Selection criteria for 3D conformal radiotherapy versus volumetric-modulated arc therapy in high-grade glioma based on normal tissue complication probability of brain.

There are no quantitative selection criteria for identifying high-grade glioma (HGG) patients who are suited for volumetric-modulated arc therapy (VMAT). This study aimed to develop selection criteria that can be used for the selection of the optimal treatment modality in HGG. We analyzed 20 patients with HGG treated by 3D conformal radiotherapy (3DCRT). First, VMAT plans were created for each patient retrospectively. For each plan, the normal tissue complication probability (NTCP) for normal brain was calculated. We then divided the patients based on the NTCPs of the 3DCRT plans for normal brain, using the threshold of 5%. We compared the NTCPs of the two plans and the gross tumor volumes (GTVs) of the two groups. For the GTVs, we used receiver operating characteristic curves to identify the cut-off value for predicting NTCP < 5%. We determined the respective correlations between the GTV and the GTV's largest cross-sectional diameter and largest cross-sectional area. In the NTCP ≥ 5% group, the NTCPs for the VMAT plans were significantly lower than those for the 3DCRT plans (P = 0.0011). The NTCP ≥ 5% group's GTV was significantly larger than that of the NTCP < 5% group (P = 0.0016), and the cut-off value of the GTV was 130.5 cm3. The GTV was strongly correlated with the GTV's largest cross-sectional diameter (R2 = 0.82) and largest cross-sectional area (R2 = 0.94), which produced the cut-off values of 7.5 cm and 41 cm2, respectively. It was concluded that VMAT is more appropriate than 3DCRT in cases in which the GTV is ≥130.5 cm3.

Definitive chemoradiotherapy with low-dose continuous 5-fluorouracil reduces hematological toxicity without compromising survival in esophageal squamous cell carcinoma patients.

BACKGROUND AND PURPOSE: To compare chemoradiotherapy (CRT) with low-dose continuous 5-fluorouracil (5FU) to CRT with 5FU+cisplatin (CDDP) for esophageal squamous cell carcinoma (ESCC) in a retrospective cohort study. METHODS AND MATERIALS: We reviewed the cases of Stage I-IV ESCC patients who underwent definitive CRT in 2000-2014. Concomitant chemotherapy was one of the three regimens: (1) high-dose intermittent 5FU and CDDP (standard-dose FP: SDFP), (2) low-dose continuous 5FU and CDDP (LDFP), or (3) low-dose continuous 5FU (LD5FU). The general selection criteria for chemotherapy were: SDFP for patients aged <70 yrs; LDFP for those aged 70-74 yrs; LD5FU for those aged ≥75 yrs or with performance status (PS) ≥3. Propensity scores were derived with chemotherapy (LD5FU vs. 5FU+CDDP) as the dependent variable. RESULTS: In a multivariate analysis, chemotherapy (LD5FU vs. SDFP, p = .24; LDFP vs. SDFP, p = .52) did not affect the overall survival (OS). LD5FU caused significantly less grade 3-4 leukopenia (9%) compared to SDFP (47%) and LDFP (44%) (p < .001). In a propensity-matched analysis, LD5FU affected neither OS (HR 1.06; 95%CI 0.55-2.05; p = .87) nor progression-free survival (HR 0.95, 95%CI 0.50-1.81; p = .87). CONCLUSION: CRT with low-dose continuous 5FU may be a less toxic option for elderly ESCC patients.

Respiratory gating and multifield technique radiotherapy for esophageal cancer.

PURPOSE: To investigate the effects of a respiratory gating and multifield technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer. METHODS AND MATERIALS: Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multifield technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans. RESULT: In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V5Gy, V20Gy, mean dose with all three plans and the Heart V25Gy-V40Gy with Gating-2-field plan, V35Gy, V40Gy, mean dose with No Gating-4-field plan and V30Gy-V40Gy, and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan. CONCLUSION: The lung parameters were reduced by the respiratory gating technique and increased by the multifield technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications.