate if nodal volume delineates according to FDG uptake within the primary tumor (PET-GTVnt) is suitable for nodal target volume delineation or if individualized nodal FDG uptake measure (PET-GTVnn) is necessary to better nodal target definition., Methods and Materials: Forty cases, who underwent a diagnostic (18)F-FDG PET/computed tomography (CT) scan, were included. Two PET-based GTVs for each lymph node were contoured and compared. First, we used an isocontour of 40% of the maximum tumor uptake (PET-GTVnt). Second, an isocontour of 40% of the maximum uptake of each node (PET-GTVnn) was employed. To avoid interobserver variability, this was carried out by the same radiation oncologist. Afterwards, the difference between both lymph node volumes was plotted against the ratio of the maximum uptakes (I(n)/I(t)) in a linear regression analysis., Results: Compared with CT-based lymph node volume (CT-GTVn), the intraclass correlation coefficient of PET-GTVnn was higher than the coefficient of PET-GTVnt (p < 0.001). All cases could be divided into four groups: undetected (17.5%), detected but overestimated (10%), detected but underestimated (35%), and correctly detected (37.5%)., Conclusions: If a method of automatic delineation shall be applied, this method must be applied to every lesion separately. However, to facilitate the delineation in daily practice, when I(n)/I(t) is ≤25%, lymph nodes could be delineated in accordance with tumor uptake, keeping an absolute difference in radii <5 mm., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Purpose: To evaluate the risk factors for acute esophagitis (AET) in lung cancer patients treated with concurrent 3D-CRT and chemotherapy., Methods and Materials: Data from 100 patients treated with concurrent chemoradiotherapy with a mean dose of 62.05 +/- 4.64 Gy were prospectively evaluated. Esophageal toxicity was graded according to criteria of the Radiation Therapy Oncology Group. The following dosimetric parameters were analyzed: length and volume of esophagus in treatment field, percentage of esophagus volume treated to >or=10, >or=20, >or=30, >or=35, >or=40, >or=45, >or=50, >or=55, and >or=60 Gy, and the maximum (D(max)) and mean doses (D(mean)) delivered to the esophagus. Also, we developed an esophagitis index (EI) to account the esophagitis grades over treatment time., Results: A total of 59 patients developed AET (Grade 1, 26 patients; Grade 2, 29 patients; and Grade 3, 4 patients). V50 was associated with AET duration (p = 0.017), AET Grade 1 duration (p = 0.016), maximum analgesia (p = 0.019), esophagitis index score (p = 0.024), and AET Grade >or=1 (p = 0.058). If V50 is <30% there is a 47.3% risk of AET Grade >or=1, which increases to 73.3% if V50 is >or=30% (p = 0.008). The predictive abilities of models (sensitivity and specificity) were calculated by receiver operating characeristic curves., Conclusions: According to the receiver operating characeristic curve analysis, the 30% of esophageal volume receiving >or=50 Gy was the most statistically significant factor associated with AET Grade >or=1 and maximum analgesia (A(max)). There was an association with AET Grade >or=2 but it did not achieve statistical significance (p = 0.076).

Purpose: To assess the usefulness of oral glutamine to prevent radiochemotherapy-induced esophagitis in patients with lung cancer, and to determine the dosimetric parameter predictive of esophagitis., Methods and Materials: Seventy-five patients were enrolled; 34.7% received sequential radiochemotherapy, and 65.3% received concomitant radiochemotherapy. Every patient received prophylactic glutamine powder in doses of 10 g/8 h. Prescribed radiation doses were 45-50 Gy to planning target volume (PTV)1 (gross tumor volume plus wide margins) and 65-70 Gy to PTV2 (reduced margins). The primary endpoint was the incidence of Grade 2 or greater acute esophagitis., Results: No patient experienced glutamine intolerance or glutamine-related toxicity. Seventy-three percent of patients who received sequential chemotherapy and 49% of those who received concomitant chemotherapy did not present any form of esophagitis. V50 was the dosimetric parameter with better correlation between esophagitis and its duration. A V50 of or=2, which increased to 71% with a V50 of >30% (p = 0.0009)., Conclusions: The use of oral glutamine may have an important role in the prevention of esophageal complications of concomitant radiochemotherapy in lung cancer patients. However, randomized trials are needed to corroborate that effect. V50 is the dosimetric parameter with better correlation with esophagitis grade and duration.