Clinical Outcomes After Stereotactic Body Radiation Therapy for Nonspinal Bone Metastases: A Systematic Review and Meta-analysis.

There are limited data available on clinical outcomes after stereotactic body radiation therapy (SBRT) for nonspinal bone metastases. We performed a systematic review and meta-analysis to characterize local control (LC), overall survival (OS), pain response rates, and toxicity after SBRT. The primary outcomes were 1-year LC, incidence of acute and late grade 3 to 5 toxicities, and overall pain response rate at 3 months. The secondary outcome was 1-year OS. The Newcastle-Ottawa scale was used for assessment of study bias, with a median score of 5 for included studies (range, 4-8). Weighted random-effects meta-analyses were conducted to estimate effect sizes. We identified 528 patients with 597 nonspinal bone lesions in 9 studies (1 prospective study and 8 retrospective observational studies) treated with SBRT. The estimated 1-year LC rate was 94.6% (95% CI, 87.0%-99.0%). The estimated 3-month combined partial and complete pain response rate after SBRT was 87.7% (95% CI, 55.1%-100.0%). The estimated combined acute and late grade 3 to 5 toxicity rate was 0.5% (95% CI, 0%-5.0%), with an estimated pathologic fracture rate of 3.1% (95% CI, 0.2%-9.1%). The estimated 1-year OS rate was 71.0% (95% CI, 51.7%-87.0%). SBRT results in excellent LC and palliation of symptoms with minimal related toxicity. Prospective investigations are warranted to further characterize long-term outcomes of SBRT for patients with nonspinal bone metastases.

Stereotactic body radiation therapy as a salvage treatment for single viable hepatocellular carcinoma at the site of incomplete transarterial chemoembolization: a retrospective analysis of 302 patients.

BACKGROUND: To evaluate the clinical outcomes of patients who received stereotactic body radiation therapy (SBRT) for single viable hepatocellular carcinoma (HCC) at the site of incomplete transarterial chemoembolization (TACE). METHODS: Patients treated with SBRT for single viable HCC after incomplete TACE between 2012 and 2017 at Asan Medical Center (Seoul, South Korea) were included. Incomplete TACE was defined as (1) evidence of viable HCC at the site of TACE on follow-up dynamic computed tomography (CT) or magnetic resonance imaging following one or more consecutive TACEs, (2) no definite tumor staining on superselective hepatic angiogram, or (3) no definite iodized oil uptake on post-embolization angiogram or CT. Doses of 10-15 Gy per fraction were given over 3-4 consecutive days. The primary outcome was local control rate at 3 years and secondary outcome included tumor response, overall survival rate, out-of-field intrahepatic recurrence-free survival, distant metastasis-free survival and treatment-related toxicities. Treatment-related adverse events were evaluated according to the common terminology criteria for adverse events, version 4.03. RESULTS: A total of 302 patients were analyzed. The median follow-up duration was 32.9 months (interquartile range [IQR], 23.6-41.7) and the median tumor size was 2.0 cm (range, 0.7-6.9). The local control (LC) and overall survival rates at 3 years were 91.2 and 72.7%, respectively. 95.4% of the tumors reached complete response (CR) during the entire follow-up period (anyCR). The median interval from SBRT to anyCR was 3.4 months (IQR, 1.9-4.7), and 39.9 and 83.3% of the lesions reached CR at 3- and 6-months after SBRT, respectively. Radiation-induced liver disease was observed in 8 (2.6%) patients. No patients experienced gastroduodenal bleeding within the radiation field. CONCLUSION: SBRT could be considered a feasible salvage treatment option for HCC after incomplete TACE.

Inoperable Early-Stage Non-Small-Cell Lung Cancer: Stereotactic Ablative Radiotherapy and Rationale for Systemic Therapy.

Stereotactic ablative radiotherapy (SABR) is the standard treatment for medically inoperable, early-stage non-small-cell lung cancer. SABR results in high rates of in-field tumor control, but among larger and more biologically aggressive tumors, regional and distant failures are problematic. Cytotoxic chemotherapy is rarely used in this patient population and the benefit is unclear. Alternative systemic therapy options with a milder side-effect profile are of considerable interest, and several randomized phase III trials are currently testing immune checkpoint inhibitors in this setting. We review the rationale, data, and ongoing studies evaluating systemic therapy in medically inoperable, early-stage non-small-cell lung cancer treated with SABR.

Managing Central Nervous System Spread of Lung Cancer: The State of the Art.

Brain metastases (BrM) are common in both non-small-cell lung cancer and small-cell lung cancer. Substantial progress in BrM management has occurred in the past decade related to advances in both radiation and medical oncology. Recent and ongoing radiation trials have focused on increasing the candidacy for focal therapy of BrM with stereotactic radiosurgery; reducing the toxicity and improving patient selection for whole brain radiotherapy; and, in small-cell lung cancer, evaluating brain magnetic resonance imaging surveillance without prophylactic cranial irradiation, hippocampal avoidance in prophylactic cranial irradiation and whole brain radiotherapy, and the role of upfront stereotactic radiosurgery for BrM. In medical oncology, the development of multiple tyrosine kinase inhibitors with encouraging CNS activity and emerging data on the CNS activity of immune checkpoint inhibitors in some patients have opened the door to novel systemic and multidisciplinary treatment strategies for the management of BrM. Future research will focus on more robust characterizations of the CNS activity of targeted therapy and immunotherapies, as well as optimal integration and patient selection for multidisciplinary strategies involving CNS-active drugs, radiation therapy, and CNS surveillance.

Radiologic and Clinical Outcomes of Stereotactic Radiosurgery for Intraventricular Metastases.

OBJECTIVE: The optimal management of intraventricular metastases remains debatable. The aim of this study is to define the safety and efficacy of Gamma-Knife radiosurgery in the treatment of intraventricular metastases. METHODS: This retrospective, single-center study involved patients that were treated with stereotactic radiosurgery (SRS) for intraventricular metastases. The study end points included SRS-related toxicity, local and distal intracranial tumor control, as well as the incidence of post-treatment hydrocephalus and leptomeningeal dissemination. Factors associated with radiologic and clinical outcomes were also analyzed. RESULTS: The cohort included 17 consecutive patients who underwent stereotactic radiosurgery for treatment of 41 intracranial metastases, of which 23 were primary intraventricular (intraventricular metastasis). Median overall survival from primary tumor diagnosis and from SRS treatment were 28 and 5 months, respectively. With a median radiological follow-up of 3 (interquartile range 3) months, 7 patients (41.18%) experienced overall intracranial disease progression, whereas 7 (27.27%) intraventricular metastases progressed radiologically. Four (23.53%) and 3 (17.65%) patients developed hydrocephalus and leptomeningeal dissemination post-SRS, respectively. Four patients (23.53%) died due to intracranial disease progression. CONCLUSIONS: SRS offers a reasonable chance of local tumor control for patients with intraventricular brain metastasis. However, the risk of hydrocephalus and leptomeningeal spread of disease is not inconsequential and merits close follow-up for patients with brain metastasis involving the ventricular system.

Stereotactic body radiotherapy in combination with non-frontline PD-1 inhibitors and targeted agents in metastatic renal cell carcinoma.

BACKGROUND: Radiotherapy may work synergistically with immunotherapy and targeted agents. We aimed to assess the safety and outcomes of stereotactic body radiotherapy (SBRT) plus non-first-line programmed death-1 (PD-1) inhibitors and targeted agents (TA) in metastatic renal cell carcinoma (mRCC). METHODS: We retrospectively reviewed 74 patients treated with non-first-line PD-1 inhibitors plus TA in non-first-line setting. Survival outcomes were calculated from the anti-PD-1 treatment using the Kaplan-Meier method. Univariate and multivariate analyses were performed by Cox proportional hazards models. RESULTS: Thirty-two (43.2%) patients received anti-PD-1/TA therapy alone (anti-PD-1/TA alone group), and 42 (56.8%) received SBRT in addition (anti-PD-1/TA + SBRT group). The median duration of first-line therapy was 8.6 months. Patients in the anti-PD-1/TA + SBRT group had significantly longer overall survival (OS) (38.5 vs 15.4 months; P = 0.022). On multivariate analysis, oligometastasis, ECOG performance status 0-1, anti-PD-1/TA + SBRT, and duration of first-line therapy ≥ 8.6 months were predictors for OS. The addition of SBRT was associated with improved OS in patients with clear-cell type (HR 0.19; 95% CI 0.07-0.55; P = 0.002) and duration of first-line therapy ≥ 8.6 months (HR 0.22; 95% CI 0.06-0.88; P = 0.032). Grade ≥ 3 toxicities occurred in 23 patients (54.8%) in the anti-PD-1/TA + SBRT group, and in 21 patients (65.6%) in the anti-PD-1/TA alone group. CONCLUSIONS: Incorporating SBRT into anti-PD-1/TA therapy is safe and tolerable. Further investigation is needed, particularly in patients with clear-cell histology and a longer duration of response to first-line antiangiogenic therapy.

Treatment outcomes of re-irradiation using stereotactic ablative radiotherapy to lung: a propensity score matching analysis.

BACKGROUND: The purpose of this study was to compare the treatment efficacy and safety of re-irradiation (re-RT) using stereotactic ablative radiotherapy (SABR) and initial SABR for primary, recurrent lung cancer or metastatic lung tumor. METHODS: A retrospective review of the medical records of 336 patients who underwent lung SABR was performed. Re-RT was defined as the overlap of the 70% isodose line of second-course SABR with that of the initial radiotherapy, and 20 patients were classified as the re-RT group. The median dose of re-RT using SABR was 54 Gy (range 48-60 Gy), and the median fraction number was 4 (range 4-6). One-to-three case-matched analysis with propensity score matching was used, and 60 patients were included in the initial SABR group of the matched cohort. RESULTS: The 1- and 2-year local control rates for the re-RT group were 73.9% and 63.3% and those for the initial SABR group in the matched cohort were 92.9% and 87.7%, respectively (P = 0.013). There was no difference in distant metastasis-free, progression-free, and overall survival rates. The crude grade ≥ 2 toxicity rates were 40.0% for the re-RT group and 25.0% for the initial SABR group (P = 0.318). Re-RT group had higher acute grade ≥ 2 toxicity rates (25.0% vs 5.0%, P = 0.031). One incident of grade 3 toxicity (pulmonary) was reported in the re-RT group; there was no grade 4‒5 toxicity. CONCLUSIONS: The local control rate of the in-field re-RT SABR was lower than that of the initial SABR without compromising the survival rates. The toxicity of re-RT using SABR was acceptable.

The role of stereotactic body radiation therapy and its integration with systemic therapies in metastatic kidney cancer: a multicenter study on behalf of the AIRO (Italian Association of Radiotherapy and Clinical Oncology) genitourinary study group.

Although systemic therapy represents the standard of care for polymetastatic kidney cancer, stereotactic body radiation therapy (SBRT) may play a relevant role in the oligometastatic setting. We conducted a multicenter study including oligometastatic kidney cancer treated with SBRT. We retrospectively analyzed 207 patients who underwent 245 SBRT treatments on 385 lesions, including 165 (42.9%) oligorecurrent (OR) and 220 (57.1%) oligoprogressive (OP) lesions. Most common sites were lung (30.9%) for OR group, and bone (32.7%) for OP group. Among 78 (31.8%) patients receiving concomitant systemic therapy, sunitinib (61.5%) and pazopanib (15.4%) were the most common for OR patients, while sunitinib (49.2%) and nivolumab (20.0%) for OP patients. End points were local control (LC), progression free survival (PFS), overall survival (OS), time to next systemic therapy (TTNS) and toxicity. Median follow-up was 18.6 months. 1, 2 and 3-year LC rates were 89.4%, 80.1% and 76.6% in OR patients, and 82.7%, 76.9% and 64.3% in those with OP, respectively. LC for OP group was influenced by clear cell histology (p = 0.000), total number of lesions (p = 0.004), systemic therapy during SBRT (p = 0.012), and SBRT dose (p = 0.012). Median PFS was 37.9 months. 1, 2- and 3-year OS was 92.7%, 86.4% and 81.8%, respectively. Median TTNS was 15.8 months for OR patients, and 13.9 months for OP patients. No grade 3 or higher toxicities were reported for both groups. SBRT may be considered an effective safe option in the multidisciplinary management of both OR and OP metastases from kidney cancer.

Stereotactic body radiation therapy for adrenal gland metastases: outcome and predictive factors from a multicenter analysis.

Adrenal metastases occur in 15-35% of oncological patients. Surgery is the first treatment option. Stereotactic body radiotherapy (SBRT) has been largely explored in oligometastatic patients unfit for surgery, representing an effective and non-invasive local treatment. The results of a multi-institutional experience of SBRT on adrenal metastases in the oligorecurrent or oligoprogressive setting are herein reported. We collected data of adrenal gland metastases treated with SBRT in three Italian centers from 2010 to 2020. End-points of the present study were: Overall survival (OS), Local control of treated metastases (LC), Progression free survival (PFS), and toxicity. 149 adrenal gland metastases were treated with SBRT in 142 patients. The most common primary tumor was lung cancer (58.4%), followed by kidney cancer (9.4%). Median lesion's volume was 28.5 cm3 (2.5-323.4). The median SBRT dose was 40 Gy (10-60). Median follow-up was 14.4 months. One- and two-year OS were 72.3% and 53.5%. At univariate analysis performance status correlated with survival (HR 1.57, p = 0.006). One- and two-year LC were 85.4% and 79.2%, with lung primary tumor (HR 0.33, p = 0.021) and BED10 (HR 0.97, p = 0.036) significant independent factors. One- and two-year PFS were 37.7% and 24.8%. Median time to polymetastatic disease was 11.3 months. Grade 1 and 2 toxicity occurred in 21 (14.7%) and 3 (2.1%) patients. The results from this large multi-center study confirm the efficacy and safety of SBRT in the management of adrenal gland metastases, as a valid alternative to other more invasive local approaches.

Stereotactic body radiotherapy to lymph nodes in oligoprogressive castration-resistant prostate cancer patients: a post hoc analysis from two phase I clinical trials.

The prognosis of prostate cancer (PC) is generally favorable but the incidence of metastases is relatively high after the treatment of the primary tumor, especially in high-risk patients. Fractionated stereotactic body radiotherapy (SBRT) or single fraction stereotactic body radiosurgery (SRS) are emerging treatment options in this setting. However, data on SBRT/SRS in patients with metastatic castration-resistant PC (mCRPC) are largely lacking, particularly in subjects with nodal lesions. Therefore, we evaluated outcomes and toxicity recorded in mCRPC patients with nodal oligoprogression. Patients included in this analysis had ≤ 5 metastatic sites without visceral lesions and underwent SBRT/SRS on nodal metastases. Thirty-eight patients carrying out 61 nodal metastases were analyzed. The median SRS dose was 20 Gy (range 12-24 Gy) and the most common schedule was 20 Gy (44.8%). The median SBRT dose was 45 Gy (range 20-50 Gy) and the most common regimen was 45 Gy in 5 fractions (37.9%). Thirty-seven patients (97.4%) showed only grade 0-1 acute toxicity while one patient reported grade 2 dysphagia. In terms of late toxicity, one grade 2 laryngeal, one grade 1 skin and one grade 1 gastrointestinal toxicities were recorded. Two-year actuarial local control (LC), distant progression-free survival, progression-free survival (PFS) and overall survival were 94.0, 47.2, 47.2, and 90.2%, respectively. Two-year next line systemic therapy-free survival (NEST-FS) was 67.7%. In conclusion, the efficacy in terms of LC of SBRT/SRS in patients with nodal metastases from PC was confirmed. Moreover, this analysis suggests the efficacy in terms of PFS and NEST-FS also in the setting of oligoprogressive PC. In fact, about one-third of patients were free from progressive disease and two-third of subjects did not require hormonal therapy switch or discontinuation three years after treatment.

Stereotactic and Hypofractionated Radiotherapy Associated With Immune Checkpoint Inhibitor Drugs: Analysis of Local Control, Toxicity, and Outcome in a Single Research Centre Case Study.

BACKGROUND/AIM: We evaluated local control and toxicity in patients receiving radiotherapy associated with immune check point inhibitors and analyzed which oligometastatic disease setting benefits the most from local ablation in terms of advantage in overall survival. PATIENTS AND METHODS: We retrospectively identified 60 oligoprogressive patients treated with a PD-1 inhibitor in association with radiotherapy on the site of progression (119 lesions). RESULTS: After a median follow-up of 11.7 months (range=1-39 months), we observed complete response (CR) in 45/119, partial response (RP) in 42/119, and stable disease (SD) in 30/119 patients. Nine radionecrotic events occurred. Two patients experienced grade 3 toxicities and 32 patients reported grade 2 toxicities. The number of radiologically evident metastatic organs in patients who received concomitant PD-1 inhibitors and radiotherapy showed a significant increase in survival (respectively, 73% after 12 months and 47% after 24 months) in patients with 0-3 metastatic organs compared to those with more than 3 organ sites involved (p<0.0001). CONCLUSION: Radiotherapy associated with PD-1 inhibitors is overall safe and efficacious. Patients eligible for intensification of local treatments should have less or equal to 3 metastatic organ sites.

Stereotactic ablative radiotherapy for operable stage I non-small-cell lung cancer (revised STARS): long-term results of a single-arm, prospective trial with prespecified comparison to surgery.

BACKGROUND: A previous pooled analysis of the STARS and ROSEL trials showed higher survival after stereotactic ablative radiotherapy (SABR) than with surgery for operable early-stage non-small-cell lung cancer (NSCLC), but that analysis had notable limitations. This study reports long-term results of the revised STARS trial, in which the SABR group was re-accrued with a larger sample size, along with a protocol-specified propensity-matched comparison with a prospectively registered, contemporary institutional cohort of patients who underwent video-assisted thoracoscopic surgical lobectomy with mediastinal lymph node dissection (VATS L-MLND). METHODS: This single-arm prospective trial was done at the University of Texas MD Anderson Cancer Center (Houston, TX, USA) and enrolled patients aged 18 years or older with a Zubrod performance status of 0-2, newly diagnosed and histologically confirmed NSCLC with N0M0 disease (squamous cell, adenocarcinoma, large cell, or NSCLC not otherwise specified), and a tumour diameter of 3 cm or less. This trial did not include patients from the previous pooled analysis. SABR dosing was 54 Gy in three fractions (for peripheral lesions) or 50 Gy in four fractions (for central tumours; simultaneous integrated boost to gross tumour totalling 60 Gy). The primary endpoint was the 3-year overall survival. For the propensity-matching analysis, we used a surgical cohort from the MD Anderson Department of Thoracic and Cardiovascular Surgery's prospectively registered, institutional review board-approved database of all patients with clinical stage I NSCLC who underwent VATS L-MLND during the period of enrolment in this trial. Non-inferiority could be claimed if the 3-year overall survival rate after SABR was lower than that after VATS L-MLND by 12% or less and the upper bound of the 95% CI of the hazard ratio (HR) was less than 1·965. Propensity matching consisted of determining a propensity score using a multivariable logistic regression model including several covariates (age, tumour size, histology, performance status, and the interaction of age and sex); based on the propensity scores, one patient in the SABR group was randomly matched with one patient in the VATS L-MLND group using a 5:1 digit greedy match algorithm. This study is registered with ClinicalTrials.gov, NCT02357992. FINDINGS: Between Sept 1, 2015, and Jan 31, 2017, 80 patients were enrolled and included in efficacy and safety analyses. Median follow-up time was 5·1 years (IQR 3·9-5·8). Overall survival was 91% (95% CI 85-98) at 3 years and 87% (79-95) at 5 years. SABR was tolerated well, with no grade 4-5 toxicity and one (1%) case each of grade 3 dyspnoea, grade 2 pneumonitis, and grade 2 lung fibrosis. No serious adverse events were recorded. Overall survival in the propensity-matched VATS L-MLND cohort was 91% (95% CI 85-98) at 3 years and 84% (76-93) at 5 years. Non-inferiority was claimed since the 3-year overall survival after SABR was not lower than that observed in the VATS L-MLND group. There was no significant difference in overall survival between the two patient cohorts (hazard ratio 0·86 [95% CI 0·45-1·65], p=0·65) from a multivariable analysis. INTERPRETATION: Long-term survival after SABR is non-inferior to VATS L-MLND for operable stage IA NSCLC. SABR remains promising for such cases but multidisciplinary management is strongly recommended. FUNDING: Varian Medical Systems and US National Cancer Institute (National Institutes of Health).

Comparison of stereotactic body radiation therapy versus fractionated radiation therapy for primary liver cancer with portal vein tumor thrombus.

BACKGROUND: To compare the clinical outcomes of stereotactic body radiation therapy (SBRT) and fractionated radiation therapy (FRT) for primary liver cancer with portal vein tumor thrombus (PVTT). METHODS: This retrospective study included 36 patients who underwent SBRT and 36 patients who underwent FRT from August 2016 to June 2018. Patients were evaluated for short-term efficacy, long-term efficacy, AEs, and quality of life before and after treatment. RESULTS: With a median follow-up of 28.8 months (26-36 months), 27 patients survived in the SBRT group while 19 patients survived in the FRT group. The survival rate in the SBRT group was statistically higher than that of the FRT group after 6 months (80.56% vs. 58.33%; P = 0.041), 12 months (77.78% vs. 55.56%; P = 0.046) and 24 months 75.00% vs. 52.78%; P = 0.049). The median whole survival time of the SBRT group was 13.3 months (95% CI 12.83-13.97), which was statistically longer than 9.8 months in the FRT group (95% CI 8.83-10.97, P < 0.05) based on the Kaplan-Meier method. The SBRT group had better survival quality and fewer adverse events than the FRT group. CONCLUSION: SBRT had better clinical outcomes than FRT for primary liver cancer with PVTT.

Stereotactic ablative body radiotherapy boost for cervical cancer when brachytherapy boost is not feasible.

BACKGROUND: The purpose of this study was to analyze the treatment efficacy and safety of stereotactic ablative body radiotherapy (SABR) boost for cervical cancer patients not amenable to brachytherapy. METHODS: A retrospective review of the medical records from single institution of 25 eligible patients was performed. The patients underwent pelvic radiotherapy (RT) in 25 or 28 fractions with a median dose of 45 Gy (range 44-50.4 Gy). SABR boost was delivered after pelvic RT, with a median dose of 25 Gy (range 20-33 Gy), and a median fraction number of 5 (range 4-6). 21 patients with a follow-up period of more than one year were included in the toxicity analysis, and hematuria and hematochezia that occurred later than 3 months after the RT were graded. RESULTS: The median follow-up period after radiotherapy was 2.85 years (range 0.33-6.60). The 3-year local control, locoregional control, disease-free survival, and overall survival rates were 80.9%, 75.8%, 40.9%, and 77.1%, respectively. 5 patients experienced grade 3 toxicity (3 genitourinary, 3 gastrointestinal), and no grade 4-5 toxicity was reported. Univariate analysis showed that cumulative D2cc in equivalent dose in 2 Gy fractions (EQD2) of rectum was marginally predictive for any grade of hematochezia (P = 0.051). Cumulative D2cc EQD2 of bladder was not predictive for hematuria. In the receiver operating characteristic (ROC) curve analysis, the optimal threshold of cumulative rectal D2cc EQD2 was 81.2 Gy for any grade of hematochezia. CONCLUSION: SABR boost for cervical cancer was effective and tolerable. Although it cannot substitute brachytherapy, it can be a treatment option when brachytherapy is not possible.

Comparison of liver exposure in CT-guided high-dose rate (HDR) interstitial brachytherapy versus SBRT in hepatocellular carcinoma.

BACKGROUND: In unresectable hepatocellular carcinoma several local ablative treatments are available. Among others, radiation based treatments such as stereotactic body radiotherapy (SBRT) and high-dose rate interstitial brachytherapy (HDR BT) have shown good local control rates. METHODS: We conducted a dose comparison between actually performed HDR BT versus virtually planned SBRT to evaluate the respective clinically relevant radiation exposure to uninvolved liver tissue. Moreover, dose coverage and conformity indices were assessed. RESULTS: Overall, 46 treatment sessions (71 lesions, 38 patients) were evaluated. HDR BT was applied in a single fraction with a dose prescription of 1 × 15 Gy. D98 was 17.9 ± 1.3 Gy, D50 was 41.8 ± 8.1 Gy. The SBRT was planned with a prescribed dose of 3 × 12.5 Gy (65%-Isodose), D98 was 50.7 ± 3.1 Gy, D2 was 57.0 ± 2.3 Gy, and D50 was 55.2 ± 2.3 Gy. Regarding liver exposure Vliver10GyBT was compared to Vliver15.9GySBRT, Vliver16.2GySBRT (EQD2 equivalent doses), and Vliver20GySBRT (clinically relevant dose), all results showed significant differences (p < .001). In a case by case analysis Vliver10GyBT was smaller than Vliver20GySBRT in 38/46 cases (83%). Dmean of the liver was significantly smaller in BT compared to SBRT (p < .001). GTV volume was correlated to the liver exposure and showed an advantage of HDR BT over SBRT in comparison of clinically relevant doses, and for EQD2 equivalent doses. The advantage was more pronounced for greater liver lesions The Conformity Index (CI) was significantly better for BT, while Healthy Tissue Conformity Index (HTCI) and Conformation Number (CN) showed an advantage for SBRT (p < .001). CONCLUSION: HDR BT can be advantageous in respect of sparing of normal liver tissue as compared to SBRT, while providing excellent target conformity.

Liver Metastasis-Directed Ablative Radiotherapy in Pancreatic Cancer Offers Prolonged Time Off Systemic Therapy in Selected Patients: Data From a Multi-institutional Retrospective Study.

OBJECTIVES: We evaluated the outcomes of metastatic pancreatic cancer (MPC) patients who underwent liver metastases (LMs)-directed ablative radiotherapy (RT) and sought to characterize patients with more favorable prognosis. METHODS: A retrospective analysis of 76 MPC patients who underwent ablative RT (median dose, 50 Gy) to LM at 3 academic centers between 2008 and 2018 was performed. Endpoints were local control (LC), progression-free survival, and overall survival (OS) since RT. RESULTS: Median follow-up was 10.9 months. Liver metastases were metachronous in 68%. Before RT, LM was responsive/stable on chemotherapy (CTX) in 36% whereas progressive in 43%. Median carbohydrate antigen 19-9 (CA 19-9) at RT was 334 U/mL. After RT, 32% had ≥6 months of CTX break. Twelve-month outcomes were: LC, 66%; progression-free survival, 7%; and OS, 38%. On multivariable analysis, Eastern Cooperative Oncology Group 2-3 (hazard ratio [HR], 13.49; P < 0.01), progressive LM on CTX (HR, 3.26; P < 0.01), and higher CA 19-9 (log10 scale; HR, 1.39; P < 0.01) at RT predicted worse OS. CONCLUSIONS: Ablative RT to LM in setting of MPC may offer LC of systemic disease and thus quality time off CTX. Selected patients with good performance status, stable/responsive LM on CTX, and lower CA 19-9 have more favorable prognosis.

A multi-institutional analysis of fractionated versus single-fraction stereotactic body radiotherapy (SBRT) in the treatment of primary lung tumors: a comparison between two antipodal fractionations.

OBJECTIVES: Stereotactic body radiotherapy (SBRT) is a consolidate treatment for inoperable early-stage lung tumors, usually delivered in single or multi-fraction regimens. We aimed to compare these two approaches in terms of local effectiveness, safety and survival. MATERIALS AND METHODS: Patients affected by medically inoperable early-stage lung tumor were treated at two Institutions with two different schedules: 70 Gy in ten fractions (TF) (BED10: 119 Gy) or 30 Gy in single fraction (SF) (BED10: 120 Gy). RESULTS: 73 patients were treated with SBRT delivered with two biological equivalent schedules: SF (44) and TF (29). The median follow-up was 34 months (range 3-81 months). Three-year Overall survival (OS) was 57.9%, 3-year cancer-specific survival (CSS) was 77.2%, with no difference between treatment groups. Three-year progression-free survival (LPFS) was 88.9% and did not differs between SF and TF. Overall, four cases (5.4%) of acute grade ≥ 3 pneumonitis occurred. No differences in acute and late toxicity between the two groups were detected. CONCLUSION: SF and TF seems to be equally safe and effective in the treatment of primary inoperable lung tumors especially for smaller lesion. The SF may be preferentially offered to reduce patient access to hospital with no negative impact on tumor control and survival.

Single-Session Stereotactic Radiosurgery for Large Benign Meningiomas: Medium-to Long-Term Results.

BACKGROUND: The use of stereotactic radiosurgery for the treatment of intracranial meningiomas has been established as an effective and safe treatment modality. Larger meningiomas typically are managed by surgery followed by radiosurgery. Treatment of large meningiomas (usually defined as >10 cc) by stereotactic radiosurgery has been investigated in some recent reports, either by single-session, volume-staged, or the hypofractionation technique. We sought to assess the long-term efficacy and safety of single-session stereotactic radiosurgery for large (10 cc or more) intracranial benign meningiomas. PATIENTS AND METHODS: In this retrospective study, we included 273 patients with large benign meningiomas (≥10 cc) who were treated by single-session SRS and followed up for more than 2 years. Tumors were in a basal location in 228 patients (84%). There were 161 tumors (59%) in the perioptic location. The median tumor volume was 15.5 (10-57.3 cc [interquartile range {IQR} 12.3 cc]). The median prescription dose was 12 Gy (9-15 Gy [IQR 1 Gy]). RESULTS: The median follow-up period was 6.1 years (2-18 years [IQR 5.5 years]). The tumor control rate was 90%. The progression-free survival at 5 and 10 years was 96% and 81%, respectively, for the whole cohort. Among 161 patients with perioptic meningiomas, favorable (better/stable) visual outcome was reported in 155 patients (96%) and unfavorable (worse) outcome in 6 patients (4%). Temporary adverse radiation effects were observed in 41 patients (15%) but only 16 (6%) were symptomatic. CONCLUSIONS: Stereotactic radiosurgery provides an effective and safe treatment option for large meningiomas.