Outcomes Of Stereotactic Body Radiotherapy Research Articles

Stereotactic Body Radiation Therapy versus Concurrent Chemoradiotherapy for Locally Advanced Pancreatic Cancer: A Propensity Score-Matched Analysis.

Simple SummaryIn the lack of direct comparative evidence of stereotactic body radiation therapy, we reviewed one of the largest locally advanced pancreatic cancer cohort homogeneously treated in a tertiary cancer center. Our propensity score–matched analysis shows comparable outcomes between stereotactic body radiation therapy and concurrent chemoradiotherapy in terms of survival, local control, and treatment-related toxicities. Considering the advantages of SBRT such as short treatment duration, better tolerance, easy combination with systemic treatment, and the potential for dose escalation, further investigation of the feasibility of SBRT as an alternative to CCRT in treating locally advanced pancreatic cancer is required.In locally advanced pancreatic cancer (LAPC), stereotactic body radiation therapy (SBRT) has been applied as an alternative to concurrent chemoradiotherapy (CCRT); however, direct comparative evidence between these two modalities is scarce. The aim of this study was to compare the clinical outcomes of SBRT with CCRT for LAPC. We retrospectively reviewed the medical records of patients with LAPC who received SBRT (n = 95) or CCRT (n = 66) with a concurrent 5-FU-based regimen between January 2008 and July 2016. The clinical outcomes of freedom from local progression (FFLP), progression-free survival (PFS), overall survival (OS), and toxicities were analyzed before and after propensity score (PS) matching. After a median follow-up duration of 15.5 months (range, 2.3–64.5), the median OS, PFS, and FFLP of the unmatched patients were 17.3 months, 11 months, and 19.6 months, respectively. After PS matching, there were no significant differences between the SBRT and CCRT groups in terms of the 1-year rates of OS (66.7% vs. 80%, p = 0.455), PFS (40.0% vs. 54.2%, p = 0.123), and FFLP (77.2% and 87.1%, p = 0.691). Our results suggest SBRT could be a feasible alternative to CCRT in treating patients with LAPC.

Early-Stage Non-Small Cell Lung Cancer Stereotactic Body Radiation Therapy Outcomes in a Single Institution.

IntroductionThe gold standard treatment of stage I non-small cell lung cancer (NSCLC) is surgical resection. For medically inoperable patients, stereotactic body radiation therapy (SBRT) can provide comparable local control (LC) and overall survival (OS). The objectives of this study are to determine the three-year LC and OS for SBRT compared to early-stage NSCLC patients treated with alternative radiation modalities at our institution.Materials and methodsThis retrospective study included a total of 139 consecutive patients who were diagnosed with stage I (T1-2 N0 M0) NSCLC and treated with radiation therapy at our institution between 2015 and 2020. Patient demographics and clinical data were obtained from chart reviews. Treatment subgroups were: SBRT (48Gy/4 or 60Gy/8), hypofractionation (60Gy/15), conventional fractionation (60Gy/30 or 50Gy/20), and palliative radiation (20Gy/5, 30Gy/10, or 40Gy/15). Kaplan-Meier curves were plotted for LC and OS. We also performed Cox’s proportional hazard regression analysis.ResultsThe median patient age was 74 (range 52-91). The numbers of patients in each treatment subgroup were: SBRT (44), hypofractionation (78), conventional fractionation (8), and palliative (9). Differences in age, gender, and histopathological cell type between subgroups were not statistically significant. Metastatic progression was the most common outcome amongst treatment failures, followed by local recurrence and regional spread. Median post-treatment follow-up in months for each subgroup was: SBRT (20.2), hypofractionated (20.7), conventional fractionation (13.9), and palliative (14.4). Post-treatment three-year LC was found to be significantly better with SBRT (94%) versus hypofractionation (71%), conventional fractionation (80%), and palliative (71%). OS at three years were SBRT (67%), hypofractionation (59%), conventional fractionation (66%), and palliative (44%). As a whole, 72% (100/139) of patients had biopsy-proven NSCLC. Analysis showed biopsy status had no statistical significance with regards to LC or OS. Every 20 years of age had a 3.2x risk of death (95% CI: 1.425-7.268). Concerning the treatment modalities, there were significant differences for the hazard of death compared to SBRT: hypofractionation had 2.58x increased risk while palliative had 5.83x increased risk.The proportion of patients who experienced post-treatment radiation pneumonitis or dermatitis were: SBRT (7%, 2%), hypofractionation (8%, 3%), conventional fractionation (13%, 25%), and palliative (0%, 0%), respectively. No patients who experienced grade III or higher toxicities were observed as defined by Common Terminology Criteria for Adverse Events (CTCAE). ConclusionOur experience confirms SBRT can provide durable three-year local control with a comparable rate of post-treatment complications versus other radiation modalities for early-stage NSCLC. SBRT appears to be non-inferior to hypofractionation with regards to three-year LC.

Systematic Review of Single-Fraction Stereotactic Body Radiation Therapy for Early Stage Non-Small-Cell Lung Cancer and Lung Oligometastases: How to Stop Worrying and Love One and Done.

Simple SummaryAdoption of single-fraction stereotactic body radiation therapy for lung tumors has been limited among different institutions even during the coronavirus disease 2019 (COVID-19) pandemic. Potential reasons may include a lack of familiarity and concerns regarding potential toxicities. To address this knowledge gap, we performed a systematic review of prospective literature on single-fraction SBRT. Our PubMed search of prospective trials resulted in nine studies that showed favorable local control and survival outcomes among peripheral tumors. Many toxicities were grade 1–2, with 0–17% of patients experiencing grade ≥3 toxicity. Encouraging outcomes suggest that the utility of single-fraction stereotactic body radiation therapy may extend beyond the current COVID-19 pandemic.Adoption of single-fraction lung stereotactic body radiation therapy (SBRT) for patients with medically inoperable early stage non-small-cell lung cancer (NSCLC) or oligometastatic lung disease, even during the coronavirus disease 2019 (COVID-19) pandemic, was limited despite encouraging phase II trial results. Barriers to using single-fraction SBRT may include lack of familiarity with the regimen and lack of clarity about the expected toxicity. To address these concerns, we performed a systematic review of prospective literature on single-fraction SBRT for definitive treatment of early stage and oligometastatic lung cancer. A PubMed search of prospective studies in English on single-fraction lung SBRT was conducted. A systematic review was performed of the studies that reported clinical outcomes of single-fraction SBRT in the treatment of early stage non-small-cell lung cancer and lung oligometastases. The current prospective literature including nine trials supports the use of single-fraction SBRT in the definitive treatment of early stage peripheral NSCLC and lung oligometastases. Most studies cite local control rates of >90%, mild toxicity profiles, and favorable survival outcomes. Most toxicities reported were grade 1–2, with grade ≥3 toxicity in 0–17% of patients. Prospective trial results suggest potential consideration of utilizing single-fraction SBRT beyond the COVID-19 pandemic.

Outcomes of SBRT for lung oligo-recurrence of non-small cell lung cancer: a retrospective analysis.

The benefit of local ablative therapy (LAT) for oligo-recurrence has been investigated and integrated into the treatment framework. In recent decades, stereotactic body radiation therapy (SBRT) has been increasingly used to eliminate metastasis owing to its high rate of local control and low toxicity. This study aimed to investigate the outcomes of SBRT for patients with lung oligo-recurrence of non-small cell lung cancer (NSCLC) from our therapeutic center. Patients with lung oligo-recurrence of NSCLC treated with SBRT between December 2011 and October 2018 at Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) were reviewed. The characteristics, treatment-related outcomes, and toxicities of the patients were analyzed. Univariable and multivariable Cox regression were performed to identify the factors associated with survival. A total of 50 patients with lung oligo-recurrence of NSCLC were enrolled. The median follow-up period was 23.6 months. The 3-year local progression-free survival (LPFS), progression-free survival (PFS) and overall survival (OS) after SBRT were 80.2%, 21.9% and 45.3%, respectively. Patients in the subgroup with LAT to all residual diseases showed significantly improved OS and PFS. No treatment-related death occurred after SBRT. SBRT is a feasible option to treat patients with lung oligo-recurrence of NSCLC, with high rates of local control and low toxicity. LAT to all residual diseases was associated with better survival outcomes. Future prospective randomized clinical trials should evaluate SBRT strategies for such patients.

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

BackgroundRadiotherapy 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).MethodsWe 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.ResultsThirty-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.ConclusionsIncorporating 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.

Phase 2 Clinical Trial of Separation Surgery Followed by Stereotactic Body Radiation Therapy for Metastatic Epidural Spinal Cord Compression

Stereotactic body radiation therapy (SBRT) is a postoperative treatment option for spinal metastases. Because data on surgery with SBRT are limited to retrospective studies, this single-center, single-arm, phase 2 study aimed to prospectively evaluate the outcomes of separation surgery and SBRT for metastatic epidural spinal cord compression (MESCC). Patients with symptomatic MESCC due to a solid carcinoma were enrolled. The protocol for treatments comprised preoperative embolization, separation surgery, and spine SBRT. Surgical procedures were performed via the posterior approach, with decompression and a fixation procedure. The prescribed dose for spine SBRT was 24 Gy in 2 fractions. The primary endpoint was the 12-month local failure rate. The secondary endpoints were ambulatory functions and adverse effects. A total of 33 patients were registered between November 2017 and October 2019. All patients met the inclusion criteria, and all but 1 completed the protocol treatment. Of the included patients, 23 (70%) had radioresistant lesions. The Bilsky grade at registration was 1c in 3 patients, 2 in 8 patients, and 3 in 21 patients. The median follow-up duration after registration was 15 months (range, 3-35 months). Three months after the administration of treatments according to the protocol, 90% of patients (26 of 29) had disease of Bilsky grade ≤1. The 12-month local failure rate was 13%. Twenty patients could walk normally or with a cane 12 months after registration. Radiation-induced myelopathy, radiculopathy, and vertebral compression fracture were observed in 0, 1, and 6 patients, respectively. Separation surgery with SBRT for MESCC was effective in decompression and long-term local control. These findings suggest that larger randomized controlled trials are warranted to compare SBRT with conventional radiation therapy.

The Treatment Outcomes of Stereotactic Body Radiotherapy for Bone Oligo-Metastatic Disease.

<h3>Purpose/Objective(s)</h3> Stereotactic body radiotherapy (SBRT) has been increasingly expected to be a treatment option for bone metastases, especially in oligometastatic disease (OMD). This study aimed to clarify the efficacy of SBRT for bone oligo-metastases. <h3>Materials/Methods</h3> Patients who met the following criteria were retrospectively reviewed from a prospective database; 1) with bone metastases, 2) treated with SBRT for bone metastases and 3) with active lesion less than 5 in 3 different sites. OMD was defined as the patients with active lesion less than 5 in 3 different sites. Progression free survival (PFS), local failure (LF), overall survival (OS) and adverse events (AEs) were evaluated. LF was estimated using the cumulative incidence function adjusted for the competing risk of death. AEs were evaluated based on Common Terminology Criteria for Adverse Events 5.0. <h3>Results</h3> There were 219 cases in 188 patients selected from our database showed: median age, 66 years (range, 23-85 years); performance status, 0/1/2/3/4, 123/74/13/6/3; lesion histopathology, lung/prostate/ colorectal/breast/thyroid/kidney/others, 35/31/22/21/21/21/68; region of bone metastases, spine/non-spine, 139/80; number of metastases, 1/2/3/4/5, 146/45/20/6/2; type of OMD, synchronous OMD/metachronus OMD/repeat OMD/induced OMD, 39/93/64/23; treatment for primary site, local therapy/systemic therapy/none, 196/20/3; systemic therapy before SBRT, yes/no, 96/123; systemic therapy after SBRT, yes/no/unknown, 105/111/3; median interval from upfront treatment, 36 months (range, 1-300 months); radiotherapy history for targeted lesion, yes/no, 49/170; the prescribed dose, 20 Gy in single fraction/24 Gy in 2 fractions/30 Gy in 5 fractions/35 Gy in 5 fractions, 9/121/21/68. Median follow-up after SBRT was 16 months (range, 1-82 months). The 1-year PFS rate, LF rate and OS rate were 43.1%, 12.8% and 89.7%, respectively. The median PFS was 11 months. Most dominant first failure pattern was another bone metastasis. In univariate analysis of PFS, good performance status (<i>P</i> = 0.028), metastasis from prostate cancer (<i>P</i> = 0.00052) and longer interval from upfront treatment (<i>P</i> = 0.012) were associated with a significant better prognosis. In multivariate analysis, metastasis from prostate cancer (<i>P</i> = 0.010) and interval from upfront treatment (<i>P</i> = 0.019) were independent prognostic factors. In the cases excluding prostate cancer, median PFS was 9 months and the 1-year PFS rate was 39.4%. In 111 cases with treated before December 2018, 2-year progression-free survival was achieved in 22 cases (19.8%). Grade 5 infection, grade 4 radiation myelopathy and grade 3 dermatitis were observed in one case, respectively. Seventeen cases of fracture were encountered. <h3>Conclusion</h3> SBRT for bone oligo-metastases provided long term systemic disease control in about 20% of cases. SBRT is effective treatment option for bone OMD especially for the cases with long interval from upfront treatment.

Stereotactic Radiotherapy to Oligoprogressive Lesions Detected With 68Ga-PSMA-PET/CT in Castration-Resistant Prostate Cancer Patients

Few studies have investigated the feasibility of MDT in metastatic castration-resistant prostate cancer (CRPC) patients with heterogeneous patient populations with different treatment strategies and various imaging modalities other than gallium prostate-specific membrane antigen-positron emission tomography (68Ga-PSMA-PET/CT) for detecting oligoprogressive lesions. We assessed the outcomes of stereotactic body radiotherapy (SBRT) to treat oligoprogressive castration-resistant prostate cancer (CRPC) patients with ≤5 lesions using 68Ga-PSMA-PET/CT.The clinical data of 67 CRPC patients with 133 lesions treated with 68Ga-PSMA-PET/CT-based SBRT were retrospectively analyzed. All of the patients had oligoprogressive disease during androgen-deprivation therapy (ADT). The inclusion criteria were as follows: a histologic diagnosis of PC on primary tumor biopsy, less than or equal to 5 bone and/or lymph node metastases detected with 68Ga-PSMA-PET/CT during ADT, being castration-resistant according to the European Association of Urology guidelines, a controlled primary tumor, SBRT fraction doses of at least 6 Gy per fraction and a biologically effective dose (BED) of at least 90 Gy using α⁄β of 3 Gy. The prognostic factors for overall- (OS) and progression-free survival (PFS) and the predictive factors for switching to next-line systemic treatment (NEST) and NEST-free survival (NEST-FS) were analyzed.With a median follow-up of 17.5 months, the 2-year overall survival (OS) and PFS rates were 86.9% and 34.4%, respectively. Most of the patients had GS 9 or 10 tumors and locally advanced disease. The most frequent oligoprogressive site was bone only (64.2%), and more than half of the patients (53.7%) had a single metastasis. The median number of metastases was 1 (range, 1-5). In the case of bone metastasis, the most adopted methods were single-dose 16 Gy and 18 Gy, and the most adopted prescription for nodal metastasis was 30-35 Gy delivered in 5 fractions. The PSA response after SBRT was observed in 49 patients (73.1%). Progression was observed in 37 patients (55.2%) at a median of 11.0 months following SBRT. Forty-five patients (67.2%) remained on ADT after SBRT, and 22 patients (32.8%) had a NEST change at a median of 16.4 months after MDT. Patients with a NEST change had higher post-SBRT PSA values and fewer PSA nadirs after MDT than their counterparts. In multivariate analysis, higher pre-SBRT PSA values were the only significant predictor for worse OS and NEST-FS, and no significant factor was found for PFS. No serious acute or late toxicities were observed.This study demonstrated the feasibility of MDT using SBRT to treat oligoprogressive lesions by 68Ga-PSMA-PET/CT in CRPC patients is efficient and well-tolerated, prolonging the effectiveness of ADT by delaying NEST.

Phase II Clinical Trial of Separation Surgery Followed by Stereotactic Body Radiotherapy for Metastatic Epidural Spinal Cord Compression

Stereotactic body radiotherapy (SBRT) is a postoperative treatment option for spinal metastases. As data on surgery with SBRT are limited to retrospective studies, this single-center, single-arm, phase II study prospectively evaluated the outcomes of separation surgery and SBRT for metastatic epidural spinal cord compression (MESCC).Patients with symptomatic MESCC from solid carcinoma were enrolled. Protocol treatments comprised separation surgery and spine SBRT. Surgical procedures were performed via the posterior approach, with decompression and a fixation procedure. The prescribed dose for spine SBRT was 24 Gy in two fractions. The primary endpoint was the 12-month local failure (LF) rate. Secondary endpoints were ambulatory functions and adverse effects.Thirty-three patients were registered during November 2017-October 2019. All patients satisfied the inclusion criteria, and all but one completed the protocol treatment. Twenty-three patients (70%) had radioresistant lesions. The Bilsky grade at registration was 1c, 2, and 3 in 4, 8, and 21 patients, respectively. The median follow-up duration after registration was 15 (range 3-35) months. Ninety percent of patients (26/29) had Bilsky grade 1 or less disease at 3 months after protocol treatments. The 12-month LF rate was 13%. Twenty patients could walk normally or with a cane 12 months after registration. Radiation-induced myelopathy, radiculopathy, and vertebral compression fracture were observed in 0, 1, and 6 patients, respectively.Separation surgery with SBRT for MESCC was effective in decompression and long-term local control. These findings warrant larger randomized controlled trials to compare SBRT with conventional radiotherapy.

Stereotactic Body Radiotherapy (SBRT) for the Palliation of Unirradiated Mucosal Head and Neck Tumors

We report the treatment outcomes of palliative SBRT to primary mucosal unirradiated head and neck cancer (HNC) patients that were ineligible to receive conventional radiation therapy (RT) MATERIALS/METHODS: We retrospectively reviewed patients with primary mucosal HNC treated with SBRT from 2011-2020. Patients with histologies other than squamous cell carcinoma, with primary skin disease or with recurrent tumors were excluded. SBRT was used in this cohort of patients because of associated comorbidities that precluded full course RT. All patients were followed regularly with clinical examination and imaging. The endpoints were local failure (LF) defined as recurrence of tumor at the irradiated site, overall survival (OS), acute and late grade 3 and 4 toxicity.Sixty patients with a median age of 81 years were treated with SBRT technique. The median follow-up was 7.8 months. 8(13%), 38(63%), 13(22%) and 1(2%) were ECOG 1, 2, 3 and 4, performance status respectively. Oral cavity was the most common cancer site in our cohort (60%, 36 patients), followed by oropharyngeal cancer (15%, 9 patients), larynx (7%, 4 patients), hypopharynx (5%, 3 patients), parotid cancer (5%, 3 patients), unknown primary (5%, 3 patients) and nasal cavity/sinonasal cancer (3%, 2 patients). Tx-2 and T3-4 lesions were found in 18(30%) and 42(70%), respectively, while 32(53%) and 28(47%) were staged N0-1, N2-3, respectively. GTV was prescribed to 45 Gy in 5 fractions, most commonly used (55%), followed by 40 Gy in 5 fractions (37%). A high dose CTV was not used around GTV although an elective nodal volume of 25 Gy in 5 fractions was also used. 52 patients were treated twice a week completed in 13-20 days, 2 patients completed their treatments in 9 and 10 days, while 5 patients over 21-28 days. The cumulative incidence of LF at 6 and 12 months was 5.3% (95% CI 1.4-13.3) and 12.4% (95% CI 4.9-23.7), respectively. The median (OS) was 9.2 months. The 6 and 12 month OS rates were 67.9% (95% CI 56.6-81.4) and 41.4% (95% CI 29.2-58.7), respectively. Cancer was the cause of death in 12 patients (38%), while 20 deaths (62%) were not related to malignant disease. Acute G3 toxicity was observed in 23 patients, including G3 mucositis in 19 patients, G3 dermatitis in 2 patients and G3 dysphagia in 2 patients. Five patients developed G3+ late toxicity, including osteoradionecrosis (n = 3), soft tissue supraglottic ulceration (n = 1) and trismus (n = 1). Four of these 5 patients did not have evidence of concurrent local recurrence.HN SBRT has been largely reported in the re-irradiation setting, however, SBRT may have greater utility in the palliative management of previously untreated HNC patients. Despite the advanced age and performance status noted in this group of patients with mucosal SCC of the head and neck, who were not eligible for conventional RT, SBRT was associated with low local failure rates and reasonable toxicity profile. A randomized controlled trial is warranted to confirm the efficacy of HN SBRT in this setting.

Outcomes and Toxicities in Oligometastatic Patients Treated With Stereotactic Body Radiotherapy for Adrenal Gland Metastases: A Multi-Institutional Study

Stereotactic body radiation therapy (SBRT) has emerged as an effective treatment approach in oligometastatic patients with adrenal gland metastases (AGM). Nevertheless, most of the literature reporting SBRT outcomes for AGM comes from published single institutional experience, and no specific guidelines are yet established to guide patients' inclusion and dosimetric planning.The Consortium for Oligometastases Research (CORE) is currently the largest retrospective series of patients with oligometastases (OM). Among CORE patients, those treated with SBRT for AGM were included. Adrenal metastatic burden (AMB) was defined as the sum of all adrenal GTV if more than one OM is present. BED10 was calculated with tumor alpha/beta ratio of 10. Competing risk analysis was used to estimate the risk of local recurrence (LR) and widespread progression (WP) over time, using death from any cause as a competing risk factor. Kaplan-Meier method was used to estimate the overall survival (OS), local recurrence-free survival (LRFS), and progression-free survival (PFS). Univariable and multivariable regression was used to quantify the relationship between potential predictors and the main endpoints. A P-value threshold of 0.05 was used for statistical significance.46 patients with 57 adrenal lesions were included. Median follow-up was 18.2 months. The most common primary malignancy was NSCLC. The mean (standard deviation) age at diagnosis was 65.84 (10.84) years, with 25 (53.2%) male patients and 22 (46.8%) female patients. 8 out of the 46 patients had developed more than one AGM. The most used fractionation scheme was 30 - 35 Gy in 3 - 5 fractions, and the mean prescribed BED10 was 69.37 Gy10. Median LRFS, PFS, and OS were 15.3, 5.29, and 19.1 months, respectively. The 1-year and 5-year LRFS were 65% and 25.4%, respectively. The 1-year and 5-year OS were 70% and 33%, respectively. Only 1 patient developed a Grade 3 GI toxicity. On multivariable regression, a minimum received PTV dose > 46 Gy10 was associated with an improved OS (HR 0.42, 95% CI [0.20 - 0.89], P = 0.024) and LRFS (HR 0.37, [0.18 - 0.76], P = 0.006), after adjusting for primary site. A prescribed BED10 more than 70 Gy10 was an independent prognostic factor of a lower LR rate (HR 0.31, [0.102-0.94], P = 0.039). Interestingly, AMB greater than 10 cc was an independent predictor of a lower risk WP (HR 0.29, [0.11 - 0.80], P = 0.017), after adjusting for primary histology and number of OM.SBRT to AGM is a safe procedure that achieves a satisfactory local control and survival in oligometastatic patients. The current results suggest that patients should be treated with a prescription BED10 dose of at least 70 Gy10, and a minimum PTV dose > 46 Gy10, if safely achievable. Paradoxically, AMB > 10cc was favorable, and a high AMB should not preclude the administration of a definitive course of SBRT. Prospective studies are needed to determine comprehensive criteria for patients SBRT eligibility and dosimetric planning.

Stereotactic body radiotherapy for head and neck skin cancer

AimTo report outcomes of Stereotactic Body Radiotherapy (SBRT) for head and neck skin cancer (HNSC) patients treated at a high-volume center. MaterialsA retrospective review of HNSC SBRT patients from 2012 to 2019 was conducted. Kaplan–Meier method was used to estimate local control (LC), locoregional control (LRC) outside of SBRT field, overall survival (OS), progression-free survival (PFS) and late toxicity (LT). Univariate and multivariate analyses were performed. Grade 3-4 acute and late toxicities were reported by the Common Terminology Criteria for Adverse Events v5.0. ResultsOne hundred and six medically unfit HNSC patients (112 lesions) were included. Median follow-up was 8 months. Median patient age at diagnosis was 86 years (range: 56–102 years). The majority of patients had advanced disease (overall stage III-IV [n = 90, 85%]) with median gross tumor volumes (GTV) of 31 cm3 (range: 17–56 cm3). Treated sites were: primary (n = 51), nodal (n = 47) or primary plus nodal (n = 8). SBRT doses ranged from 32-50 Gy delivered twice weekly in 4–6 fractions to the gross tumor volume (GTV). One and 2-year LC rates were 78% (69–88) and 67% (53–82), respectively. One-year LRC outside of SBRT field, OS, PFS and LT rates were 72% (62–84), 53% (43–65), 52% (40–62), and 7% (2–17), respectively. Thirty-three patients (31%) developed acute grade ≥ 3 treatment-related toxicity, most commonly dermatitis (n = 31). Nine patients (8%) experienced late grade ≥ 3 toxicity, including 7 grade 3 fibrosis, 1 grade 3 bone radionecrosis and 1 grade 4 skin ulceration. No treatment-related deaths (grade 5) were observed. ConclusionSBRT provides durable disease control with acceptable toxicity for medically unfit high-risk HNSC patients unable to undergo standard of care curative treatment approaches.

160: Early Stage Lung Cancer Stereotactic Body Radiation Therapy Outcomes in a Single Instituiton

160: Early Stage Lung Cancer Stereotactic Body Radiation Therapy Outcomes in a Single Instituiton

FP08.01 Lung Stereotactic Body Radiation Therapy for Treatment of Oligoprogressive and Oligorecurrent Metastatic Disease: A Multi-Center Analysis

There is growing clinical utilization of stereotactic body radiation therapy (SBRT) in the treatment of advanced lung cancer and lung metastases. In patients with limited progression, SBRT offers an ablative local therapy to address resistant clones. However, the role of lung SBRT in this setting is not well-defined. The purpose of this study is to determine clinical outcomes of SBRT for oligoprogressive and oligorecurrent intra-thoracic disease and its impact on the use of systemic therapy.

A 54 Gy in three fractions of stereotactic body radiotherapy using CyberKnife for T1b-2aN0M0 pathologically confirmed non-small cell lung cancer

Abstract Objective Optimal dose-fractionation regimen of stereotactic body radiotherapy for peripheral early-stage non-small cell lung cancer remains unclear. We retrospectively investigated outcomes of stereotactic body radiotherapy using CyberKnife at 54 Gy in three fractions in 26 patients (median age: 76 years) with pathologically confirmed T1b–T2aN0M0 non-small cell lung cancer. Methods A 54 Gy in three fractions was prescribed to cover the 99% of gross tumor volume. We estimated cumulative local control, progression-free survival and overall survival rates (Kaplan–Meier method), and toxicity (Common Toxicity Criteria for Adverse Events, version 5.0). Results All the tumors were located at peripheral area of lung. Mean distance from chest wall to tumor was 6.5 mm (range: 0–32 mm). The patients’ pathological diagnoses were: adenocarcinoma: n = 18, squamous cell carcinoma: n = 7 and non-small cell carcinoma: n = 1. Their stages were T1b: n = 9, T1c: n = 14 and T2a: n = 3. Median follow-up was 24 months (range: 6–54). Cumulative 2-year effect rates were local control: 100%, progression-free survival 70% and overall survival: 92%. Twenty patients developed grade one radiation pneumonitis, but grade 2 or greater radiation pneumonitis was not observed. Conclusions We found CyberKnife-stereotactic body radiotherapy for pathologically confirmed T1b–T2aN0M0 non-small cell lung cancer to be effective and safe. However, these results should be validated with a larger patient cohort and prospective follow-up monitoring.

Five-year outcomes of stereotactic body radiation therapy (SBRT) for prostate cancer: the largest experience in China

ObjectiveTo evaluate the efficacy and safety of SBRT for localized prostate cancer (PCa) with CyberKnife in China. Moreover, it is the largest-to-date pilot study to report 5-year outcomes of SBRT for localized PCa from China.MethodsIn this retrospective study, 133 PCa patients in our center were treated by SBRT with CyberKnife (Accuray Inc., Sunnyvale, USA) from October 2012 to July 2019. Follow-up was performed every 3 months for efficacy and toxicity evaluation. Biochemical progression-free survival (bPFS) and toxicities were assessed using the Phoenix definition and the Common Terminology Criteria for Adverse Events (CTCAE) v.5.0, respectively. Factors predictive of bPFS were identified with COX regression analysis.Results133 patients (10 low-, 21 favorable intermediate-, 31 unfavorable intermediate-, 45 high-, and 26 very high risk cases on the basis of NCCN risk classification) with a median age of 76 years (range 54–87 years) received SBRT. The median dose was 36.25 Gy (range 34–37.5 Gy) in 5 fractions. Median follow-up time was 57.7 months (3.5–97.2 months). The overall 5-year bPFS rate was 83.6% for all patients. The 5-year bPFS rate of patients with low-, favorable intermediate-, unfavorable intermediate-, high-, and very high risk PCa was 87.5%, 95.2%, 90.5%, 86.3%, and 61.6%, respectively. Urinary symptoms were all alleviated after SBRT. All patients tolerated SBRT with 1 (0.8%) patient reporting grade-3 acute and 1 (0.8%) patient reporting grade-3 late genitourinary (GU) toxicity, respectively. There were no grade 4 toxicities. Gleason score (P < 0.001, HR = 7.483, 95%CI: 2.686–20.846) was the independent predictor of bPFS rate after multivariate analysis.ConclusionSBRT is an efficient and safe treatment modality for localized PCa with high 5-year bPFS rates and acceptable toxicities.

Long-term outcomes of spinal SBRT. Is it important to select the treatment time?

SBRT (stereotactic body radiation therapy) is widely used as a curative treatment in tumoral lesions and has become a fundamental tool for the treatment of spine metastasis. In this study, we present survival and toxicity outcomes of spine SBRT after a 2-year follow-up. Data from spine SBRT treatments performed at our institution between March 2012 and February 2020 was collected. Medical records, including demographic, primary tumor, and treatment characteristics were reviewed. Patient follow-up included clinical evaluation, imaging, and blood tests. Toxicity was recorded according to CTCAE v4.0. We analyzed 73 consecutive spine SBRT treatments in 60 patients. 39.7% of the cases had primary breast cancer and 23.3% had prostate cancer. Most cases (87.7%) were treated with a single SBRT fraction of 16Gy. Median follow-up was 26.1months (range 1.7-78.6), and 1- and 2-year overall survival (OS) rates were 96.9% and 84.2%, respectively. Local control (LC) rates at 1- and 2-years were 76.3% and 70.6%, respectively. Multivariate analysis identified histology as a prognostic factor for both OS and LC. Patients who underwent spine SBRT 6months after the spinal lesion diagnosis had LC at 2years of 88%, vs 61.7% for those who underwent SBRT before this period. No grade III or higher toxicity was reported. The vertebral compression fracture (VCF) rate was 4.1%. Spine SBRT at our institution showed a 2-year LC of 70.6%, without G3 toxicities. Delaying SBRT at least 6months to administer systemic treatment was related to an improvement in local control.

PO-1186 Treatment outcomes of stereotactic body radiotherapy for lung cancer according to tumor appearances

PO-1186 Treatment outcomes of stereotactic body radiotherapy for lung cancer according to tumor appearances

Prolonged overall treatment time negatively affects the outcomes of stereotactic body radiotherapy for early-stage non-small-cell lung cancer: A propensity score-weighted, single-center analysis.

Previous studies have reported conflicting results for the effect of overall treatment time with stereotactic body radiotherapy on tumor control in early-stage non-small-cell lung cancer. To examine this effect, we conducted a propensity score-weighted, retrospective, observational study at a single institution. We analyzed the data of 200 patients with early-stage non-small-cell lung cancer who underwent stereotactic body radiotherapy (48 Gy in 4 fractions) at our institution between January 2007 and October 2013. Patients were grouped into consecutive (overall treatment time = 4–5 days, n = 116) or non-consecutive treatment groups (overall treatment time = 6–10 days, n = 84). The outcomes of interest were local control and overall survival. The Cox regression model was used with propensity score and inverse probability of treatment weighting. The median overall treatment times in the consecutive and non-consecutive groups were 4 and 6 days, respectively. The 5-year local control and overall survival rates in the consecutive vs. the non-consecutive group were 86.3 vs. 77.2% and 55.5 vs. 51.8%, respectively. After propensity score weighting, consecutive stereotactic body radiotherapy was associated with positive local control (adjusted hazard ratio 0.30, 95% confidence interval 0.14–0.65; p = 0.002) and overall survival (adjusted hazard ratio 0.56, 95% confidence interval 0.34–0.91; p = 0.019) benefits. The prolonged overall treatment time of stereotactic body radiotherapy treatment negatively affected the outcomes of patients with early-stage non-small-cell lung cancer. To our knowledge, this is the first study to show that in patients with early-stage non-small-cell lung cancer treated with the same dose-fractionation regimen, consecutive stereotactic body radiotherapy has a more beneficial effect on tumor control than non-consecutive stereotactic body radiotherapy.

Outcomes of extra-cranial stereotactic body radiotherapy for metastatic breast cancer: Treatment indication matters

Background and purposeTo summarize the clinical outcomes of stereotactic body radiotherapy (SBRT) for metastatic breast cancer (mBC) from a large institution. Materials and methodsPatients with mBC who received extra-cranial SBRT to metastatic lesions from 2011 to 2017 were identified. Treatment indications were: oligometastases, oligoprogression, and local control of dominant tumor (CDT). Endpoints included overall survival (OS), progression-free survival (PFS), local control (LC) and cumulative incidence of starting/changing chemo or hormonal therapy (SCT). Univariate and multivariate analyses were used to identify predictive factors. ResultsWe analyzed 120 patients (193 treated metastatic lesions) with a median follow up of 15.25 months. 1-and 2-year LC rates were 89% and 86.6%, respectively. 1-and 2-year OS rates were 83.5% and 70%, respectively, with treatment indication and molecular subtype being the predictive factors on MVA. 1-year OS was 91.0%, 78.5% and 63.9% for oligometastases, oligoprogression and CDT, respectively (p = 0.003). The worst OS was seen in basal subtype with 1-and 2-year OS rates of 59.2% and 39.5% (p = 0.01). Treatment indication was found to be predictive for PFS and lower rates of SCT on MVA. 1-and 2-year PFS rates were 45% and 32%, respectively. The 1-year PFS for oligometastases, oligoprogression, and CDT was 66%, 19.6%, and 14.3%, respectively (p < 0.001). The cumulative incidence of SCT at 1-year was 12% for oligometastases, 39.7% for oligoprogression and 53.3% for CDT (p < 0.001). ConclusionPatients treated for oligometastases have better OS and PFS than those treated for oligoprogression or CDT. SBRT may delay SCT in mBC patients, particularly those with oligometastases. SBRT provided an excellent LC in mBC patients.