TY - GEN
T1 - Proton therapy during pregnancy
T2 - experimental assessment of fetal doses
AU - De Saint-Hubert, Marijke
AU - Brkic, Hrvoje
AU - Krzempek, Dawid
AU - Mojzeszek, Natalia
AU - Kasabasic, Mladen
AU - Matamoros Ortega, Andrea
AU - Gajewski, Jacek (Jan)
AU - Borys, Damian
AU - Krzempek, Katarzyna
AU - Lipa, Monika
AU - Foltynska, Gabriela
AU - Radolińska, Monika
AU - Skóra, Tomasz
AU - Colson, Dries
AU - Van Hoey, Olivier
AU - Stolarczyk, Liliana
AU - Kopec, Renata
N1 - Score=3
PY - 2024/6
Y1 - 2024/6
N2 - Proton therapy (PT) can reduce dose to healthy tissues and improve cancer treatment during pregnancy. Still only few data exist of PT during pregnancy. Besides the need to use pregnant anthropomorphic phantoms, dedicated dosimetry equipment is needed to assess fetal dose in a mixed field of radiation dominated by neutrons. Furthermore, Monte Carlo (MC) simulations are critical for fetal dose characterization and personalized dosimetry. A recently developed pregnant phantom, Tena, based on MRI images of a female at 18th week of pregnancy [Kopačin, 2022], was developed using 3D printed molds filled with substitute tissues (bone, soft tissue and lungs) and is able to host detectors at the fetus position. Thermoluminescent dosimeters (TLD), type MCP-7 and MCP-6, assessed the non-neutron and thermal neutron dose. The MiniPIX Timepix based detector allowed assessment of particle-specific energy deposition, while the BTI BD-PND bubble detectors were used as a neutron specific dosimeter. Intensity modulated proton therapy (IMPT) clinical plans for glioma, Hodgkin lymphoma (HL) with and without range shifter (RS/noRS) and submandibular gland cancer (neck) were transferred to the Tena phantom with varying location, tumour volume, beam angles, distance to the fetus and fractionation schemes. The neutron dose equivalent in the fetus position ranged between 2.5 and 50 µSv/Gy for glioma and HL-RS plans, respectively. The HL-noRS plan reduced the neutron dose equivalent to 16 µSv/Gy, while the neck case resulted in 20 µSv/Gy. The neutrons were dominant as the non-neutron dose contribution to the total dose equivalent was below 20% (figure). A total dose equivalent at the fetus position was calculated considering the prescribed dose per treatment and ranged between 0.2 mSv and 1.7 mSv for glioma and HL-RS, respectively. Data are supported by MC simulations for fetal dose calculations and demonstrating the applicability of the phantom materials for out-of-field dosimetry in PT. Dedicated pregnant phantom and dosimetry systems allowed a full description of the fetal dose for 3 different clinical cases. The use of a RS increased the fetal dose by more than a factor of 3. Still all doses were below 2 mSv, far below the 50mSv radiation dose considered safe.
AB - Proton therapy (PT) can reduce dose to healthy tissues and improve cancer treatment during pregnancy. Still only few data exist of PT during pregnancy. Besides the need to use pregnant anthropomorphic phantoms, dedicated dosimetry equipment is needed to assess fetal dose in a mixed field of radiation dominated by neutrons. Furthermore, Monte Carlo (MC) simulations are critical for fetal dose characterization and personalized dosimetry. A recently developed pregnant phantom, Tena, based on MRI images of a female at 18th week of pregnancy [Kopačin, 2022], was developed using 3D printed molds filled with substitute tissues (bone, soft tissue and lungs) and is able to host detectors at the fetus position. Thermoluminescent dosimeters (TLD), type MCP-7 and MCP-6, assessed the non-neutron and thermal neutron dose. The MiniPIX Timepix based detector allowed assessment of particle-specific energy deposition, while the BTI BD-PND bubble detectors were used as a neutron specific dosimeter. Intensity modulated proton therapy (IMPT) clinical plans for glioma, Hodgkin lymphoma (HL) with and without range shifter (RS/noRS) and submandibular gland cancer (neck) were transferred to the Tena phantom with varying location, tumour volume, beam angles, distance to the fetus and fractionation schemes. The neutron dose equivalent in the fetus position ranged between 2.5 and 50 µSv/Gy for glioma and HL-RS plans, respectively. The HL-noRS plan reduced the neutron dose equivalent to 16 µSv/Gy, while the neck case resulted in 20 µSv/Gy. The neutrons were dominant as the non-neutron dose contribution to the total dose equivalent was below 20% (figure). A total dose equivalent at the fetus position was calculated considering the prescribed dose per treatment and ranged between 0.2 mSv and 1.7 mSv for glioma and HL-RS, respectively. Data are supported by MC simulations for fetal dose calculations and demonstrating the applicability of the phantom materials for out-of-field dosimetry in PT. Dedicated pregnant phantom and dosimetry systems allowed a full description of the fetal dose for 3 different clinical cases. The use of a RS increased the fetal dose by more than a factor of 3. Still all doses were below 2 mSv, far below the 50mSv radiation dose considered safe.
KW - Proton therapy
KW - Cancer treatment
U2 - 10.1016/j.ijpt.2024.100358
DO - 10.1016/j.ijpt.2024.100358
M3 - In-proceedings paper
VL - 12
T3 - International Journal of Particle Therapy
SP - 113
EP - 114
BT - Proceedings to the 62nd Annual Conference of the Particle Therapy Cooperative Group (PTCOG)
PB - Elsevier
ER -