Simplified field-in-field technique for a large-scale implementation in breast radiation treatment

doi:10.1016/j.meddos.2011.03.002

Medical Dosimetry

Volume 37, Issue 2, Summer 2012, Pages 131-137

https://doi.org/10.1016/j.meddos.2011.03.002 Get rights and content

Abstract

We wanted to evaluate a simplified “field-in-field” technique (SFF) that was implemented in our department of Radiation Oncology for breast treatment. This study evaluated 15 consecutive patients treated with a simplified field in field technique after breast-conserving surgery for early-stage breast cancer. Radiotherapy consisted of whole-breast irradiation to the total dose of 50 Gy in 25 fractions, and a boost of 16 Gy in 8 fractions to the tumor bed. We compared dosimetric outcomes of SFF to state-of-the-art electronic surface compensation (ESC) with dynamic leaves. An analysis of early skin toxicity of a population of 15 patients was performed. The median volume receiving at least 95% of the prescribed dose was 763 mL (range, 347–1472) for SFF vs. 779 mL (range, 349–1494) for ESC. The median residual 107% isodose was 0.1 mL (range, 0–63) for SFF and 1.9 mL (range, 0–57) for ESC. Monitor units were on average 25% higher in ESC plans compared with SFF. No patient treated with SFF had acute side effects superior to grade 1-NCI scale. SFF created homogenous 3D dose distributions equivalent to electronic surface compensation with dynamic leaves. It allowed the integration of a forward planned concomitant tumor bed boost as an additional multileaf collimator subfield of the tangential fields. Compared with electronic surface compensation with dynamic leaves, shorter treatment times allowed better radiation protection to the patient. Low-grade acute toxicity evaluated weekly during treatment and 2 months after treatment completion justified the pursuit of this technique for all breast patients in our department.

Introduction

Breast-conserving surgery, followed by whole-breast radiotherapy (RT), is the standard of care for patients with early-stage breast cancer.1, 2, 3 Patients also benefit from the addition of a tumor bed boost, which has been shown to decrease local recurrence after conservative treatment.4, 5 Although the use of boost irradiation is recommended, the standard technique and definition of the tumor bed volume have not been clearly established.6, 7 This issue is becoming paramount with the improvement of RT planning, such as the use of techniques adapted to the patient's anatomy⁸ or intensity-modulated radiotherapy (IMRT) boost,9, 10 and is essential in the case of dose escalation.¹¹

In addition, some authors have already suggested that minimization of unwanted radiation dose heterogeneity in the breast could reduce late adverse effects. Incidence of change in breast appearance was statistically higher in patients in the standard 2D treatment arm compared with the IMRT arm.¹² A beneficial effect on quality of life remains to be demonstrated. It was already shown that breast IMRT significantly reduces the occurrence of moist desquamation compared with a standard wedged technique.¹³

Today, there is a large choice of techniques for breast radiation treatment owing to advances in linear accelerators (LINAC) technology and treatment planning systems. Ideally, we need a technique that is applicable to the large majority of breast patients, that simplifies and shortens treatment delivery, that is well understood by dosimetrists and technologists to avoid unwanted events, that requires very little quality assurance (QA), and that is not labor-intensive for the treatment machines.

At our institution, forward planned breast fields are set on the virtual simulation after computed tomography (CT) scan acquisition. Contouring the breast planning target volume (PTV) is rarely performed (except in complex cases for patients who undergo tomotherapy). A time lapse of 5–7 working days includes CT with virtual simulation, dosimetry, approval by radiation oncologist, physics quality assurance (QA), plan transfer to LINAC record and verify, approval for treatment. It is therefore important that each step in the treatment preparation is kept as short as possible.

The aim of this study was to assess a simplified field-in-field technique (SFF) that is easily implemented in a Department of Radiation Oncology and to compare it with the state-of-the-art electronic surface compensation (ESC) regarding dose homogeneity and coverage. Early skin toxicity in 15 patients is reported.

Section snippets

Patients

This study evaluated 15 consecutive patients (7 right and 8 left-breast patients) treated with a SFF technique at the Institut Curie. All patients underwent conserving surgery for early-stage breast cancer, followed by whole-breast irradiation to the total dose of 50 Gy in 25 fractions, and a boost of 16 Gy in 8 fractions to the tumor bed using a technique described previously.9, 10

In our standard practice, all patients are followed up weekly during RT and acute toxicity is assessed using the

Clinical outcome

Treatment tolerance was very good, with no patient experiencing acute side effects superior to grade 1. The skin pigmentation during radiation was homogenous; there was no increase of toxicity at the breast inferior fold nor in the axillary superficial region. At 2-month follow-up, all patients showed no sign of residual dermatitis.

Dosimetric comparison of SFF and ESC

Table 1a, Table 1b show dosimetric results for the 2 techniques.

The median irradiated volume was 1114 mL (range, 576–2431). Nonoptimized plans showed a median volume

Implementation of SFF

Before releasing the SFF into clinical use, tests have been performed to check the accuracy of dose calculation and treatment delivery. QA plans were created that allowed dose calculation in flat homogeneous phantoms using the optimized fluence from patients' plans. Main discrepancies were found at leaf edges and beam corners but were within acceptable levels: <3% in high dose−low dose gradient regions, <3 mm in low dose–high dose gradient areas. We have fixed rules for minimum subfield MU and

Conclusion

This study presents a SFF breast technique that was implemented in our radiation oncology department. This technique creates homogenous 3D dose distribution equivalent to electronic surface compensation with dynamic leaves. It is easily implemented in an RT department without adding workload in the planning, QA, and treatment processes. It allows the integration of a forward-planned concomitant tumor bed boost as an additional MLC subfield of the tangential fields. Shorter treatment times allow

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Cited by (31)

Patient selection and early tolerance of whole breast irradiation according to the “Fast Forward” protocol: Preliminary results
2022, Cancer/Radiotherapie
La radiothérapie hypofractionnée modérée est devenue une pratique de routine pour une population sélectionnée de patientes traitées pour un cancer du sein de stade précoce. En avril 2020 est publiée l’étude Fast Forward qui introduit un autre schéma de radiothérapie hypofractionnée extrême en cinq séances sur une semaine. L’objectif de ce travail était d’évaluer la population de premières patientes chez qui ce schéma a été utilisé dans notre département, ainsi que les résultats en termes de toxicité précoce.
Nous avons rétrospectivement analysé toutes les patientes traitées dans notre département selon le protocole Fast Forward après la sortie de la publication originale et après établissement d’un consensus institutionnel vis-à-vis de la sélection des patientes atteintes d’un cancer du sein sans indication à une irradiation ganglionnaire. Toutes les patientes ont reçu une irradiation du sein seul à la dose totale de 26 Gy en cinq fractions conformément au protocole. Toutes les patientes ont été traitées par des techniques modernes conformationnelles avec une couverture du volume cible prévisionnel entre 95 et 100 %. La toxicité aiguë du traitement a été évaluée à l’aide de l’échelle du National Cancer Institute (NCI) des Common Toxicity Criteria (CTC) v4.0 et l’état général a été évalué selon la classification de l’Organisation mondiale de la santé.
Entre août 2020 et mai 2021, 30 patientes ont été incluses, traitées dans le sein seul sans complément dans le lit tumoral ni irradiation des aires ganglionnaires. L’âge médian des patientes était 80 ans (entre 60 et 85 ans) avec un état général moyen OMS 2 dans 27 cas (90 %). Une seule patiente était atteinte d’une maladie métastatique (3 %), et 29 (97 %) patientes étaient atteintes d’une maladie de stade précoce. Trois patientes (10 %) ont été traitées en décubitus dorsal selon la technique « champ dans le champ » et 27 patientes (90 %) en décubitus latéral isocentrique, qui a permis d’éviter les organes à risque comme le cœur (dose moyenne de moins d’1 Gy) et les poumons. La toxicité précoce observée était une radiodermite de grade I chez huit patientes (27 %). Aucun cas de douleurs ou lymphœdème radio-induits n’a été observé.
Les résultats de cette série de patientes traitées par une irradiation hypofractionnée selon le protocole Fast Forward sur le sein seul avec des techniques adaptées montrent que le protocole est faisable, avec peu de toxicité précoce mais un recul plus important est nécessaire pour évaluer la toxicité à long terme.
Moderate hypofractionated radiotherapy has become routine practice for a selected population of patients treated for early-stage breast cancer. In April 2020, the Fast Forward (FF) study was published which introduced another extreme hypofractionated radiotherapy regimen in five sessions over a week. The aim of this work is to evaluate the population of first patients in whom this regimen was used in our department, as well as the results in terms of early toxicity.
We retrospectively analysed all the patients treated in our department according to the Fast Forward protocol after establishing an institutional consensus regarding the selection of patients with breast cancer without indication for lymph node irradiation. All patients received breast-only irradiation at a total dose of 26 Gy in five fractions according to protocol. All patients were treated by modern conformational techniques with planning large volume coverage between 95 and 100%. Acute toxicity of the treatment was assessed using the NCI CTC v4.0 scale and the general condition was assessed according to the WHO classification.
Between August 2020 and May 2021, 30 patients were included, treated on the breast alone without complement on the tumour bed or irradiation of the lymph node areas. The median age of the patients was 80 years (range: 60–85 years) with performance status 2 in 27 cases (89%). Only one patient had metastatic disease (3%), one patient presented locally advanced and 28 (94%) patients had early stage disease. Three patients (10%) were treated in dorsal decubitus according to the “field in the field” technique and 27 patients (90%) in isocentric lateral decubitus, which made it possible to avoid the organs at risk such as the heart (average dose of less than 1 Gy) and the lungs. The early toxicity observed was grade I radio dermatitis in 8 patients (27%). No grade 2 and 3 toxicity, as well as radiation-induced pain or lymphedema were observed.
The results of this series of patients treated with hypofractionated radiotherapy according to the Fast Forward protocol on the breast alone with adapted techniques show that the protocol is feasible, with little early toxicity but a greater follow-up is necessary to assess long-term toxicity.
Concurrent radiation therapy and dual HER2 blockade in breast cancer: Assessment of toxicity
2021, Cancer/Radiotherapie
La tolérance de l’association d’une radiothérapie concomitante à un traitement par pertuzumab et trastuzumab ) est encore inconnue. L’objectif de ce travail était d’évaluer la tolérance de cette association chez des patientes traitées pour un cancer du sein localement évolué ou métastatique surexprimant HER2 .
Étude rétrospective menée à l’institut Curie chez toutes les patientes traitées en concomitance par pertuzumab, trastuzumab et irradiation. La radiothérapie a été délivrée pendant un traitement par maintenance par pertuzumab et trastuzumab à respectivement 420 mg (dose totale) et 6 mg/kg toutes les trois semaines sans chimiothérapie. L’évaluation de la toxicité a été faite selon la « National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0 ». La fraction d’éjection ventriculaire gauche (FEVG) a été évalué dans le bilan pré-thérapeutique et puis tous les 3 à 4 mois.
Nous avons étudié 77 patientes traitées entre octobre 2013 et décembre 2019 avec un suivi médian de 38 mois (extrêmes : 0–246 mois). L’âge médian était de 53 ans (extrêmes : 36–86 ans). Il y avait 50 patientes (64,9 %) atteintes de métastatses au moment du diagnostic et 27 patientes (35,1 %) en situation de récidive. Toutes les patientes ont reçu comme première ligne thérapeutique une chimiothérapie à base de taxanes suivie par pertuzumab et trastuzumab avec un nombre de cycle médian de 34 (10–85). Toutes les patientes avaient une réponse partielle ou complète selon les critères RECIST. Les volumes de radiothérapie étaient le sein (41 patientes, 53,2 %) et la paroi thoracique (29 patientes, 37,7 %) à la dose de 50 Gy avec une durée médiane de traitement de 39 jours. Une irradiation des aires ganglionnaires régionales a été délivrée chez 53 patientes (68,8 %) comme suit : irradiation sus/sous claviculaire axillaire chez 52 patientes (67,5 %) et mammaire interne chez 31 patientes (40,3 %). Pour 20 patientes, la radiothérapie était à visée palliative : osseuse (12 patientes, 15,6 %), de encéphale in toto (2 patientes, 2,6 %), de nodules métastatiques cérébraux (six patientes). Comme toxicité aiguë, nous avons observé : une radioépithéliite de grade 1 chez 36 patientes (46,8 %), de grade 2 chez 17 patientes (22,1 %) et de grade 3 chez trois patientes (3,9 %). Une patiente a souffert d'une œsophagite de grade 2 et une d'une baisse asymptomatique de la FEVG en cours de traitement par pertuzumab, trastuzumab et irradiation. Comme toxicité tardive, nous avons observé des télangiectasies chez deux patientes, de grade 1 (1,3 %) et de grade 2 (1,3 %) ; il y a eu un cas de cardiotoxicité de grade 3 huit mois après la fin de la radiothérapie.
Le traitement concomitant par irradiation, pertuzumab et trastuzumab semble avec un bon profil de tolérance ; une étude prospective plus large avec un suivi plus prolongé reste cependant nécessaire pour confirmer ces résultats.
The tolerance of the concurrent use of radiotherapy, pertuzumab and trastuzumab is unknown. The purpose of this study was to evaluate the toxicity of this association in patients treated for HER2 positive metastatic and/or locally recurrent unrespectable breast cancer.
A retrospective study was performed in our institution for all consecutive patients treated with concurrent irradiation, pertuzumab and trastuzumab. The radiotherapy was performed while pertuzumab and trastuzumab were administrated as a maintenance treatment at the dose of 420 mg (total dose) and 6 mg/kg respectively every 3 weeks without chemotherapy. Toxicity was assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Left ventricular ejection fraction (LVEF) was measured at baseline and then every 3–4 months.
We studied 77 patients. treated in between 2013 and 2019 with median follow-up of 38 months (range 0–264 months). Median age was 53 years (33–86). There were 50 patients (64.9%) with metastatic and 27 patients (35.1%) with recurrent disease. All patients received docetaxel followed by P–T as first line treatment and they received 34 cycles (10–85) of pertuzumab and trastuzumab. All patients experienced partial or complete response according to RECIST criteria. Irradiation volumes were whole breast (41 patients, 53.2%) and chest wall (29 patients, 37.7%) at a dose of 50 Gy with a median duration of 39 days. Radiotherapy of lymph nodes was performed in 53 patients (68.8%) as following: supraclavicular–infraclavicular and axillary lymph nodes in 52 patients (67.5%), and internal mammary nodes in 31 patients (40.3%). For 20 patients. (26.0%) radiotherapy was palliative: bone irradiation (12 patients, 15.6%), whole-brain radiotherapy (2 patients, 2.6%), cerebral metastasis irradiation (6 patients). As early toxicity we observed: radio dermatitis as following: 36 patients (46.8%) presented grade I, 17 patients (22.1%) presented grade II, and 3 patients (3.9%) presented grade III. One patient (1.3%) presented grade II esophagitis. One patient (1.3%) presented asymptomatic decrease of LVEF during treatment and 6 patients (7.7%) presented a decrease of LVEF. There was no radiation-induced pneumonitis. As late toxicity, we observed 1 (1.3%) case of grade I and 1 (1.3%) with grade II telangiectasia. There was 1 case (1.3%) of grade III cardiac toxicity, 8 months after the concurrent treatment.
The concurrent use of radiotherapy, pertuzumab and trastuzumab is feasible with good tolerance. Larger prospective data with longer follow-up is needed to confirm these results.
In Reply to Khosla et al
2019, International Journal of Radiation Oncology Biology Physics
Disseminated Tumor Cells Predict Efficacy of Regional Nodal Irradiation in Early Stage Breast Cancer
2019, International Journal of Radiation Oncology Biology Physics
Citation Excerpt :
The IMN region was treated by a mixed photon–electron technique. Whole breast or chest wall and SCN/axillary regions were irradiated, using previously described techniques set up at Institut Curie.17-19 Follow-up was performed at Institut Curie for the first 5 years after treatment and included clinical examination every 6 months and annual bilateral mammography.
Disseminated tumor cells (DTCs) collect in the bone marrow and indicate micrometastatic spread. We previously reported that DTCs could be a predictive factor for the efficacy of regional node irradiation (internal mammary nodes [IMNs]/supra- and infraclavicular nodes [SCNs]). In this article, we report the long-term results (>10 years) on the impact of DTC status in early stage breast cancer.
Patients with localized breast cancer were eligible for inclusion in this prospective cohort. DTCs were obtained from a medullary iliac crest sample performed before any primary therapy. DTC status was prospectively assessed by pathologists. Irradiation volumes were defined per standard of care. Cumulative incidence rates and hazard ratios were obtained using both Cox and Fine-Gray models. Interaction tests were performed to confirm the predictive value of DTC status in a multivariate analysis.
Six hundred twenty patients with localized breast cancer were included. Overall, 94 patients (15.2%) were DTC-positive. After a median follow-up of 11.7 years, 47 patients (7.6%) experienced locoregional relapse. DTC detection was associated with a higher risk of locoregional relapse in univariate and multivariate analyses (Cox hazard ratio, 3.26; 95% confidence interval, 1.6-5.7; P = .001). In the multivariate subgroup analysis, IMN/SCN irradiation significantly reduced locoregional relapse among DTC-positive patients compared with DTC-negative patients (interaction test: hazard ratio, 0.3; 95% confidence interval, 0.1-0.9; P = .02). IMN/SCN was the only irradiation volume with an impact on locoregional relapse in patients according to DTC status, and the predictive value of DTC status for the benefit of locoregional irradiation was independent of locoregional nodal status.
This long-term analysis confirms the predictive impact of DTC status on the efficacy of regional radiation therapy for locoregional relapse in early breast cancer. After further studies, DTC status could be used as a decision tool to better tailor adjuvant radiation therapy in patients with early stage breast cancer.
Radiation therapy after sentinel lymph node biopsy for early stage breast cancer using a magnetic tracer: Results of a single institutional prospective study of tolerance
2019, Cancer/Radiotherapie
Citation Excerpt :
In case of positive sentinel lymph node biopsy (with or without axillary lymph node dissection), a normofractionated regimen was delivered (46 to 48 Gy in 23 to 24 fractions to the supraclavicular and axillary lymph nodes and a photon/electron mix to internal mammary lymph nodes). Patients were placed in the standard supine or isocentric lateral supine positions depending on anatomical and/or dosimetric constraints [8,9]. Delineation of lymph node areas was based on atlases published in the literature [10–13].
. The aim of the study was, through a single institutional analysis of a large population of breast cancer patients, to assess the feasibility of and the tolerance to radiotherapy after the use of magnetic detection method for sentinel lymph node biopsy.
The super paramagnetic iron oxide particles database was collected prospectively and identified 520 cases from October 2013 to December 2016 at our institution. All of them received super paramagnetic iron oxide particles injection 20 minutes before the surgical procedure and some of them received also isotope technique. Injection site for super paramagnetic iron oxide particles and isotope was periareolar. Among them, 288 patients received adjuvant radiotherapy. In our study, we evaluated the tolerance of postoperative radiotherapy.
The median age of the patients was 64 years. The median follow-up period was 16 months (range: 1–42 months). Double detection of sentinel lymph node was done in the first 30 patients (10.4%). The sentinel lymph node identification rate was 99.7% (287 out of 288). There were 34 axillary lymph node dissections, of which 58.8% were realized straightaway. The total radiation dose was 50 Gy EQD2 (range: 28.5–66 Gy). Regarding the occurrence of radiodermatitis, 95.8% of patients had grade 0–2 radiodermatitis and 1% had grade 3. During follow-up, 19.4% of patients developed grade 1–2 post-therapeutic fibrosis (of which 92.9% grade 1).
The results of this large-scale study show that the radiotherapy after sentinel lymph node biopsy using super paramagnetic iron oxide particles is feasible, and that no increase of the toxicity was observed.
Évaluer la faisabilité et la tolérance de la radiothérapie après utilisation d’un traceur ferromagnétique pour la détection du ganglion sentinelle chez des patientes opérées d’emblée pour un cancer du sein.
Une base de données d’utilisation d’un traceur ferromagnétique a été collectée prospectivement et a identifié 520 cas d’octobre 2013 à décembre 2016 dans notre établissement. Tous les patients ont reçu une injection de traceur ferromagnétique 20 minutes avant l’intervention chirurgicale et certains d’entre eux ont également reçu une injection d’isotope. Le site d’injection était périaréolaire. Parmi eux, 288 ont reçu une radiothérapie adjuvante. Dans notre étude, nous avons évalué la tolérance de la radiothérapie postopératoire.
. L’âge médian des patients était de 64 ans. La période de suivi médian était de 16 mois (1–42). Une double détection du ganglion sentinelle a été réalisée chez les 30 premiers patients (10,4 %). Le taux d’identification du ganglion sentinelle était de 99,7 % (287/288). Il y avait 34 curages axillaires (dont 58,8 % ont été réalisés en situation peropératoire). La dose totale de radiothérapie était de 50 Gy en EQD2 (équivalence 2 Gy) (28,5–66). En ce qui concerne la survenue d’une radiodermite, 95,8 % des patients étaient atteints d’une radiodermite de grade 0–2 et 1 % d’une grade 3. Pendant le suivi, 19,4 % des patients ont été atteints d’une fibrose post-thérapeutique de grade 1-2 (dont 92,9 % de grade 1).
Cette large étude a montré que la radiothérapie après utilisation d’un traceur ferromagnétique pour détecter le ganglion sentinelle était faisable, sans augmentation de la toxicité.
Feasibility and tolerance of Sienna+<sup>®</sup> for the procedure of sentinel lymph node biopsy: Single centre pilot study of 30 consecutive patients
2017, Cancer/Radiotherapie

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Simplified field-in-field technique for a large-scale implementation in breast radiation treatment

Abstract

Introduction

Section snippets

Patients

Clinical outcome

Dosimetric comparison of SFF and ESC

Implementation of SFF

Conclusion

Clin. Oncol.

Int. J. Radiat. Oncol. Biol. Phys.

Int. J. Radiat. Oncol. Biol. Phys.

Int. J. Radiat. Oncol. Biol. Phys.

Cancer. Radiother.

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Semin. Radiat. Oncol.

Int. J. Radiat. Oncol. Biol. Phys.

Int. J. Radiat. Oncol. Biol. Phys.

Int. J. Radiat. Oncol. Biol. Phys.

Radiother. Oncol.

Int. J. Radiat. Oncol. Biol. Phys.

Effects of radiotherapy and of differences in the extent of surgery for early breast cancer on local recurrence and 15-year survival: An overview of the randomised trials

Lancet