On the performances of Intensity Modulated Protons, RapidArc and Helical Tomotherapy for selected paediatric cases

Fogliata Antonella, Yartsev Slav, Nicolini Giorgia, Clivio Alessandro, Vanetti Eugenio, Wyttenbach Rolf, Bauman Glenn, Cozzi, Cozzi Luca

Description

To evaluate the performance of three different advanced treatment techniques on a group of complex paediatric cancer cases. Methods CT images and volumes of interest of five patients were used to design plans for Helical Tomotherapy (HT), RapidArc (RA) and Intensity Modulated Proton therapy (IMP). The tumour types were: extraosseous, intrathoracic Ewing Sarcoma; mediastinal Rhabdomyosarcoma; metastastis of base of skull with bone, para-nasal and left eye infiltration from Nephroblastoma of right kidney; metastatic Rhabdomyosarcoma of the anus; Wilm's tumour of the left kidney with multiple liver metastases. Cases were selected for their complexity regardless the treatment intent and stage. Prescribed doses ranged from 18 to 53.2 Gy, with four cases planned using a Simultaneous Integrated Boost strategy. Results were analysed in terms of dose distributions and dose volume histograms. Results For all patients, IMP plans lead to superior sparing of organs at risk and normal healthy tissue, where in particular the integral dose is halved with respect to photon techniques. In terms of conformity and of spillage of high doses outside targets (external index (EI)), all three techniques were comparable; CI 90% ranged from 1.0 to 2.3 and EI from 0 to 5%. Concerning target homogeneity, IMP showed a variance (D 5% –D 95% ) measured on the inner target volume (highest dose prescription) ranging from 5.9 to 13.3%, RA from 5.3 to 11.8%, and HT from 4.0 to 12.2%. The range of minimum significant dose to the same target was: (72.2%, 89.9%) for IMP, (86.7%, 94.1%) for RA, and (79.4%, 94.8%) for HT. Similarly, for maximum significant doses: (103.8%, 109.4%) for IMP, (103.2%, 107.4%) for RA, and (102.4%, 117.2%) for HT. Treatment times (beam-on time) ranged from 123 to 129 s for RA and from 146 to 387 s for HT. Conclusion Five complex pediatric cases were selected as representative examples to compare three advanced radiation delivery techniques. While differences were noted in the metrics examined, all three techniques provided satisfactory conformal avoidance and conformation.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2009
• Nombre de lectures: 48
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Radiation Oncology

Bio

ntral

Research Open Access On the performances of Intensit y Modulated Protons , RapidArc and Helical Tomotherapy for se lected paediatric cases Antonella Fogliata 1 , Slav Yartsev 2 , Giorgia Nicolini 1 , Alessandro Clivio 1 , Eugenio Vanetti 1 , Rolf Wyttenbach 3 , Glenn Bauman 2 and Luca Cozzi* 1

Address: 1 Oncology Institute of Southern Switzerland, Me dical Physics Unit, Bellinzona, Switzerland, 2 London Regional Cancer Program, London Health Sciences Centre, Lo ndon, Ontario, Canada and 3 Ospedale Regionale Bellinzona e Valli, Radiology Dept, Bellinzona, Switzerland Email: Antonella Fogliata - Antonell [e-mail]; Slav Ya rtsev - [e-mail]; Giorgia Nicolini - [e-mail]; Alessandro Clivio - [e-mail]; Eugenio Vanetti - [e-mail]; Rolf Wyttenbach - [e-mail]; Glenn Bauman - Glenn.Baum [e-mail]; Luca Cozzi* - [e-mail] * Corresponding author

Published: 14 January 2009 Received: 8 November 2008 Radiation Oncology2009,4  14 January 2009 Accepted: :2 doi:10.1186/1748-717X-4-2 This article is available from: h ttp://www.ro-journal.com/content/4/1/2 © 2009 Fogliata et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons. org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the orig inal work is properly cited.

Abstract Background: advanced treatment techniques on fferentTo evaluate the performance of three di a group of complex paediatric cancer cases. Methods:CT images and volumes of interest of five pati ents were used to design plans for Helical Tomotherapy (HT), RapidA rc (RA) and Intensity Modulated Proton therapy (IMP). The tumour types were: extraosseous, intr athoracic Ewing Sarcoma; me diastinal Rhabdomyosarcoma; metastastis of base of skull with bone, para-nasal and left eye infiltration from Nephroblastoma of right kidney; metastatic Rhabdomyosarcoma of th e anus; Wilm's tumour of the left kidney with multiple liver metastases. Cases were selected for their complexity regardl ess the treatment intent and stage. Prescribed doses ranged from 18 to 53.2 Gy, with four cases planned using a Simultaneous Integrated Boost stra tegy. Results were analysed in terms of dose distributions and dose volume histograms. Results:to superior sparing of organs at risk and normal healthyFor all patients, IMP plans lead tissue, where in particular the inte gral dose is halved with respe ct to photon techniques. In terms of conformity and of spillage of high doses outsid e targets (external index (EI)), all three techniques were comparable; CI 90% ranged from 1.0 to 2.3 and EI from 0 to 5%. Concerning target homogeneity, IMP showed a variance (D 5% –D 95% ) measured on the inner target volume (highest dose prescription) ranging from 5.9 to 13.3%, RA from 5.3 to 11.8%, and HT from 4.0 to 12.2%. The range of minimum significant dose to the sa me target was: (72.2%, 89.9%) for IMP, (86.7%, 94.1%) for RA, and (79.4%, 94.8%) for HT. Simila rly, for maximum significant doses: (103.8%, 109.4%) for IMP, (103.2%, 107.4%) for RA, and (1 02.4%, 117.2%) for HT. Treatment times (beam- on time) ranged from 123 to 129 s for RA and from 146 to 387 s for HT. Conclusion:Five complex pediatric cases were selected representative examples to compare as three advanced radiation delivery techniques. While differences were noted in the metrics examined, all three techniques provided satisf actory conformal avoidance and conformation.

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