Feasibility of fast, four-dimensional computed tomography-based O-ring LINAC plans for lung stereotactic body radiotherapy in patients with poor performance status.

Purpose: We aimed to retrospectively analyzed the feasibility of fast four-dimensional computed tomography (4DCT)-based O-ring LINAC treatment for patients with an average respiratory amplitude was< 0.5 cm and who cannot endure long treatment times due to poor performance status in lung 4D-stereotactic body radiotherapy (SBRT). Methods: This study included data of 38 patients who received lung 4D-SBRT and had average respiratory amplitude< 0.5 cm in the full phase. C-arm LINAC plans were based on 4DCT data obtained at phase values ranging from 20-70% using a C-arm LINAC. O-ring LINAC plans were retrospectively established based on 4DCT data obtained at phase values of 0-90% using an O-ring LINAC. The conformity index (CI), homogeneity index (HI), and gradient measurement of the planning target volumes (PTV) were analyzed to compare dosimetric data between C-arm LINAC and O-ring LINAC plans. Organs at risk were analyzed in accordance with the Radiation Therapy Oncology Group 0915 protocol. Treatment delivery time and total monitor units were analyzed to compare the efficiency of treatment delivery. Statistical comparisons were performed using the Wilcoxon signed-rank test (P< 0.05). Results: For the PTV, there was no significant difference in the CI or HI between C-arm LINAC and O-ring LINAC plans. For organs-at-risk, all plans met the criteria for dose constraint. There was a significant difference between C-arm LINAC and O-ring LINAC plans except in the spinal cord. Treatment delivery time was 92% longer for C-arm LINAC plans than for O-ring LINAC plans. The total MU value for C-arm LINAC plans was 9.6% higher than that for O-ring LINAC plans. Conclusion: We verified the feasibility of fast 4DCT-based O-ring LINAC treatment for patients with average respiratory amplitude< 0.5 cm and who cannot endure long treatment times due to poor performance status in lung 4D-SBRT.

Dosimetric comparison of VitalBeam® and HalcyonTM 2.0 for hypofractionated VMAT with simultaneous integrated boost treatment of early-stage left-sided breast cancer.

PURPOSE: This study compared the quality of treatment plans for early-stage, left-sided breast cancer, as planned for and delivered by the HalcyonTM and VitalBeam® . MATERIALS AND METHODS: Fifteen patients diagnosed with early-stage left-sided breast cancer, who had received VMAT with hypofractionated SIB, were recruited. All cases were planned using HalcyonTM comprising a dual-layer MLC (DL-MLC) and VitalBeam® with a Millennium 120 MLC (VB-MLC). For the PTVs, the quality of coverage (QC), conformity index (CI), and homogeneity index (HI) were calculated for each plan. The dosimetric differences between the two treatment plans were statistically compared using the Wilcoxon signed-rank test (p < 0.05). To evaluate delivery efficiency, the average delivery time for each patient's treatment plan was recorded and compared. RESULTS: For the PTVs, the two plans (DL-MLC and VB-MLC) were comparable in terms of the QC, CI, and HI. However, V30Gy and Dmean for the heart in the DL-MLC plan were significantly reduced by 0.49% and 14.6%, respectively, compared with those in the VB-MLC plan (p < 0.05). The Dmean value for the ipsilateral lung in the DL-MLC plan significantly decreased by 5.5%, compared with that in the VB-MLC plan (p < 0.05). In addition, the delivery times for the DL-MLC and VB-MLC plans were 79 ± 10 and 101 ± 11 s, respectively. CONCLUSIONS: DL-MLC plans were found to improve OAR sparing. In particular, when treating left-sided breast cancer via DL-MLC plans, the risk of heart toxicity is expected to be reduced.

Randomized Phase II study of two opposite administration sequences of irinotecan and cisplatin in patients with advanced nonsmall cell lung carcinoma.

BACKGROUND: Combined chemotherapy with irinotecan and cisplatin (IP) is active in patients with nonsmall cell lung carcinoma (NSCLC). However, the optimal administration schedule needs to be defined to maximize its synergic effect. The authors evaluated the efficacy, toxicity, and pharmacokinetics (PK) of IP chemotherapy given on two administration sequences in chemotherapy-naive patients with NSCLC. METHODS: Eighty eligible patients were assigned randomly to receive 1 of 2 irinotecan and cisplatin administration sequences on Day 1: irinotecan followed by cisplatin (I-P) (n = 39 patients) or cisplatin followed by irinotecan (P-I) (n = 41 patients). Treatment was comprised of irinotecan at a dose of 80 mg/m(2) intravenously on Days 1 and 8 and cisplatin at a dose of 60 mg/m(2) intravenously on Day 1 of a 21-day cycle for a maximum of 6 cycles. For PK analysis, serial plasma samples were obtained on Day 1 of the first cycle. RESULTS: In total, 77 patients were assessable for efficacy. The overall response rate was 47%, and there was a trend in favor of P-I (54%) compared with I-P (39%). In multivariate logistic regression analysis, the P-I sequence and female gender were found to be significant predictors of a better response (P = 0.047 and P = 0.011, respectively). Overall toxicity profiles and PK parameters were similar in both arms. CONCLUSIONS: IP chemotherapy showed promising activity with a favorable 1-year survival rate. For future clinical use, the authors recommend administering cisplatin first and then irinotecan, because that sequence was associated with a higher response rate.

Phase II study of weekly irinotecan plus capecitabine for chemotherapy-naive patients with advanced nonsmall cell lung carcinoma.

BACKGROUND: A Phase II study was conducted to evaluate the efficacy and toxicity of an irinotecan plus capecitabine combination, a new nonplatinum regimen, in chemonaive patients with advanced nonsmall cell lung carcinoma (NSCLC). METHODS: Between July 2003 and April 2004, 53 patients with a histologically confirmed diagnosis of NSCLC were enrolled. All but 5 patients were male, 52 (98%) had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1, 39 (74%) had AJCC Stage IV disease, and the median age was 61 years. Treatment consisted of intravenous irinotecan at a dose of 90 mg/m(2) on Days 1 and 8 and oral capecitabine at a dose of 1000 mg/m(2) twice daily on Days 1-14 of each 21-day cycle, given up to 12 cycles. RESULTS: Of 53 patients enrolled, 22 achieved objective tumor responses (all partial responses) for an overall response rate of 41.5% (95% confidence interval [95% CI], 28.2-54.8%). After a median follow-up of 17.4 months, the median survival was 14.6 months with a 1-year survival rate of 60.1% (95% CI, 46.9-73.4%) and a median progression-free survival of 5.1 months. Treatment was very well tolerated, with only 10% of patients experiencing NCI-CTC Grade 3 or 4 toxicities. The most common toxicities were hand-foot syndrome and diarrhea. In multiple logistic regression analysis for overall response, only the stage predicted for significantly better response (P = 0.04). Squamous cell carcinoma was marginally predictive for better response (P = 0.08). CONCLUSIONS: The irinotecan plus capecitabine regimen demonstrated an antitumor activity that is favorably comparable with other commonly used cisplatin-based regimens. Given the mild toxicity profile and favorable survival outcome, this nonplatinum regimen warrants further evaluation in a randomized trial.

A phase II study of dose-intensified weekly concomitant administration of cisplatin and irinotecan in chemonaive patients with extensive-disease small-cell lung cancer.

Irinotecan/cisplatin (IP) is an active regimen for extensive-disease small-cell lung cancer (ED-SCLC). However, the optimal dose/schedule is unsettled. To evaluate the efficacy and safety of a dose-intensified, weekly concomitant administration of IP, we conducted a phase II study in chemo-naive patients with ED-SCLC. Between October 2001 and February 2004, 37 patients were enrolled. Twenty-nine (78%) were male, 21 (57%) had ECOG PS 0 or 1, and the median age was 62 yr. The initial six patients received cisplatin 50 mg/m2 followed by irinotecan 90 mg/m2 iv on d 1 and 8 of a 21-d cycle (dose level I), with one treatment-related death, three febrile neutropenias. Thereafter, the doses of cisplatin and irinotecan were reduced to 40 mg/m2 and 80 mg/m2, respectively (dose level II). The treatment was continued for up to six cycles. The overall response rate was 97%, with a complete response (CR) rate of 26%. The median duration of response was 6.4 mo (range, 1.6-13.1 mo). At a median follow-up of 27.3 mo, the median survival time was 11.1 mo and 1- and 2-yr survival rates were 44.1% and 11.8%, respectively. The median progression-free survival (PFS) was 6.0 mo (range, 1.5-13.1 mo) and 1-year PFS rate was 7%. Major grade 3 or 4 toxicities included neutropenia (89%), anemia (59%), and diarrhea (27%). Despite of significant myelosuppresion, this dose-intensified weekly concomitant administration of cisplatin and irinotecan was feasible. This dose-schedule showed promising activity with high rate of complete remission in patients with ED-SCLC.