Cumulative Intracranial Tumor Volume as a Prognostic Factor in Patients with Brain Metastases Undergoing Stereotactic Radiosurgery.

Approximately 25-35% of all cancer patients suffer from brain metastases (BM), and many of them-in particular, those with a limited number of intracranial tumors-are treated with stereotactic radiosurgery (SRS). Accurate prediction of survival remains a key clinical challenge in this population. Several prognostic scales have been developed to facilitate this prognostication, including the Recursive Partitioning Analysis (RPA) classification, the modified Recursive Partitioning Analysis (mRPA) subclassifications, the Basic Score for Brain Metastases (BS-BM), the Score Index for Radiosurgery (SIR), the Graded Prognostic Assessment (GPA), and the diagnosis-specific Graded Prognostic Assessment (dsGPA). However, none of these scales include consideration of the cumulative intracranial tumor volume (CITV), which is defined as the sum of all intracranial tumor volumes. Since there is mounting evidence that the CITV carries significant prognostic value in SRS-treated patients with BM, this variable should be considered during survival prognostication, along with other pertinent clinical, pathological, and molecular characteristics.

Survival trends of oligodendroglial tumor patients and associated clinical practice patterns: a SEER-based analysis.

There is limited information on the management strategies and survival trends for oligodendroglioma patients. Here we used the Surveillance, Epidemiology and End Results (SEER, 1999-2012) database to analyze the historical trends of oligodendroglioma patient survival and correlate these trends to evolving clinical practice of radiation therapy (RT) use and surgical practice of gross total resection (GTR). We identified 2689 World Health Organization (WHO) grade II oligodendroglioma (abbreviated as O2) and 1191 WHO grade III oligodendroglioma (abbreviated as O3). Time-trend analyses were performed for overall survival, radiation treatment (RT) use, and extent of surgical resection (EOR). In multivariable Cox models that accounted for age, race, sex, tumor size, tumor location, EOR, and RT status, the hazard of dying from O3 has significantly decreased over the study period (p  <  0.01), while the hazard of dying from O2 has remained largely unchanged. A search of the published literature revealed articles reporting results largely supportive of these observations. The pattern of surgical practice and RT for O3 patients remained unchanged throughout the study period, suggesting that the survival improvement may be related to evolving patterns of medical management. Results from the SEER database indicate significant gains have been made in survival for O3 patients between 1999 and 2012. Such gains were not observed for O2 patients during this study period.

Safety of stereotactic laser ablations performed as treatment for glioblastomas in a conventional magnetic resonance imaging suite.

OBJECTIVE Stereotactic laser ablation (SLA) is typically performed in the setting of intraoperative MRI or in a staged manner in which probe insertion is performed in the operating room and thermal ablation takes place in an MRI suite. METHODS The authors describe their experience, in which SLA for glioblastoma (GBM) treatment was performed entirely within a conventional MRI suite using the SmartFrame stereotactic device. RESULTS All 10 patients with GBM (2 with isocitrate dehydrogenase 1 mutation [mIDH1] and 8 with wild-type IDH1 [wtIDH1]) were followed for > 6 months. One of these patients underwent 2 independent SLAs approximately 12 months apart. Biopsies were performed prior to SLA for all patients. There were no perioperative morbidities, wound infections, or unplanned 30-day readmissions. The average time for a 3-trajectory SLA (n = 3) was 436 ± 102 minutes; for a 2-trajectory SLA (n = 4) was 321 ± 85 minutes; and for a single-trajectory SLA (n = 4) was 254 ± 28 minutes. No tumor recurrence occurred within the blue isotherm line ablation zone, although 2 patients experienced recurrence immediately adjacent to the blue isotherm ablation line. Overall survival for the patient cohort averaged 356 days, with the 2 patients who had mIDH1 GBMs exhibiting the longest survival (811 and 654 days). CONCLUSIONS Multitrajectory SLA for treatment of GBM can be safely performed using the SmartFrame stereotactic device in a conventional MRI suite.

Stereotactic laser ablation as treatment for brain metastases that recur after stereotactic radiosurgery: a multiinstitutional experience.

OBJECTIVE Therapeutic options for brain metastases (BMs) that recur after stereotactic radiosurgery (SRS) remain limited. METHODS The authors provide the collective experience of 4 institutions where treatment of BMs that recurred after SRS was performed with stereotactic laser ablation (SLA). RESULTS Twenty-six BMs (in 23 patients) that recurred after SRS were treated with SLA (2 patients each underwent 2 SLAs for separate lesions, and a third underwent 2 serial SLAs for discrete BMs). Histological findings in the BMs treated included the following: breast (n = 6); lung (n = 6); melanoma (n = 5); colon (n = 2); ovarian (n = 1); bladder (n = 1); esophageal (n = 1); and sarcoma (n = 1). With a median follow-up duration of 141 days (range 64-794 days), 9 of the SLA-treated BMs progressed despite treatment (35%). All cases of progression occurred in BMs in which < 80% ablation was achieved, whereas no disease progression was observed in BMs in which ≥ 80% ablation was achieved. Five BMs were treated with SLA, followed 1 month later by adjuvant SRS (5 Gy daily × 5 days). No disease progression was observed in these patients despite ablation efficiency of < 80%, suggesting that adjuvant hypofractionated SRS enhances the efficacy of SLA. Of the 23 SLA-treated patients, 3 suffered transient hemiparesis (13%), 1 developed hydrocephalus requiring temporary ventricular drainage (4%), and 1 patient who underwent SLA of a 28.9-cm3 lesion suffered a neurological deficit requiring an emergency hemicraniectomy (4%). Although there is significant heterogeneity in corticosteroid treatment post-SLA, most patients underwent a 2-week taper. CONCLUSIONS Stereotactic laser ablation is an effective treatment option for BMs in which SRS fails. Ablation of ≥ 80% of BMs is associated with decreased risk of disease progression. The efficacy of SLA in this setting may be augmented by adjuvant hypofractionated SRS.

Placement of a Kickstand Rod in Adult Spinal Deformity Surgery: A Simple 8-Step Process With Intraoperative Images and Video.

BACKGROUND AND OBJECTIVES: In adult spinal deformity (ASD) surgery, operative correction of coronal malalignment remains a challenging surgical task. Given the proven effectiveness and longevity of the kickstand rod (KSR) technique and its powerful ability to correct coronal malalignment, this technique is an important tool to have available. Therefore, we sought to provide a simple 8-step description of the KSR technique using intraoperative images and video in a patient undergoing combined sagittal and coronal malalignment correction. METHODS: A 68-year-old female with a previous history of T11-S1 posterior spinal fusion presented with mid thoracic back pain, leg paresthesias, and a right-leaning posture. The patient underwent a T4-pelvis extension of fusion, T8-11 posterior column osteotomies, and placement of a right-sided KSR to address her coronal malalignment. RESULTS: The KSR technique is summarized in the following steps: (1) place kickstand screw, (2) place contralateral main rod and tighten all set plugs, (3) place ipsilateral main rod and keep rod long distally, (4) place a domino in the lower/mid thoracic area, (5) place the KSR and leave the rod long proximally, (6) tighten the ipsilateral main rod above the domino, (7) loosen the ipsilateral main rod below the domino, and (8) place a rod gripper below the domino and distract. Postoperatively, the coronal vertical axis improved from 4.8 to 0.6 cm, and the sagittal vertical axis improved from 9.5 to 3.9 cm. CONCLUSION: The current case report provides a simple 8-step description of the KSR technique to improve coronal malalignment accompanied by intraoperative images and video.

Do Iliac Screws Placed Close to the Sciatic Notch Have Greater Pullout Strength?

BACKGROUND AND OBJECTIVES: Optimal iliac screw position in relation to the sciatic notch remains unknown. In 12 cadavers undergoing S2 alar-iliac (S2AI) screw placement, we tested the pullout strength of screws placed in proximity to the sciatic notch (≤5 mm) vs farther away from the sciatic notch (>5 mm). METHODS: A biomechanical, cadaver-based study was performed on 12 cadavers undergoing bilateral S2AI screw insertion. The position of the S2AI screw regarding the sciatic notch was dichotomized as ≤5 mm from the sciatic notch on the right side and >5 mm on the left side, confirmed using c-arm fluoroscopy. The primary outcome was the pullout strength of the screw (N). Secondary outcomes were stiffness (N/mm), yield force (N), and work to failure (N mm). Ischial tuberosity was embedded into polymethyl methacrylate and secured to a custom 3-axis vise grip mounted to a 14.5-kN load cell. Pullout testing was performed at 5 mm/min. Force and displacement data were collected at 100 Hz and evaluated using MATLAB. The Mann-Whitney test was performed. RESULTS: Of 24 S2AI screws, 3 screws could not be tested because of cement-bone interface failure. A positive though nonsignificant trend of screw pullout strength was found for screws close to the notch compared with those farther from the notch (861.8 ± 340.7 vs 778.7 ± 350.8 N, P = .859). Similarly, screws close to the notch demonstrated a higher trend of stiffness (149.4 ± 145.4 vs 111.34 ± 128.2 N/mm, P = .320) and force to yield (806.9 ± 352.0 vs 618.6 ± 342.9 N, P = .455). Conversely, screws farther from the notch had a higher but similarly nonsignificant area under the force-displacement curve (10 867.0 ± 9565.0 vs 14 196.6 ± 9578.3 N mm, P = .455), which might be due to excess sheer/translation force that could not be reliably quantified. CONCLUSION: Although placing S2AI screws ≤5 mm of the sciatic notch provided stronger fixation in 3 of 4 biomechanical testing categories, these results were not statistically significant. Therefore, placing S2AI screws ≤5 mm of the sciatic notch did not provide stronger fixation.

Artificial Intelligence to Preoperatively Predict Proximal Junction Kyphosis Following Adult Spinal Deformity Surgery: Soft Tissue Imaging May Be Necessary for Accurate Models.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: In a cohort of patients undergoing adult spinal deformity (ASD) surgery, we used artificial intelligence to compare three models of preoperatively predicting radiographic proximal junction kyphosis (PJK) using: (1) traditional demographics and radiographic measurements, (2) raw preoperative scoliosis radiographs, and (3) raw preoperative thoracic magnetic resonance imaging (MRI). SUMMARY OF BACKGROUND DATA: Despite many proposed risk factors, PJK following ASD surgery remains difficult to predict. MATERIALS AND METHODS: A single-institution, retrospective cohort study was undertaken for patients undergoing ASD surgery from 2009 to 2021. PJK was defined as a sagittal Cobb angle of upper-instrumented vertebra (UIV) and UIV+2>10° and a postoperative change in UIV/UIV+2>10°. For model 1, a support vector machine was used to predict PJK within 2 years postoperatively using clinical and traditional sagittal/coronal radiographic variables and intended levels of instrumentation. Next, for model 2, a convolutional neural network (CNN) was trained on raw preoperative lateral and posterior-anterior scoliosis radiographs. Finally, for model 3, a CNN was trained on raw preoperative thoracic T1 MRIs. RESULTS: A total of 191 patients underwent ASD surgery with at least 2-year follow-up and 89 (46.6%) developed radiographic PJK within 2 years. Model 1: Using clinical variables and traditional radiographic measurements, the model achieved a sensitivity: 57.2% and a specificity: 56.3%. Model 2: a CNN with raw scoliosis x-rays predicted PJK with a sensitivity: 68.2% and specificity: 58.3%. Model 3: a CNN with raw thoracic MRIs predicted PJK with average sensitivity: 73.1% and specificity: 79.5%. Finally, an attention map outlined the imaging features used by model 3 elucidated that soft tissue features predominated all true positive PJK predictions. CONCLUSIONS: The use of raw MRIs in an artificial intelligence model improved the accuracy of PJK prediction compared with raw scoliosis radiographs and traditional clinical/radiographic measurements. The improved predictive accuracy using MRI may indicate that PJK is best predicted by soft tissue degeneration and muscle atrophy.

Prognostic Importance of Cumulative Intracranial Tumor Volume in Patients with Gastrointestinal Brain Metastasis Treated with Stereotactic Radiosurgery.

BACKGROUND: The disease-specific Graded Prognostic Assessment (ds-GPA) for patients with gastrointestinal (GI) tract cancer brain metastases (BM) suggests Karnofsky Performance Status (KPS) as the only pertinent prognostic factor. We evaluated the prognostic importance of cumulative intracranial tumor volume (CITV). METHODS: KPS, CITV, and overall survival were collected from consecutive patients with stereotactic radiosurgery-treated GI BM. Patients were grouped into 2 independent cohorts for development and validation of the model (termed "exploratory" and "validation" cohorts). Analyses were performed using logistic regression, Cox proportional hazards models, Net Reclassification Index (NRI >0), integrated discrimination improvement (IDI >0), and Akaike information criterion. RESULTS: In univariable logistic regression models, both CITV and KPS were independently associated with patient survival. The association between CITV and overall survival remained robust after controlling for KPS (P < 0.001) in a multivariable Cox proportional hazards model. Based on NRI analysis of the exploratory cohort, we found that a CITV cutoff of 12 cm3 best augments the prognostic accuracy of GI-ds-GPA. In this analysis, incorporation of CITV (as < or ≥12 cm3) improved prognostication of the GI-specific GPA model by NRI >0 of 0.397 (95% confidence interval [CI], 0.165-0.630; P < 0.001) and IDI of 0.019 (95% CI, 0.004-0.033; P = 0.013). We confirmed the prognostic usefulness of the CITV-incorporated GI-ds-GPA in an independent validation cohort, in which CITV incorporation improved prognostic usefulness with an NRI >0 of 0.478 (95% CI, 0.257-0.699; P < 0.001) and IDI of 0.028 (95% CI, 0.014-0.043; P < 0.001). CONCLUSIONS: CITV is an important prognostic variable in patients with stereotactic radiosurgery-treated GI BM and augments the prognostic accuracy of the GI-ds-GPA index.

Variation in Practice Pattern of Male Hypogonadism: A Comparative Analysis of Primary Care, Urology, Endocrinology, and HIV Specialists.

The objective of the current study was to measure the adherence of guideline-based evaluation and treatment of hypogonadism by medical specialty. A retrospective review was performed analyzing patients from a single academic institution within the past 10 years. The cohort of 193 men was grouped according to medical specialty of the diagnosing physician (50 urology, 49 primary care, 44 endocrinology, and 50 HIV medicine). Adherence to guidelines was assessed using the Endocrine Society's criteria. Primary care patients were older compared to the rest of the cohort ( p < .001) but BMI and cardiovascular risk factors were similar ( p = .900). Patients treated by urologists and endocrinologists had the highest percentage of low testosterone findings at initial encounter at 72% ( p < .001). Sixty-two percent of urology patients had low LH or FSH compared to 63.6% for endocrinology and 16% for primary care ( p < .001). As for brain MRI findings, no urology patients had positive findings (0/9) while eight pituitary adenomas (40%) were found by endocrinologists. Forty-five percent of men treated by urologists received TRT without repeat confirmation, compared to 58% of endocrinologists, 77% of primary care, and 88% of HIV medicine ( p < .001). All urology patients had PSA checked before TRT compared to 77.5% of primary care and 61.2% of endocrinology patients ( p = .063). Adherence to the guidelines helps prevent undue over-diagnosis and over-treatment of hypogonadism. This study suggests that adherence to guideline-based screening is varied among specialties.

Oligodendroglioma resection: a Surveillance, Epidemiology, and End Results (SEER) analysis.

OBJECTIVE The available evidence suggests that the clinical benefits of extended resection are limited for chemosensitive tumors, such as primary CNS lymphoma. Oligodendroglioma is generally believed to be more sensitive to chemotherapy than astrocytoma of comparable grades. In this study the authors compare the survival benefit of gross-total resection (GTR) in patients with oligodendroglioma relative to patients with astrocytoma. METHODS Using the Surveillance, Epidemiology, and End Results (SEER) Program (1999-2010) database, the authors identified 2378 patients with WHO Grade II oligodendroglioma (O2 group) and 1028 patients with WHO Grade III oligodendroglioma (O3 group). Resection was defined as GTR, subtotal resection, biopsy only, or no resection. Kaplan-Meier and multivariate Cox regression survival analyses were used to assess survival with respect to extent of resection. RESULTS Cox multivariate analysis revealed that the hazard of dying from O2 and O3 was comparable between patients who underwent biopsy only and GTR (O2: hazard ratio [HR] 1.06, 95% confidence interval [CI] 0.73-1.53; O3: HR 1.18, 95% CI 0.80-1.72). A comprehensive search of the published literature identified 8 articles without compelling evidence that GTR is associated with improved overall survival in patients with oligodendroglioma. CONCLUSIONS This SEER-based analysis and review of the literature suggest that GTR is not associated with improved survival in patients with oligodendroglioma. This finding contrasts with the documented association between GTR and overall survival in anaplastic astrocytoma and glioblastoma. The authors suggest that this difference may reflect the sensitivity of oligodendroglioma to chemotherapy as compared with astrocytomas.

Superior Prognostic Value of Cumulative Intracranial Tumor Volume Relative to Largest Intracranial Tumor Volume for Stereotactic Radiosurgery-Treated Brain Metastasis Patients.

BACKGROUND: Two intracranial tumor volume variables have been shown to prognosticate survival of stereotactic-radiosurgery-treated brain metastasis patients: the largest intracranial tumor volume (LITV) and the cumulative intracranial tumor volume (CITV). OBJECTIVE: To determine whether the prognostic value of the Scored Index for Radiosurgery (SIR) model can be improved by replacing one of its components-LITV-with CITV. METHODS: We compared LITV and CITV in terms of their survival prognostication using a series of multivariable models that included known components of the SIR: age, Karnofsky Performance Score, status of extracranial disease, and the number of brain metastases. Models were compared using established statistical measures, including the net reclassification improvement (NRI > 0) and integrated discrimination improvement (IDI). The analysis was performed in 2 independent cohorts, each consisting of ∼3000 patients. RESULTS: In both cohorts, CITV was shown to be independently predictive of patient survival. Replacement of LITV with CITV in the SIR model improved the model's ability to predict 1-yr survival. In the first cohort, the CITV model showed an NRI > 0 improvement of 0.2574 (95% confidence interval [CI] 0.1890-0.3257) and IDI of 0.0088 (95% CI 0.0057-0.0119) relative to the LITV model. In the second cohort, the CITV model showed a NRI > 0 of 0.2604 (95% CI 0.1796-0.3411) and IDI of 0.0051 (95% CI 0.0029-0.0073) relative to the LITV model. CONCLUSION: After accounting for covariates within the SIR model, CITV offers superior prognostic value relative to LITV for stereotactic radiosurgery-treated brain metastasis patients.

Cumulative Intracranial Tumor Volume Augments the Prognostic Value of Diagnosis-Specific Graded Prognostic Assessment Model for Survival in Patients with Melanoma Cerebral Metastases.

BACKGROUND: The diagnosis-specific graded prognostic assessment scale (ds-GPA) for patients with melanoma brain metastasis (BM) utilizes only 2 key prognostic variables: Karnofsky performance status and the number of intracranial metastases. We wished to determine whether inclusion of cumulative intracranial tumor volume (CITV) into the ds-GPA model for melanoma augmented its prognostic value. OBJECTIVE: To determine whether or not CITV augments the ds-GPA prognostic scale for melanoma. METHODS: We analyzed the survival pattern of 344 melanoma patients with BM treated with stereotactic radiosurgery (SRS) at separate institutions and validated our findings in an independent cohort of 201 patients. The prognostic value of ds-GPA for melanoma was quantitatively compared with and without the addition of CITV using the net reclassification index (NRI > 0) and integrated discrimination improvement (IDI) metrics. RESULTS: The incorporation of CITV into the melanoma-specific ds-GPA model enhanced its prognostic accuracy. Addition of CITV to the ds-GPA model significantly improved its prognostic value, with NRI > 0 of 0.366 (95% CI: 0.125-0.607, P = .002) and IDI of 0.024 (95% CI: 0.008-0.040, P = .004). We validated these findings that CITV improves the prognostic utility of melanoma ds-GPA in an independent cohort of 201 melanoma cohort. CONCLUSION: The prognostic value of the ds-GPA scale for melanoma BM is enhanced by the incorporation of CITV.

Effect of Gross Total Resection in World Health Organization Grade II Astrocytomas: SEER-Based Survival Analysis.

INTRODUCTION: We sought to compare the survival benefit associated with gross total resection (GTR) in World Health Organization grade II astrocytomas (A2) with those of grade III (A3) and grade IV (glioblastoma) astrocytomas. METHODS: Using the Surveillance, Epidemiology, and End Results program database (1999-2010), we identified 4113 A2 patients. Surgical resection was defined as GTR, subtotal resection (STR), or no resection. Kaplan-Meier and multivariate Cox proportional hazards analyses were used to assess survival with respect to extent of resection. Results were compared with the benefit of GTR over STR in 2755 A3 and 21,962 glioblastoma patients from the same database. RESULTS: A multivariate Cox proportional hazards analysis indicated that A2 patients who underwent a GTR had a 28.3% reduction in the hazard of death relative to A2 patients who underwent STR. Similar risk reductions were observed in A2 patients age <50 and ≥50. However, because of differences in the natural history of these cohorts, the relative hazard reduction translated into distinct overall survival profiles. For A2 patients ≥50 years old, the GTR-associated survival benefit was approximately 6 months, resembling that observed in glioblastoma patients. In contrast, GTR in A2 patients <50 years old was associated with survival profiles superior to those observed in A3 patients. CONCLUSIONS: In the Surveillance, Epidemiology, and End Results (SEER) program database, GTR-associated survival benefit in A2 patients ≥50 years old resembled that observed in glioblastoma, while GTR in A2 patients <50 years old was associated with a distinctly more favorable survival profile.

Management and Survival Patterns of Patients with Gliomatosis Cerebri: A SEER-Based Analysis.

OBJECTIVE: We used the SEER (Surveillance Epidemiology and End Results) database (1999-2010) to analyze the clinical practice patterns and overall survival in patients with gliomatosis cerebri (GC), or glioma involving 3 or more lobes of the cerebrum. METHODS: We identified 111 patients (age ≥18 years) with clinically or microscopically diagnosed GC in the SEER database. Analyses were performed to determine clinical practice patterns for these patients and whether these practices were associated with survival. RESULTS: Fifty-eight percent of the 111 patients with GC received microscopic confirmation of their diagnosis. Of the remaining patients, 40% were diagnosed via imaging or laboratory tests, and 2% had unknown methods of diagnosis. Seven percent of patients who did not have microscopic confirmation of their diagnosis received radiation therapy. Radiation therapy and surgery were not associated with survival. The only variable significantly associated with overall survival was age at diagnosis. Patients aged 18-50 years showed improved survival relative to patients aged >50 years (median survival, 11 and 6 months, respectively; P = 0.03). For patients aged >50 years, improved overall survival was observed in the post-temozolomide era (2005-2010) relative to those treated in the pre-temozolomide era (1999-2004) (median survival, 9 and 4 months, respectively; P = 0.005). CONCLUSIONS: In the SEER database, ∼40% of the patients with glioma with imaging findings of GC do not receive microscopic confirmation of their diagnosis. We propose that tissue confirmation is warranted in patients with GC, because genomic analysis of these specimens may provide insights that will contribute to meaningful therapeutic intervention.

Survival Patterns of 5750 Stereotactic Radiosurgery-Treated Patients with Brain Metastasis as a Function of the Number of Lesions.

BACKGROUND: The number of brain metastases (BMs) plays an important role in the decision between stereotactic radiosurgery (SRS) and whole-brain radiation therapy. METHODS: We analyzed the survival of 5750 SRS-treated patients with BM as a function of BM number. Survival analyses were performed with Kaplan-Meier analysis as well as univariate and multivariate Cox proportional hazards models. RESULTS: Patients with BMs were first categorized as those with 1, 2-4, and 5-10 BMs based on the scheme proposed by Yamamoto et al. (Lancet Oncology 2014). Median overall survival for patients with 1 BM was superior to those with 2-4 BMs (7.1 months vs. 6.4 months, P = 0.009), and survival of patients with 2-4 BMs did not differ from those with 5-10 BMs (6.4 months vs. 6.3 months, P = 0.170). The median survival of patients with >10 BMs was lower than those with 2-10 BMs (6.3 months vs. 5.5 months, P = 0.025). In a multivariate model that accounted for age, Karnofsky Performance Score, systemic disease status, tumor histology, and cumulative intracranial tumor volume, we observed a ∼10% increase in hazard of death when comparing patients with 1 versus 2-10 BMs (P < 0.001) or 10 versus >10 BMs (P < 0.001). When BM number was modeled as a continuous variable rather than using the classification by Yamamoto et al., we observed a step-wise 4% increase in the hazard of death for every increment of 6-7 BM (P < 0.001). CONCLUSIONS: The contribution of BM number to overall survival is modest and should be considered as one of the many variables considered in the decision between SRS and whole-brain radiation therapy.

Improving the Prognostic Value of Disease-Specific Graded Prognostic Assessment Model for Renal Cell Carcinoma by Incorporation of Cumulative Intracranial Tumor Volume.

BACKGROUND: We tested the prognostic value of cumulative intracranial tumor volume (CITV) in the context of a disease-specific Graded Prognostic Assessment (ds-GPA) model for renal cell carcinoma (RCC) patients with brain metastasis (BM) treated with stereotactic radiosurgery (SRS). METHODS: Patient and tumor characteristics were collected from RCC cohorts with new BM who underwent SRS. Univariable and multivariable logistic regression model was used to test the prognostic value of CITV, Karnofsky Performance Score (KPS), and the number of BM. Net reclassification index (NRI) and integrated discrimination improvement (IDI) were used to assess whether CITV improved the prognostic utility of RCC ds-GPA. RESULTS: In univariable logistic regression models, CITV, KPS, and the number of BM were independently associated with RCC patient survival. In a multivariable Cox proportional hazard model, the association between CITV and survival remained robust after controlling for KPS and the number of BM (P = 0.042). The incorporation of the CITV into the RCC ds-GPA model (consisting of KPS and number of BM) improved prognostic accuracy with NRI >0 of 0.3156 (95% confidence interval [CI], 0.0883-0.5428; P = 0.0065) and IDI of 0.0151 (95% CI, 0.0036-0.0277; P = 0.0183). These findings were validated in an independent cohort of 107 SRS-treated RCC BM patients. CONCLUSION: CITV is an important prognostic variable in SRS-treated RCC patients with BM. The prognostic value of the ds-GPA scale for RCC brain metastasis was enhanced by the incorporation of CITV.