Improved local control following dose-escalated stereotactic ablative radiation therapy (SABR) for metastatic sarcomas: An international multi-institutional experience

BACKGROUND

We aimed to characterize local control (LC) and overall survival (OS) following stereotactic ablative radiation therapy (SABR) for extracranial sarcoma metastases.

METHODS

A prospectively-maintained institutional registry was queried for patients with metastases from sarcoma primaries managed with SABR. Kaplan-Meier analysis was utilized for univariate analyses to assess potential prognostic factors regarding LC and OS. A Cox proportional hazards multivariate (MVA) model was employed to further assess initially identified independent variables.

RESULTS

A total of 94 patients with 118 lesions with LC information were identified. Common metastatic sites treated were lung (77), non-spinal bone (15), and spine (10). The median biologically effective dose (BED4) was 175 Gy4 (range56.3 Gy4-360 Gy4) with a median dose/fractionation schedule of 50 Gy/5 fractions. One- and 2-year OS rates were 81.3 % (95 % CI: 71.2-88.1 %6) and 50.5 % (95 % CI: 38.6-61.3 %, respectively. On Cox MVA, advanced age and non-lung metastases were associated with inferior OS (p < 0.03) with patients with 0-2 of these risk factors having estimated 2-year OS of 65.1 %, 38.9 %, and N/A, respectively. One- and 2-year LC rates were 85.3 % (95 % CI: 77.7-90.9 %) and 78.2 % (95 % CI: 67.9-85.6 %), respectively. On MVA, only BED4 < 175 Gy was associated with inferior LC (hazard ratio (HR) = 3.33; p = 0.01). Ten of 118 treated lesions had treatment-related toxicities (all Grade 1-2).

CONCLUSION

Age and lung vs. non-lung metastases were prognostic of OS and should be considered in patient selection for SABR. Dose escalation when feasible with BED4 ≥ 175 Gy is recommended given durable LC achieved without a subsequent increase in toxicity.

Is Substantial Lymphovascular Space Invasion Prognostic in Patients With Pathologically Lymph Node-Negative Endometrial Cancer?

PURPOSE

Lymphovascular space invasion (LVSI) predicts for higher rates of recurrence and increased mortality in endometrial cancer. Using 3-tier LVSI scoring, a PORTEC-1 and -2 trials analysis demonstrated that substantial LVSI was associated with worse locoregional (LR-DFS) and distant metastasis disease-free survival (DM-DFS), and these patients possibly benefited from external beam radiation therapy (EBRT). Furthermore, LVSI is a predictor for lymph node (LN) involvement, but the significance of substantial LVSI is unknown in patients with a pathologically negative LN assessment. We aimed to evaluate clinical outcomes of these patients in relation to the 3-tier LVSI scoring system.

METHODS AND MATERIALS

We performed a single-institutional retrospective review of patients with stage I endometrioid-type endometrial cancer who underwent surgical staging with pathologically negative LN evaluation from 2017 to 2019 with 3-tier LVSI scoring (none, focal, or substantial). Clinical outcomes (LR-DFS, DM-DFS, and overall survival) were analyzed using the Kaplan-Meier method.

RESULTS

A total of 335 patients with pathologically LN-negative stage I endometrioid-type endometrial carcinoma were identified. Substantial LVSI was present in 17.6% of patients; 39.7% of patients received adjuvant vaginal brachytherapy and 6.9% of patients received EBRT. Adjuvant radiation treatment varied by LVSI status. In patients with focal LVSI, 81.0% received vaginal brachytherapy. Among patients with substantial LVSI, 57.9% received vaginal brachytherapy alone, and 31.6% of patients received EBRT. The 2-year LR-DFS rates were 92.5%, 98.0%, and 91.4% for no LVSI, focal LVSI, and substantial LVSI, respectively. The 2-year DM-DFS rates were 95.5%, 93.3%, and 93.8% for no LVSI, focal LVSI, and substantial LVSI, respectively.

CONCLUSIONS

In our institutional study, patients with pathologically LN-negative stage I endometrial cancer with substantial LVSI had similar rates of LR-DFS and DM-DFS compared with patients with none or focal LVSI. These findings highlight the need for multi-institutional studies to validate the prognostic value of substantial LVSI in this patient population.

Concurrent immunoradiation for HPV-associated oropharyngeal squamous cell carcinoma

OBJECTIVES

Current trials for HPV-associated oropharyngeal SCCs (OP-SCCs) are evaluating treatment de-escalation including use of concurrent immunotherapy with radiation therapy (I-RT). Given limited prospective data following I-RT, we aimed to examine this question utilizing the National Cancer Data Base (NCDB).

METHODS

The NCDB was queried for patients with HPV-associated OP-SCCs eligible for current de-escalation studies with AJCC 7th edition T1-T2/N1-N2b and T3/N0-N2b disease. Patients were stratified into I-RT, concurrent chemoradiation (C-RT), and radiation therapy alone (RT) arms. Kaplan-Meier analysis was utilized to compare overall survival (OS) between treatment arms followed by a Cox multivariate (MVA) proportional hazards model controlling for tumor and patient characteristics and propensity-score analyses with inverse probability treatment weighting (IPTW).

RESULTS

We identified 4768 patients; 313 received I-RT, 3660 patients received C-RT, and 795 received RT. Median age was 62 years (range 27-90) with a median Charlson-Deyo co-morbidity score of 0 (range: 0-3). The vast majority were cN1-N2a (88.8%) and 26.5% were cT3. On MVA, inferior 3-year and 8-year OS was noted following I-RT (81.6% and 70.5%) vs. C-RT (90.6% and 79.4%) (HR = 1.69 (95% CI: 1.29-2.21); p < 0.0001) with no significant difference vs. RT (88.1% and 75.8%) (HR = 1.07; p = 0.80). This was also maintained on IPTW-analysis (HR = 1.62 (95% CI: 1.23-2.15); p = 0.001).

CONCLUSIONS

I-RT was associated with significantly poorer OS vs. C-RT with no benefit compared to RT for HPV-associated OP-SCCs. I-RT is not recommended outside of currently accruing clinical trials.

Is Substantial Lymphovascular Space Invasion Prognostic for Clinical Outcomes in Type II Endometrial Cancer?

AIMS

Substantial lymphovascular space invasion (LVSI) compared with none or focal LVSI is predictive of lymph node involvement and worse clinical outcomes in endometrioid-type endometrial carcinoma. We aimed to quantify the incidence of substantial LVSI in type II (clear cell and serous) endometrial cancer and correlate the extent of LVSI with clinical outcomes.

MATERIALS AND METHODS

A retrospective review was conducted on type II endometrial cancer patients who underwent surgical management from July 2017 to December 2019 using the three-tier LVSI scoring system. Binary logistic regression and Cox regression were used to analyse predictors of lymph node involvement or survival outcomes, respectively. The Kaplan-Meier method and Log-rank test were used to analyse differences in locoregional disease-free survival (LR-DFS), distant metastasis disease-free survival (DM-DFS) and overall survival between patients with substantial versus none/focal LVSI.

RESULTS

In 79 patients with type II endometrial carcinoma, no LVSI, focal LVSI and substantial LVSI was present in 48.1%, 15.2% and 36.7% of patients, respectively. Lymph nodes were involved in 0.0% with no LVSI, 20.0% with focal LVSI and 60.0% with substantial LVSI (P < 0.001). The median follow-up was 22.2 months. In patients with none/focal versus substantial LVSI, the 2-year LR-DFS and DM-DFS rates were 91.5% versus 71.4% (P = 0.01) and 90.2% versus 63.8% (P = 0.005), respectively. On univariate analysis, myometrial invasion ≥50%, tumour size ≥3.6 cm, substantial versus none/focal LVSI, lymph node involvement and omission of adjuvant radiotherapy were significant predictors for worse LR-DFS and DM-DFS (P < 0.05).

DISCUSSION

Substantial LVSI has a high incidence in type II pathology at our institution and predicts for lymph node involvement and worse clinical outcomes.

A multi-institutional analysis of outcomes following stereotactic body radiation therapy for management of metastases from squamous cell carcinomas of the head and neck

Background

There is limited data on clinical outcomes following SBRT for patients with metastatic head and neck squamous cell carcinoma (mHNC).

Method

An international SBRT registry was utilized to identify patients. LC and OS were evaluated with the Kaplan-Meier method and a Cox-proportional hazards model for multivariate analysis (MVA) to assess potential prognostic factors.

Results

We identified 81 patients with 98 lesions treated with SBRT. Areas treated included the lung (53.0%), non-regional lymph nodes (16.0%), and spine (12.3%). OS rates at 1 year and 2 years were 66.4% and 43.1%, respectively. Utilizing KPS, spinal disease, and GTV, 1-year OS estimates were 90.9%, 70.4%, 54.5%, and 25% for patients with 0-3 of these factors, respectively (p = 0.002). One-year and 2-year LC rates were both 93.3%. Roughly 17% of patients reported toxicities (none Grade 3+).

Conclusions

SBRT resulted in promising LC for mHNC patients. Spinal disease, GTV, and KPS should be considered in selecting patients with mHNC that may benefit from SBRT.

Palliative radiation therapy for children with cancer

Radiation therapy (RT) is often used as a palliative treatment for children with recurrent malignant disease to ameliorate or prevent symptoms. However, no guidelines exist regarding the clinical indications or dose fractionation for palliative RT. The goal of this report is to provide guidelines for the use of palliative RT in children with cancer. In this guideline, appropriate indications for palliative RT, recommended dose-fractionation schedules, relevant toxicities, and avenues for future research are explored. RT is an effective palliative treatment for bone, brain, liver, lung, abdominopelvic and head-and-neck metastases, spinal cord compression, superior vena cava syndrome, and bleeding. Single-fraction regimens (8 Gy in one fraction) for children with short life expectancy are recommended for simple, uncomplicated bone metastases and can be considered for some patients with lung or liver metastases. A short, hypofractionated regimen (20 Gy in five fractions) may be used for other indications to minimize overall burden of therapy. There are little data supporting use of more prolonged fractionation regimens, though they may be considered for patients with very good performance status. Future research should focus on response and outcomes data collection, and to rigorously evaluate the role of stereotactic body RT in well-designed, prospective studies.

Supportive care for toxicities in children undergoing radiation therapy

Radiation therapy (RT) is an integral part of the management of many pediatric tumors; however, it is associated with both acute and permanent adverse events that can significantly impact a child's quality of life, lead to treatment delays, and potentially affect outcomes of cancer therapy. Prevention, early detection, and optimal management of these adverse effects will help reduce their impact on the patients' quality of life and overall well-being. Unfortunately, there has not been a coordinated effort to study the etiology, evaluate risk factors, and explore novel treatments for these conditions. Studies of supportive care for children undergoing RT are often small and uncontrolled. This review will focus on the impact of irradiation on the different organ systems and their current management. Further studies are required to improve our understanding of the contributing factors and explore novel treatment options for these adverse effects and to enable children and their families to better cope with some of the unavoidable toxicities following multimodality therapy.

Early outcomes after definitive chemoradiation therapy with Vienna/Venezia hybrid high-dose rate brachytherapy applicators for cervical cancer: A single-institution experience

PURPOSE

The Vienna and Venezia (Elekta) are hybrid intracavitary/interstitial brachytherapy (BT) applicators for cervical cancers unsuitable for intracavitary BT alone to improve target coverage or reduce critical organ dose. There is limited outcome data with the use of these applicators outside published experience of the EMBRACE group. We report feasibility and early outcomes with the use of these hybrid applicators at our institution.

METHODS AND MATERIALS

Hybrid applicators were used to treat 61 patients with cervical cancer from November 2011 to December 2019. Indications for hybrid applicator use were involvement of the vagina in 10 patients (16%), residual central or parametrial disease in 46 patients (75%), and a narrow introitus in 5 patients (9%). Toxicities were graded using the CTCAE v4.0. Outcomes were assessed with the Kaplan-Meier method.

RESULTS

Median follow-up was 16 months (IQR 9-32 mos). Median HRCTV volume was 31.6 cm³ (IQR 25-48 cm³). Median HRCTV D90 was 86.1 Gy (IQR 84.3-88.0 Gy). In 54 patients with follow-up PET/CT at 3 months, complete initial imaging response locally was seen in 46 patients.Estimated 12-month Kaplan-Meier overall survival, locoregional control, distant control, and recurrence-free survival estimates were 86.9%, 80.6%, 73.8%, and 65.9%, respectively. The 12-month incidence of Grade 3+ GI/GU chronic toxicities was 5.7%, consisting of vesicovaginal fistula, rectovaginal fistula, and ureterovesical fistula.

CONCLUSIONS

Our single-institution data support the use of the hybrid applicators, as an alternative to traditional BT applicators when clinically warranted. Use of hybrid applicators is feasible with adequate coverage of disease in the vagina and parametrium.

Stereotactic body radiation therapy (SBRT) for metastatic renal cell carcinoma: A multi-institutional experience

Objectives: Examine local control(LC), overall survival(OS), and toxicity following stereotactic body radiation therapy(SBRT) for patients with metastatic renal cell carcinoma(mRCC). Methods: A multi-institutional registry was queried. Potential predictive factors of LC and OS were evaluated with a Cox-proportional hazards model for multivariate analysis(MVA). Results: We identified 115 mRCC patients with 181 lesions. Median biologically effective dose (BED₇) was 72.9 Gy₇ (range: 42.9-231.4 Gy₇) with a median dose/fraction of 10 Gy (range: 5-24 Gy). Utilizing both Karnofsky Performance Score (KPS) and presence of osseous metastatic disease as prognostic indicators, estimated 2-year OS rates were 67.7% (95% CI: 49.9-89.5%), 31.8% (95% CI: 19.0-45.3%), and 20% (95% CI: 1.4-54.7%; p=0.0012). One- and 2-year LC rates were 88.2% and 82.7%, respectively, with no prognostic factors identified. Roughly 13% of patients reported toxicities with one Grade 3-5 toxicity. Conclusion: SBRT was well-tolerated with promising LC. Both KPS and osseous metastatic disease should be considered in determining which patients with mRCC may preferentially benefit from SBRT.

Cancer antigen 125 is associated with disease status in uterine carcinosarcoma

Uterine carcinosarcoma is a rare and aggressive tumor with poor outcomes. Cancer antigen 125 is routinely used to track the disease course of ovarian cancer and has been suggested as a biomarker in other aggressive forms of uterine cancer. We sought to characterize cancer antigen 125 as a potential biomarker of disease status in uterine carcinosarcoma. Clinical and pathological data were abstracted for patients who had surgical staging for a pathologically confirmed uterine carcinosarcoma at our institution from January 2000 to March 2014. Non-parametric tests were used to compare changes in cancer antigen 125. Elevated cancer antigen 125 (>35 U/mL) as a predictor of survival was assessed via Kaplan–Meier curves. Among the 153 patients identified, 66 patients had at least one paired measure of cancer antigen 125 drawn preoperatively, post-treatment, or at the time of disease recurrence, and 19 patients had cancer antigen–125 levels at all three time points. Analysis of the 51 patients with both preoperative and post-treatment values found a significant drop in cancer antigen 125 (p < 0.001). Among the 30 patients who had end-of-treatment and recurrence levels, a significant increase was noted (p = 0.001). There was no significant difference in cancer antigen–125 levels preoperatively compared to at recurrence among the 23 patients with levels at both time-points (p = 0.99). Elevated preoperative cancer antigen 125 was not associated with overall survival (p = 0.12); elevated post-treatment cancer antigen 125 was associated with a worse overall survival (p < 0.001). Based on this dataset, there seems to be utility in trending a cancer antigen–125 level in patients with uterine carcinosarcoma. A cancer antigen–125 level could predict recurrence and provide prognostic information regarding survival.

Intraoperative radiotherapy (IORT) for surgically resected brain metastases: outcome analysis of an international cooperative study

BACKGROUND AND OBJECTIVE

The ideal delivery of radiation to the surgical cavity of brain metastases (BMs) remains the subject of debate. Risks of local failure (LF) and radiation necrosis (RN) have prompted a reappraisal of the timing and/or modality of this critical component of BM management. IORT delivered at the time of resection for BMs requiring surgery offers the potential for improved local control (LC) afforded by the elimination of delay in time to initiation of radiation following surgery, decreased uncertainty in target delineation, and the possibility of dose escalation beyond that seen in stereotactic radiosurgery (SRS). This study provides a retrospective analysis with identification of potential predictors of outcomes.

METHODS

Retrospective data was collected on patients treated with IORT immediately following surgical resection of BMs at three institutions according to the approval of individual IRBs. All patients were treated with 50kV portable linear accelerator using spherical applicators ranging from 1.5 to 4.0 cm. Statistical analyses were performed using IBM SPSS with endpoints of LC, DBC, incidence of RN, and overall survival (OS) and p < 0.05 considered significant.

RESULTS

54 patients were treated with IORT with a median age of 64 years. The most common primary diagnosis was non-small cell lung cancer (40%) with the most common location in the frontal lobe (38%). Median follow-up was 7.2 months and 1-year LC, DBC, and OS were 88%, 58%, and 73%, respectively. LMD was identified in 2 patients (3%) and RN present in 4 patients (7%). The only predictor of LC was extent of resection with 1-year LC of 94% for GTR versus 62% for STR (p = 0.049).

CONCLUSIONS

IORT is a safe and effective means of delivering adjuvant radiation to the BM resection cavities with high rates of LC and low incidence of RN. Further studies are warranted directly comparing LC outcomes to SRS.

Intraoperative radiotherapy (IORT) for surgically resected brain metastases: Local control and dosimetric analysis

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Background: The optimal use of adjuvant radiation following surgical resection of large brain metastases (BM) remains undetermined. Time to initiation following surgery and target delineation both impact local control (LC). Intraoperative radiotherapy (IORT) allows for elimination of lag time between surgery and radiation, direct cavity targeting, and safe dose escalation beyond traditional stereotactic radiosurgery (SRS). The current study provides an analysis of local disease control and dosimetric parameters related to intracranial IORT. Methods: Retrospective data was collected on patients treated with IORT immediately following surgical resection of BMs at three institutions according to the approval of individual IRBs. All patients were treated with the Zeiss Intrabeam device (Carl Zeiss Meditech, Germany) using spherical applicators ranging from 1.5 to 4.0cm with 50kV output. Statistical analyses were performed using SPSS (IBM) with endpoints of LC and incidence of RN, with p < 0.05 considered significant. Dosimetric comparisons between IORT and SRS were made based on V10, V12, and dose homogeneity based on percent of GTV receiving greater than 20Gy or 30Gy. Results: 54 patients were treated with IORT with a median age of 64 years. The most common primary diagnosis was non-small cell lung cancer (40%) with the most common location in the frontal lobe (38%). Median follow-up was 7.2 months and 1-year LC rate was 88% with radiation necrosis (RN) present in 4 patients (7%). The dosimetric comparison of a single IORT case revealed non-target V10 and V12 volumes as 24.75cm3 and 14.76cm3, respectively, for the SRS treatment plan of 16Gy to the margin. The V10 and V12 for the IORT treatment plan were 20.83cm3 and 9.93cm3 with a surface dose of 30Gy. The volumes exceeding 20Gy and 30Gy in the SRS plan were 14.73cm3 and 0.328cm3, respectively, while the corresponding volumes in the IORT plan were 9.8cm3 and 0cm3. Conclusions: IORT is a safe and effective means of delivering adjuvant radiation to the BM resection cavities with a high rate of LC, low incidence of RN, increased homogeneity of target dose and ability to escalate dose beyond traditional SRS plans.

Stereotactic radiosurgery and fractionated stereotactic radiosurgery for vestibular schwannomas: A comparison of clinical outcomes from the RSSearch patient registry

PURPOSE

To compare clinical outcomes following stereotactic radiosurgery (SRS) and fractionated stereotactic radiosurgery (fSRS) for vestibular schwannomas (VS).

MATERIALS/METHODS

We identified 64 VS patients from the RSSearch Patient Registry (12 treated with SRS and 52 patients treated with fSRS). Potential factors predictive of local control (LC) and toxicity were estimated using the Kaplan-Meier method, Cox proportional hazards model, and binary logistic regressions with propensity score weighting.

RESULTS

SRS (100%) and fSRS (94.2%) resulted in similar LC (p = 0.33). fSRS was associated with a higher likelihood of experiencing toxicities (42.3% vs. 8.3%; p = 0.054 on time-to-event analysis) that was maintained following a propensity-score weighted binary logistic regression (p = 0.037) and propensity-score weighted Cox regression (p = 0.039; hazard ratio (HR) = 8.85 (95% CI: 1.1 - 70.1)).

CONCLUSION

In a multi-institutional analysis, we note equivalent LC but higher toxicity with fSRS compared to SRS for VS.

Dural venous sinus thrombosis in anaplastic astrocytoma following concurrent temozolomide and focal brain radiotherapy plus bevacizumab

Malignant gliomas have long been a therapeutic dilemma in neuro-oncology, with a poor overall prognosis. Standard treatment, consisting of primary resection, followed by radiation therapy and temozolomide, has improved prognosis. Recently, studies have looked at the addition of bevacizumab (Avastin), a humanized murine IgG1 monoclonal antibody against vascular endothelial growth factor-A, to conventional regiments. Bevacizumab gained US FDA approval for single agent use in recurrent glioblastoma in 2009. Known side effects of bevacizumab include increased risk of arterial and venous thromboembolism, as well as hemorrhage. With emerging data for the use of bevacizumab in malignant gliomas, the extent of risks such as bleeding and thrombosis in patients with primary brain tumors treated with bevacizumab remains unknown. Here, we present only the second reported case of dural venous sinus thrombosis during treatment with bevacizumab and the first reported case for a primary glioma treated with temozolomide, radiation, and bevacizumab.

Gender Differences in Musculoskeletal Lipid Metabolism as Assessed by Localized Two-Dimensional Correlation Spectroscopy

Gender differences in lipid metabolism are poorly understood and difficult to study using conventional approaches. Magnetic resonance spectroscopy (MRS) permits non-invasive investigation of lipid metabolism. We employed novel two-dimensional MRS techniques to quantify intramyocellular (IMCL) and extramyocellular (EMCL) lipid compartments and their degree of unsaturation in normal weight adult male and female subjects. Using muscle creatine (Cr) for normalization, a statistically significant (p < 0.05) increase in IMCL/Cr (7.8 ± 1.6) and EMCL/Cr (22.5 ± 3.6) for female subjects was observed (n=8), as compared to IMCL/Cr (5.9 ± 1.7) and EMCL/Cr (18.4 ± 2.64) for male subjects. The degree of unsaturation within IMCL and EMCL was lower in female subjects, 1.3 ± 0.075 and 1.04 ± 0.06, respectively, as compared to that observed in males (n=8), 1.5 ± 0.08 and 1.12 ± 0.03, respectively (p < 0.05 male vs female for both comparisons). We conclude that certain salient gender differences in lipid metabolism can be assessed noninvasively by advanced MRS approaches.