Tumor Control Outcomes After Hypofractionated and Single-Dose Stereotactic Image-Guided Intensity-Modulated Radiotherapy for Extracranial Metastases From Renal Cell Carcinoma

Abstract

Purpose To report tumor local progression-free outcomes following treatment with single-dose image-guided intensity-modulated radiotherapy (SD-IGRT) and hypofractionated regimens for extracranial metastases from renal cell primary tumors. Methods and Materials Between 2004 and 2010, a total of 105 lesions from renal cell carcinomas were treated with either SD-IGRT to prescription doses of 18–24 Gy (median, 24 Gy) or hypofractionation (3 or 5 fractions) with prescription doses ranging between 20 and 30 Gy. The median follow-up was 12 months (range, 1–48 months). Results The overall 3-year actuarial local progression-free survival (LPFS) for all lesions was 44%. The 3-year LPFS for those who received high single-dose (24 Gy; n = 45), low single-dose (< 24 Gy; n = 14), and hypofractionation regimens (n = 46) were 88%, 21%, and 17%, respectively (high single dose versus low single dose, p = 0.001; high single dose versus hypofractionation, p < 0.001). Multivariate analysis revealed the following variables as significant predictors of improved LPFS: dose of 24 Gy compared with lower dose (p = 0.009), and single dose versus hypofractionation (p = 0.008). Conclusion High-dose SD-IGRT is a non-invasive procedure resulting in high probability of local tumor control for metastatic renal cell cancers, generally considered radioresistant according to classical radiobiological ranking.

Local treatments for metastases of renal cell carcinoma: a systematic review

“…We have described the best available contemporary evidence base, from which 12 Amiraliev et al (2012) 23 Brinkmann et al (2007) 29 Eggener et al (2008) 27 Fokas et al (2010) 36 Fuchs et al (2005) 35 Hunter et al (2012) 34 Ikushima et al (2000) 37 Kwak et al (2007) 30 Lee et al (2006) 32 Pretalia et al (2010) 24 Russo et al (2007) 31 Staehler et al (2009) 26 Staehler et al (2010) 25 Zelefsky et al (2012) 33 Zerbi et al (2008) Review some conclusions can be made, and identifi ed knowledge gaps that can only be addressed through well-designed, prospective comparative studies. However, there are several limitations.…”

“…Eight studies assessed local treatments of metastases from renal cell carcinoma in various organs, 12,24,26,27,[29][30][31][32] of which the most common sites were lung, bone, liver, and brain, and less common sites were pancreas, adrenal gland, lymph nodes, thyroid gland, spleen, ethmoid sinus, and skin (table 1). Other studies also assessed local treatments for metastases from renal cell carcinoma in bone (including the vertebrae), 33 29 used treatment beforehand. In one study, 30 systemic treatment was not used.…”

“…In one study, 33 single-dose image-guided radiotherapy (IGRT) was compared with hypofractionated IGRT in patients with bone metastases in various locations. Patients treated with single-dose IGRT (≥24 Gy) had a signifi cantly better 3-year actuarial local progression-free survival than those treated with hypofractionated IGRT (88% vs 17%; p=0·001), which was also shown with a Cox regression analysis (p=0·008).…”

“…There was a moderate-to-high risk of confounding regarding previous treatment, tumour histology, grade, and size or volume of metastases, especially in studies on local treatments of bone and brain metastases. [33][34][35][36][37] Regarding diff erent sites treated in the same study, there was generally a moderate-to-high risk of confounding, especially for studies pertaining to treatment of metastases at various sites, 12,27,[30][31][32] because it was often unclear if these confounders were adjusted. Evidence quality was not assessed by GRADE because of the nature of the included studies (ie, retrospective comparative studies), and the high risk of bias across the studies.…”

Spinal metastases: From conventional fractionated radiotherapy to single-dose SBRT

“…In a retrospective analysis of 105 cases of metastatic renal cell carcinomas treated (59 spinal lesions) with either hypofractionated or high dose IGRT (dose range 18-24 Gy), Zelefsky et al confirmed a strong predictive value of high prescription dose. 33 The overall 3-year actuarial local progression-free survival for all lesions was 44%. The 3-year local control for high single-dose (24 Gy), low single-dose (<24 Gy), and hypofractionation were 88%, 21%, and 17%, respectively (high single dose versus low single dose, p = 0.001).…”