SBRT-SG-01: final results of a prospective multicenter study on stereotactic body radiotherapy for liver metastases.

OBJECTIVE: This study aimed to assess the efficacy and tolerability of stereotactic body radiation therapy (SBRT) for the treatment of liver metastases. METHODS: Patients with up to 5 liver metastases were enrolled in this prospective multicenter study and underwent SBRT. Efficacy outcomes included in-field local control (LC), progression-free survival (PFS), and overall survival (OS). Acute and late toxicities were evaluated using CTCAE v.4.0. RESULTS: A total of 52 patients with 105 liver metastases were treated between 2015 and 2018. The most common primary tumor was colorectal cancer (72% of cases). Liver metastases were synchronous with the primary tumor diagnosis in 24 patients (46.2%), and 21 patients (40.4%) presented with other extrahepatic oligometastases. All patients underwent intensity-modulated radiation therapy (IMRT)/volumetric-modulated arc therapy (VMAT) with image-guided radiation therapy (IGRT) and respiratory gating, and a minimum biologically effective dose (BED10Gy) of 100 Gy was delivered to all lesions. With a median follow-up of 23.1 months (range: 13.4-30.9 months) since liver SBRT, the median actuarial local progression-free survival (local-PFS) was not reached. The actuarial in-field LC rates were 84.9% and 78.4% at 24 and 48 months, respectively. The median actuarial liver-PFS and distant-PFS were 11 and 10.8 months, respectively. The actuarial median overall survival (OS) was 27.7 months from SBRT and 52.5 months from metastases diagnosis. Patients with lesion diameter ≤ 5 cm had significantly better median liver-PFS (p = 0.006) and OS (p = 0.018). No acute or late toxicities of grade ≥ 3 were observed. CONCLUSIONS: This prospective multicenter study confirms that liver SBRT is an effective alternative for the treatment of liver metastases, demonstrating high rates of local control and survival while maintaining a low toxicity profile.

Ultra-hypofractionated one-week locoregional radiotherapy for patients with early breast cancer: Acute toxicity results.

Purpose: Moderate hypofractionated radiotherapy is the standard of care for all patients with breast cancer, irrespective of stage or prior treatments. While extreme hypofractionation is accepted for early-stage tumours, its application in irradiating locoregional lymph nodes remains controversial. Materials and methods: A prospective registry analysis from July 2020 to September 2023 included 276 patients with early-stage breast cancer treated with one-week ultra-hypofractionation (UHF) at 26 Gy in 5 fractions on the whole breast (58.3 %) or thoracic wall (41.7 %) and ipsilateral regional lymph nodes and simultaneous integrated boost (58.3 %). Primary endpoint was assessment of acute adverse events (AEs). Secondarily, onset of early-delayed toxicity was assessed. A minimum 6-month follow-up was required for assessing potential treatment-related early-delayed complications. Acute or late complications attributable to treatment were assessed at inclusion using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 criteria. Results: With a median follow-up of 19 months (range 1-49 months), 159 (57.6 %) patients reported AEs, predominantly grade (G) 1 (n = 139, 50.4 %) and G2 (n = 20, 7.8 %). Skin acute toxicity was common (G1/2: 134, G3: 14), while breast oedema occurred in 10 patients (G1: 9, G2: 1), and 15.9 % reported breast pain (G1: 42, G2: 2). Ipsilateral arm oedema was observed in 1.8 % patients. For patients with a follow-up beyond 6 months (n = 213), 23.4 % patients reported G1/G2 skin AEs, 8.8 % had G1/G2 breast/chest wall oedema, and 8.9 % experienced arm lymphedema. There were no cases of brachial plexopathy or G3 toxicity in this group of patients. Conclusions: One-week UHF adjuvant locoregional radiation is well-tolerated, displaying low-toxicity profiles comparable to other studies using similar irradiation schedules.

Moderate hypofractionated radiation therapy and pathologic response for soft tissue sarcomas (STS) of limbs and trunk: experience from a tertiary cancer center.

BACKGROUND: Preoperative radiation therapy following by limb-sparing or conservative surgery is a standard approach for limb and trunk STS. Data supporting hypofractionated radiotherapy schedules are scarce albeit biological sensitivity of STS to radiation would justify it. We sought to evaluate the impact of moderate hypofractionation on pathologic response and its influence on oncologic outcomes. MATERIAL AND METHODS: From October 2018 to January 2023, 18 patients with limb or trunk STS underwent preoperative radiotherapy at a median dose of 52.5 Gy (range 49.5-60 Gy) in 15 fractions of 3.5 Gy (3.3-4 Gy) with or without neoadjuvant chemotherapy. A favorable pathologic response (fPR) was considered as ≥ 90% tumor necrosis on specimen examination. RESULTS: All patients completed planned preoperative radiotherapy. Eleven patients (61.1%) achieved a fPR, and 7 patients (36.8%) a complete pathologic response with total disappearance of tumor cells. Nine patients (47%) developed grade 1-2 acute skin toxicity, and 7 patients (38.8%) had wound complications on follow-up. With a median follow-up of 14 months (range 1-40), no cases of local relapse were observed, and actuarial 3-year overall survival (OS) and distant metastases-free survival (DMFS) are 87% and 76.4%, respectively. In the univariate analysis, the presence of a favorable pathologic response (fPR) was associated with improved 3-year OS (100% vs. 56.03%, p = 0.058) and 3-year DMFS (86.91% vs. 31.46%, p = 0.002). Moreover, both complete or partial RECIST response and radiological stabilization of the tumor lesion showed a significant association with higher rates of 3-year distant metastasis-free survival (DMFS) (83% vs. 83% vs. 56%, p < 0.001) and 3-year overall survival (OS) (100% vs. 80% vs. 0, p = 0.002). CONCLUSIONS: Preoperative moderate hypofractionated radiation treatment for STS is feasible and well tolerated and associates encouraging rates of pathologic response that could have a favorable impact on final outcomes.

Acute skin toxicity of ultra-hypofractionated whole breast radiotherapy with simultaneous integrated boost for early breast cancer.

Background: Whole-breast irradiation (WBI) after breast conserving surgery (BCS) is indicated to improve loco-regional control and survival. Former studies showed that addition of tumor bed boost in all age groups significantly improved local control although no apparent impact on overall survival but with an increased risk of worse cosmetic outcome. Even though shortened regimens in 3 weeks are considered the standard, recent studies have shown the non-inferiority of a treatment regimen of 5 fractions in one-week in both locoregional control and toxicity profile, although simultaneous integrated boost (SIB) in this setting has been scarcely studied. Materials and Methods: From March-2020 to March-2022, 383 patients with early breast cancer diagnosis and a median age of 56 years-old (range 30-99)were included in a prospective registry of ultra-hypofractionated WBI up to a total dose of 26 Gy in 5.2 Gy/fraction with a SIB of 29 Gy in 5.8 Gy/fraction in 272 patients (71%), 30-31 Gy in 6-6.2 Gy/fraction in 111 patients (29%) with close/focally affected margins. Radiation treatment was delivered by conformal 3-D technique in 366 patients (95%), VMAT in 16patients (4%) and conformal 3-D with deep inspiration breath hold (DIBH) in 4patients (1%). Ninety-three per cent of patients received endocrine therapy and 43% systemic or targeted chemotherapy. Development of acute skin complications was retrospectively reviewed. Results: With a median follow-up of 18 months (range 7-31), all patients are alive without evidence of local, regional or distant relapse. Acute tolerance was acceptable, with null o mild toxicity: 182 (48%) and 15 (4%) patients developed skin toxicity grade 1 and 2 respectively; 9 (2%) and 2 (0.5%) patients breast edema grade 1and 2 respectively. No other acute toxicities were observed. We also evaluated development of early delayed complications and observed grade 1 breast edema in 6 patients (2%); grade 1 hyperpigmentation in 20 patients (5%); and grade 1 and 2 breast induration underneath boost region in 10(3%) and 2 patients (0.5%) respectively. We found a statistically significant correlation between the median PTVWBI and presence of skin toxicity (p = 0.028) as well as a significant correlation between late hyperpigmentation with the median PTVBOOST (p = 0.007) and the ratio PTVBOOST/PTVWBI (p = 0.042). Conclusion: Ultra-hypofractionated WBI + SIB in 5 fractions over one-week is feasible and well tolerated, although longer follow-up is necessary to confirm these results.

Stereotactic body radiation therapy (SBRT) for spinal metastases: 12 years of a single center experience.

OBJECTIVE: To assess the clinical outcomes of patients with spine metastases treated with SBRT at our institution. MATERIALS AND METHODS: Patients with spine metastases treated with SBRT (1 fraction/18 Gy or 5 fractions/7 Gy) during the last 12 years have been analyzed. All patients were simulated supine in a vacuum cushion or with a shoulder mask. CT scans and MRI image registration were performed. Contouring was based on International Spine-Radiosurgery-Consortium-Consensus-Guidelines. Highly conformal-techniques (IMRT/VMAT) were used for treatment planning. Intra and interfraction (CBCT or X-Ray-ExacTrac) verification were mandatory. RESULTS: From February 2010 to January 2022, 129 patients with spinal metastases were treated with SBRT [1 fraction/18 Gy (75%) or 5 fractions/7 Gy] (25%). For patients with painful metastases (74/129:57%), 100% experienced an improvement in pain after SBRT. With a median follow-up of 14.2 months (average 22.9; range 0.5-140) 6 patients (4.6%) experienced local relapse. Local progression-free survival was different, considering metastases's location (p < 0.04). The 1, 2 and 3 years overall survival (OS) were 91.2%, 85.1% and 83.2%, respectively. Overall survival was significantly better for patients with spine metastases of breast and prostate cancers compared to other tumors (p < 0.05) and significantly worse when visceral metastases were present (p < 0.05), when patients were metastatic de novo (p < 0.05), and in those patients receiving single fraction SBRT (p: 0.01). CONCLUSIONS: According to our experience, SBRT for patients with spinal metastases was effective in terms of local control and useful to reach pain relief. Regarding the intent of the treatment, an adequate selection of patients is essential to propose this ablative approach.

Real-world efficacy of postoperative radiotherapy with a moderate dose-escalation for phyllodes tumors of the breast.

Background: Phyllodes tumors are rare breast tumors comprising less than 1% of cases, categorized as benign, borderline, or malignant. Treatment typically involves complete surgical excision with wide margins. Adjuvant radiotherapy may be recommended for borderline or malignant tumors, or when clear margins cannot be achieved through surgery alone. Methods: We conducted a retrospective review of 14 women diagnosed with phyllodes tumors between 2015 and 2023. Among them, 36% had benign tumors and 64% had borderline/malignant tumors. The majority (86%) underwent breast-conserving surgery. Postoperative radiation therapy was delivered to the whole breast/chest wall, with a median biologically effective dose (BED) of 92.7 Gy (90.0-102.6 Gy), representing a moderate dose-escalation over conventional breast cancer schedules. Results: After a median follow-up of 48.5 months, no local or distant recurrence were observed. Mild to moderate skin toxicity occurred in all patients: 36% reported grade 1, 43% grade 2, and 21% grade 3 toxicity. One patient developed grade 2 fibrosis during follow-up. No significant correlations were found between the severity of acute/late toxicity and tumor size, surgical approach, or the radiation field's planning target volume (PTV). Conclusions: Adjuvant radiation therapy appears to be well tolerated and feasible for high-risk phyllodes tumors. However, the decision to utilize radiotherapy should be personalized, considering tumor characteristics and the risks and benefits associated with treatment.

Intrafraction target shift comparison using two breath-hold systems in lung stereotactic body radiotherapy.

Background and purpose: In lung Stereotactic Body Radiotherapy (SBRT) respiratory management is used to reduce target motion due to respiration. This study aimed (1) to estimate intrafraction shifts through a Cone Beam Computed Tomography (CBCT) acquired during the first treatment arc when deep inspiration breath-hold (DIBH) was performed using spirometry-based (SB) or surface-guidance (SG) systems and (2) to analyze the obtained results depending on lesion localization. Material and methods: A sample of 157 patients with 243 lesions was analyzed. A total of 860 and 410 fractions were treated using SB and SG. Averaged intrafraction shifts were estimated by the offsets obtained when registering a CBCT acquired during the first treatment arc with the planning CT. Offsets were recorded in superior-inferior (SI), left-right (LR) and anterior-posterior (AP). Significance tests were applied to account for differences in average offsets and variances between DIBH systems. Systematic and random errors were computed. Results: Average offset moduli were 2.4 ± 2.2 mm and 3.5 ± 2.6 mm for SB and SG treatments (p < 0.001). When comparing SB and SG offset distributions in each direction no differences were found in average values (p > 0.3). However, variances were statistically smaller for SB than for SG (p < 0.001). The number of vector moduli offsets greater than 5 mm was 2.1 times higher for SG. Compared to other locations, lower lobe lesions moduli were at least 2.3 times higher. Conclusions: Both systems were accuracy-equivalent but not precision-equivalent systems. Furthermore, the SB system was more precise than the SG one. Despite DIBH, patients with lower lobe lesions had larger offsets than superior lobe ones, mainly in SI.

Radiation therapy with curative intention in men with de novo metastatic prostate carcinoma: shoot'em all!

BACKGROUND: About 5% of prostate cancer cases are metastatic at diagnoses. Radiotherapy of both primary tumor and secondary lesions can be, in addition to systemic treatments, a radical alternative for selected patients. MATERIALS AND METHODS: Patients with de novo prostate carcinoma with bone or lymph node metastases were retrospectively reviewed. All patients received moderate hypofractionated IMRT/VMAT up to 63 Gy in 21 daily fractions of 3 Gy to prostate and metastases with neoadjuvant and concurrent androgen deprivation therapy (ADT). According to known advances some patients also received abiraterone, enzalutamide, or docetaxel. RESULTS: Between 2015-2020, we attended 26 prostate cancer patients (median age 69.5 years, range 52-84) with simultaneous oligometastases [mean 2.1 metastases, median 1.5 metastases (range 1-6)]. Eighteen patients (69%) presented lymph node metastases, 4 (15.5%) bone metastases and 4 (15.5%) both lymph node and bone metastases. With a median follow-up of 15.5 months (range 3-65 months), 16 patients (62%) are alive and tumor free while 10 (38%) are alive with tumor. Four patients (17%) developed tumor progression, out of irradiated area in all cases, with a median time to progression of 43.5 months (range 27-56 months). Actuarial progression-free survival (PFS) rates at 12 and 24 months were 94.1% and 84.7%, respectively. No grade > 2 acute or late complications were recorded. CONCLUSIONS: Simultaneous directed radical hypofractionated radiation therapy for prostate and metastases is feasible, well tolerated and achieves an acceptable PFS rate. However, further studies with longer follow-up are necessary to definitively address these observations.

Radiotherapy CT-based contouring atlas for non-malignant skeletal and soft tissue disorders: a practical proposal from Spanish experience.

OBJECTIVE: Interest in low-dose radiotherapy (LD-RT) for the symptomatic treatment of nonmalignant conditions, including inflammatory and degenerative disorders of the joints and para-articular soft tissues, has increased substantially in recent years. In the present document, we provide a CT-based contouring atlas to help identify and delineate the most common osteoarticular regions susceptible to LD-RT. METHODS: The clinical efficacy of LD-RT is supported by a large body of evidence. However, there is no consensus on the parameters for contouring the planning target volume (PTV). Moreover, 3D simulation and planning should be the standard of care even for nonmalignant disorders. For this reason, the present guidelines were prepared to help guide PTV contouring based on CT images, with the same quality criteria for patient immobilization, treatment simulation, planning and delivery as those routinely applied for cancer radiotherapy. RESULTS: PTV for radiotherapy requires precise identification of the target areas based on CT and other imaging techniques. Using a series of cases treated at our institution, we have defined the PTVs for each location on the simulation CT to establish the relationship between the image and the anatomical structures to be treated. We also specify the immobilization systems used to ensure treatment accuracy and reproducibility. CONCLUSIONS: This comprehensive atlas based on CT images may be of value to radiation oncologists who wish to use LD-RT for the symptomatic treatment of degenerative or inflammatory osteoarticular diseases. ADVANCES IN KNOWLEDGE: The recommendations and contouring atlas described in this article provide an eminently practical tool for LD-RT in non-malignant conditions, based on the same quality criteria recommended for all modern radiotherapy treatments in Spain.

Image guided SBRT for multiple liver metastases with ExacTrac® Adaptive Gating.

AIM: To report the outcome and toxicity of sequential stereotactic body radiotherapy (SBRT) for multiple liver metastases in patients treated with ExacTrac Adaptive Gating. BACKGROUND: In selected patients with a limited number of liver metastases, SBRT has been evaluated as a safe and effective treatment, with minimal toxicity and high rates of local control. MATERIALS AND METHODS: From April 2008 to October 2013, 21 patients with multiple (3-14) liver metastases (n = 101) were treated sequentially with SBRT at our institution. Maximum tumor diameter was 7.5 cm. Prior to treatment, internal markers were placed inside or near the tumor. CT or PET-CT simulation was used for the definition of gross tumor volume (GTV). Median planning target volume was 32.3 cc (3.6-139.3 cc). Treatment consisted of 3 fractions (12-20 Gy/fraction) or 5 fractions (10 Gy/fraction), prescribed to the 90-95% of the PTV volume. Daily intra-fraction image guidance was performed with ExacTrac Adaptive Gating. Regular follow-up included CT or PET-CT imaging. RESULTS: After a median of 23.2 months, the estimated local control rate was 94.4%, 80.6%, 65% and 65% after 1, 2, 3 and 4 years; the median overall survival was 62 months (95% CI 49.12-74.87) and the actuarial survival reached at 60 months was 57.6%. The univariate data analysis revealed that only primary histology other than colorectal adenocarcinoma was shown as an independent significant prognostic factor for local control (p = 0.022). Number of treated metastases did not modify significantly the overall survival (p = 0.51). No toxicity higher than G3 (1 patient with chest wall pain) and no radiation-induced liver disease were observed. CONCLUSIONS: Sequential SBRT with ExacTrac Adaptive Gating for multiple liver metastases can be considered an effective, safe therapeutic option, with a low treatment-related toxicity. Excellent rates of local control and survival were obtained.