Search

Purpose: We report on a dosimetrical study of three patient positions (supine, prone dive, and prone crawl) and four irradiation techniques for whole-breast irradiation (WBI): wedged-tangential fields (W-TF), tangential-field intensity-modulated radiotherapy (TF-IMRT), multi-beam IMRT (MB-IMRT), and intensity-modulated arc therapy (IMAT). This is the first study to evaluate prone crawl positioning in WBI and the first study to quantify dosimetrical and anatomical differences with prone dive positioning., Methods: We analyzed five datasets with left- and right-sided patients (n = 51). One dataset also included deep-inspiration breath hold (DIBH) data. A total of 252 new treatment plans were composed. Dose-volume parameters and indices of conformity were calculated for the planning target volume (PTV) and organs-at-risk (OARs). Furthermore, anatomical differences among patient positions were quantified to explain dosimetrical differences., Results: Target coverage was inferior for W-TF and supine position. W-TF proved overall inferior, and IMAT proved foremost effective in supine position. TF-IMRT proved competitive to the more demanding MB-IMRT and IMAT in prone dive, but not in prone crawl position. The lung-sparing effect was overall confirmed for both prone dive and prone crawl positioning and was largest for prone crawl. For the heart, no differences were found between prone dive and supine positioning, whereas prone crawl showed cardiac advantages, although minor compared to the established heart-sparing effect of DIBH. Dose differences for contralateral breast were minor among the patient positions. In prone crawl position, the ipsilateral breast sags deeper and the PTV is further away from the OARs than in prone dive position., Conclusions: The prone dive and prone crawl position are valid alternatives to the supine position in WBI, with largest advantages for lung structures. For the heart, differences are small, which establishes the role of DIBH in different patient positions. These results may be of particular interest to radiotherapy centers with limited technical resources., (© 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.)

Introduction: A simultaneous integrated boost (SIB) leads to less acute toxicity. Less is known for late toxicity due to SIB. In this first and only randomized trial, two-years toxicity is analysed., Materials and Methods: Physician-assessed toxicity, using the LENT SOMA scale, and photographs, analysed with the BCCT.core software, was examined for 150 patients, randomized between SIB and sequential boost (SEB)., Results: Differences in physician-assessed two-years toxicity and photographic analysis between SIB and SEB are very small and not significant., Conclusion: There is no indication that a SIB leads to an excess in toxicity or worse cosmetic outcome at 2 years., Competing Interests: Conflict of interest This work was supported by the Cancer Plan Action 29 (project 015 and 008) by the Federal Public Service of Health, Food Chain Safety and Environment, Belgium and by grants of Stand up to Cancer (Flemish Cancer Society) and Foundation against Cancer (FAF-C/2016/854). Liv Veldeman holds a Clinical Mandate of Foundation against Cancer. None of the other auteurs have a conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: To investigate, in a prospective phase 1 to 2 trial, the safety and feasibility of delivering external beam radiation therapy in 5 fractions to the breast or thoracic wall, including boost and/or lymph nodes if needed, to women aged ≥65 years with breast cancer., Methods and Materials: Ninety-five patients aged ≥65 years, referred for adjuvant radiation therapy, were treated in 5 fractions over 12 days with a total dose of 28.5 Gy/5.7 Gy to the breast or thoracic wall and, if indicated, 27 Gy/5.4 Gy to the lymph node regions and 32.5 Gy/6.5 Gy to 34.5 Gy/6.9 Gy to the tumor bed. The primary endpoint was clinically relevant dermatitis (grade ≥2)., Results: Mean follow-up time was 5.6 months, and mean age was 73.6 years. Clinically relevant dermatitis was observed in 11.6% of patients and only occurred in breast irradiation with boost (17.5% grade 2-3 vs 0% in the no-boost group). Although doses were high, treatment delivery with intensity modulated radiation therapy was swift, except for complex treatments, including lymph nodes for which single-arc volumetric modulated arc therapy was needed to reduce beam-on time., Conclusion: Accelerated radiation therapy in 5 fractions was technically feasible and resulted in low acute toxicity. Clinically relevant erythema was only observed in patients receiving a boost, but still at an acceptable rate. Although the follow-up is still short, the results on acute toxicity after accelerated radiation therapy were encouraging. A 5-fraction schedule is well tolerated in the elderly and may lower the threshold for radiation therapy in this population., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Investigating reproducibility and instability of deep inspiration breath hold (DIBH) in the prone position to reduce heart dose for left-sided whole breast irradiation., Methods: Thirty patients were included and underwent 2 prone DIBH CT-scans during simulation. Overlap indices were calculated for the ipsilateral breast, heart and lungs to evaluate the anatomical reproducibility of the DIBH maneuver. The breathing motion of 21 patients treated with prone DIBH were registered using magnetic probes. These breathing curves were investigated to gain data on intra-fraction reproducibility and instability of the different DIBH cycles during treatment., Results: Overlap index was 0.98 for the ipsilateral breast and 0.96 for heart and both lungs between the 2 prone DIBH-scans. The magnetic sensors reported population amplitudes of 2.8 ± 1.3 mm for shallow breathing and 11.7 ± 4.7 mm for DIBH, an intra-fraction standard deviation of 1.0 ± 0.4 mm for DIBH, an intra-breath hold instability of 1.0 ± 0.6 mm and a treatment time of 300 ± 69 s., Conclusion: Prone DIBH can be accurately clinically implemented with acceptable reproducibility and instability.

Purpose: To quantify the influence on heart dose metrics of prone left-sided whole-breast irradiation in an end-inspiratory phase (PrIN) versus an end-expiratory phase (PrEX)., Patients and Methods: Twenty patients underwent CT-simulation in PrIN and PrEX. Dynamic intensity-modulated radiotherapy was planned for whole-breast irradiation with a median prescription dose of 40.05Gy in 15 fractions and maximal sparing of the organs at risk. Dose-volume parameters were analyzed for heart, left anterior descending coronary artery, ipsilateral lung and both breasts., Results: PrIN consistently reduced (P<0.001) heart and left anterior descending coronary artery dose metrics compared to PrEX. Population averages for maximum and mean heart dose were 6.2Gy and 1.3Gy for PrIN versus 21.4Gy and 2.5Gy for PrEX, respectively. Moreover, a maximum heart dose less than 10Gy was achieved in 80% of patients for PrIN. Target dose distribution, ipsilateral lung and contralateral breast sparing by radiation dose were similar for both procedures., Conclusions: Inspiratory gating consistently reduced heart dose metrics pointing to a possible benefit of breathing-adapted radiotherapy for prone left-sided whole-breast irradiation., (Copyright © 2014 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.)

Background: After breast-conserving radiation therapy most patients experience acute skin toxicity to some degree. This may impair patients' quality of life, cause pain and discomfort. In this study, we investigated treatment and patient-related factors, including genetic polymorphisms, that can modify the risk for severe radiation-induced skin toxicity in breast cancer patients., Methods: We studied 377 patients treated at Ghent University Hospital and at ST.-Elisabeth Clinic and Maternity in Namur, with adjuvant intensity modulated radiotherapy (IMRT) after breast-conserving surgery for breast cancer. Women were treated in a prone or supine position with normofractionated (25 × 2 Gy) or hypofractionated (15 × 2.67 Gy) IMRT alone or in combination with other adjuvant therapies. Patient- and treatment-related factors and genetic markers in regulatory regions of radioresponsive genes and in LIG3, MLH1 and XRCC3 genes were considered as variables. Acute dermatitis was scored using the CTCAEv3.0 scoring system. Desquamation was scored separately on a 3-point scale (0-none, 1-dry, 2-moist)., Results: Two-hundred and twenty patients (58%) developed G2+ dermatitis whereas moist desquamation occurred in 56 patients (15%). Normofractionation (both p < 0.001), high body mass index (BMI) (p = 0.003 and p < 0.001), bra cup size ≥ D (p = 0.001 and p = 0.043) and concurrent hormone therapy (p = 0.001 and p = 0.037) were significantly associated with occurrence of acute dermatitis and moist desquamation, respectively. Additional factors associated with an increased risk of acute dermatitis were the genetic variation in MLH1 rs1800734 (p=0.008), smoking during RT (p = 0.010) and supine IMRT (p = 0.004). Patients receiving trastuzumab showed decreased risk of acute dermatitis (p < 0.001)., Conclusions: The normofractionation schedule, supine IMRT, concomitant hormone treatment and patient related factors (high BMI, large breast, smoking during treatment and the genetic variation in MLH1 rs1800734) were associated with increased acute skin toxicity in patients receiving radiation therapy after breast-conserving surgery. Trastuzumab seemed to be protective.

Background and Purpose: Comparison of acute toxicity of whole-breast irradiation (WBI) in prone and supine positions., Materials and Methods: This non-blinded, randomized, prospective, mono-centric trial was undertaken between December 29, 2010, and December 12, 2012. One hundred patients with large breasts were randomized between supine multi beam (MB) and prone tangential field (TF) intensity modulated radiotherapy (IMRT). Dose-volume parameters were assessed for the breast, heart, left anterior descending coronary artery (LAD), ipsilateral lung and contralateral breast. The primary endpoint was acute moist skin desquamation. Secondary endpoints were dermatitis, edema, pruritus and pain., Results: Prone treatment resulted in: improved dose coverage (p<0.001); better homogeneity (p<0.001); less volumes of over-dosage (p=0.001); reduced acute skin desquamation (p<0.001); a 3-fold decrease of moist desquamation p=0.04 (chi-square), p=0.07 (Fisher's exact test)); lower incidence of dermatitis (p<0.001), edema (p=0.005), pruritus (p=0.06) and pain (p=0.06); 2- to 4-fold reduction of grades 2-3 toxicity; lower ipsilateral lung (p<0.001) and mean LAD (p=0.007) dose; lower, though statistically non-significant heart and maximum LAD., Conclusions: This study provides level I evidence for replacing the supine standard treatment by prone IMRT for whole-breast irradiation in patients with large breasts. A confirmatory trial in a multi-institutional setting is warranted., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Early stage breast cancer patients are long-term survivors and finding techniques that may lower acute and late radiotherapy-induced toxicity is crucial. We compared dosimetry of wedged tangential fields (W-TF), tangential field intensity-modulated radiotherapy (TF-IMRT) and multi-beam IMRT (MB-IMRT) in prone and supine positions for whole-breast irradiation (WBI)., Methods: MB-IMRT, TF-IMRT and W-TF treatment plans in prone and supine positions were generated for 18 unselected breast cancer patients. The median prescription dose to the optimized planning target volume (PTVoptim) was 50 Gy in 25 fractions. Dose-volume parameters and indices of conformity were calculated for the PTVoptim and organs-at-risk., Results: Prone MB-IMRT achieved (p<0.01) the best dose homogeneity compared to WTF in the prone position and WTF and MB-IMRT in the supine position. Prone IMRT scored better for all dose indices. MB-IMRT lowered lung and heart dose (p<0.05) in supine position, however the lowest ipsilateral lung doses (p<0.001) were in prone position. In left-sided breast cancer patients population averages for heart sparing by radiation dose was better in prone position; though non-significant. For patients with a PTVoptim volume ≥600 cc heart dose was consistently lower in prone position; while for patients with smaller breasts heart dose metrics were comparable or worse compared to supine MB-IMRT. Doses to the contralateral breast were similar regardless of position or technique. Dosimetry of prone MB-IMRT and prone TF-IMRT differed slightly., Conclusions: MB-IMRT is the treatment of choice in supine position. Prone IMRT is superior to any supine treatment for right-sided breast cancer patients and left-sided breast cancer patients with larger breasts by obtaining better conformity indices, target dose distribution and sparing of the organs-at-risk. The influence of treatment techniques in prone position is less pronounced; moreover dosimetric differences between TF-IMRT and MB-IMRT are rather small.

Purpose: The objective of this study was to compare setup precision, respiration-related breast movement and treatment time between prone and supine positions for whole-breast irradiation., Methods and Materials: Ten patients with early-stage breast carcinoma after breast-conserving surgery were treated with prone and supine whole breast-irradiation in a daily alternating schedule. Setup precision was monitored using cone-beam computed tomography (CBCT) imaging. Respiration-related breast movement in the vertical direction was assessed by magnetic sensors. The time needed for patient setup and for the CBCT procedure, the beam time, and the length of the whole treatment slot were also recorded., Results: Random and systematic errors were not significantly different between positions in individual patients for each of the three axes (left-right, longitudinal, and vertical). Respiration-related movement was smaller in prone position, but about 80% of observations showed amplitudes <1 mm in both positions. Treatment slots were longer in prone position (21.2 ± 2.5 min) than in supine position (19.4 ± 0.8 min; p = 0.044)., Conclusion: Comparison of setup precision between prone and supine position in the same patient showed no significant differences in random and systematic errors. Respiratory movement was smaller in prone position. The longer treatment slots in prone position can probably be attributed to the higher repositioning need., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: To investigate the association between dose-related parameters and polymorphisms in DNA DSB repair genes XRCC3 (c.-1843A>G, c.562-14A>G, c.722C>T), Rad51 (c.-3429G>C, c.-3392G>T), Lig4 (c.26C>T, c.1704T>C), Ku70 (c.-1310C>G), and Ku80 (c.2110-2408G>A) and the occurrence of acute reactions after radiotherapy., Materials and Methods: The study population consisted of 88 intensity-modulated radiation therapy (IMRT)-treated head-and-neck cancer patients. Mucositis, dermatitis, and dysphagia were scored using the Common Terminology Criteria (CTC) for Adverse Events v.3.0 scale. The population was divided into a CTC0-2 and CTC3+ group for the analysis of each acute effect. The influence of the dose on critical structures was analyzed using dose-volume histograms. Genotypes were determined by polymerase chain reaction (PCR) combined with restriction fragment length polymorphism or PCR-single base extension assays., Results: The mean dose (D(mean)) to the oral cavity and constrictor pharyngeus (PC) muscles was significantly associated with the development of mucositis and dysphagia, respectively. These parameters were considered confounding factors in the radiogenomics analyses. The XRCC3c.722CT/TT and Ku70c.-1310CG/GG genotypes were significantly associated with the development of severe dysphagia (CTC3+). No association was found between the investigated polymorphisms and the development of mucositis or dermatitis. A risk analysis model for severe dysphagia, which was developed based on the XRCC3c.722CT/TT and Ku70c.-1310CG/GG genotypes and the PC dose, showed a sensitivity of 78.6% and a specificity of 77.6%., Conclusions: The XRCC3c.722C>T and Ku70c.-1310C>G polymorphisms as well as the D(mean) to the PC muscles were highly associated with the development of severe dysphagia after IMRT. The prediction model developed using these parameters showed a high sensitivity and specificity.

Since its introduction more than a decade ago, intensity-modulated radiotherapy (IMRT) has spread to most radiotherapy departments worldwide for a wide range of indications. The technique has been rapidly implemented, despite an incomplete understanding of its advantages and weaknesses, the challenges of IMRT planning, delivery, and quality assurance, and the substantially increased cost compared with non-IMRT. Many publications discuss the theoretical advantages of IMRT dose distributions. However, the key question is whether the use of IMRT can be exploited to obtain a clinically relevant advantage over non-modulated external-beam radiation techniques. To investigate which level of evidence supports the routine use of IMRT for various disease sites, we did a review of clinical studies that reported on overall survival, disease-specific survival, quality of life, treatment-induced toxicity, or surrogate endpoints. This review shows evidence of reduced toxicity for various tumour sites by use of IMRT. The findings regarding local control and overall survival are generally inconclusive.