Factors modifying the risk for developing acute skin toxicity after whole-breast intensity modulated radiotherapy

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 x 2 Gy) or hypofractionated (15 x 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 = 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

Reproducibility of deep inspiration breath hold for prone left-sided whole breast irradiation

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

Une enquête de l'utilisation en Belgique de la radiothérapie pour des affections bénignes, non-tumorales

Two prior surveys were carried out in 1995 and 1999 to evaluate the use of radiotherapy in the treatment of non-malignant disease. In 2016, the same questionnaire was used and sent to the 24 centers of the country: 22 responded. A major decrease was observed in the number of patients treated: 360 in 2016 in contrast to 954 in 1999 and 1113 in 1995. The most frequent indications remain the prevention of heterotopic bone formation, keloids or gynecomastia. A new indication was observed: trigeminal nevralgia treated with radiosurgery. Two frequent indications in the past disappeared: the prevention of coronary restenosis and the macular degeneration. A great agreement was observed regarding the possible indications for radiotherapy but also to avoid it for inflammatory pathologies.SCOPUS: ar.jDecretOANoAutActifinfo:eu-repo/semantics/publishe

Multimodality imaging using PET/CT (F)-fluorodeoxyglucose for radiotherapy field delineation of localized Hodgkin lymphoma.

It is now well demonstrated that (F)-fluorodeoxyglucose PET/CT is the most accurate imaging method for determining disease extent in Hodgkin lymphoma. Thus, up-front PET/CT is mandatory for involved node radiation therapy design. For a proper use of this new imaging modality for radiotherapy, some adaptations should be made to the PET/CT acquisition as well as to the report. Initial PET/CT should be performed in the radiotherapy treatment position. Nuclear medicine physicians should report to the radiation oncologist the precise location of each involved lymph node, for which the use of a common atlas of upper diaphragmatic nodal stations could be useful. All these new procedures have to be implemented in close collaboration among the different medical specialists providing care to Hodgkin lymphoma patients. We report here the usual procedures of PET/CT acquisition in the radiotherapy environment and propose a more sophisticated description of the different lymph nodes for a more efficient nuclear medicine report to the radiation oncologist.[Imagerie multimodale incluant la TEP/TDM au (18F)-fluorodésoxyglucose pour ladélinéation des champs d’irradiation du lymphome de Hodgkin localisé] Il est maintenant clairement établi que la TEP/tomodensitométrie au (18F)-fluorodésoxyglucose est la technique d’imagerie de référence pour le bilan d’extension des lymphomes de Hodgkin. Par conséquent, l’utilisation de la TEP/tomodensitométrie est indispensable pour la réalisation d’une radiothérapie de type involved-node. L’utilisation de cette imagerie fonctionnelle par les radiothérapeutes nécessite une acquisition des images et un compte rendu d’examen particuliers. La TEP préthérapeutique doit être réalisée en position de traitement. Le compte rendu doit décrire précisément l’ensemble des ganglions supposés envahis, raison pour laquelle une classification unique décrivant l’ensemble des aires ganglionnaires sus-diaphragmatiques est proposée. Cette nouvelle technique thérapeutique nécessite une collaboration étroite entre différentes spécialités médicales. Cet article a pour objet la description de la réalisation pratique de la TEP/tomodensitométrie en position de radiothérapie ainsi qu’une trame de compte rendu d’examen prenant en compte la description des différents ganglions sus-diaphragmatiques

Characteristics and dosimetric impact of intrafraction motion during peripheral lung cancer stereotactic radiotherapy: is a second midpoint cone beam computed tomography of added value?

Background: In our department, during lung stereotactic body radiation therapy (SBRT), all patients receive an intra-fractional midpoint cone beam computed tomography (CBCT). This study aimed to quantify the benefit of adding a second midpoint CBCT over a course of peripheral lung SBRT. Materials and methods: Six-hundred-sixty-four CBCTs from 166 patients were retrospectively analyzed. Treatments were based on the internal target volume (ITV) approach. An isotropic 0.5 cm margin was used to create the planning target volume (PTV) around the ITV. The prescribed dose was 48 Gy in 4 fractions to the PTV. Patients were divided into two groups: patients for whom the 3D-intra-fractional-variation (IFV) was &lt; 0.5 cm (105 patients) and patients with at least one 3D-IFV ≥ 0.5 cm (high-risk groups). Plans simulating the dosimetric impact of the IFV were created as follows: the original 2 arcs (ARC) were copied into a new plan consisting of 4 times ARC1 and 4 times ARC2. The delivery of ARC1 was always assumed to have occurred with the isocenter initially coordinated, whereas the positions of ARC2 were modified for each arc by the measured the 3D-IFV. Results: For the PTV, we obtained: D99% (Gy) = 45.2 vs. 48.2 Gy (p &lt; .0001); Dmean = 53 vs. 54 Gy (p &lt; .0001) for the reconstructed vs. planned dose values, respectively. For the ITV, the changes are less pronounced: D99%(Gy) = 52.2 vs. 53.6 Gy (p =.0007); Dmean = 56 vs. 56.8 Gy (p =.0144). The V48 Gy (%)-ITV coverage did not statistically change between the delivered vs. planned dose (p =.1803). Regarding the organs at risk for both groups, dose-volume-histograms were near-identical. Conclusion: We demonstrated that a single CBCT is sufficient and reliable to manage the IFV during peripheral lung SBRT

Characteristics and dosimetric impact of intrafraction motion during peripheral lung cancer stereotactic radiotherapy: is a second midpoint cone beam computed tomography of added value?

In our department, during lung stereotactic body radiation therapy (SBRT), all patients receive an intra-fractional midpoint cone beam computed tomography (CBCT). This study aimed to quantify the benefit of adding a second midpoint CBCT over a course of peripheral lung SBRT. Six-hundred-sixty-four CBCTs from 166 patients were retrospectively analyzed. Treatments were based on the internal target volume (ITV) approach. An isotropic 0.5 cm margin was used to create the planning target volume (PTV) around the ITV. The prescribed dose was 48 Gy in 4 fractions to the PTV. Patients were divided into two groups: patients for whom the 3D-intra-fractional-variation (IFV) was < 0.5 cm (105 patients, low risk group) and patients with at least one 3D-IFV ≥ 0.5 cm (61 patients, high-risk group). Plans simulating the dosimetric impact of the IFV were created as follows: the original 2 arcs (ARC ) were copied into a new plan consisting of 4 times ARC 1 and 4 times ARC 2. The delivery of ARC 1 was always assumed to have occurred with the isocenter initially coordinated, whereas the positions of ARC 2 were modified for each arc by the measured the 3D-IFV. For the PTV, we obtained: D99% (Gy) = 45.2 . 48.2 Gy (p < 0.0001); Dmean = 53 . 54 Gy (p < .0001) for the reconstructed . planned dose values, respectively. For the ITV, the changes are less pronounced: D99% (Gy) = 52.2 . 53.6 Gy (p = 0.0007); Dmean = 56 . 56.8 Gy (p = 0.0144). The V48 Gy(%)-ITV coverage did not statistically change between the delivered . planned dose (p = 0.1803). Regarding the organs at risk for both groups, dose-volume-histograms were near-identical. We demonstrated that a single CBCT is sufficient and reliable to manage the IFV during peripheral lung SBRT

Dosimetric Impact of Intrafraction Motion During Peripheral Lung Cancer Stereotactic Radiotherapy: Is a Second Cone Beam Computed Tomography of Added Value?

PURPOSE/OBJECTIVE(S): In our department, during lung SBRT, all patients (regardless of tumor location) receive an additional intra-fractional CBCT, allowing us to adjust the beam delivery accordingly to the intra-fractional variation (IFV). It is to be expected that each IFV exceeding the planning target volume (PTV) margins could lead to potential discrepancies between planned and delivered plans. A posteriori robust dosimetric evaluation will help us to quantify the actual impact on the target's volumes coverage. MATERIALS/METHODS: Six hundred sixty-four CBCTs from 166 consecutives free-breathing lung SBRT patients were retrospectively analyzed. Treatments were based on the internal target volume (ITV) approach with a 4D-CT at simulation and performed using volumetric modulated arc therapy. An isotropic 0.5 cm margin was used to create the PTV around the ITV. The prescribed dose was 48 Gy in 4 fractions to the PTV (80% isodose line). Patients were divided into two groups: patients for whom the 3D-IFV was below 0.5 cm (low-risk group: 105 patients, 573/664 fractions) and patients with at least one 3D-IFV ≥ 0.5 cm (high-risk group: 61 patients, 91/664 fractions). Plans simulating the dosimetric impact of the IFV were created as follows: the original two arcs were copied into a new plan consisting of 4 times ARC1 and 4 times ARC2. The delivery of ARC1 was always assumed to have occurred with the isocenter coordinates as those in the original plan, whereas the positions of ARC2 were modified for each arc by the measured the 3D displacement for that fraction according to the intra-fraction CBCT. RESULTS: The IFV reduces both the minimal (D99%) and mean (Dmean) dose to both the PTV and the ITV. For the PTV, we obtained: D99(%) = 45.2 vs 48.2 Gy (P 0.5 cm was observed for 3 and 4 fractions, respectively. Regarding the organs at risk (D99%; Dmean; Dmax): for both the low- and high-risk groups, dose-volume histograms were near-identical (no significant difference). CONCLUSION: Although IFV results in a significant change between the delivered vs planned dose distributions for the PTV (D99%; V48Gy; Dmean) and on the ITV (D99%; Dmean), the V48Gy-ITV coverage did not statistically change. Based on our data we demonstrated that a single CBCT is sufficient and reliable to manage the IFV during peripheral lung SBRT.SCOPUS: ar.jDecretOANoAutActifinfo:eu-repo/semantics/publishe

Standardizing mediastinal nodal CTV delineation in Stage III NSCLC: results of a two-phase dummy run

[Purpose or Objective] Lymph node delineation in stage III non-small cell lung cancer (NSCLC) remains the subject of discussion as the inclusion or omission of a lymph node or station can have an important impact on both oncological outcome and toxicity. The Belgian College for Physicians in Radiation Oncology aims to improve the quality of radiotherapy in Belgium. Within this framework the Project on Cancer of the Lung (ProCaLu) focuses on standardizing delineation for locally advanced NSCLC. A two-phase contouring dummy-run on a single test case was performed to analyze the baseline interobserver variability on target definition and delineation and evaluate the effects of a national consensus before the start of a peer-review program for routine clinical practice. [Material and Methods] All 25 radiotherapy centers in Belgium and Luxembourg were invited to take part in a delineation dummy-run by sending contours from at least one radiation oncologist (RO) dedicated to lung cancer treatments. The case consisted of a squamous cell carcinoma of the right upper lobe with nodal extension to station 4R staged cT1bN2M0 (TNM 7). The results of chest CT, PET/CT and endoscopic samplings were provided to participants and the planning CT was made available through a secure transfer platform. RO's were asked to delineate and upload back the GTV and CTV for the nodal disease. More than a year later and after the formulation of a national consensus based on current ESTRO guidelines (inclusion of only involved nodes with a 5 mm CTV margin) the case was resent to all centers with the same purpose. On all received contours, a description of the TV definition and delineation was obtained through visual inspection. Using an open-source software (3D Slicer with SlicerRT), the DICE Similarity Index and Hausdorff distances were analyzed to compare the delineations. To allow an evaluation of uniformity with these metrics, independent GTV and CTV contours by the first author were used as reference. [Results] At the first phase, 16 contours sent by 14 RT centers were analyzed. Important variations were due to the inclusion of a negative node in GTV (ninfo:eu-repo/semantics/publishedESTRO 38, 26-30 April 2019, Milan, Ital

Illustration of a fatal radiation-induced lung aneurysm: Is central lung stereotactic radiotherapy to be banned?

Stereotactic body radiation therapy is still controversial for inoperable patients with central lung lesion. We report the case of a 59-year-old woman with previous history of head and neck squamous cell carcinoma who was treated by lung stereotactic body irradiation for an inoperable lymph node in station 10R. One year after, a fibroscopy showed a necrosis of the right main bronchus mucosae and the CT showed a radio-induced aneurysm protruding into the right inferior lobular bronchus. The patient eventually died a few hours later with a massive haemoptysis. This case highlights the potential toxicity of central lung stereotactic body radiation therapy and raises the question of its legitimacy