Purpose
To assess
the feasibility and toxicity of consolidative
intensity-modulated whole abdominal radiotherapy (WAR) after
surgery and chemotherapy in high-risk patients with advanced
ovarian cancer.
Methods and Materials
Ten
patients with optimally debulked ovarian cancer
International Federation of Gynecology and Obstetrics
Stage IIIc were
treated in a Phase I study with intensity-modulated WAR up
to a total dose of 30 Gy in 1.5-Gy fractions as
consolidation therapy after adjuvant carboplatin/taxane
chemotherapy. Treatment was delivered using
intensity-modulated radiotherapy in a step-and-shoot
technique (n = 3) or a helical tomotherapy (Tomotherapy)
technique (n = 7). The planning target volume included the
entire peritoneal cavity and the pelvic and para-aortal node
regions. Organs at risk were kidneys, liver, heart,
vertebral bodies, and pelvic bones.
Results
Intensity-modulated WAR resulted in an excellent coverage of
the planning target volume and an effective sparing of the
organs at risk. The treatment was well tolerated, and no
severe Grade 4 acute side effects occurred. Common Toxicity
Criteria Grade III toxicities were as follows: diarrhea (n =
1), thrombocytopenia (n = 1), and leukopenia (n = 3).
Radiotherapy could be completed by all the patients without
any toxicity-related interruption. Median follow-up was 23
months, and 4 patients had tumor recurrence (intraperitoneal
progression, n = 3; hepatic metastasis, n = 1). Small bowel
obstruction caused by adhesions occurred in 3 patients.
Conclusions
The
results of this Phase I study showed for the first time, to
our knowledge, the
clinical feasibility of intensity-modulated whole abdominal
radiotherapy, which could offer a new therapeutic option for
consolidation treatment of advanced ovarian carcinoma after
adjuvant chemotherapy in selected subgroups of
patients. We initiated a Phase II study to further evaluate
the toxicity of this intensive multimodal treatment
