The effect of biological effective dose on time to symptom progression in metastatic renal cell carcinoma

Predictive Factors and the Role of Conventionally Fractionated Radiation Therapy for Bone Metastasis from Renal Cell Carcinoma in the Era of Targeted Therapy

Background and Objectives: Despite rapid advances in targeted therapies for renal cell carcinoma (RCC), bone metastases remain a major problem that significantly increases morbidity and reduces patients' quality of life. Conventional fractionated radiotherapy (CF-RT) is known to be an important local treatment option for bone metastases; however, bone metastases from RCC have traditionally been considered resistant to CF-RT. We aimed to investigate the effectiveness of CF-RT for symptomatic bone metastasis from RCC and identify the predictive factors associated with treatment outcomes in the targeted therapy era. Materials and Methods: Between January 2011 and December 2023, a total of 73 lesions in 50 patients treated with a palliative course of CF-RT for symptomatic bone metastasis from RCC were evaluated, and 62 lesions in 41 patients were included in this study. Forty-five lesions (72.6%) were treated using targeted therapy during CF-RT. The most common radiation dose fractionations were 30 gray (Gy) in 10 fractions (50%) and 39 Gy in 13 fractions (16.1%). Results: Pain relief was experienced in 51 of 62 lesions (82.3%), and the 12-month local control (LC) rate was 61.2%. Notably, 72.6% of the treatment course in this study was combined with targeted therapy. The 12-month LC rate was 74.8% in patients who received targeted therapy and only 10.9% in patients without targeted therapy (p < 0.001). Favorable Eastern Cooperative Oncology Group performance status (p = 0.026) and pain response (p < 0.001) were independent predictors of improved LC. Radiation dose escalation improved the LC in radiosensitive patients. A consistent treatment response was confirmed in patients with multiple treatment courses. Conclusions: CF-RT enhances pain relief and LC when combined with targeted therapy. Patients who responded well to initial treatment generally showed consistent responses to subsequent CF-RT for additional painful bone lesions. CF-RT could therefore be an excellent complementary local treatment modality for targeted therapy.

Bone Metastasis in Renal Cell Carcinoma Patients: Risk and Prognostic Factors and Nomograms

Background

Bone metastasis (BM) is one of the common sites of renal cell carcinoma (RCC), and patients with BM have a poorer prognosis. We aimed to develop two nomograms to quantify the risk of BM and predict the prognosis of RCC patients with BM.

Methods

We reviewed patients with diagnosed RCC with BM in the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. Multivariate logistic regression analysis was used to determine independent factors to predict BM in RCC patients. Univariate and multivariate Cox proportional hazards regression analyses were used to determine independent prognostic factors for BM in RCC patients. Two nomograms were established and evaluated by calibration curve, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA).

Results

The study included 37,554 patients diagnosed with RCC in the SEER database, 537 of whom were BM patients. BM's risk factors included sex, tumor size, liver metastasis, lung metastasis, brain metastasis, N stage, T stage, histologic type, and grade in RCC patients. Currently, independent prognostic factors for RCC with BM included grade, histologic type, N stage, surgery, brain metastasis, and lung metastasis. The calibration curve, ROC curve, and DCA showed good performance for diagnostic and prognostic nomograms.

Conclusions

Nomograms were established to predict the risk of BM in RCC and the prognosis of RCC with BM, separately. These nomograms strengthen each patient's prognosis-based decision making, which is critical in improving the prognosis of patients.

The promising role of radiotherapy in the treatment of advanced or metastatic renal cell carcinoma: a narrative review

Traditionally, renal cell carcinoma (RCC) has been regarded to be “radioresistant”. Conventional fractionated radiation (CFRT) has played a limited role in RCC as a palliative treatment to relieve pain and bleeding. Succeed to the rapid development of precise radiotherapy techniques, realizing safe delivery of high-dose radiotherapy, an increasing amount of convincing data suggests that the delivery of high-dose-per-fraction radiation through stereotactic radiosurgery (SRS) or stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy (SABR) can help to overcome resistance to radiotherapy. Herein, we summarized and analyzed the data from randomized controlled trials, retrospective and prospective studies, and meta-analyses relating to the treatment of advanced and metastatic RCC (mRCC) with CFRT, SBRT, or SBRT combined with systemic therapy. CFRT has a limited effect on local control (LC) of advanced RCC and mRCC, but it is a major palliative treatment which could obviously relieve pain caused by cancer. SBRT and SRS have the significant advantage of being able to precisely deliver a high dose of radiation to the target tissues. SBRT could cause a higher LC for advanced and metastatic RCC and could be used as an alternative to surgery for patients with oligometastatic RCC. The combination of SBRT with systemic therapy, such as targeted therapy or immunotherapy, is safe and tolerable. Concurrent immunotherapy and SBRT is a promising treatment strategy for patients with advanced or metastatic RCC. However, research on radiotherapy combined with systemic therapy is still limited and further studies to explore this treatment for RCC are urgently needed.

The Reintroduction of Radiotherapy Into the Integrated Management of Kidney Cancer

The incidence of renal cell carcinoma (RCC) has been increasing, with a moderate subgroup of individuals who later develop metastatic disease. Historically, metastatic RCC has been managed with systemic therapy because RCC was believed to be radioresistant. Local therapies, such as stereotactic body radiation therapy, also known as stereotactic ablative radiotherapy, which utilize focused high-dose-rate radiation delivered over a limited number of treatments, have been successful in controlling local disease and, in some cases, extending survival in patients with intracranial and extracranial metastatic RCC. Stereotactic ablative radiotherapy is highly effective in treating intact disease when patients are not surgical candidates. Stereotactic ablative radiotherapy is well tolerated when used in conjunction with systemic therapy such as tyrosine kinase inhibitors and immune checkpoint inhibitors. These successes have prompted investigators to evaluate the efficacy of stereotactic body radiation therapy in novel settings such as neoadjuvant treatment of advanced RCC with tumor thrombus and oligometastatic/oligoprogressive disease states.

Outcomes of patients with spinal metastases from renal cell carcinoma treated with conventionally-fractionated external beam radiation therapy

Renal cell carcinoma (RCC) has been traditionally thought to be radioresistant. This retrospective cohort study aims to assess the outcomes of patients with spinal metastases from RCC treated with conventionally-fractionated external beam radiation therapy (cEBRT) in our institution.Patients diagnosed with histologically or radiologically-proven RCC who received palliative cEBRT to spinal metastases, using 3-dimensional conformal technique between 2009 and 2018 were reviewed. Local progression-free survival (PFS), overall survival (OS) and common terminology criteria for adverse events version 4.0-graded toxicity were assessed. Univariable and multivariable Cox proportional hazards regression analyses were performed to evaluate for predictors associated with survivals.Thirty-five eligible patients with forty spinal segments were identified, with a median follow-up of 7 months (range, 0-47). The median equivalent dose in 2 Gy fractions (EQD2) was 32.5 Gy 10 (range, 12-39). Thirty-seven percent of patients underwent surgical intervention. At the time of last follow-up, all but 1 patient had died. Seven patients developed local progression, with the median time to local progression of 10.2 months. The median local PFS and OS were 3.3 and 4.8 months. There was no grade 3 or higher toxicity. A higher radiation dose (equivalent dose to 2 Gy fraction <32.5 Gy 10 vs ≥32.5Gy 10) (hazard ratio [HR], 0.47; 95% confidence interval [CI], 0.17-3.18; P-value (P) = .68) and spinal surgery (HR, 2.35; 95% CI, 0.53-10.29; P = .26) were not significantly associated with local PFS on univariable analysis. Multivariable analysis showed that higher Tokuhashi score (HR, 0.41; 95% CI, 0.19-0.88; P = .02), lower number of spinal segments irradiated (HR, 1.18; 95% CI, 1.01-1.37; P = .04) and use of targeted therapy (HR, 0.41; 95% CI, 0.18-0.96; P = .04) were independent predictors for improved OS.For an unselected group of patients with RCC, there is no significant association between higher radiation dose and improved local control following cEBRT. This may be due to their short survivals. With the use of more effective systemic therapy, including targeted therapy and immunotherapy, survival will likely be prolonged. A tailored-approach is needed to identify patients with good prognosis who may still benefit from aggressive local treatments.

Treating the Chameleon: Radiotherapy in the management of Renal Cell Cancer

PURPOSE

To review the role of radiotherapy (RT) in the treatment of renal cell cancer (RCC) in the curative and palliative setting.

CONTENT

Details related to the clinical outcomes of primary, preoperative, postoperative and palliative RT are discussed, along with a presentation of the established role of surgery and systemic therapy. An overview of data derived from mono- and multi-institutional trials is provided.

CONCLUSION

Radiotherapy has been shown to provide good symptom palliation and local control in RCC depending on the dose that can be delivered. There is emerging data suggesting that with the use of high-precision RT methods the indication spectrum of RT can be exploited covering different clinical situations particularly for unresectable local recurrences and oligometastatic disease.

Cancer symptom response as an oncology clinical trial end point

Introduction

A critical challenge in oncology is interpreting clinical trial results to inform clinical decision making. Clinical trials typically focus on overall survival (OS) and progression-free survival (PFS) as primary endpoints, which do not reflect early signs of meaningful patient benefit or harm. Cancer symptom response (CSR) can provide information about early treatment response, and studies show that CSR predicts long-term health outcomes.

Areas covered

CSR requires careful consideration of its measurement and interpretation to facilitate integration into clinical practice. We describe considerations for the evaluation, analysis, and interpretation of CSR in clinical trials. To illustrate the potential clinical value of CSR, we performed a retrospective analysis of a three-arm randomized cooperative-group clinical trial.

Expert commentary

Evaluation of CSR provides a meaningful assessment of early cancer treatment effects. It can act as an early signal of disease progression and death and thus can identify which patients with stable disease will have a more favorable prognosis. Future research will include development of methods for more accurate assessment of CSR, reduction of the number of symptoms used as signals for disease progression or survival by tumor type, and statistical methods that effectively correct for missing data and informative censoring.

The Efficacy of Conventionally Fractionated Radiation in the Management of Osseous Metastases from Metastatic Renal Cell Carcinoma

Background

There is little data regarding the effectiveness of palliative radiation with conventional fractionation for metastatic renal cell carcinoma (RCC), which has been described as radioresistant. We conducted a retrospective analysis of patients with metastatic bony disease from RCC treated with radiation therapy at our institution.

Methods

Forty patients with histologically confirmed RCC with a total of 53 treatment courses were included. Pain response after radiotherapy was recorded and freedom from progression was generated using posttreatment radiographs. Patient data was analyzed to assess influence on local control.

Results

Patients had a median age of 63. Median follow-up was 9.3 months. The most common radiation dose was 30 Gy in 10 fractions. Pain control after radiotherapy was achieved in 73.6% of patients. Increasing age was associated with nonresponse at the initial pain assessment post-RT (p = 0.02). In lesions with initial pain response, nonclear cell histology was associated with increased pain recurrence (p = 0.01) and a shorter duration to pain recurrence (p = 0.01). Radiographic control at 1 year was 62%.

Conclusions

Pain response and control rates for osseous metastatic disease in RCC are comparable to other histologies when treated with conventional fractionation. These appear to be inferior to reported control rates from stereotactic treatments.

Radiotherapy for renal cell carcinoma: renaissance of an overlooked approach

Conventional radiotherapy previously had a limited role in the definitive treatment of renal cell carcinoma (RCC), owing to the disappointing outcomes of several trials and the perceived radioresistance of this type of cancer. In this context, radiotherapy has been relegated largely to the palliation of symptoms in patients with metastatic disease, with variable rates of response. Following the availability of newer technologies that enable safe delivery of high-dose radiotherapy, stereotactic ablative radiotherapy (SABR) has become increasingly used in patients with RCC. Preclinical evidence demonstrates that RCC cells are sensitive to ablative doses of radiotherapy (≥8-10 Gy). Trials in the setting of intracranial and extracranial oligometastases, as well as primary RCC, have demonstrated excellent tumour control using this approach. Additionally, an awareness of the capacity of high-dose radiation to stimulate antitumour immunity has resulted in novel combinations of SABR with immunotherapies. Here we describe the historical application of conventional radiotherapy, the current biological understanding of the effects of radiation, and the clinical evidence supporting the use of ablative radiotherapy in RCC. We also explore emerging opportunities to combine systemic targeted agents or immunotherapies with radiation. Radiotherapy, although once an overlooked approach, is moving towards the forefront of RCC treatment.

Stereotactic body radiotherapy for renal cell cancer and pancreatic cancer : Literature review and practice recommendations of the DEGRO Working Group on Stereotactic Radiotherapy

PURPOSE

This report of the Working Group on Stereotactic Radiotherapy of the German Society of Radiation Oncology (DEGRO) aims to provide a literature review and practice recommendations for stereotactic body radiotherapy (SBRT) of primary renal cell cancer and primary pancreatic cancer.

METHODS

A literature search on SBRT for both renal cancer and pancreatic cancer was performed with focus on prospective trials and technical aspects for clinical implementation.

RESULTS

Data on renal and pancreatic SBRT are limited, but show promising rates of local control for both treatment sites. For pancreatic cancer, fractionated SBRT should be preferred to single-dose treatment to reduce the risk of gastrointestinal toxicity. Motion-compensation strategies and image guidance are paramount for safe SBRT delivery in both tumor entities.

CONCLUSION

SBRT for renal cancer and pancreatic cancer have been successfully evaluated in phase I and phase II trials. Pancreatic SBRT should be practiced carefully and only within prospective protocols due to the risk of severe gastrointestinal toxicity. SBRT for primary renal cell cancer appears a viable option for medically inoperable patients but future research needs to better define patient selection criteria and the detailed practice of SBRT.

Versatility of the Novalis System to Deliver Image-Guided Stereotactic Body Radiation Therapy (SBRT) for Various Anatomical Sites

Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) programs to treat brain tumors were implemented when we first acquired the Brainlab Novalis system in 2003. Two years later, we started an extra-cranial stereotactic radio-ablation or more appropriately a stereotactic body radiation therapy (SBRT) program using the Brainlab Novalis image-guided system at The Methodist Hospital in Houston, Texas. We hereby summarize our initial experience with this system in delivering image-guided SBRT to a total of 80 patients during our first year of clinical implementation, from February 2005 to January 2006.

Over 100 lesions in more than 20 distinct anatomical sites were treated. These include all levels of spine from cervical, thoracic, lumbar, and sacral lesions. Spinal lesions encompass intramedullary, intradural, extradural, or osseous compartments. Also treated were lesions in other bony sites including orbit, clavicle, scapula, humerus, sternum, rib, femur, and pelvis (ilium, ischium, and pubis). Primary or metastatic lesions located in the head and neck, supraclavicular region, axilla, mediastinum, lung (both central and peripheral), abdominal wall, liver, kidney, para-aortic lymph nodes, prostate, and pelvis were also treated. In addition to primary radiotherapy, SBRT program using the Brainlab Novalis system allows re-irradiation for recurrence and “boost” after conventional treatment to various anatomical sites. Treating these sites safely and efficaciously requires knowledge in radiation tolerance, fraction size, total dose, biologically equivalent dose (BED), prior radiotherapy, detailed dose volume histograms (DVH) of normal tissues, and the radiosensitive/radioresistant nature of the tumor.

Placement of radio-opaque markers (Visicoil, Radiomed) in anatomical sites not in close proximity to bony landmarks (e.g., kidney and liver) helps in measuring motion and providing image guidance during each treatment fraction. Tumor/organ motion data obtained using 4D-CT while the patient is immobilized in the body cast aids in planning treatment margin and determining the need for respiratory motion control, e.g., abdominal compressor, gating, or active breathing control. The inclusion of PET/CT to the Brainlab treatment planning system further refines the target delineation and possibly guides differential fraction size prescription and delivery.

The majority of the patients tolerated the SBRT treatment well despite the longer daily treatment time when compared to that of conventional treatment. All patients achieved good pain relief after SBRT. Compared to conventional standard radiotherapy of lower daily fraction size, we observed that the patients achieved faster pain relief and possibly more durable symptom control. Very high local control with stable disease on imaging was observed post SBRT.

Our initial experience shows that the Brainlab Novalis system is very versatile in delivering image-guided SBRT to various anatomical sites. This SBRT approach can be applied to either primary or metastatic lesions in the primary, “boost,” or re-irradiation settings. The understanding of fraction size, total dose, BED, and DVH of normal tissues is very important in the treatment planning. Appropriate use of immobilization devices, radio-opaque markers for image-guidance, 4D-CT for tumor/organ motion estimates, and fusion of planning CT scans with biological/functional imaging will further improve the planning and delivery of SBRT, hopefully leading to better treatment outcome.

Prognostic significance of intensive local therapy to bone lesions in renal cell carcinoma patients with bone metastasis

We evaluated the prognostic roles of local therapy to bone metastasis (BM) in metastatic renal cell carcinoma (mRCC) patients with BM. This retrospective study included 71 mRCC patients with BM. Local therapy to BM included en bloc resection, curettage, and radiotherapy (RT). RT was classified into RT with biological effective dose (BED) ≥85 Gy and <85 Gy by its therapeutic intensity. Local therapy to BM was given for 64 patients (90 %): en bloc resection, curettage, and RT for 16, 10, and 38 patients, respectively. Fifteen patients received RT with BED ≥85 Gy. The median overall survival (OS) was 25 months (median follow-up 16 months). For 46 patients with solitary BM, patients treated with en bloc resection, curettage, and RT with BED ≥85 Gy showed significantly better OS than those treated with RT with BED <85 Gy or no local therapy (P = 0.006). Because OS was comparable among patients treated with en bloc resection, curettage, and RT with BED ≥85 Gy, these three treatment modalities were defined as "intensive local therapy". Intensive local therapy to BM was also associated with favorable OS with marginal significance (P = 0.052) in a cohort of 25 patients with multiple BM. A multivariate analysis in the whole cohort revealed that intensive local therapy to BM was independently associated with favorable OS (hazard ratio 0.23, P < 0.001) along with Memorial-Sloan Kettering Cancer Center risk category (P < 0.001). Thus, intensive local therapy to BM might improve OS in mRCC patients with BM including multiple BM.

Treatment outcome of radiation therapy and concurrent targeted molecular therapy in spinal metastasis from renal cell carcinoma

PURPOSE

To evaluate the clinical outcomes of patients who underwent radiation therapy with or without targeted molecular therapy for the treatment of spinal metastasis from renal cell carcinoma (RCC).

MATERIALS AND METHODS

A total of 28 spinal metastatic lesions from RCC patients treated with radiotherapy between June 2009 and June 2015 were retrospectively reviewed. Thirteen lesions were treated concurrently with targeted molecular therapy (concurrent group) and 15 lesions were not (nonconcurrent group). Local control was defined as lack of radiographically evident local progression and neurological deterioration.

RESULTS

At a median follow-up of 11 months (range, 2 to 58 months), the 1-year local progression-free rate (LPFR) was 67.0%. The patients with concurrent targeted molecular therapy showed significantly higher LPFR than those without (p = 0.019). After multivariate analysis, use of concurrent targeted molecular therapy showed a tendency towards improved LPFR (hazard ratio, 0.13; 95% confidence interval, 0.01 to 1.16). There was no difference in the incidence of systemic progression between concurrent and nonconcurrent groups. No grade ≥2 toxicities were observed during or after radiotherapy.

CONCLUSION

Our study suggests the possibility that concurrent use of targeted molecular therapy during radiotherapy may improve LPFR. Further study with a large population is required to confirm these results.

Stereotactic Radiosurgery for Renal Cancer Brain Metastasis: Prognostic Factors and the Role of Whole-Brain Radiation and Surgical Resection

Background. Renal cell carcinoma is a frequent source of brain metastasis. We present our consecutive series of patients treated with Stereotactic Radiosurgery (SRS) and analyse prognostic factors and the interplay of WBRT and surgical resection. Methods. This is a retrospective study of 66 patients with 207 lesions treated with the Cyberknife radiosurgery system in our institution. The patients were followed up with imaging and clinical examination 1 month and 2-3 months thereafter for the brain metastasis. Patient, treatment, and outcomes characteristics were analysed. Results. 51 male (77.3%) and 15 female (22.7%) patients, with a mean age of 58.9 years (range of 31–85 years) and a median Karnofsky Performance Status (KPS) of 90 (range of 60–100), were included in the study. The overall survival was 13.9 months, 21.9 months, and 5.9 months for the patients treated with SRS only, additional surgery, and WBRT, respectively. The actuarial 1-year Local Control rates were 84%, 94%, and 88% for SRS only, for surgery and SRS, and for WBRT and additional SRS, respectively. Conclusions. Stereotactic radiosurgery is a safe and effective treatment option in patients with brain metastases from RCC. In case of a limited number of brain metastases, surgery and SRS might be appropriate.

Stability of Spinal Bone Metastases and Survival Analysis in Renal Cancer after Radiotherapy

Purpose

This retrospective analysis evaluated the outcome of patients with spinal bone metastases of renal cell cancer after radiotherapy (RT) in terms of stability and survival, using a validated scoring system for spinal stability assessment.

Materials and Methods

The survival rates of 155 patients with bone metastases of renal cancer treated from January 2000 to January 2012 were determined. The stability of irradiated osteolytic lesions of the thoracic and lumbar spine was evaluated retrospectively using the Taneichi score and analyzed for predictive factors. The effects of therapy in terms of changes in neurological signs and tumor-related pain were recorded.

Results

Follow-up with regular computed tomography (CT) was available for 28 patients, 14 with unstable metastases. One hundred thiry-two patients (85%) died during follow-up. RT could not improve the stability of vertebral bodies after 3 and 6 months. Consequently, none of the examined predictive factors such as age, number of bone metastases and systemic therapy showed a significant correlation with stability 6 months after RT. The median survival of all 155 patients after diagnosis of bone metastases was 12.9 months. Improvement of pain and neurological deficits occurred in 60%, and in 24% of the respective affected in all patients.

Conclusions

RT was unable to improve the stability of vertebral metastases, probably due to the short overall survival, which resulted in an insufficient number of patients with evaluable follow-up. RT allowed reduction of pain and neurological deficits. A short fractionation schedule may be preferred in this situation.

Zoledronic acid enhances the effect of radiotherapy for bone metastases from renal cell carcinomas: more than a 24-month median follow-up

BACKGROUND

Renal cell carcinoma (RCC) is thought to respond unreliably to radiotherapy (RT). Zoledronic acid significantly reduces the risk of skeletal complications. This study investigated whether RT with zoledronic acid prolonged the time to bone-lesion progression in comparison with RT alone.

METHOD

Twenty-seven patients (34 lesions) with bone metastases secondary to RCC undergoing treatment with RT with or without zoledronic acid were retrospectively evaluated at two institutions between 1999 and 2009. Twelve patients were treated with RT alone from 1999 to 2008 (RT group). Fifteen patients were treated with RT and zoledronic acid from 2006 to 2009 (RT + Z group). The time to skeletal-related events and pain progression were assessed from patients' medical records.

RESULTS

The median (range) follow-up was 26 (3-75) and 24 (3-55) months in the RT and RT + Z groups, respectively. Three patients (three lesions) in the RT + Z group had skeletal-related events (SREs). In contrast, six patients (eight lesions) in the RT group had SREs. SREs comprised pathological fractures in five, additional surgeries in three, spinal cord or cauda equine compression in two, and repeat RT in one. There was a significant difference in SRE-free survival time and duration of site-specific pain response between groups.

CONCLUSIONS

RT combined with zoledronic acid significantly prolonged SRE-free survival and duration of pain response compared with RT alone in the treatment of osseous metastases from RCC.

A dose-response relationship for time to bone pain resolution after stereotactic body radiotherapy (SBRT) for renal cell carcinoma (RCC) bony metastases

BACKGROUND

To investigate the utility of stereotactic body radiotherapy (SBRT) in the treatment of painful renal cell carcinoma (RCC) bone metastases, and for a possible dose effect on time to symptom relief.

MATERIAL AND METHODS

Eighteen patients with 24 painful osseous lesions from metastatic RCC were treated with SBRT. The most common treatment regimens were 24 Gy in 3 fractions and 40 Gy in 5 fractions. The times from treatment to first reported pain relief and time to symptom recurrence were evaluated. Median follow-up was 38 weeks (1-156 weeks).

RESULTS

Seventy-eight percent of all patients had pain relief. Patients treated with a BED > 85 Gy achieved faster and more durable pain relief compared to those treated with a BED < 85 Gy. There was decrease in time to pain relief after a change in treatment regimen to 8 Gy × 5 fractions (BED = 86). There was only one patient with grade 1 skin toxicity. No neurological or other toxicity was observed.

CONCLUSIONS

SBRT can safely and effectively treat painful RCC bony metastases. There appears to be a relationship between radiation dose and time to stable pain relief.

Role of radiation therapy in the management of renal cell cancer

Renal cell carcinoma (RCC) is traditionally considered to be radioresistant; therefore, conventional radiotherapy (RT) fraction sizes of 1.8 to 2 Gy are thought to have little role in the management of primary RCC, especially for curative disease. In the setting of metastatic RCC, conventionally fractionated RT has been an effective palliative treatment in 50% of patients. Recent technological advances in radiation oncology have led to the clinical implementation of image-guided radiotherapy, allowing biologically potent doses to the tumors intra- and extra-cranially. As predicted by radiobiologic modeling, favorable outcomes have been observed with highly hypofractionated schemes modeled after the experience with intracranial stereotactic radiosurgery (SRS) for RCC brain metastases with reported local control rates averaging 85%. At present, both primary and metastatic RCC tumors may be successfully treated using stereotactic approaches, which utilize steep dose gradients to maximally preserve function and avoid toxicity of adjacent organs including liver, uninvolved kidney, bowel, and spinal cord regions. Future endeavors will combine stereotactic body radiation therapy (SBRT) with novel targeted therapies, such as tyrosine kinase inhibitors and targeted rapamycin (mTOR) inhibitors, to maximize both local and systemic control.

Treatment outcome and prognostic factors in renal cell cancer patients with bone metastasis

We retrospectively analyzed treatment outcomes and factors for poor prognosis for patients with renal cell cancer (RCC) bone metastases. Patients with bone metastases at initial diagnosis of metastasis secondary from RCC, treated at our hospital between 1984 and 2009, were retrospectively reviewed and statistically analyzed. Among 214 RCC patients with metastasis, 71 patients (33%) were found to have bone metastases at initial diagnosis of metastasis. The median follow-up was 21.1 months (intra-quartile range: IQR, 9.1-47.4 months). The estimated median overall survival time from the diagnosis of bone metastasis was 27.7 months. The probability of patients surviving at 1, 2, and 5 years was 63.7, 52.2, and 19.3%, respectively. When they were stratified by MSKCC scores, the probability of the median overall survival of the populations classified as favorable, intermediate, and poor was not reached, 32.9, and 10.5 months, respectively (P = 0.002). In addition, poor performance status (PS) (hazard ratio [HR]: 1.938, P = 0.035) and no prior nephrectomy (HR: 3.008, P = 0.004) were extracted as independent poor prognostic factors by multivariate analysis. All treatment modalities-including radical en bloc surgery, radiation therapy, cytokine therapy, molecular targeted therapy, and administration of zoledronic acid-seemed to contribute to favorable survival. More than half of the patients with bone metastases secondary from RCC were predicted to survive more than 24 months. In this population, MSKCC scores were valid predictors of survival. With increased treatment options, RCC patients with bone metastasis may benefit further from subsequent modalities and/or agents.

Preoperative stereotactic body radiotherapy to a skull renal cell metastasis: an alternative to preoperative embolization?

INTRODUCTION

This is the first case study to report on using stereotactic body radiotherapy as an alternative and novel treatment modality for embolization to reduce the risk of operative bleeding for a metastatic renal cell tumor.

CASE PRESENTATION

A 58-year-old woman presented with an asymptomatic large 7-cm tumor on the parieto-occipital vertex of the skull. Given the location of this lesion along with its vascular histology, it was a challenge to provide safe and effective treatment using conventional management strategies.

CONCLUSION

We report on a rare presentation of a metastatic renal cell cancer and the use of stereotactic body radiotherapy as an innovative radiation approach to deliver high-dose radiation safely to control this large aggressive and vascular metastasis. The success of this management strategy allowed for minimal intraoperative blood loss, and the patient continues with local control 1-year posttreatment.

Dose escalation for metastatic spinal cord compression in patients with relatively radioresistant tumors

PURPOSE

Radiotherapy alone is the most common treatment for metastatic spinal cord compression (MSCC) from relatively radioresistant tumors such as renal cell carcinoma, colorectal cancer, and malignant melanoma. However, the results of the "standard" regimen 30 Gy/10 fractions need to be improved with respect to functional outcome. This study investigated whether a dose escalation beyond 30 Gy can improve treatment outcomes.

METHODS AND MATERIALS

A total of 91 patients receiving 30 Gy/10 fractions were retrospectively compared to 115 patients receiving higher doses (37.5 Gy/15 fractions, 40 Gy/20 fractions) for motor function and local control of MSCC. Ten further potential prognostic factors were evaluated: age, gender, tumor type, performance status, number of involved vertebrae, visceral or other bone metastases, interval from tumor diagnosis to radiotherapy, pretreatment ambulatory status, and time developing motor deficits before radiotherapy.

RESULTS

Motor function improved in 18% of patients after 30 Gy and in 22% after higher doses (p = 0.81). On multivariate analysis, functional outcome was associated with visceral metastases (p = 0.030), interval from tumor diagnosis to radiotherapy (p = 0.010), and time developing motor deficits (p < 0.001). The 1-year local control rates were 76% after 30 Gy and 80% after higher doses, respectively (p = 0.64). On multivariate analysis, local control was significantly associated with visceral metastases (p = 0.029) and number of involved vertebrae (p = 0.043).

CONCLUSIONS

Given the limitations of a retrospective study, escalation of the radiation dose beyond 30 Gy/10 fractions did not significantly improve motor function and local control of MSCC in patients with relatively radioresistant tumors.

Do patients receiving whole-brain radiotherapy for brain metastases from renal cell carcinoma benefit from escalation of the radiation dose?

PURPOSE

Whole-brain radiotherapy (WBRT) is the most common treatment for brain metastases from renal cell carcinoma (RCC). Most patients cannot receive more aggressive therapies including surgery or radiosurgery. The standard WBRT regimen, 30 Gy/10 fractions (10 × 3 Gy), has resulted in poor survival (OS). This study investigates whether escalation of the WBRT dose improves treatment outcomes.

METHODS AND MATERIALS

Data from 60 patients receiving WBRT for brain metastases from RCC were retrospectively analyzed. A dose of 10 × 3 Gy (n = 31) was compared with higher doses (40 Gy/20 fractions or 45 Gy/15 fractions; n = 29) for OS and local control (LC). Additional factors evaluated were patient age, sex, performance status, number of metastases, interval from diagnosis of RCC to WBRT, extracerebral metastases, recursive partitioning analysis (RPA) class, and year of WBRT.

RESULTS

The OS at 6 months was 29% after 10 × 3 Gy and 52% after higher doses (p = 0.003). The OS at 12 months was 13% and 47%, respectively. On multivariate analysis, higher WBRT doses (p = 0.022), Karnofsky performance status score ≥70 (p = 0.017), fewer than four brain metastases (p = 0.035), and RPA Class 1 (p = 0.003) resulted in better OS. The LC at 6 months was 21% after 10 × 3 Gy and 57% after higher doses (p = 0.013). The LC at 12 months was 7% and 35%, respectively. On multivariate analysis, fewer than four brain metastases (p < 0.001) were associated with LC. A trend was found for WBRT regimen (p = 0.06) and RPA class (p = 0.06).

CONCLUSIONS

The findings suggest that escalation of the WBRT dose beyond 10 × 3 Gy improves outcomes in patients with brain metastases from RCC. The results should be confirmed in a randomized trial stratifying for significant prognostic factors.

Radiotherapy for oligometastatic disease in patients with spinal cord compression (MSCC) from relatively radioresistant tumors

BACKGROUND

Radiotherapy alone is the most common treatment for metastatic spinal cord compression (MSCC). Patients with relatively radioresistant tumors and oligometastatic disease may benefit from more intensive therapies (surgery, high-precision radiotherapy). If such therapies are not available, one can speculate whether patients benefit from dose escalation beyond the standard regimen 30 Gy in ten fractions.

PATIENTS AND METHODS

Of 206 patients with MSCC from relatively radioresistant tumors (renal cell carcinoma, colorectal cancer, malignant melanoma), 51 had oligometastatic disease (no visceral or other bone metastases, involvement of only one to three vertebrae). In this subset, 21 patients receiving 30 Gy in ten fractions were retrospectively compared to 30 patients receiving higher doses. Seven further potential prognostic factors were investigated: age, gender, tumor type, performance status, interval from tumor diagnosis to radiotherapy of MSCC, pretreatment ambulatory status, and time developing motor deficits before radiotherapy.

RESULTS

Motor function improved in 52% of patients after 30 Gy and 40% after higher doses (p = 0.44). On multivariate analysis, functional outcome was associated with interval from tumor diagnosis to radiotherapy (p = 0.020). 1-year local control rates were 84% after 30 Gy and 82% after higher doses (p = 0.75). No factor was associated with local control. 1-year survival rates were 76% after 30 Gy and 63% after higher doses (p = 0.52). On multivariate analysis, survival was associated with performance status (p = 0.022) and interval from tumor diagnosis to radiotherapy (p = 0.039), and almost with pretreatment ambulatory status (p = 0.069).

CONCLUSION

Dose escalation beyond 30 Gy in ten fractions did not improve motor function, local control, and survival in MSCC patients with oligometastatic disease from relatively radioresistant tumors.

Further Radiobiologic Modeling of Palliative Radiotherapy: Use of Virtual Trials

PURPOSE

To study duration of response in palliative radiotherapy in a population of tumors.

METHODS AND MATERIALS

Models of dynamic changes in cell number with time were used to develop a function for the remission time (T(rem)) after palliative radiotherapy: [See Equation], where BED is the biologically effective dose, t(1) the duration of symptoms (i.e., the time between the onset of symptoms and the initiation of radiotherapy), K the daily BED repopulation equivalent, alpha the linear radiosensitivity parameter in the linear-quadratic model, and z the tumor regression rate.

RESULTS

Simulations of clinical trials show marked variations in remission statistics depending on the tumor characteristics and are highly compatible with the results of clinical trials. Dose escalation produces both a higher proportion and extended duration of remissions, especially in tumors with high alpha/beta ratios and K values, but the predicted dose responses of acute and late side effects show that caution is necessary. The prospect of using particle beam therapy to reduce normal tissue radiation exposures or using hypoxic sensitizers to improve the tumor cell kill might significantly improve the results of palliative radiotherapy in carefully selected patients and could also be used for safer palliative re-treatments in patients with the potential for prolonged survival. The effect of tumor heterogeneity in determining palliative responses probably exceeds that in radical radiotherapy; as few as 100 patients in each treatment arm produce statistically unreliable results.

CONCLUSIONS

Virtual trials of palliative radiotherapy can be useful to test the effects of competing schedules and better determine future strategies, including improved design of clinical trials as well as combinations of radiotherapy with other anticancer modalities.

Pathologic Complete Response in Renal Cell Carcinoma Brain Metastases Treated with Stereotactic Radiosurgery

Renal cell carcinoma (RCC) is often regarded as a radiation-resistant tumor. However, radiation therapy (RT) in the form of stereotactic radiosurgery (SRS) or whole-brain irradiation has been used to treat brain metastases from RCC. To date, there have been no clinical pathologic correlative findings before and after RT. Herein, we present a case of a patient with brain metastases from RCC treated with SRS. The diagnosis of clear-cell RCC was made in 2001 after right radical nephrectomy. He was also found to have lung metastases at diagnosis. He presented with neurologic symptoms in 2004, and magnetic resonance imaging showed 3 brain lesions with a significant amount of edema consistent with brain metastases. The largest lesion caused a midline shift and was surgically resected. Pathology revealed metastatic RCC. The other 2 smaller brain lesions were treated at 20 Gy respectively with shaped-beam SRS using the BrainLab Novalis system. No whole-brain irradiation was delivered. However, the patient had difficulty weaning off his steroids, and a magnetic resonance imaging performed 6 months after SRS was read as "progression of the lesions." He then underwent resection of both the irradiated brain lesions. Pathologic examination revealed necrotic tissues without any viable tumor identified. The patient has since been doing very well, now 18 months after SRS and 5 years from the initial diagnosis. This is the first reported case that demonstrates that precise high-dose radiation in the form of SRS can cause significant tumor cell death (pathologic complete response) in radiation-resistant brain metastases from RCC. This finding also provides a rationale to deliver stereotactic body RT for primary and metastatic RCC extracranially. A prospective clinical trial using stereotactic body RT for primary and metastatic RCC is under way.

Eyelid-sparing adjuvant radiation therapy for renal cell carcinoma

PURPOSE

To describe the use of debulking surgery with adjuvant external beam irradiation as an eyelid-sparing treatment for renal cell carcinoma.

DESIGN

Interventional case report.

METHODS

A 63-year-old male presented with a right upper lid tumor. He had a history of renal cell carcinoma and pulmonary metastasis treated with surgery and systemic chemotherapy. The eyelid tumor was biopsied, followed by debulking surgery and external beam radiation therapy to treat this metastatic tumor.

RESULTS

Histopathological evaluation of the excised tumor revealed a metastatic renal cell carcinoma, clear cell type. At 4 months' follow-up, he had no evidence of recurrence or radiation oculopathy. He was pleased with his cosmetic result.

CONCLUSIONS

Meta static renal cell carcinoma presenting in the eye and orbit can be the initial manifestation of the primary tumor. It is important to include this tumor in the differential diagnosis of recurrent eyelid lesions. Debulking surgery followed by external beam radiation therapy can be used to control the tumor with an eyelid-sparing cosmetic result.

Short-Course Radiotherapy (RT) for Metastatic Spinal Cord Compression (MSCC) Due to Renal Cell Carcinoma: Results of a Retrospective Multi-Center Study

OBJECTIVE

For MSCC treatment, a short treatment time is desirable, especially if survival prognosis is poor. Survival depends on the primary tumor, extent of disease, performance status, ambulatory status, and the number of involved vertebrae. These factors may help to define the appropriate regimen for the individual patient. Our study compares short-course (1 x 8 Gy, 5 x 4 Gy) and long-course RT (10 x 3 Gy, 15 x 2.5 Gy, 20 x 2 Gy) for functional outcome in MSCC patients with renal cell carcinoma.

METHODS

The following potential prognostic factors for functional outcome were retrospectively investigated: age, performance status, involved vertebra, ambulatory status, time of developing motor deficits before RT, radiation schedule (short-course RT, n=37; long-course RT, n=50).

RESULTS

Eighty-seven patients were included in this retrospective study, 25 patients (29%) showed improvement of motor function, 52 patients (60%) no change, 10 patients (11%) deterioration. 25% of non-ambulatory patients became ambulatory after RT. Functional outcome was affected by the time of developing motor deficits before RT (p<0.001). The RT schedule had no significant impact (p=0.91). In the short-course RT sub-group, functional outcome was similar for 1 x 8 Gy and 5 x 4 Gy (p=0.99).

CONCLUSION

Short-course and long-course RT appear similarly active for MSCC in patients with renal cell carcinoma. Short-course RT appears preferable, as it is means less patient discomfort. Because 1 x 8 Gy and 5 x 4 Gy were comparably effective, 1 x 8 Gy may be suggested the best actual choice.

A phase II trial of palliative radiotherapy for metastatic renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) has previously been described as being less responsive to radiotherapy (RT) than other tumor types. The authors conducted a prospective study to assess the effect of RT on symptoms and quality of life (QOL) in patients with metastatic RCC.

METHODS

Between 1996 and 2002, patients with symptomatic metastatic RCC were entered into a prospective study in two cancer centers. Symptomatic sites of disease were treated with 30 grays (Gy) in 10 fractions. Patients reported pain, analgesic use, symptoms, and QOL using validated questionnaires before RT, 1 month and 3 months after treatment, and every 3 months to 1 year thereafter.

RESULTS

Thirty-one patients (19 males and 12 females) were entered into the trial. The median age of the patients was 61 years (range, 35-81 yrs). The most common indication for RT was bone pain (n = 24). The median duration of follow-up was 4.3 months (range, 1-15 mos). Of 23 evaluable patients treated for pain, 83% (n = 19) experienced site-specific pain relief after RT, and 48% (n = 11) did not have an associated increase in analgesic medication use. The median duration of site-specific pain response was 3 months (range, 1-15 mos). The global pain response rate was only 15% (n = 3) because many patients developed other painful metastases. Global QOL was found to improve in 33% (n = 8) of the evaluable patients.

CONCLUSIONS

A palliative radiotherapy dose of 30 Gy in 10 fractions can result in a significant response rate and the relief of local symptoms in patients with bone metastases from RCC. Improvements in global pain and QOL appear to be limited by the effects of progressive systemic disease.

Prolonged low dose IL-2 and thalidomide in progressive metastatic renal cell carcinoma with concurrent radiotherapy to bone and/or soft tissue metastasis: a phase II study

Metastatic renal cell cancer is one of the immuno-sensitive tumors. Apart from the immuno-modulating agents IFNalpha and IL-2, thalidomide has been reported to be effective in this type of cancer. However, bone metastases and bulky metastases, show limited response to immunotherapy, are often site of recurrent disease and are therefore often treated later with radiotherapy. In this phase II study, we evaluated toxicity and efficacy of the combination of continuous low dose (1 mIU/m2) s.c. IL-2 and thalidomide (200 mg once daily) in 22 patients with progressive metastatic renal cell cancer. In addition, 13 soft tissue lesions and two bone metastases in 13 patients were concurrently treated with fractionated radiotherapy. T cell number and activation in blood was measured by immunoflowcytometry. Nearly all patients developed grade 1-2 toxicity consisting of fatigue, sensory neuropathy, constipation and dizziness. Five patients had a grade 3-4 toxic event: four patients with deep venous thrombosis requiring anticoagulant therapy, and one patient who developed radiation myelopathy. On systemic response evaluation ten patients showed ongoing SD with a mean progression free survival of 9 months. One patient showed a PR (at an irradiated site). Regarding local response to irradiation, seven lesions showed a PR for a mean time period of 8.7 months, whereas seven were stable for 6 months. The radiation response of one lesion was not evaluable. Immunoflowcytometry showed an increase in number and activation of lymphocytes (mainly Natural Killer--NK-cells), which was absent or even decreased in irradiated patients. The combination of sc. low dose IL-2, thalidomide and radiotherapy is feasible, but relatively toxic and does not lead to higher responses at non-irradiated sites. The combination of immunotherapy and concurrent radiotherapy is effective at 60% of the relatively large evaluable sites. Progressive myelopathy developed in one patient, possibly due to radiotherapy in combination with thalidomide.