Risk stratification of abdominopelvic failure for FIGO stage III epithelial ovarian cancer patients: implications for adjuvant radiotherapy

The utility of 1.5 tesla MR-guided adaptive stereotactic body radiotherapy for recurrent ovarian tumor – Case reports and review of the literature

Introduction

Although epithelioid ovarian cancer (EOC) is a radiosensitive tumor and radiotherapy (RT) played a significant role in adjuvant treatment management in the past, the role of RT has evolved with the advent of platinum-based chemotherapy regimens. Nonetheless, modern RT techniques may be useful in certain patients particularly those with recurrent disease.

Presentation of case

After surgery and chemotherapy, two patients, aged 57 and 70, presented with recurrent lesions in the parailiac region. The recurrent lesions were treated with high field 1.5-Tesla MR-Linac treatment in 5 fractions at a dose of 30 Gy. The patients tolerated the treatment well and were disease free after 12 and 20 months of magnetic resonance guided radiotherapy (MRgRT), respectively.

Discussion

MRgRT is a novel and rapidly evolving technology that allows for the highly precise treatment of even mobile targets through direct visualization of the tumor. The majority of patients with EOC frequently present with abdominal-pelvic recurrences. It has been demonstrated that EOC requires high radiation doses for curative treatment. MR-Linac enables monitoring of organ motion during treatment, which is necessary for delivering higher doses to target volumes while sparing surrounding organs.

Conclusion

To reduce radiation doses to nearby normal tissues, MRgRT allows for the delivery of hypofractionated RT with tight safety margins. Regardless of initial resistance or gradual development of intolerance to standard chemotherapy regimens, the role of RT in patients with persistent or recurrent EOC should be reconsidered.

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Abdominal-pelvic region or other distant recurrence is common in ovarian cancer patients.

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The role of radiotherapy is debatable in ovarian cancer patients due to toxicity.

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Magnetic resonance guided RT allows direct target visualization during treatment delivery.

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We present two cases of recurrent ovarian cancer treated with adaptive MRgRT using 1.5 T-MR linac.

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MRgRT may be an alternative treatment option in patients with persistent or recurrent ovarian cancer.

The role of radiotherapy in epithelial ovarian cancer: a literature overview

Ovarian cancer (OC) accounts for 3% of all cancer in women and for 5% of all cancer-related deaths. Epithelial Ovarian Cancer (EOC) is a radiosensitive malignancy with a poor prognosis. In the pre-chemotherapy era, radiation therapy (RT) delivered to the abdominopelvic region (whole abdominal irradiation, WAI) has historically played a role in the adjuvant and consolidation setting. Specific cluster of patients with early-stage disease and definite histologies may take advantage of RT. Platinum-based chemotherapy (CT) has replaced RT and plays a major role in most of the clinical settings. Radiation Therapy for palliation is recommended in patients with localized symptoms. Nevertheless, modern RT represents a reliable treatment option, with a mild toxicity profile, particularly effective for oligo-recurrent or progressive disease. The present literature review aims to highlight the historical role of RT in EOC, the actual lines of evidence, and the future perspectives.

Involved-field radiation therapy for recurrent ovarian cancer: Results of a multi-institutional prospective phase II trial

OBJECTIVE

To evaluate the efficacy and safety of involved-field radiation therapy (IFRT) in patients with locoregionally confined recurrent or persistent epithelial ovarian cancer.

METHODS

This study included patients with recurrent epithelial ovarian cancer eligible for IFRT either during diagnosis of the recurrence or after salvage therapies. IFRT was performed at a dose of ≥45 Gy for all tumors with 10-15-mm margins as seen on standard imaging. The primary endpoint was progression-free survival (PFS); the secondary endpoints were safety, response rate, local control, and overall survival (OS).

RESULTS

Thirty patients with a mean number of 5.7 metastatic lesions each were enrolled between 2014 and 2016. Seventeen were treated with 3-D conformal radiation therapy (RT) and 13 with intensity-modulated RT. IFRT was well tolerated in all patients, and acute toxicity ≥ grade 2 was not observed. One case of grade 3 abdominal pain was reported 10 months post-RT. The overall and complete response rates were 85.7% and 50%, respectively. After a median follow-up of 28 (range, 17-42) months, the median PFS was 7 months. The 2-year PFS rate was 39.3%. Six of the 16 patients who developed outfield disease progression after IFRT were successfully treated with repeat IFRT as salvage treatment. The 3-year local control and OS rates were 84.4% and 55.8%, respectively.

CONCLUSIONS

Although the primary endpoint was not met, IFRT might be safe and effective for in-field tumor control in patients with persistent epithelial ovarian cancer with a limited number of metastatic foci. We plan to conduct a larger scale multi-center phase II prospective study.

Impact on survival with adjuvant radiotherapy for clear cell, mucinous, and endometriod ovarian cancer: the SEER experience from 2004 to 2011

OBJECTIVE

Evaluate the impact of radiotherapy on cause specific survival (CSS) and overall survival (OS) for stage (I-III) clear cell, mucinous, and endometriod ovarian cancer.

METHODS

We analyzed incidence, survival, and treatments from the Surveillance, Epidemiology, and End Results (SEER) Program from 2004 to 2011 for clear cell, mucinous, and endometriod histologies of the ovary for stages (I-III). We examined CSS and OS for all three histologies combined and each histology with relation to the use of adjuvant radiation therapy (RT). Survival analysis was calculated by Kaplan-Meier and log-rank analysis.

RESULTS

CSS was higher in individuals not receiving RT at 5 years (81% vs. 74%) and 10 years (74% vs. 65%, p=0.003). OS was higher in individuals not receiving RT at 5 years (76% vs. 73%) and 10 years (64% vs. 59%, p=0.039). Stage III patients receiving RT had a higher OS at 5 years (54% vs. 44%) and 10 year intervals (36% vs. 30%, p=0.037). Stage III patients with mucinous histology receiving RT had a higher OS at 5 years (50% vs. 36%) and 10 years (45% vs. 26%, p=0.052).

CONCLUSION

Those receiving RT had a lower CSS and OS at 5 and 10 years. However, subgroup analysis revealed a benefit of RT in terms of OS for all stage III patients and for stage III patients with mucinous histology.

Radiotherapy for ovarian cancers - redefining the role

Radiation therapy in ovarian cancers has been considered an outdated concept for many years, mainly due to toxicity and failure to show benefit in terms of survival. Chemotherapy has been extensively used after surgery for these cancers and it has almost replaced radiation therapy as an adjuvant treatment. Nevertheless, failures in ovarian cancers continue to occur even with the use of newer and effective chemotherapy regimens. About 70% patients demonstrate recurrence in the abdomen or pelvis after first line chemotherapy in ovarian cancers. With advances in technology and sophistication of radiation techniques, along with the molecular and biological knowledge of distinct histological subtypes, there is a need to redefine the role of radiation therapy. This review article focuses on the literature on use of radiation in ovarian cancers and its rationale and indications in the present day. For this, a literature pub med/medline search was performed from January 1975 to March 2014 to redefine the role of radiotherapy in ovarian cancers.