Abstract
In vivo dosimetry (IVD) is the last step of a radiotherapy quality control program aimed to ensure that the dose delivered is in agreement with that prescribed. IVD procedures based on single detectors are time-consuming and impossible to use for the modern radiotherapy techniques, based on static or kinetic beams (modulated in intensity fluence); this means that more efficient and practical methods are highly recommended. The practical method SOFTDISO, based on the use of electronic portal image device (EPID), provides two tests (i) the R ratio between the reconstructed and the planned isocenter doses to verify an agreement within 5% and (ii) the γ-analysis of the EPID images, to verify γ% ≥ 90% and γmean ≤ 0.4. This paper reports the results of 11,357 IVD tests carried out for 823 patients treated by three-dimensional conformal radiation therapy and volumetric modulated arc therapy techniques. In particular, the dose disagreements are reported distinguishing two kinds of causes, those of (i) class 1 that includes the errors due to inadequate quality controls and (ii) the class 2, due to patient morphological changes. About the tests out of tolerance, 6% were by VMAT and 21% by 3DCRT, but taking into account the only class 1 of errors, i.e., removing the causes of class 2, only 7% of patients examined presented at least one of the three mean indexes out of tolerance. The workload for IVD on 9 patients/day per linac is about 52 min/day but recently, a new automated SOFTDISO version has been implemented to reduce the time to about 34 min/day.

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References
Best Medical Italy srl, Manuale SOFTDISO.
Bogdanich W (2010) A pinpoint beam strays invisibly, harming instead of healing. New York Times, December 29.
Bogdanich W (2010) As technology surges, radiation safeguards lag. New York Times, January 26.
Bogdanich W (2010) Radiation offers new cures and ways to do harm. New York Times, January 23.
Chiesa S, Placidi L, Azario L, Mattiucci GC, Greco F, Damiani A, Mantini G, Frascino V, Piermattei A, Valentini V, Balducci M (2015) Adaptive optimization by 6 DOF robotic couch in prostate volumetric IMRT treatment: rototranslational shift and dosimetric consequences. J Appl Clin Med Phys 16(5)
Cilla S, Meluccio D, Fidanzio A, Azario L, Ianiro A, Macchia G, Digesu C, Deodato F, Valentini V, Morganti AG, Piermattei A (2016) Initial clinical experience with EPID-based in-vivo dosimetry for VMAT treatments of head and neck tumors. Phys Med 32(1):52–58
Cilla S, Ianiro A, Deodato F, Macchia G, Disegù C,F, Picardi V, Nuzzo M, Labroupoulos F, Viola P, Piermattei A, Valentini V, Morganti AG (2016) VMAT in nasopharyngeal tumor: clinical implications after a change in the dose calculation algorithm. Radiother Oncol 119(Supplement 1):S721–S722
Derreumaux S, Etard C, Huet C, Trompier F, Clairand I, BottollierDepois JF, Aubert B, Gourmelon P (2008) Lessons from recent accidents in radiation therapy in France. Radiat Prot Dosim 131:130–135
Dunlop A, McQuaid D, Nill S, Murray J, Poloundniowski G, Hansen V, Bhide S, Nutting C, Harrington K, Newbold K, Oelfke U (2015) Comparison of CT number calibration techniques for CBCT-based dose calculation. Strahlenther Onkol 191:970–978
ESTRO (2001) European Society for Radiotherapy & Oncology. Practical guidelines for the implementation of in vivo dosimetry radiotherapy with photon beams (entrance dose). Physics for clinical radiotherapy, Booklet No. 5.
Fidanzio A, Porcelli A, Azario L, Greco F, Cilla S, Grusio M, Balducci M, Valentini V, Piermattei A (2013) Quasi real time in vivo dosimetry for VMAT. Medical Physics 41(6):062103
Fidanzio A, Menna S, Greco F, Porcelli A, Benecchi G, Azario L, Piermattei A (2016) Dosimetric ealuation of new method for patient specific CBCT scan calibration. Radiother Oncol 119:S852
Greco F, Piermattei A, Azario L, Placidi L, Cilla S, Caivano R, Fusco V, Fidanzio A (2013) ASi-EPID transit signal calibration for dynamic beams: a needeful step for the IMRT in vivo dosimetry. Med Biol Eng Comput 51:1137–1145
IAEA (2001) International Atomic Energy Agency. Absolute dose in external beam radiotherapy: an international code of practice for dosimetry based on standards of absorbed dose to water. IAEA TRS 398.
International Commission on Radiological Protection (2009) ICRP Publication 112: Preventing accidental exposures from new external beam radiation therapy technologies. ICRP 39(4):1–86
ISS (1999) Controlli di qualità essenziai in radioterapia con fasci esterni, Rapporti ISTISAN 99/6
ISS (2004) Indicazioni per l’assicurazione di qualità nella radioterapia conformazionale, Rapporti ISTISAN 04/34
Low DA, Harms WB, Mutic S, Purdy JA (1998) A technique for the quantitative evaluation of dose distributions. Med Phys 25:656–661
Marajh C (2011) Anatomy of an error: cancer treatment radiation overdose. Trinidad Express Newspapers, July 20
Mayles WPM (2007) The Glasgow incident—a physicist’s reflections. Clin Oncol 19:4–7
Mijnheer B, Beddar S, Izewska J, Reft C (2013) In vivo dosimetry in external beam radiotherapy. Med Phys 40(7):070903
Nijsten SM, Mijnheer BJ, Dekker AL, Minken AW (2007) Routine individualized patient dosimetry using electronic portal imaging devices. Radiother Oncol 83:65–75
Piermattei A, Cilla S, Grimaldi L et al (2009) Integration between in vivo dosimetry and image guided radiotherapy for lung tumors. Medical Physics 36(6):2206–2214
Piermattei A, Fidanzio A, Stimato G, Azario L, Grimaldi L, D’Onofrio G, Cilla S, Balducci M, Gambacorta MA, Di Napoli N, Cellini N (2010) In vivo dosimetry by an aSi-based EPID. Med Phys 33(11):4414–4422
Piermattei A, Fidanzio A, Cilla S, Greco F, Azario L, Sabatino D, Cozzolino M, Grusio M, Fusco V (2010) Dose-guide radiotherapy for lung tumors. Med Biol Eng Comp 48:79–86
Piermattei A, Greco F, Azario L, Porcelli A et al (2012) A National Project for in-vivo dosimetry procedures in radiotherapy: first results. Nucl Instrum Methods Phys Res, Sect B 274:42–50
Piermattei A, Cilla S, Azario L, Greco F, Russo M, Grusio M, Orlandini L, Fidanzio A (2015) aSi EPIDs for the in-vivo dosimetry of static and dynamic beams. Nucl Instrum Methods Phys Res A 796:93–95
Russo M, Piermattei A, Greco F, Azario L, Orlandini L, Zucca S, Cilla S, Menna S, Grusio M, Chiatti L, Fidanzio A (2015) Step and shoot IMRT by Siemens beams: an EPID dosimetry verification during treatment. Technol Cancer Res Treat 15(4):535–545
The Swedish Radiation Protection Institute (2000) Regulations on radiation therapy. Report SSI FS 2000:4
van Elmpt W, Nijsten S, Petit S, Mijnheer B, Lambin P, Dekker A (2009) 3D in vivo dosimetry using magavoltages cone-beam CT and EPID dosimetry. Int J Radiat Oncol Biol Phys 73(5):1580–1587
Williams MV (2007) Radiotherapy near misses, incidents and errors: radiotherapy incident in Glasgow. Clin Oncol 19:1–3
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Piermattei, A., Greco, F., Grusio, M. et al. A validation study of a dedicated software for an automated in vivo dosimetry control in radiotherapy. Med Biol Eng Comput 56, 1939–1947 (2018). https://doi.org/10.1007/s11517-018-1822-3
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DOI: https://doi.org/10.1007/s11517-018-1822-3