Stereotactic Radiotherapy In Patients Research Articles

Long-Term Results of Stereotactic Radiotherapy in Patients with at Least 10 Brain Metastases at Diagnosis.

to evaluate an SRT approach in patients with at least 10 lesions at the time of BM initial diagnosis. This is a monocentric prospective cohort of patients treated by SRT, followed by a brain MRI every two months. Subsequent SRT could be delivered in cases of new BMs during follow-up. The main endpoints were local control rate (LCR), overall survival (OS), and strategy success rate (SSR). Acute and late toxicity were evaluated. Seventy patients were included from October 2014 to January 2019, and the most frequent primary diagnosis was non-small-cell lung cancer (N = 36, 51.4%). A total of 1174 BMs were treated at first treatment, corresponding to a median number of 14 BMs per patient. Most of the patients (N = 51, 72.6%) received a single fraction of 20-24 Gy. At 1 year, OS was 62.3%, with a median OS of 19.2 months, and SSR was 77.8%. A cumulative number of 1537 BM were treated over time, corresponding to a median cumulative number of 16 BM per patient. At 1-year, the LCR was 97.3%, with a cumulative incidence of radio-necrosis of 2.1% per lesion. Three patients (4.3%) presented Grade 2 toxicity, and there was no Grade ≥ 3 toxicity. The number of treated BMs and the treatment volume did not influence OS or SSR (p > 0.05). SRT was highly efficient in controlling the BM, with minimal side effects. In this setting, an SRT treatment should be proposed even in patients with ≥10 BMs at diagnosis.

How Does the Number of Brain Metastases Correlate With Normal Brain Exposure in Single-Isocenter Multitarget Multifraction Stereotactic Radiosurgery

PurposeTo investigate the relationship between normal brain exposure in linac-based single-isocenter multi-target multi-fraction stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) and the number or volume of treated brain metastases, especially for high numbers of metastases. Methods and MaterialsA cohort of 44 SRT patients with 709 brain metastases was studied. Renormalizing to a uniform prescription of 27 Gy in 3 fractions, normal brain dose volume indices, including V23Gy (volume receiving >23Gy), V18Gy (volume receiving >18Gy), and mean dose, were evaluated on these plans against the number and the total volume of targets for each plan. To compare with exposures from whole-brain radiotherapy (WBRT), the SRT dose distributions were converted to equivalent dose in 3 Gy fractions (EQD3) using an alpha-beta ratio of 2 Gy. ResultsWith increasing number of targets and increasing total target volume, normal brain exposures to dose ≥18 Gy increases, and so does the mean normal brain dose. The factors of number of targets and total target volume are both significant, though the number of targets has a larger effect on the mean normal brain dose and the total target volume has a larger effect on V23Gy and V18Gy. The EQD3 mean normal brain dose with SRT planning is lower than conventional WBRT. On the other hand, SRT results in higher hot spot (i.e. maximum dose outside of tumor) EQD3 dose than WBRT. ConclusionsBased on clinical SRT plans, our study provides information on correlations between normal brain exposure and the number and total volume of targets. As SRT becomes more greatly utilized for patients with increasingly extensive brain metastases, more clinical data on outcomes and toxicities is necessary to better define the normal brain dose constraints for high-exposure cases and to optimize the SRT management for those patients.

Efficacy and Safety of Stereotactic Radiotherapy in Patients With Recurrent Ventricular Tachycardias: The Czech Experience

BackgroundStereotactic arrhythmia radiotherapy (STAR) has been proposed recently in patients with refractory ventricular tachycardia (VT). ObjectivesThe purpose of this study was to describe the efficacy and safety of STAR in the Czech Republic. MethodsVT patients were recruited in 2 expert centers after at least 1 previously failed catheter ablation (CA). A precise strategy of target volume determination and CA was used in 17 patients treated from December 2018 until June 2022 (EFFICACY cohort). This group, together with an earlier series of 19 patients with less-defined treatment strategies, composed the SAFETY cohort (n = 36). A dose of 25 Gy was delivered. ResultsIn the EFFICACY cohort, the burden of implantable cardioverter-defibrillator therapies decreased, and this drop reached significance for direct current shocks (1.9 ± 3.2 vs 0.1 ± 0.2 per month; P = 0.03). Eight patients (47%) underwent repeated CA for recurrences of VT during 13.7 ± 11.6 months. In the SAFETY cohort (32 procedures, follow-up >6 months), 8 patients (25%) presented with a progression of mitral valve regurgitation, and 3 (9%) required intervention (median follow-up of 33.5 months). Two cases of esophagitis (6%) were seen with 1 death caused by the esophago-pericardial fistula (3%). A total of 18 patients (50%) died during the median follow-up of 26.9 months. ConclusionsAlthough STAR may not be very effective in preventing VT recurrences after failed CA in an expert center, it can still modify the arrhythmogenic substrate, and when used with additional CA, reduce the number of implantable cardioverter-defibrillator shocks. Potentially serious sides effects require close follow-up.

Stereotactic radiotherapy of intracranial tumor beds on a ring-mounted Halcyon LINAC.

This study sought to evaluate the feasibility and efficacy of the Halcyon Ring Delivery System (RDS) for delivering stereotactic radiotherapy (SRT) treatments for intracranial tumors beds. Ten previously treated brain SRT patients for 30Gy in five fractions with non-coplanar HyperArc plans on TrueBeam (6MV-FFF) were replanned on Halcyon (6MV-FFF) using the same number of arcs and Eclipse's AcurosXB dose engine. Plan quality evaluation metrics per SRT protocol included: PTV coverage, GTV dose (minimum and mean), target conformity indices (CI), heterogeneity index (HI), gradient index (GI), maximum dose 2cm away from the PTV (D2cm ), and doses to organs-at-risk (OAR). Additionally, patient-specific quality assurance (QA) results and beam-on-time (BOT) were analyzed. The Halcyon RDS provided highly conformal SRT plans for intracranial tumor beds with similar dose to target. When benchmarked against clinically delivered HyperArc plans, target coverage, CI(s) and HI were statistically similar. The Halcyon plans saw no statistical difference in maximum OAR doses to the brainstem, spinal cord, and cochlea. Due to the machine's coplanar geometry, the Halcyon plans showed a decrease in optic pathway dose (0.75Gy vs. 2.08Gy, p=0.029). Overall, Halcyon's coplanar geometry resulted in a larger GI (3.33vs. 2.72, p=0.008) and a larger D2cm (39.59%vs. 29.07%, p<0.001). In this cohort, multiple cases had the PTV and the optic pathway in the same axial plane. In one such instance, the PTV was<2cm away from the optic pathway but even at this close proximity OAR, Halcyon still adequately spared the optic pathway. Additionally, the Halcyon's geometry provided slightly larger amount of normal brain dose receiving 24.4Gy (8.99 cc vs. 7.36 cc) and 28.8Gy (2.9 cc vs. 2.5 cc), although statistically insignificant. The Halcyon plans achieved similar delivery accuracy, quantified by patient-specific QA results evaluated with a 2%/2mm gamma criteria (99.42%vs. 99.70%). For both plans, independent Monte Carlo second checks calculation agreed within 1%. Average Halcyon BOT was slightly higher by 0.35min (p=0.045), however, due to the one-step patient set-up and verification overall estimated treatment times on Halcyon were lower compared to HyperArc treatments (7.61min vs. 10.26min, p<0.001). When benchmarked against clinically delivered HyperArc treatments, the Halcyon brain SRT plans provided similar plan quality and delivery accuracy but achieved faster overall treatment times. We have started treating select brain SRT patients on the Halcyon RDS for patients having tumor beds greater than 1cm in diameter with the closest OAR distance of greater than 2cm away from the target. We recommend other clinics to consider commissioning SRT treatments on their Halcyon systems-allowing including remote Halcyon-only clinics to provide exceptionally high-quality therapeutic brain SRT treatments to an otherwise underserved patient cohort.

Dose-effect relationship of linear accelerator based stereotactic radiotherapy for brain metastases

ObjectiveThe purpose of this study is to reveal the dose-effect relationship of linear accelerator (LINAC)-based stereotactic radiotherapy (SRT) in patients with brain metastases (BM).Materials and methodsThe PubMed, Cochrane, and Web of Science databases were used to identify studies that reported local tumour control after LINAC-based SRT in patients with BMs. Studies of other approaches that could affect local tumour control, such as whole brain radiotherapy, targeted therapy, and immunotherapy, were excluded from the dose-effect relationship analysis. Data extracted included patient and treatment characteristics and tumour local control. Probit model in XLSTAT 2016 was used for regression analysis, and P < 0.05 was set as the statistically significant level.ResultsAfter literature screening, 19 eligible studies involving 1523 patients were included in the probit model regression analysis. There was no significant dose-effect relationship between nominal BED10 and peripheral BED10 versus 12-month local control probability. There were significant dose effect relationships between the centre BED10 and the average BED10 versus the 12-month local control probability, with P values of 0.015 and 0.011, respectively. According to the model, the central BED10 and the average BED10 corresponding to probabilities of 90% 12-month local control were 109.2 GyBED10 (95% confidence interval (CI): 88.7–245.9 GyBED10) and 87.8 GyBED10 (95% CI: 74.3–161.5 GyBED10), respectively. A 12-month local control rate of 86.9% (95% CI: 81.7–89.7%) and 85.5% (95% CI: 81.2–89.2%) can be expected at a centre BED10 of 80 Gy and an average BED10 of 60 Gy, respectively.ConclusionFor patients with BM treated with LINAC-based SRT, more attention should be given to the central and average doses of PTV. A clear definition of the dose prescription should be established to ensure the effectiveness and comparability of treatment.

Stereotactic Radiotherapy (SRT) in Combination with Aumolertinib to Treat Intracranial Oligometastatic Non-Small Cell Lung Cancer (NSCLC): An Update of a Phase II, Prospective Study

Stereotactic radiotherapy (SRT) is highly effective and less toxic for limited intracranial metastases. Aumolertinib is a tolerable third-generation epidermal growth factor receptor tyrosine kinase inhibitor that has CNS efficacy in patients with EGFR-mutant NSCLC. We aim to investigate the efficacy and safety of aumolertinib followed by SRT in patients with intracranial oligometastatic NSCLC. Intracranial oligometastatic Patients with EGFR sensitive mutations (EGFR-TKIs naive) were enrolled and received aumolertinib 110mg daily until intracranial disease progression. Then SRT (32-40 Gy total, 8 Gy/f) was given to intracranial oligo-progression disease if possible. The primary endpoint was intracranial objective response rate (iORR). Secondary endpoints included intracranial progression-free survival (iPFS), intracranial duration of response (iDOR)according to RECIST 1.1, cerebral radiation necrosis rate (CRNR) and overall survival (OS). Safety was evaluated according to Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0). This trial is registered with ClinicalTrials.gov, NCT04519983. To February 10, 2023, a total of 38 patients were enrolled and 35 patients were assessable followed for 3 months to 18 months. All patients received 110mg aumolertinib daily and received at least one independent imaging evaluation by a radiologist. After oral administration of aumolertinib, the best response of 94% patients in intracranial and extracranial lesions was partial response (PR). Two patients had stable intracranial disease. At data cut-off, one patient developed intracranial primary lesion progression at 12 months after oral administration of aumolertinib but stable in extracranial lesions. SRT treatment was given to this patient. No grade ≥3 adverse events occurred after continued oral administration of aumolertinib. The most common adverse reactions were rash and abnormal liver enzymes, 1 patient had grade 2 CK elevation. This report showed pronounced intracranial objective response benefit in patients with intracranial oligometastatic disease followed by SRT after intracranial oligo-progression and no new safety signals. Aumolertinib has promising efficacy and good tolerability in intracranial oligometastatic EGFR mutated NSCLC. [Keywords] Non-small cell lung cancer; epidermal growth factor receptor tyrosine kinase inhibitor; Aumolertinib; Stereotactic radiotherapy.

Intraoperative or postoperative stereotactic radiotherapy for brain metastases: time to systemic treatment onset and other patient-relevant outcomes

PurposeIntraoperative radiotherapy (IORT) has become a viable treatment option for resectable brain metastases (BMs). As data on local control and radiation necrosis rates are maturing, we focus on meaningful secondary endpoints such as time to next treatment (TTNT), duration of postoperative corticosteroid treatment, and in-hospital time.MethodsPatients prospectively recruited within an IORT study registry between November 2020 and June 2023 were compared with consecutive patients receiving adjuvant stereotactic radiotherapy (SRT) of the resection cavity within the same time frame. TTNT was defined as the number of days between BM resection and start of the next extracranial oncological therapy (systemic treatment, surgery, or radiotherapy) for each of the groups.ResultsOf 95 BM patients screened, IORT was feasible in 84 cases (88%) and ultimately performed in 64 (67%). The control collective consisted of 53 SRT patients. There were no relevant differences in clinical baseline features. Mean TTNT (range) was 36 (9 − 94) days for IORT patients versus 52 (11 − 126) days for SRT patients (p = 0.01). Mean duration of postoperative corticosteroid treatment was similar (8 days; p = 0.83), as was mean postoperative in-hospital time (11 versus 12 days; p = 0.97). Mean total in-hospital time for BM treatment (in- and out-patient days) was 11 days for IORT versus 19 days for SRT patients (p < 0.001).ConclusionIORT for BMs results in faster completion of interdisciplinary treatment when compared to adjuvant SRT, without increasing corticosteroid intake or prolonging in-hospital times. A randomised phase III trial will determine the clinical effects of shorter TTNT.

Impact of magnetic resonance imaging-related geometric distortion of dose distribution in fractionated stereotactic radiotherapy in patients with brain metastases.

The geometric distortion related to magnetic resonance (MR) imaging in adiagnostic radiology (MRDR) and radiotherapy (MRRT) setup is evaluated, and the dosimetric impact of MR distortion on fractionated stereotactic radiotherapy (FSRT) in patients with brain metastases is simulated. An anthropomorphic skull phantom was scanned using a1.5‑T MR scanner, and the magnitude of MR distortion was calculated with (MRDR-DC and MRRT-DC) and without (MRDR-nDC and MRRT-nDC) distortion-correction algorithms. Automated noncoplanar volumetric modulated arc therapy (HyperArc, HA; Varian Medical Systems, Palo Alto, CA, USA) plans were generated for 53patients with 186 brain metastases. The MR distortion at each gross tumor volume (GTV) was calculated using the distance between the center of the GTV and the MR image isocenter (MIC) and the quadratic regression curve derived from the phantom study (MRRT-DC and MRRT-nDC). Subsequently, the radiation isocenter of the HA plans was shifted according to the MR distortion at each GTV (HADC and HAnDC). The median MR distortions were approximately 0.1 mm when the distance from the MIC was < 30 mm, whereas the median distortion varied widely when the distance was > 60 mm (0.23, 0.47, 0.37, and 0.57 mm in MRDR-DC, MRDR-nDC, MRRT-DC, and MRRT-nDC, respectively). The dose to the 98% of the GTV volume (D98%) decreased as the distance from the MIC increased. In the HADC plans, the relative dose difference of D98% was less than 5% when the GTV was located within 70 mm from the MIC, whereas the underdose of GTV exceeded 5% when it was 48 mm (-26.5% at maximum) away from the MIC in the HAnDC plans. Use of adistortion-correction algorithm in the studied MR diagnoses is essential, and the dosimetric impact of MR distortion is not negligible, particularly for tumors located far away from the MIC.

Effectiveness of Robotic Stereotactic Radiotherapy in Patients Undergoing Re-irradiation: A Review.

Stereotactic ablative radiotherapy (SABR) is a possible treatment option for patients who develop recurrence within or at the edge of a previously irradiated volume.Robotic stereotactic radiotherapy is the result of technological advances in robotic precision, real-time imaging, non-invasive, highly customizable treatment plan, and delivery with sub-millimeter accuracy. This article reviews the radiobiologic, technical, and clinical aspects of robotic-based SABR re-irradiation for various anatomical sites. An extensive literature search was performed to identify articles on the utilization of robotic stereotactic radiotherapy for patients undergoing re-irradiation.The reported prescription dose and fractionation data along with outcomes such as overall survival, local control rates, and toxicities were qualitatively reviewed. The findings consistently indicate that re-irradiation using robotic SABR provides encouraging survival rates with minimal toxicity in the clinical setting of various anatomical sites delivered using locally non-invasive means where other treatment options are scarce.

An exploratory analysis of MR-guided fractionated stereotactic radiotherapy in patients with brain metastases

PurposeTo assess the feasibility and potential benefits of online adaptive MR-guided fractionated stereotatic radiotherapy (FSRT) in patients with brain metastases (BMs). Methods and materialsTwenty-eight consecutive patients with BMs were treated with FSRT of 30 Gy in 5 fractions on the 1.5 T MR-Linac. The FSRT fractions employed daily MR scans and the contours were utilized to create each adapted plan. The brain lesions and perilesional edema were delineated on MR images of pre-treatment simulation (Fx0) and all fractions (Fx1, Fx2, Fx3, Fx4 and Fx5) to evaluate the inter-fractional changes. These changes were quantified using absolute/relative volume, Dice similarity coefficient (DSC) and Hausdorff distance (HD) metrics. Planning target volume (PTV) coverage and organ at risk (OAR) constraints were used to compare non-adaptive and adaptive plans. ResultsA total of 28 patients with 88 lesions were evaluated, and 23 patients (23/28, 82.1%) had primary lung adenocarcinoma. Significant tumor volume reduction had been found during FSRT compared to Fx0 for all 88 lesions (median −0.75%, −5.33%, −9.32%, −17.96% and −27.73% at Fx1, Fx2, Fx3, Fx4 and Fx5, p < 0.05). There were 47 (47/88, 53.4%) lesions being accompanied by perilesional edema and the inter-fractional changes were significantly different compared to those without perilesional edema (p < 0.001). Patients with multiple lesions (13/28, 46.4%) had more significant inter-fractional tumor changes than those with single lesion (15/28, 53.6%), including tumor volume reduction and anatomical shift (p < 0.001). PTV coverage of non-adaptive plans was below the prescribed coverage in 26/140 fractions (19%), with 12 (9%) failing by more than 10%. All 140 adaptive fractions met prescribed target coverage. The adaptive plans also had lower dose to whole brain than non-adaptive plans (p < 0.001). ConclusionsSignificant inter-fractional tumor changes could be found during FSRT in patients with BMs treated on the 1.5 T MR-Linac. Daily MR-guided re-optimization of treatment plans showed dosimetric benefit in patients with perilesional edema or multiple lesions.

Immunotherapy Plus Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy in Patients with Brain Metastases

1.1. Aim: To investigate the association of stereotactic radiosurgery (SRS) plus immunotherapy with overall survival (OS) compared to 3-5 fractions of stereotactic radiation therapy (SRT) plus immunotherapy in patients with brain metastases (BMs) from breast cancer, non-small cell lung cancer (NSCLC), and melanoma.

Improvement of target coverage using automated non-coplanar volumetric modulated arc therapy planning in stereotactic radiotherapy for cervical metastatic spinal tumors.

This study aimed to compare dosimetric parameters for targets and organs at risk (OARs) between volumetric modulated arc therapy (VMAT) and automated VMAT (HyperArc, HA) plans in stereotactic radiotherapy for patients with cervical metastatic spine tumors. VMAT plans were generated for 11 metastases using the simultaneous integrated boost technique to deliver 35 to 40 and 20 to 25 Gy for high dose and elective dose planning target volume (PTVHD and PTVED), respectively. The HA plans were retrospectively generated using 1 coplanar and 2 noncoplanar arcs. Subsequently, the doses to the targets and OARs were compared. The HA plans provided significantly higher (p < 0.05) Dmin (77.4 ± 13.1%), D99% (89.3 ± 8.9%), and D98% (92.5 ± 7.7%) for gross tumor volume (GTV) than those of the VMAT plans (73.4 ± 12.2%, 84.2 ± 9.6 and 87.3 ± 8.8% for Dmin, D99% and D98%, respectively). In addition, D99% and D98% for PTVHD were significantly higher in the HA plans, whereas dosimetric parameters were comparable between the HA and VMAT plans for PTVED. The Dmax values for the brachial plexus, esophagus, and spinal cord were comparable, and no significant difference was observed in the Dmean for the larynx, pharyngeal constrictor, thyroid, parotid grand (left and right), and Submandibular gland (left and right). The HA plans provided significantly higher target coverage of GTV and PTVHD, with a comparable dose for OARs with VMAT plans. The results of this study may contribute to the improvement of local control in clinical practice.

Implementation of triggered kilovoltage imaging for stereotactic radiotherapy of the spine for patients with spinal fixation hardware.

Mitigation of intrafraction motion (IM) is valuable in stereotactic radiotherapy (SRT) radiotherapy where submillimeter accuracy is desired. The purpose of this study was to investigate the application of triggered kilovoltage (kV) imaging for spine SRT patients with hardware by correlating kV imaging with patient motion and summarizing implications of tolerance for IM based on calculated dose. Ten plans (33 fractions) were studied, correlating kV imaging during treatment with pre- and post-treatment cone beam computed tomography (CBCT). Images were taken at 20-degree gantry angle intervals during the arc-based treatment. The contour of the hardware with a 1mm expansion was displayed at the treatment console to manually pause treatment delivery if the hardware was visually detected outside the contour. The treatment CBCTs were compared using retrospective image registration to assess the validity of contour-based method for pausing treatment. Finally, plans were generated to estimate dose volume objective differences in case of 1mm deviation. When kV imaging during treatment was used with the 1mm contour, 100% of the post-treatment CBCTs reported consistent results. One patient in the cohort exhibited motion greater than 1mm during treatment which allowed intervention and re-setup during treatment. The average translational motion was 0.35mm. Treatment plan comparison at 1mm deviation showed little differences in calculated dose for the target and cord. Utilizing kV imaging during treatment is an effective method of assessing IM for SRT spine patients with hardware without increasing treatment time.

Daily irradiation versus irradiation at two- to three-day intervals in stereotactic radiotherapy for patients with 1-5 brain metastases: study protocol for a multicenter open-label randomized phase II trial

BackgroundRadiobiological daily changes within tumors are considered to be quite different between stereotactic radiotherapy (SRT) (e.g., 50 Gy in 4 fractions) and conventional radiotherapy (e.g., 60 Gy in 30 fractions). We aim to assess the optimal interval of irradiation in SRT and compare outcomes of daily irradiation with irradiation at two- to three-day intervals in SRT for patients with one to five brain metastases (BM).MethodsThis study is conducted as a multicenter open-label randomized phase II trial. Patients aged 20 or older with one to five BM, less than 3.0 cm diameter, and Karnofsky Performance Status ≥70 are eligible. A total of 70 eligible patients will be enrolled. After stratifying by the number of BMs (1, 2 vs. 3–5) and diameter of the largest tumor (< 2 cm vs. ≥ 2 cm), we randomly assigned patients (1:1) to receive daily irradiation (Arm 1), or irradiation at two- to three-day intervals (Arm 2). Both arms are performed with total dose of 27-30 Gy in 3 fractions. The primary endpoint is an intracranial local control rate, defined as intracranial local control at initially treated sites. We use a randomized phase II screening design with a two-sided α of 0∙20. The phase II trial is positive with p < 0.20. All analyses are intention to treat. This study is registered with the UMIN-clinical trials registry, number UMIN000048728.DiscussionThis study will provide an assessment of the impact of SRT interval on local control, survival, and toxicity for patients with 1–5 BM. The trial is ongoing and is recruiting now.Trial registrationUMIN000048728. Date of registration: August 23, 2022.https://center6.umin.ac.jp/cgi-bin/ctr/ctr_view_reg.cgi?recptno=R000055515.

375P Stereotactic radiotherapy (SRT) in combination with aumolertinib to treat intracranial oligometastatic non-small cell lung cancer (NSCLC): A phase II, prospective study

The noval third-generation EGFR-TKI aumolertinib have better initial therapeutic efficacy for intracranial lesions than first-generation TKI. Moreover, Stereotactic radiotherapy (SRT) is highly effective and less toxic for a limited number of intracranial metastases. Research suggested that existing lesions progression were likely to occur before new distant metastasis, so more effective local treatment including SRT after first-line TKIs progression may bring benefits. We aim to investigate the activity and safety of daily aumolertinib followed by SRT in patients with intracranial oligometastatic NSCLC.

Experience with stereotactic r adiation therapy for liver oligometastases of colorectal cancer

Introduction: The problem of treating patients with unresectable liver metastases of colon cancer is currently far f rom being solved. One possible approach is the use of stereotactic body radiotherapy.The purpose of this study was to evaluate the immediate and long-term results of stereotactic radiotherapy in patients with colorectal cancer and oligometastatic liver metastases.Methods: This study was designed as a retro-prospective, open-label, controlled, non-randomized clinical trial. We assessed one-year local control, one-year overall survival, progression-free survival, and toxicity in 60 patients with oligometastatic liver disease from colorectal cancer who underwent stereotactic body radiotherapy, with median dose of 54 Gy.Results: The median follow-up was 20,1 months. One-year local control (LC) was 73,7 % (95 % CI = 62,7–86,6 %). Oneyear overall survival (OS) was 92,8 % (95 % CI = 86,3–99,9 %), one-year progression-free survival (PFS) was 31,3 % (95 % CI = 21,1–46,4 %) with a median of 8,1 months. Grade ≥ 3 toxicity was not noted. No cases of radiation-induced liver failure were observed. Radiation dose (HR = 0.88, 95 % CI = 0.81–0.95, p = 0.00087), metastasis size (HR = 1.51, 95 % CI = 1.07–2.12, p = 0.01858) and their number (HR = 1.8, 95 % CI = 1.01–3.22, p = 0.04669) are significant risk factors for LC. Metastasis size &gt; 3 cm is a significant risk factor for LC (HR = 5.5, 95 % CI = 1.7–17.9, p = 0.005) and OS (HR = 3.8, 95 % CI = 1.3–11.7, p = 0.02).Conclusion: Stereotactic body radiotherapy is an effective and safe method of providing local control of oligometastatic liver metastases in colorectal cancer as part of a combined treatment approach. Further studies are required to individualize the indications for this treatment method.

Initial clinical experience of surface guided stereotactic radiation therapy with open-face mask immobilization for improving setup accuracy: a retrospective study

PurposeTo propose a specific surface guided stereotactic radiotherapy (SRT) treatment procedure with open-face mask immobilization and evaluate the initial clinical experience in improving setup accuracy.Methods and materialsThe treatment records of 48 SRT patients with head lesions were retrospectively analyzed. For each patient, head immobilization was achieved with a double-shell open-face mask. The anterior shell was left open to expose the forehead, nose, eyes and cheekbones. The exposed facial area was used as region-of-interest for surface tracking by AlignRT (VisionRT Inc, UK). The posterior shell provided a sturdy and personalized headrest. Patient initial setup was guided by 6DoF real-time deltas (RTD) using the reference surface obtained from the skin contour delineated on the planning CT images. The endpoint of initial setup was 1 mm in translational RTD and 1 degree in rotational RTD. CBCT guidance was performed to derive the initial setup errors, and couch shifts for setup correction were applied prior to treatment delivery. CBCT couch shifts, AlignRT RTD values, repositioning rate and setup time were analyzed.ResultsThe absolute values of median (maximal) CBCT couch shifts were 0.4 (1.3) mm in VRT, 0.1 (2.5) mm in LNG, 0.2 (1.6) mm in LAT, 0.1(1.2) degree in YAW, 0.2 (1.4) degree in PITCH and 0.1(1.3) degree in ROLL. The couch shifts and AlignRT RTD values exhibited highly agreement except in VRT and PITCH (p value < 0.01), of which the differences were as small as negligible. We did not find any case of patient repositioning that was due to out-of-tolerance setup errors, i.e., 3 mm and 2 degree. The surface guided setup time ranged from 52 to 174 s, and the mean and median time was 97.72 s and 94 s respectively.ConclusionsThe proposed surface guided SRT procedure with open-face mask immobilization is a step forward in improving patient comfort and positioning accuracy in the same process. Minimized initial setup errors and repositioning rate had been achieved with reasonably efficiency for routine clinical practice.

Treatment response in prostatic neoplastic lesions using CyberKnife (stereotactic body radiation therapy)

Objective: To evaluate the treatment response of CyberKnife stereotactic radiotherapy in patients with prostatic neoplastic lesions.Patients and methods: This prospective observational study was conducted at Radiology and Cyberknife Robotic Radiosurgery Department of Jinnah Post Graduate Medical Centre (JPMC), Karachi from 22nd June 2019 to 21st June 2020. Males with biopsy-proven prostatic adenocarcinoma with age 55 years or more having Gleason's score of 6 to 8, clinical stage of T1 to T2C, and prostate-specific antigen (PSA) of ≤30 ng/ml were consecutively enrolled. Detailed information regarding PSA concentration, Gleason score, T stage, risk group and ADT (Androgen Deprivation Therapy) usage were noted which were given to high risk patients only for 9 months. Drop in the PSA (biochemical marker) was assessed at baseline, at 3 months and 6 months follow-up.Results: The median age of the patients was 65 years. The overall median PSA level was 2.7 (0.86-7.3) ng/ml. Majority 49 (90.7%) patients presented with T2 N0 M0 TNM status while only 5 (9.3%) patients presented with T1 N0 M0 TNM status. There were 5 (9.3%) patients with high risk, 26 (48.1%) with intermediate risk, and 23 (42.6%) with low risk. ADT was received by 5 (9.3%) patients. The median PSA at baseline was 10.1 (6.9-18.1) ng/ml which significantly drops to 1.6 (0.8-3.6) ng/ml at 3rd months, and 0.4 (0.2-1.2) at 6th months (p-value &lt;0.01).Conclusion: The findings showed an adequate treatment response of CyberKnife stereotactic radiotherapy of patients with prostatic neoplastic lesions.

Promising outlook with sugemalimab in non-small-cell lung cancer.

Anti-PD-L1 (durvalumab) immunotherapy after chemotherapy with external beam radiotherapy (ie, the PACIFIC regimen) is standard care for patients with unresectable stage III non-small-cell lung cancer (NSCLC). In the PACIFIC trial, 1 Faivre-Finn C Vicente D Kurata T et al. Four-year survival with durvalumab after chemoradiotherapy in stage III NSCLC—an update from the PACIFIC trial. J Thorac Oncol. 2021; 16: 860-867 Summary Full Text Full Text PDF PubMed Scopus (153) Google Scholar this regimen showed durable progression-free survival, with the estimated number of randomly assigned patients who remained alive at 4 years being 50% in the group that received 12 months of anti-PD-L1 consolidation therapy using durvalumab following chemotherapy plus concurrent radiotherapy versus 36% in patients who received placebo alone. Preclinical studies have shown that radiotherapy can boost anti-tumour immune response and overcome resistance to current immunotherapies. Clinical studies have shown improved responsiveness to pembrolizumab (anti-PD-1 antibody) in metastatic NSCLC, and to durvalumab (anti-PD-L1 antibody) in operable NSCLC. In the PEMBRO-RT and MDACC trials, 2 Theelen W Chen D Verma V et al. Pembrolizumab with or without radiotherapy for metastatic non-small-cell lung cancer: a pooled analysis of two randomised trials. Lancet Respir Med. 2021; 9: 467-475 Summary Full Text Full Text PDF PubMed Scopus (98) Google Scholar the best abscopal response (for non-irradiated lesions) was 20% with pembrolizumab versus 42% with pembrolizumab plus radiotherapy (odds ratio 2·96, 95% CI 1·42–6·20; p=0·0039). Median progression-free survival was 4·4 months (95% CI 2·9–5·9) with pembrolizumab alone versus 9·0 months (6·8–11·2) with pembrolizumab plus radiotherapy (hazard ratio [HR] 0·67, 95% CI 0·45–0·99; p=0·045). 2 Theelen W Chen D Verma V et al. Pembrolizumab with or without radiotherapy for metastatic non-small-cell lung cancer: a pooled analysis of two randomised trials. Lancet Respir Med. 2021; 9: 467-475 Summary Full Text Full Text PDF PubMed Scopus (98) Google Scholar In a phase 2 trial comparing neoadjuvant durvalumab alone versus neoadjuvant durvalumab plus stereotactic radiotherapy in patients with resectable early-stage NSCLC (clinical stages I–IIIA), a major pathological response was observed in 7% of the durvalumab alone group versus 53% of the durvalumab plus radiotherapy group. 3 Altorki NK McGraw TE Borczuk AC et al. Neoadjuvant durvalumab with or without stereotactic body radiotherapy in patients with early-stage non-small-cell lung cancer: a single-centre, randomised phase 2 trial. Lancet Oncol. 2021; 22: 824-835 Summary Full Text Full Text PDF PubMed Scopus (59) Google Scholar Sugemalimab versus placebo, in combination with platinum-based chemotherapy, as first-line treatment of metastatic non-small-cell lung cancer (GEMSTONE-302): interim and final analyses of a double-blind, randomised, phase 3 clinical trialSugemalimab plus chemotherapy showed a statistically significant and clinically meaningful progression-free survival improvement compared with placebo plus chemotherapy, in patients with previously untreated squamous and non-squamous metastatic NSCLC, regardless of PD-L1 expression, and could be a newfirst-line treatment option for both squamous and non-squamous metastatic NSCLC. Full-Text PDF Sugemalimab versus placebo after concurrent or sequential chemoradiotherapy in patients with locally advanced, unresectable, stage III non-small-cell lung cancer in China (GEMSTONE-301): interim results of a randomised, double-blind, multicentre, phase 3 trialSugemalimab after definitive concurrent or sequential chemoradiotherapy could be an effective consolidation therapy for patients with stage III NSCLC whose disease has not progressed after sequential or concurrent chemoradiotherapy. Longer follow-up is needed to confirm this conclusion. Full-Text PDF

Stereotactic radiotherapy of breast cancer liver metastases

Stereotactic body radiation therapy currently occupies its place in the complex treatment of cancer patients with liver metastases. It is assumed that certain groups of patients with breast cancer can benefit from the use of this method, which can be converted into improved overall survival and survival rates without signs of progression of the process. Purpose of the study was to evaluate the efficacy and tolerability of stereotactic radiotherapy in patients with breast cancer metastases in the liver. We have analyzed the results of using stereotactic radiotherapy in 25 breast cancer patients with 43 liver metastases. The treatment was carried out in 3 fractions with a fraction dose of 10-15 Gy and a total dose of 30-45 Gy. Growth of the irradiated lesions was recorded only in 1 case out of 43 metastases (2,3%) and 25 (4%) patients. 1-, 3- and 5-year overall survival rates from the moment of stereotactic radiotherapy were 82,9%, 62% and 38,7%, respectively. Long-term post-radiation adverse events were observed in 8% of cases and did not have a significant effect on the quality of life and the possibility of antitumor treatment. So stereotactic radiotherapy can be recommended as a relatively safe and highly effective method of elimination of breast cancer liver metastases. Taking into account the high achieved local control, further studies on dose escalation in this group of patients are not required.