TY - JOUR
T1 - Effect of gastrointestinal gas on the temperature distribution in pancreatic cancer hyperthermia treatment planning
AU - van der Horst, Astrid
AU - Kok, H. Petra
AU - Crezee, Johannes
N1 - Funding Information: This work was supported by the Dutch Cancer Society (KWF Kankerbestrijding) [grant number 10873], [grant number 10882]. Publisher Copyright: © 2021 The Author(s). Published with license by Taylor & Francis Group, LLC.
PY - 2021
Y1 - 2021
N2 - Purpose: In pancreatic cancer treatment, hyperthermia can be added to increase efficacy of chemo- and/or radiotherapy. Gas in stomach, intestines and colon is often in close proximity to the target volume. We investigated the impact of variations in gastrointestinal gas (GG) on temperature distributions during simulated hyperthermia treatment (HT). Methods: We used sets of one CT and eight cone-beam CT (CBCT) scans obtained prior to/during fractionated image-guided radiotherapy in four pancreatic cancer patients. In Plan2Heat, we simulated locoregional heating by an ALBA-4D phased array radiofrequency system and calculated temperature distributions for (i) the segmented CT (sCT), (ii) sCT with GG replaced by muscle (sCT0), (iii) sCT0 with eight different GG distributions as visible on CBCT inserted (sCTCBCT). We calculated cumulative temperature-volume histograms for the clinical target volume (CTV) for all ten temperature distributions for each patient and investigated the relationship between GG volume and change in ΔT50 (temperature increase at 50% of CTV volume). We determined location and volume of normal tissue receiving a high thermal dose. Results: GG volume on CBCT varied greatly (9-991 cm3). ΔT50 increased for increasing GG volume; maximum ΔT50 difference per patient was 0.4–0.6 °C. The risk for GG-associated treatment-limiting hot spots appeared low. Normal tissue high-temperature regions mostly occurred anteriorly; their volume and maximum temperature showed moderate positive correlations with GG volume, while fat-muscle interfaces were associated with higher risks for hot spots. Conclusions: Considerable changes in volume and position of gastrointestinal gas can occur and are associated with clinically relevant tumor temperature differences.
AB - Purpose: In pancreatic cancer treatment, hyperthermia can be added to increase efficacy of chemo- and/or radiotherapy. Gas in stomach, intestines and colon is often in close proximity to the target volume. We investigated the impact of variations in gastrointestinal gas (GG) on temperature distributions during simulated hyperthermia treatment (HT). Methods: We used sets of one CT and eight cone-beam CT (CBCT) scans obtained prior to/during fractionated image-guided radiotherapy in four pancreatic cancer patients. In Plan2Heat, we simulated locoregional heating by an ALBA-4D phased array radiofrequency system and calculated temperature distributions for (i) the segmented CT (sCT), (ii) sCT with GG replaced by muscle (sCT0), (iii) sCT0 with eight different GG distributions as visible on CBCT inserted (sCTCBCT). We calculated cumulative temperature-volume histograms for the clinical target volume (CTV) for all ten temperature distributions for each patient and investigated the relationship between GG volume and change in ΔT50 (temperature increase at 50% of CTV volume). We determined location and volume of normal tissue receiving a high thermal dose. Results: GG volume on CBCT varied greatly (9-991 cm3). ΔT50 increased for increasing GG volume; maximum ΔT50 difference per patient was 0.4–0.6 °C. The risk for GG-associated treatment-limiting hot spots appeared low. Normal tissue high-temperature regions mostly occurred anteriorly; their volume and maximum temperature showed moderate positive correlations with GG volume, while fat-muscle interfaces were associated with higher risks for hot spots. Conclusions: Considerable changes in volume and position of gastrointestinal gas can occur and are associated with clinically relevant tumor temperature differences.
KW - Hyperthermia treatment
KW - gastrointestinal gas
KW - locoregional hyperthermia
KW - pancreatic cancer
KW - radiative heating
KW - thermal dose
KW - treatment planning
UR - http://www.scopus.com/inward/record.url?scp=85101238172&partnerID=8YFLogxK
U2 - https://doi.org/10.1080/02656736.2021.1882709
DO - https://doi.org/10.1080/02656736.2021.1882709
M3 - Article
C2 - 33602033
SN - 0265-6736
VL - 38
SP - 229
EP - 240
JO - International journal of hyperthermia
JF - International journal of hyperthermia
IS - 1
ER -