Treatment planning of epithelial ovarian cancers using helical tomotherapy

Whole abdomen radiotherapy (WAR) for epithelial ovarian cancer, though effective, has been used sparingly due to inadequate target coverage and poor sparing of organs at risk (OAR) leading to significantly higher toxicities. Newer radiation techniques have shown potential for significant improvement in the therapeutic ratio. The purpose of this study was to evaluate helical tomotherapy (HT) for WAR. The objective parameters were to obtain uniform and adequate target coverage with maximum OAR sparing. HT plans were generated for five patients with field width of 5.0/2.5 cm, modulation factor of 3.5/3.0, and a pitch of 0.3. A dose of 25 Gy in 25 fractions was prescribed to the abdomen with a simultaneous boost of 45 Gy in 25 fractions to the pelvis. Dose‐volume parameters and various indices were analyzed and compared. Mean volume (standard deviation) of abdominal and pelvic PTV (planning target volume) was [Formula: see text] and [Formula: see text] , respectively. Mean length of PTV in cranio‐caudal direction was [Formula: see text]. Volume receiving 95% and 107% of the prescription dose (V95% and V107%) was [Formula: see text] and [Formula: see text] for abdominal‐PTV, and [Formula: see text] and 0% for pelvic‐PTV, respectively. Homogeneity and conformity indices were [Formula: see text] for abdominal PTV, and [Formula: see text] for pelvic‐PTV, respectively. Median dose received by the kidneys, liver and bone marrow was [Formula: see text] and [Formula: see text] , respectively. HT achieves an excellent coverage of WAR target with simultaneous pelvic boost and better organ (kidneys and liver) sparing. HT for WAR has the potential as consolidative therapy; this is being evaluated further in a phase II cohort study in epithelial ovarian cancers. PACS number: 87.53 Kn, 87.55. D‐, 87.55.dk.