Dosimetric comparison of three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, and volumetric-modulated arc therapy for free-breathing whole-breast irradiation: A planning study.

Background: Currently, recommended heart dose constraints are difficult to meet in whole-breast irradiation (WBI) for left-sided breast cancer patients, who cannot be treated with the deep inspiration breath hold. We performed a radiotherapy planning study to establish if the use of intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) allows for better sparing of the heart and its subvolumes than the three-dimensional conformal radiation therapy (3D-CRT), and how these attempts affect the dose delivered to the other organs. Methods: A total of 17 left-sided and 10 right-sided consecutive patients treated with free-breathing WBI were retrospectively included. The 3D-CRT, IMRT, and VMAT plans were generated. Several dose-volume parameters and plan quality indices were compared, separately for the left- and right-sided plans. Results: All the techniques fulfilled the planning objectives. In the left-sided plans, there was no heart or left ventricle dose reduction with IMRT, nor with VMAT; the maximum dose in the left anterior descending coronary artery was reduced with VMAT (P = 0.005); V5 for the contralateral breast, contralateral lung, and total-body increased markedly in VMAT, and for the ipsilateral lung (V5IL) also in IMRT, compared with 3D-CRT (P < 0.001). In the right-sided plans, the V5 values, except for V5IL, did not differ between the three techniques. Conclusions: IMRT and VMAT had a limited heart-sparing benefit in the left-sided free-breathing WBI, at the cost of increased low-dose volumes, measured by V5. The low-dose volumes are not increased by IMRT or VMAT in the right-sided WBI, where heart sparing is not a problem, but the attempts to reduce cardiac doses in the left-sided WBI increase them.

Postoperative radio-chemotherapy for rectal cancer: A retrospective analysis from a tertiary referral hospital.

AIM: To report results of postoperative radio-chemotherapy (RT-CHT) for rectal cancer (RC). BACKGROUND: Total mesorectal excision (TME) is an essential treatment method in rectal cancer (RC). Perioperative radiotherapy in locally advanced RC improves loco-regional free survival (LRFS). Preoperative radiotherapy is a preferred option; however, some patients are not referred for it. In case of the risk of loco-regional failure postoperative radio-chemotherapy (RT-CHT) is indicated. MATERIAL AND METHODS: Between 2004 and 2010, 182 patients with pathological stage II-III RC (TME performed - 41%, resection R0 - 88%, circumferential resection margin evaluated - 55.5% and was above 2 mm in 66% of them) received postoperative RT-CHT in our institution. Overall survival (OS) and LRFS were estimated with the Kaplan-Meier method. Univariate and multivariate analysis were performed to compare the impact of prognostic factors on survival. RESULTS: Five-year OS and LRFS rates were 63% and 85%, respectively. Loco-regional recurrence and isolated distant metastases rates were 11.5% and 19%, respectively. Multivariate analysis showed stage (III vs. II), HR: 2.3 (95% confidence interval [CI]: 1.4-3.8), p = 0.0001; extent of resection (R1-2 vs. R0), HR: 2.14 (95%CI: 1.14-3.99), p = 0.017, and age (>65 vs. ≤65 years), HR: 1.66 (95%CI: 1.06-2.61), p = 0.027 as prognostic factors for OS. Extent of resection (R1-2 vs. R0), HR: 3.65 (95%CI: 1.41-9.43), p = 0.008 had significant impact on LRFS. CONCLUSION: Despite a suboptimal quality of surgery and pathological reports, the outcome in our series is close to that reported in the literature. We confirm a strong impact of the extent of resection on patient's outcome, which confirms the pivotal role of surgery in the management of RC.

Selection of patients with left breast cancer for deep-inspiration breath-hold radiotherapy technique: Results of a prospective study.

AIM: To assess prospectively which patients with left breast cancer have the dosimetric benefit from the use of deep-inspiration breath-hold radiotherapy (DIBH-RT). BACKGROUND: Improvement in selection of patients for DIBH-RT would spare time of radiotherapy staff by removing the need for preparation of two comparative treatment plans. MATERIALS AND METHODS: Thirty-one patients qualified for whole left breast irradiation underwent breath-hold training and their free-breathing (FB) and DIBH planning-CT were included in the analysis of dosimetric outcome. Mean heart dose (MHD), heart V20 Gy (V20Heart), maximum dose to LAD (LADmax), V20 for left lung (V20L.lung) were recorded from FB and DIBH plans and the differences (Δ) of these values were calculated. If relative improvement of at least 20% for any evaluated dosimetric parameter was found for the DIBH-RT, this plan was selected for treatment. Correlations of Δ of dosimetric parameters with patient-related parameters (BMI, age, PTV, cardiac contact distance [CCD], lung volume at FB) were sought. RESULTS: In 30 of 31 patients, a predefined reduction in evaluated parameters was achieved. CCD, BMI correlated positively with ΔMHD, ΔV20Heart, ΔLADmax; PTV with ΔMHD and ΔV20Heart (p < 0.05; AUC > 0.6); Lung volume correlated negatively with ΔLADmax, ΔMHD and ΔV20Heart. No specific thresholds for the lack of predefined improvement of any dosimetric parameters was identified in ROC analysis. 19/30 (63%) patients with dosimetric benefit completed their RT with DIBH. CONCLUSIONS: Despite a strong correlation between patient-related and dosimetric parameters, we cannot use the anatomical characteristics' thresholds to select patients for whom DIBH-RT will not be considered.

Stereotactic radiotherapy of the tumor bed compared to whole brain radiotherapy after surgery of single brain metastasis: Results from a randomized trial.

PURPOSE: To evaluate if neurological/cognitive function outcomes in patients with resected single brain metastasis (BM) after stereotactic radiotherapy of the tumor bed (SRT-TB) are not inferior compared to those achieved with whole-brain radiotherapy (WBRT). METHODS: Patients with total/subtotal resection of single BM were randomly assigned either to SRT-TB (n=29) or WBRT (n=30). SRT-TB arm consisted of 15Gy/1 fraction, or 5×5Gy. WBRT consisted of 30Gy/10 fractions. Neurological/cognitive failure was defined as a decrease of neurological score by one point or more, or a worsening of the MiniMental test by at least 3 points, or neurological death. Cumulative incidence of neurological/cognitive failure (CINCF), neurological death (CIND), and overall survival (OS) were compared. RESULTS: Median follow-up was 29months (range: 8-45) for 15 patients still alive. The difference in the probability of CINCF at 6months (primary endpoint) was -8% in favor of WBRT (95% confidence interval: +17% -35%; non-inferiority margin: -20%). In the intention-to-treat analysis, two-year CIND rates were 66% vs. 31%, for SRT-TB and WBRT arm, respectively, p=.015. The corresponding figures for OS were 10% vs. 37%, p=.046. CONCLUSIONS: Non-inferiority of SRT-TB was not demonstrated in our underpowered study. More data from randomized studies are needed for confirmation of the value of this method.

Clinical outcome and toxicity of 3D-conformal radiotherapy combined with chemotherapy based on the Intergroup SWOG 9008/INT0116 study protocol for gastric cancer.

PURPOSE: To retrospectively evaluate the efficacy and toxicity of adjuvant radio-chemotherapy in patients with gastric cancer and to relate them to the outcome of the landmark INT0116 study that is criticized because of the high toxicity and poor treatment compliance. METHODS: A total of 102 patients who underwent postoperative fluorouracil (5-FU)-based radio-chemotherapy in our institution between 2004 and 2010 for stage IB-IV (AJCC 6th Edn.) gastric cancer were selected. Radiotherapy to 45 Gy was defined individually and delivered with 3D conformal technique. Chemotherapy was carried out during the first 4 and the last 3 days of radiotherapy with continuous infusion of 5-FU (400mg/m²/day) and leucovorin. Patients received an additional 3 cycles of chemotherapy of 5-FU (425mg/m²/day), mostly 1 before and 2 after radio-chemotherapy. Acute hematological and gastrointestinal toxicities were evaluated according to the CTC v3.0 scale. RESULTS: Stage distribution was as follows: IB-5 (5%), II-32 (31%), III-49 (48%), and IV-14 (14%). There were 96% R0 resections; 15% of the patients had a D2 resection. Seventy-four patients (72.5%) received all 5 planned cycles and 98 (96%) completed radiotherapy. The 3- and 5-year overall survival (OS) rates were 57% and 48%, respectively. Multivariate analysis showed that variables significantly affecting OS were pT3-T4, pN2-3, R1 resection and female gender. Only 2% of the patients experienced grade 3 gastrointestinal toxicity; 7% had grade 3 or higher hematological toxicity. CONCLUSIONS: We demonstrated better treatment tolerance, compliance, OS of adjuvant radio-chemotherapy for gastric cancer in comparison with INT0116 study. Conformal radiation techniques might have contributed to this improvement.

Neoadjuvant treatment for unresectable rectal cancer: an interim analysis of a multicentre randomized study.

PURPOSE: To present an interim analysis of the trial comparing two neoadjuvant therapies for unresectable rectal cancer. METHODS: Patients with fixed cT3 or cT4 or locally recurrent rectal cancer without distant metastases were randomized to either 5 × 5 Gy and 3 courses of FOLFOX4 (schedule I) or 50.4 Gy delivered in 28 fractions given simultaneously with 5-Fu, leucovorin and oxaliplatin (schedule II). Surgery in both groups was performed 12 weeks after the beginning of radiation and 6 weeks after neoadjuvant treatment. RESULTS: 49 patients were treated according to schedule I and 48 according to schedule II. Grade III+ acute toxicity was observed in 26% of patients in group I and in 25% in group II. There were two toxic deaths, both in group II. The microscopically radical resection (primary endpoint) rate was 73% in group I and 71% in group II. Overall and severe postoperative complications were recorded in 27% and 9% of patients vs. 16% and 7%, respectively. Pathological complete response was observed in 21% of the patients in group I and in 9% in group II. CONCLUSIONS: The interim analysis revealed no major differences in acute toxicity and local efficacy between the two evaluated strategies.

Prognostic value of IDH1 mutations identified with PCR-RFLP assay in glioblastoma patients.

BACKGROUND AND OBJECTIVE: It has been shown that somatic missense mutations in codon 132 of the NADP+ dependent isocitrate dehydrogenase 1 (IDH1) gene occur frequently in primary brain tumors including highly malignant glioblastoma (GBM). The aim of this study was to evaluate a PCR-restriction fragment length polymorphism (RFLP)-based method for missense mutation detection and to estimate the prognostic value of the two most frequent IDH1 codon 132 mutations, R132H and R132C, in patients with newly diagnosed GBM treated with radiation combined with temozolomide. METHODS: DNA was extracted from formalin-fixed, paraffin-embedded tissue. The PCR-RFLP method was adapted to IDH1 codon 132 mutation screening. The mutation status was determined in a group of 58 patients. RESULTS: We found R132H mutations in 14% of patients. No R132C mutation was found in this study. Median follow-up for living patients was 31 (range 17-51) months. Median progression-free survival in the group of patients with IDH1 mutation was 29 months compared with 10 months in the IDH1 wild-type group (p = 0.004; hazard ratio [HR] 3.09, 95% CI 1.25, 4.78). Median overall survival in the group with IDH1 mutation has not been reached, whereas in the group with wild-type IDH1 it was 19.5 months (p < 0.001; HR 4.76, 95% CI 1.22, 6.30). Three-year overall survival was 60% in the group with IDH1 mutation while in the wild-type IDH1 group it dropped to 29%. IDH1 mutations significantly correlated with younger age (p = 0.02). CONCLUSIONS: Our results indicate that the IDH1 R132H mutation is a powerful prognostic marker in GBM treated with chemoradiation. The PCR-RFLP method allows for a fast, inexpensive, and sensitive mutation screening.