Cardiological Safety of 5-Fraction Whole Breast Irradiation

PURPOSE/OBJECTIVE(S)

Our study aims to assess heart toxic effect using a reliable cardiac assessment with standard and 3-dimensional (3D) echocardiography and left ventricular (LV) global longitudinal strain (GLS) in patients receiving a 5-fraction (total dose 26 Gy) postoperative radiation therapy (RT) for breast cancer (BC).

MATERIALS/METHODS

SAFE-FORWARD is an observational prospective cohort study (NCT04842409). Inclusion criteria were: (1) patients with invasive BC receiving ultra-hypofractionated whole breast irradiation (WBI) (26 Gy in 5 fractions) after breast conserving surgery (BCS) (2) without cardiovascular comorbidity and (3) previous thoracic irradiation. All enrolled patients are prospectively monitored for 12 months, receiving a complex cardiological assessment before RT start (baseline), and at 2-, 6-, and 12-month after RT end of treatment. Both acute and early-late toxicity are evaluated according to CTCAE (v.5) scales. The primary endpoint is defined as detection of any subclinical impairment in myocardial function and deformation (decrease ≥10%) measured with standard and 3D echocardiography and LV GLS.

RESULTS

Overall, 40 women (median age 66 years; range, 48-84) were enrolled in the study. We analyzed patients who had completed the cardiological assessment at 12 months. Baseline patient's characteristics are summarized in Table 1. All patients received ultra-hypofractionated WBI (26 Gy in 5 fractions), 25 patients also received adjuvant endocrine therapy. GLS worsened 4% or less, both for the left- and right-side treated breast, and remained in normal range for all the time points. The only exception was for RVGLS at 6 months for right-sided treatment where it reached a borderline value (-17.4±4.9 SE). 3D-LVEF remains stable during observation, both for the left- and right-side treated breast CONCLUSION: The 5-fraction schedule after BCS is well tolerated and the intensive 1-year cardiological monitoring showed no significant differences overtime in cardiac functioning.

ABBREVIATIONS

DIBH, deep inspiration breath hold; AI, aromatase inhibitors; BCCT, Breast Cancer Conservation Treatment.

End-to-end test for lung SBRT: An Italian multicentric pilot experience

PURPOSE

Set up a lung SBRT end-to-end (e2e) test and perform a multicentre validation.

MATERIAL AND METHODS

A group of medical physicists from four hospitals and the Italian Institute of Ionizing Radiation Metrology designed the present e2e test. One sub-group set up the test, while another tested its feasibility and ease of use. A satisfaction questionnaire was used to collect user feedback. Each participating centre (PC) received the ADAM breathing phantom, a microDiamond detector and radiochromic films. Following the e2e protocol, each PC performed its standard internal procedure for simulating, planning, and irradiating the phantom. Each PC uploaded its planning and treatment delivery data in a shared Google Drive. A single centre analyzed all the data.

RESULTS

The e2e test was successfully performed by all PCs. Participants' comments indicated that ADAM was well suited to the purpose and the protocol well described. All PCs performed the test in static and dynamic modes. The ratio between measured and planned point dose obtained by PC1, PC2, PC3, PC4 was: 0.99, 0.96, 1.01 and 1.01 (static track) and 0.99, 1.02, 1.01 and 0.94 (dynamic track). The gamma passing rates (3 % global, 3 mm) between planned and measured dose maps were 98.5 %, 94.0 %, 99.1 % and 94.0 % (static track) and 99.5 %, 96.5 %, 86.0 % and 94.5 % (dynamic track) for PC1, PC2, PC3 and PC4, respectively.

CONCLUSIONS

An e2e test for lung SBRT has been proposed and tested in a multicentre framework. The results and user feedback prove the validity of the proposed e2e test.

In phantom evaluation of targeting accuracy in MRI-based brain radiosurgery

PURPOSE

To determine the targeting accuracy of brain radiosurgery when planning procedures employing different MRI and MRI + CT combinations are adopted.

MATERIALS AND METHOD

A new phantom, the BrainTool, has been designed and realized to test image co-registration and targeting accuracy in a realistic anatomical situation. The phantom was created with a 3D printer and materials that mimic realistic brain MRI and CT contrast using a model extracted from a synthetic MRI study of a human brain. Eight markers distributed within the BrainTool provide for assessment of the accuracy of image registrations while two cavities that host an ionization chamber are used to perform targeting accuracy measurements with an iterative cross-scan method. Two procedures employing 1.5 T MRI-only or a combination of MRI (taken with 1.5 T or 3 T scanners) and CT to carry out Gamma Knife treatments were investigated. As distortions can impact targeting accuracy, MR images were preliminary evaluated to assess image deformation extent using GammaTool phantom.

RESULTS

MR images taken with both scanners showed average and maximum distortion of 0.3 mm and 1 mm respectively. The marker distances in co-registered images resulted below 0.5 mm for both MRI scans. The targeting mismatches obtained were 0.8 mm, 1.0 mm and 1.2 mm for MRI-only and MRI + CT (1,5T and 3 T), respectively.

CONCLUSIONS

Procedures using a combination of MR and CT images provide targeting accuracies comparable to those of MRI-only procedures. The BrainTool proved to be a suitable tool for carrying out co-registration and targeting accuracy of Gamma Knife brain radiosurgery treatments.

TomoTherapy treatments of multiple brain lesions: an in-phantom accuracy evaluation

Aim of the present study was to evaluate the accuracy which can be obtained with helical TomoTherapy^® (HT, Accuray) systems in the case of multiple intracranial targets treatments. Set-up accuracy was measured, for different registration options and MegaVoltage CT (MVCT) slice thickness, by applying known misalignments to an ad-hoc developed phantom. End-to-end (E2E) tests were performed to assess the delivery accuracy in phantoms containing multiple targets by using radiochromic films: measured dose distribution centroids were compared with physical and calculated target positions on axial and coronal planes. A Gamma index analysis was carried out on planned and measured planar dose maps. The bone and tissue algorithm with the fine MVCT reconstruction grid gave the best results among the automatic options. The most accurate registration modality resulted to be the manual one with a sub-voxel accuracy shifts and a capability in the detection of rotations within 0.3°. For the E2E along the coronal plane (six targets), a mean deviation between measured dose distribution centroids and physical barycenters of 0.6 mm (range 0.1 mm-1.3 mm) was observed. Along the axial plane (five targets), a mean deviation of 1.2 mm (range 0.7 mm-2.1 mm) was found for the centroids shifts. Gamma index (5%, 1 mm, local) passing rates higher than 87.5% between planned and delivered dose distributions were measured. These results demonstrate that multiple brain lesion HT treatments are feasible with an accuracy at least comparable to frameless linac-based delivery, when a set-up capable to assure angular corrections and a reliable patient immobilization is employed.

Abstract P1-10-04: Accelerated partial breast irradiation versus whole breast irradiation: Health-related quality of life analysis from a phase 3 trial

Background. Accelerated partial breast irradiation (APBI) represents a valid option for selected early breast cancer (BC); potential advantages of APBI include shorter treatment time, improved safety profile, and a cost reduction compared with standard fractionation.

We reported the final analysis of quality of life (QOL) results from a phase 3 randomized trial comparing standard adjuvant radiotherapy (50 Gy in 25 fractions, plus 10 Gy boost) to APBI using IMRT technique (30 Gy in 5 daily fractions). The 5-year results have been recently published showing equivalence in terms of local control (ClinicalTrials.gov, NCT02104895).

Methods. Overall 205 patients (105 APBI and 100 WBI) fully completed the given questionnaires at time 0 (RT start), time 1 (RT end), and time 2 (2-year follow up). Patients were asked to compile two specific questionnaires on QOL, the EORTC QLQ-C30 as a reliable and valid measure of the QOL of cancer patients in multicultural clinical research settings, and the BR23 module as a supplementary questionnaire for assessing QOL issues relevant to patients with BC. The statistical software SPSS (SPSS Inc, Chicago, IL, USA) for Windows (version 22), and STATA (StataCorp LP, College Station TX77845, USA) for Windows (version 12) were used. Chi-squared test or Mann Whitney U test were used to compare the individual characteristics of the patients between two arms. Mean and standard deviations (SD) were calculated for all QOL domains, and all scores were compared between APBI and WBI arms using the Mann Whitney test due to non-parametric distribution of data. The Kruskal-Wallis test was used to compare the scores between age groups.

Results. Mean values (and SD) of QLQ-C30 scores according to arm in the series of 205 BC patients at time 2 (time 0 vs time 2), showed significant improvement in favor of APBI in terms of global health status (mean 75.5 vs 59.5, SD range 13.3-22.0; p<0.0001), main functional (p<0.01), and symptom scales (p<0.01). Concerning the BR23 module, APBI showed significantly better outcome in terms of body image perception (mean 89 vs 72.1, SD 13.2-26.6; p<0.0001) and future perspective (84.8 vs 57, SD 23.1-28.5; p<0.0001) among functional scales; breast (6.1 vs 18.9, SD 6.6-18.2; p<0.0001) and arm symptoms (11.7 vs 19.6, SD 13.4-19; p=0.002) among symptom scales.

Conclusions. Women treated with APBI reported a significantly better QOL outcome as compared with women treated using WBI. QOL improvement was evidenced in terms of functional, symptoms, and global health status/QOL scales, both at the end of radiation and at a 2-year follow-up time.

Citation Format: Meattini I, Saieva C, Desideri I, Miccinesi G, Francolini G, Meacci F, Muntoni C, Scotti V, De Luca Cardillo C, Marrazzo L, Simontacchi G, Pallotta S, Sanchez L, Casella D, Bernini M, Orzalesi L, Nori J, Bianchi S, Livi L. Accelerated partial breast irradiation versus whole breast irradiation: Health-related quality of life analysis from a phase 3 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-10-04.