Stereotactic radiation therapy of renal cancer inferior vena cava tumor thrombus

Abstract

Renal Cell Carcinoma (RCC) is a common malignancy world-wide that is rising in incidence. Up to 10% of RCC patients present with inferior vena cava (IVC) tumor thrombus (IVC-TT). Although surgery is the only treatment with proven efficacy for IVC-TT, the surgical management of advanced (level III and IV) IVC-TT is difficult with high morbidity and mortality, and offers a poor survival outcome. Currently, there are no treatment options in the setting of recurrent or unresectable RCC IVC-TT. Even though RCC may be resistant to conventionally fractionated radiation therapy, hypofractionated radiation has shown excellent control rates for both primary and metastatic RCC. We report our experience treating 2 RCC patients with Level IV IVC-TT -one recurrent and the other unresectable-with stereotactic ablative radiation therapy (SABR). The first patient is a 75-year-old gentleman with a level IV RCC IVC-TT who presented 9 months after his radical nephrectomy and thrombectomy with a growing level IV IVC-TT that became refractory to 4 targeted agents. He received SABR of 50Gy in 5 fractions and at 2-year follow-up is doing well with a significant decrease in the enhancement and size of the IVC-TT. The second patient is an 83-year-old gentleman who presented with metastatic RCC and level IV IVC-TT but was not a surgical candidate. After progression on temsirolimus, he received SABR of 36Gy in 4 fractions to his IVC-TT and survived 18 months post-SABR. Both patients improved symptomatically and did not experience any acute or late treatment-related toxicity. Their survival of 24 months and 18 months are comparable to the reported median survival of 20 months in patients with level IV IVC-TT that underwent surgical resection. Therefore, SABR can be a potentially safe treatment option in the unresectable setting for RCC patients with IVC-TT and should be further evaluated in prospective trials.

Stereotactic Body Radiation Therapy for Renal Cell Carcinoma with Inferior Vena Cava Thrombus – Initial Experience Report and Literature Review

“…We previously reported a 24month follow-up of this patient with a reduction in size and enhancement of the tumor thrombus, despite no additional systemic therapy ( Fig. 1D) [11]. After a follow-up of an additional 10 months, the patient developed left proximal femur and multiple liver metastases.…”

“…We report an update on our initial experience with SBRT to RCC IVC-TT, the first such experience reported in the literature, providing an extended follow-up [11] and a review of the literature.…”

The Emerging Role of Stereotactic Ablative Radiotherapy for Primary Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

“…Another unique application of SABR in RCC is targeting inferior vena caval tumor thrombus (IVCTT). Hannan et al [56] have demonstrated this to be feasible and tolerable, with encouraging oncological results in a recent case series. Given the high-risk nature of thrombectomy surgery, SABR may thus be an option for patients with unresectable or recurrent IVCTT.…”

Giant Tumor in the Inferior Vena Cava Treated With CyberKnife

“…One is a case report of intensity-modulated radiotherapy (56 Gy/24 fractions of one fraction per day) that stabilized a tumor embolus in clear cell RCC [7]. Another is the only existing report of SRT for IVC tumor thrombus of RCC by Hannan et al, which showed only partial remission at two years follow-up and 18-month survival [8].…”