Oligometastatic Recurrent Ovarian Cancer Treated Using Stereotactic Body Radiotherapy

Introduction

Case Presentation

Fig 1: (a) CECT image and (b) PET-CT image at the time of recurrence (c) PET-CT image after SBRT treatment and after 24 months of treatment.

After one month of EBRT completion, she underwent two cycles of palliative chemotherapy (Nab-Paclitaxel and Carboplatin). Tumor response was evaluated three months of the last cycle of Chemotherapy by PET-CT, according to Response Evaluation Criteria in Solid Tumors (RECIST). The treatment was very well tolerated by the patient and showed a major radiological response. The toxicity and tumor response was scored using the Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) Scale. Follow-up is continuing and two years of post-chemotherapy. She still has no signs of relapse, neither on PET-CT scans (Fig. 1c) nor biochemically (CA 125 Values, Fig. 2), and she remains in excellent clinical condition. Consent was obtained for this case report.

Fig 2: CA 125 Monitoring pre and post therapy.

Discussion

Prognosis of metastatic ovarian cancer is poor, but it is a radiosensitive disease. The use of radiation treatment in ovarian malignancy was drastically compromised due to toxicity issues. The toxicity was basically because of whole abdomino-pelvic (WAP) radiotherapy using the "moving strip" technique.[] The comprised radiation use has partially been resolved by the development of modern techniques, i.e., stereotactic body radiotherapy (SBRT). Considering the high local control rates for oligo-metastases (70-90% at two years) and a low toxicity profile (up to less than 10% grade three toxicity) have been reported for SBRT in several types of malignancy.[] Table 1 summarizes few studies of SBRT in the management of metastatic gynecologic malignancies have been published in the literature, including metastatic ovarian cancer.[-] In a Phase II study, Cleveland SBRT trial Kunos et al. treated 50 females (50% with primary ovarian cancer) with ≤4 sites of metastatic disease with SBRT to a dose 8 Gy×3 fractions us-ing Cyber-knife. Vallow L et al. suggest that up to 5 cm. size lesion was treated by SBRT at Mayo Clinic Florida per protocol in Liver Oligometastasis in Phase I study. Common treatment sites included para-aortic nodes (38%), pelvic nodes (28%), and the liver (16%). The treatment outcome of median disease-free survival was 7.8 months and overall survival was 20.2 months, with only 3 grade ≥3 toxicities. The local control rate for abdominal lymph nodes and hepatic metastasis suggest promising results in various published studies. Here, we present a case of re-current metastatic ovarian cancer that remains disease-free with excellent performance status and less toxicity at two years after receiving SBRT.

Table 1: SBRT doses in Oligometastasis lesion

SBRT serves to decrease tumor burden, help stimulate innate immune response or expose tumor neo antigens and, destroy chemo-resistant tumor clones, providing excellent rates of local control with minimal acute and late toxici-ties and can be used in patients who have had prior radiotherapy.[]

Conclusion

Peer-review: Externally peer-reviewed.

Conflict of Interest: None declared.

References