Frontiers in Oncology (Sep 2022)

In-vivo range verification analysis with in-beam PET data for patients treated with proton therapy at CNAO

  • Martina Moglioni,
  • Martina Moglioni,
  • Aafke Christine Kraan,
  • Guido Baroni,
  • Guido Baroni,
  • Giuseppe Battistoni,
  • Nicola Belcari,
  • Nicola Belcari,
  • Andrea Berti,
  • Andrea Berti,
  • Andrea Berti,
  • Pietro Carra,
  • Pietro Carra,
  • Piergiorgio Cerello,
  • Mario Ciocca,
  • Angelica De Gregorio,
  • Angelica De Gregorio,
  • Micol De Simoni,
  • Micol De Simoni,
  • Damiano Del Sarto,
  • Damiano Del Sarto,
  • Marco Donetti,
  • Yunsheng Dong,
  • Yunsheng Dong,
  • Alessia Embriaco,
  • Maria Evelina Fantacci,
  • Maria Evelina Fantacci,
  • Veronica Ferrero,
  • Elisa Fiorina,
  • Elisa Fiorina,
  • Marta Fischetti,
  • Marta Fischetti,
  • Gaia Franciosini,
  • Gaia Franciosini,
  • Giuseppe Giraudo,
  • Francesco Laruina,
  • Francesco Laruina,
  • Davide Maestri,
  • Marco Magi,
  • Giuseppe Magro,
  • Etesam Malekzadeh,
  • Etesam Malekzadeh,
  • Michela Marafini,
  • Michela Marafini,
  • Ilaria Mattei,
  • Enrico Mazzoni,
  • Paolo Mereu,
  • Alfredo Mirandola,
  • Matteo Morrocchi,
  • Matteo Morrocchi,
  • Silvia Muraro,
  • Ester Orlandi,
  • Vincenzo Patera,
  • Vincenzo Patera,
  • Francesco Pennazio,
  • Marco Pullia,
  • Alessandra Retico,
  • Angelo Rivetti,
  • Manuel Dionisio Da Rocha Rolo,
  • Valeria Rosso,
  • Valeria Rosso,
  • Alessio Sarti,
  • Alessio Sarti,
  • Angelo Schiavi,
  • Angelo Schiavi,
  • Adalberto Sciubba,
  • Adalberto Sciubba,
  • Giancarlo Sportelli,
  • Giancarlo Sportelli,
  • Sara Tampellini,
  • Marco Toppi,
  • Marco Toppi,
  • Giacomo Traini,
  • Giacomo Traini,
  • Antonio Trigilio,
  • Antonio Trigilio,
  • Serena Marta Valle,
  • Francesca Valvo,
  • Barbara Vischioni,
  • Viviana Vitolo,
  • Richard Wheadon,
  • Maria Giuseppina Bisogni,
  • Maria Giuseppina Bisogni

DOI
https://doi.org/10.3389/fonc.2022.929949
Journal volume & issue
Vol. 12

Abstract

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Morphological changes that may arise through a treatment course are probably one of the most significant sources of range uncertainty in proton therapy. Non-invasive in-vivo treatment monitoring is useful to increase treatment quality. The INSIDE in-beam Positron Emission Tomography (PET) scanner performs in-vivo range monitoring in proton and carbon therapy treatments at the National Center of Oncological Hadrontherapy (CNAO). It is currently in a clinical trial (ID: NCT03662373) and has acquired in-beam PET data during the treatment of various patients. In this work we analyze the in-beam PET (IB-PET) data of eight patients treated with proton therapy at CNAO. The goal of the analysis is twofold. First, we assess the level of experimental fluctuations in inter-fractional range differences (sensitivity) of the INSIDE PET system by studying patients without morphological changes. Second, we use the obtained results to see whether we can observe anomalously large range variations in patients where morphological changes have occurred. The sensitivity of the INSIDE IB-PET scanner was quantified as the standard deviation of the range difference distributions observed for six patients that did not show morphological changes. Inter-fractional range variations with respect to a reference distribution were estimated using the Most-Likely-Shift (MLS) method. To establish the efficacy of this method, we made a comparison with the Beam’s Eye View (BEV) method. For patients showing no morphological changes in the control CT the average range variation standard deviation was found to be 2.5 mm with the MLS method and 2.3 mm with the BEV method. On the other hand, for patients where some small anatomical changes occurred, we found larger standard deviation values. In these patients we evaluated where anomalous range differences were found and compared them with the CT. We found that the identified regions were mostly in agreement with the morphological changes seen in the CT scan.

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