Renal Cancer is Not Radioresistant: Slowly but Continuing Shrinkage of the Tumor After Stereotactic Body Radiation Therapy

Abstract

Purpose:To evaluate the safety and efficacy of stereotactic body radiation therapy for primary lesion of renal cell carcinoma with long-term and regular follow-up of tumor size and renal function.Methods:This prospective study included 13 patients treated with stereotactic body radiation therapy for primary lesion of stage I renal cell carcinoma between August 2007 and June 2016 in our institution. Diagnosis of renal cell carcinoma was made by 2 radiologists using computed tomography or magnetic resonance imaging. A dosage of 60 Gy in 10 fractions or 70 Gy in 10 fractions was prescribed. The higher dose was selected if dose constraints were satisfied. Tumor response on imaging examination, local progression-free rate, overall survival, and toxicity were assessed.Results:The mean follow-up period was 48.3 months (range: 11-108 months). The tumors showed very slow but continuous response during long-term follow-up. Three cases (23.1%) showed transient progression during the short follow-up. The mean duration until the day on which partial response was confirmed among the partial or complete response cases was 22.6 months (95% confidence interval, 15.3-30.0 months). Local progression-free rate was 92.3% for 3 years and overall survival rate 91.7% for 2 years and 71.3% for 3 years. Twelve cases (92.3%) had impaired renal function at baseline. Renal function decreased slowly and mildly in most of the cases, but 2 cases of solitary kidney showed grade 4 or 5 renal dysfunction.Conclusion:All renal tumors decreased in size slowly but continuously for years after stereotactic body radiation therapy. Renal cancer can be treated radically with stereotactic body radiation therapy as a radiosensitive tumor, but careful attention should be given in cases with solitary kidney.

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

“…Overall, a dose-response relationship was established wherein every 10 Gy of physical dose to ipsilateral renal parenchyma predicts a GFR decrease of 25-39%. Regarding timing, an initial plateau phase followed by late-onset renal dysfunction !1 yr after SABR has been described previously [43,44] and is also noted in studies included here [37,38]. Taken together, these data indicate that careful treatment planning to minimize high-dose exposure of ipsilateral kidney parenchyma plus long-term follow-up ideally using functional imaging (ie, MAG3 or DMSA) will be important to capture late renal function decline in the targeted kidney.…”

“…None of the 35 solitary kidney patients in this analysis required dialysis, suggesting that renal function may be adequately preserved even without compensation by the contralateral kidney. Of note, some included studies reported a late onset of renal dysfunction after SABR, with initial maintenance of baseline eGFR followed by a late decline [37,38]. Although direct comparison of renal function outcomes with surgical or TA management is difficult, our results are comparable with a previously reported large systematic review and meta-analysis comparing PN with TA, wherein median changes in eGFR (ranges) of -6.2 (-18 to +4.1) and -4.9 (-8.0 to +1.5) ml/min, respectively, were demonstrated [42].…”

Proton Therapy for Primary Renal Cell Carcinoma: The First Nationwide Retrospective Study in Japan

“…Furthermore, the studies using a BED 10 range of 60-80 Gy with a median follow-up for ≥2 years reported a relatively low local control rates (range=85.7-89%) as shown in Table III (24,25). Conversely, local control rates in all the 3 studies and the in vivo 34: 2883-2889 (2020) present study using a BED 10 ≥90 Gy with a median followup of ≥2 years were higher than 90% (11,12,23). Taking the previous reports of SBRT and particle beam therapy together, BED 10 ≥90 Gy may be necessary and high-dose RT using advanced technology can accomplish good local tumor control.…”

“…However, an analysis of nine international multi-institutional studies of SBRT using a BED 10 range of 80-87.5 Gy reported a 4-year local control rate of 97.8% (20). Table III summarizes the clinical outcomes of previous studies evaluating RT for primary RCC (8,11,12,(22)(23)(24)(25). Those studies used a wide range of dose fractionation schedules and BED 10 values (range=38-125 Gy), but local tumor control was achieved in almost all patients irrespective of the BED 10 .…”

Competing Risk Analysis of Cardiovascular/Cerebrovascular Death in T1/2 Kidney Cancer: A SEER Database Analysis

“…In our study, it was found that chemotherapy made KC patients decrease risk of CCD but increased risk of RCD, which was contrary to common sense owing to the bias existing in our study, one of the possible explanation was the patients received chemotherapy was with poor prognosis, but those who didn't received chemotherapy was with good prognosis that didn't need chemotherapy. Radiation therapy and chemotherapy were con rmed useful for KC treatment in many respects, such as reducing the risk of local recurrence 26 , delaying the metastasis of cancer 27 and so on 28 , but there were rare studies about the effect of radiation therapy and chemotherapy on CCD in KC patients. Further studies are expected to conduct in the clinic and laboratory to provide more information on the relationship between these two therapy methods and cardiovascular/cerebrovascular events in KC patients.…”