Modelling a new approach for radio-ablation after resection of breast ductal carcinoma in-situ based on the BAT-90 medical device

Anna Sarnelli,Giovanni Paganelli,Marco D’Arienzo,Matteo Negrini,Antonino Amato,Emilio Mezzenga,Giacomo Feliciani

doi:10.1038/s41598-021-03807-6

Abstract

The majority of local recurrences, after conservative surgery of breast cancer, occurs in the same anatomical area where the tumour was originally located. For the treatment of ductal carcinoma in situ (DCIS), a new medical device, named BAT-90, (BetaGlue Technologies SpA) has been proposed. BAT-90 is based on the administration of 90Y β-emitting microspheres, embedded in a bio-compatible matrix. In this work, the Geant4 simulation toolkit is used to simulate BAT-90 as a homogenous cylindrical 90Y layer placed in the middle of a bulk material. The activity needed to deliver a 20 Gy isodose at a given distance z from the BAT-90 layer is calculated for different device thicknesses, tumour bed sizes and for water and adipose bulk materials. A radiobiological analysis has been performed using both the Poisson and logistic Tumour Control Probability (TCP) models. A range of radiobiological parameters (α and β), target sizes, and densities of tumour cells were considered. Increasing α values, TCP increases too, while, for a fixed α value, TCP decreases as a function of clonogenic cell density. The models predict very solid results in case of limited tumour burden while the activity/dose ratio could be further optimized in case of larger tumour beds.

Highlights

The majority of local recurrences, after conservative surgery of breast cancer, occurs in the same anatomical area where the tumour was originally located
The widespread use of screening mammography allows the early detection of small size unifocal Ductal Carcinoma in Situ (DCIS) that represents up to 25% of all new detected breast c ancers[1,2,3]
For R = 30 mm, in each plane at constant z, that means parallel to the tumour bed plane, the dose delivered by 90Y is uniform for r < 25 mm and steeply decreases when r > 25 mm, in correspondence with the edge of the tumour bed

Summary

Introduction

The majority of local recurrences, after conservative surgery of breast cancer, occurs in the same anatomical area where the tumour was originally located. For the treatment of ductal carcinoma in situ (DCIS), a new medical device, named BAT-90, (BetaGlue Technologies SpA) has been proposed. The activity needed to deliver a 20 Gy isodose at a given distance z from the BAT-90 layer is calculated for different device thicknesses, tumour bed sizes and for water and adipose bulk materials. Abbreviations DCIS Ductal carcinoma in situ TCP Tumour control probability RT Radiotherapy BCS Breast conserving surgery LR Local recurrence APBI Accelerated partial breast irradiation EBRT External beam radiation therapy IORT Intraoperative radiation therapy PBI Partial breast irradiation SIRT Selective internal radiotherapy TARE Transarterial radioembolization WBI Whole breast irradiation IB Intracavitary brachytherapy MBI Multi-catheter interstitial brachytherapy LET Linear energy transfer RBE Relative biologic effectiveness BSA Bovine serum albumin. These studies’ results provide evidence that, despite the efforts to identify a low-risk group that could undergo BCS alone, RT reduces the relative risk for ipsilateral tumor recurrence by almost 50% in all subgroups, except for younger patients where the relative efficacy of RT was less e vident[5,10]

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Discussion

Conclusion