Thermal and resonance neutrons generated by various electron and X-ray therapeutic beams from medical linacs installed in polish oncological centers

Konefał, Adam; Orlef, A.; Łaciak, Marcin; Ciba, Aleksander; Szewczuk, Marek

doi:10.1016/j.rpor.2012.06.004

Cited by 29 publications

(10 citation statements)

References 18 publications

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“…Production of neutron secondary radiation during emission of high-energy photon therapeutic beams is generally known and widely studied issue [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]48]. Also, the phenomenon of high-energy X-rays and secondary neutron-induced radioactivity is well recognized [57].…”

Section: Spectrometry-based Dose Assessmentmentioning

confidence: 99%

“…Among the mechanisms of radionuclide activation outside the field of irradiation, neutron capture contributes the most. Linacs used nowadays are not routinely equipped with shielding constructions dedicated for neutrons; therefore, neutron fluence all over the treatment room is reported [32,[40][41][42][43][44] in the amount sufficient for inducing radioactivity at measurable level. Therefore, medical linear accelerators are often characterized in terms of neutron source strength Q [14,44], which depends on beam nominal potential, as presented in Figure 3.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Gamma Radiation in the Vicinity of the Entrance to Linac Radiotherapy Room

Polaczek-Grelik¹,

Kawa-Iwanicka²,

Rygielski³

et al. 2019

Use of Gamma Radiation Techniques in Peaceful Applications

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Radiotherapy using high-energy photon beams (10-20 MV) is accompanied by the production of secondary neutron radiation via (γ/X,n) reactions. These interactions as well as subsequent neutron capture are the source of induced gamma radioactivity. When studied with standard range of spectrometric systems, only decay gamma radiation is usually registered, whereas a significant part of radiationprompt gammas-is omitted, what might result in a significant underestimation of occupational risk for therapists in the vicinity of the door to the treatment room during therapeutic beam emission. Presented study has shown the main components of gamma radiation field in this localization investigated with the use of high-purity germanium spectrometry. Among them, prompt gamma radiation in light elements of concrete and in metal construction of the door, as well as 477.6 and 2224.6 keV photons emitted by neutron absorbing layers, contributes the most. Effective dose values depend on thickness of the door as well as on neutron production by particular linac and are within the range of 1.8-56.2 μSv/h. Standard environmental radiometry could underestimate these values by about 60% due to low efficiency for high-energy photon counting.

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Section: Spectrometry-based Dose Assessmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Gamma Radiation in the Vicinity of the Entrance to Linac Radiotherapy Room

Polaczek-Grelik¹,

Kawa-Iwanicka²,

Rygielski³

et al. 2019

Use of Gamma Radiation Techniques in Peaceful Applications

View full text Add to dashboard Cite

show abstract

“…The probability for (γ,p) reactions is also low, because of the proton charge. The neutron flux measured in linacs head, due to (γ,n) and (γ,2n) reactions, is described in [Konefal et al, 2012]. For an Elekta Synergy, the neutron flux at 15MV is about 1.4•10 5 Gy -1 .…”

Section: Samples Irradiations A)mentioning

confidence: 99%

31. Linac activation of radioisotopes and underground gammaspectroscopic analyses

et al. 2017

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“…Metode aktivasi foil menjadi salah satu pilihan yang sering digunakan untuk menentukan fluks neutron termal ( ) dalam dekade ini [2,9,[13][14][15][16]. Neutron termal dapat diidentifikasi menggunakan foil pilihan yang tepat meliputi emas ( 197 Au), indium ( 115 In), fosfor ( 31 P) dan disporsium ( 164 Dy) [17,18].…”

Section: Pendahuluanunclassified

Thermal Neutron Flux Measurements at Room Treatment LINAC iX 15 MV

Latifah

Noor

Bunawas

2013

Nat-B

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ABSTRAKLinac yang dioperasikan di atas 10 MV akan menghasilkan radiasi sekunder berupa emisi neutron yang berasal dari reaksi energi foton tinggi menumbuk material penyusun linac seperti target, kolimator dan filter. Radiasi sekunder ini akan menaikkan resiko kanker sekunder pada pasien akibat bertambahnya dosis radiasi yang diterima. Studi ini mengevaluasi fluks neutron termal spasial pada ruangan Linac yang dioperasikan 15 MV menggunakan metode aktivasi foil. Sebanyak 14 foil 115 In ditempatkan tersebar di dalam ruangan treatment yang terpapar pesawat linac 15 MV selama 1 menit. Hasil menunjukkan fluks tertinggi terdapat di sekitar isocenter sebesar , × • • Dengan nilai fluks tersebut dosis tambahan akibat neutron sebesar 0,04 Sv/menit.Nilai fluks menurun seiring bertambahnya jarak dari sumber berkas.Terkait dengan upaya proteksi radiasi untuk pekerja radiasi, adanya kontribusi dosis yang berasal dari neutron perlu ditindak lanjuti dengan menambah shielding pada pintu.Kata kunci: Fluks neutron thermal, LINAC, indium, aktivasi foil. ABSTRACTLinac is operated at above 10 MV will generate secondary radiation in the form of neutron emission from the reaction of the high photon energy linac striking the material components of linac such us targets, collimators and filters. Secondary radiation will increase the probability of the secondary cancer risk in patients due to increasing the dose of radiation received. This study evaluated the thermal neutron flux at the indoor spatial operated 15 MV linac using foil activation method. A total of 14 Indium-115 foil placed in the treatment room were exposed to 15 MV linac plane for 1 minute. Results showed the highest flux are around isocenter ( , × • • ). With the flux value of additional dose due to the neutron flux at , Sv/menit. FLux decreases as distance function. Related to radiation protection efforts for radiation workers, the contribution coming from the neutron dose necessary acted upon by adding shielding on the door.

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Thermal and resonance neutrons generated by various electron and X-ray therapeutic beams from medical linacs installed in polish oncological centers

Cited by 29 publications

References 18 publications

Gamma Radiation in the Vicinity of the Entrance to Linac Radiotherapy Room

Gamma Radiation in the Vicinity of the Entrance to Linac Radiotherapy Room

31. Linac activation of radioisotopes and underground gammaspectroscopic analyses

Thermal Neutron Flux Measurements at Room Treatment LINAC iX 15 MV

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