Can we obtain planning goals for conformal techniques in neoadjuvant and adjuvant radiochemotherapy for gastric cancer patients?
OBJECTIVE
The purpose of this study was to compare conformal radiotherapy techniques used in the treatment of gastric cancer patients. The study is dedicated to radiotherapy centres that have not introduced dynamic techniques in clinical practice.


BACKGROUND
The implementation of multi-field technique can minimise the toxicity of treatment and improve dose distribution homogeneity in the target volume with simultaneous protection of organs at risk (OaRs). Treatment plan should be personalised for each patient by taking into account the planning target volume and anatomical conditions of the individual patient.


METHODS
For each patient, four different three dimensional conformal plans were compared: 2-field plan, 3-field plan, non-coplanar 3-field plan and non-coplanar 4-field plan. Dose distributions in a volume of 107% of the reference dose, and OaRs such as the liver, kidneys, intestines, spinal cord, and heart were analysed.


RESULTS
The mean volume of the patient body covered using the isodose of 107% was 3004.73 cm(3), 1454.28 cm(3), 1426.62 cm(3), 889.14 cm(3) for the 2-field, 3-field, non-coplanar 3-field and non-coplanar 4-field techniques, respectively. For all plans the minimum dose in the PTV volume was at least 95% of the reference dose. The QUANTEC protocol was used to investigate doses in OaRs.


CONCLUSIONS
Comparison of 3D conformal radiotherapy techniques in gastric cancer patients indicates that none of the plans can fulfil simultaneously all of the criteria of the tolerance dose in the organs at risk. The implementation of the multi-field technique can minimise the toxicity of treatment and improve dose distribution homogeneity in the target volume with additional protection of organs at risk (OaRs).
Department of Radiotherapy and Brachytherapy Planning, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland.
Wojciech
W
Leszczyński
Department of Radiotherapy, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland.
Paweł
P
Polanowski
Department of Radiotherapy, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland.
Paulina
P
Leszczyńska
Department of Radiotherapy and Brachytherapy Planning, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland.
Leszek
L
Hawrylewicz
Department of Radiotherapy and Brachytherapy Planning, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland.
Iwona
I
Brąclik
Department of Radiotherapy, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland.
Rafał
R
Kawczyński
Department of Radiotherapy, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Poland.
Jerzy
J
Wydmański
Conformal radiotherapy; Gastric cancer; Treatment plan comparison