Prospective study on stereotactic body radiotherapy for small pancreatic neuroendocrine tumors: tolerance and effectiveness analysis.

INTRODUCTION: Surgery is the standard treatment for pancreatic neuroendocrine tumors (pNETs), obtaining favorable results but associating high morbidity and mortality rates. This study assesses stereotactic body radiation therapy (SBRT) as a radical approach for small (< 2 cm) nonfunctioning pNETs. MATERIALS AND METHODS: From January 2017 to June 2023, 20 patients with small pNETs underwent SBRT in an IRB-approved study. Endpoints included local control, tolerance, progression-free survival, and overall survival (OS). Diagnostic assessments comprised endoscopy, CT scans, OctreScan or PET-Dotatoc, abdominal MRI, and histological confirmatory samples. RESULTS: In a 30-month follow-up of 20 patients (median age 55.5 years), SBRT was well-tolerated with no grade > 2 toxicity. 40% showed morphological response, 55% remained stable. Metabolically, 50% achieved significant improvement. With a median OS of 41.5 months, all patients were alive without local or distant progression or need for surgical resection. CONCLUSION: SBRT is a feasible and well-tolerated approach for small neuroendocrine pancreatic tumors, demonstrating effective local control. Further investigations are vital for validation and extension of these findings.

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) (AU)

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.

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 (AU)

Oral Mucosa in Cancer Patients-Putting the Pieces Together: A Narrative Review and New Perspectives.

The oral mucosa is a key player in cancer patients and during cancer treatment. The increasing prevalence of cancer and cancer-therapy-associated side effects are behind the major role that oral mucosa plays in oncological patients. Oral mucositis is a debilitating severe complication caused by the early toxicity of chemo and/or radiotherapy that can restrict treatment outcome possibilities, even challenging a patient's survival. It has been referred to as the most feared cancer treatment complication. Predictive variables as to who will be affected, and to what extent, are still unclear. Additionally, oral mucositis is one of the sources of the increasing economic burden of cancer, not only for patients and their families but also for institutions and governments. All efforts should be implemented in the search for new approaches to minimize the apparently ineluctable outburst of oral mucositis during cancer treatment. New perspectives derived from different approaches to explaining the interrelation between oral mucositis and the oral microbiome or the similarities with genitourinary mucosa may help elucidate the biomolecular pathways and mechanisms behind oral mucosa cancer-therapy-related toxicity, and what is more important is its management in order to minimize treatment side effects and provide enhanced cancer support.

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.

Primary Chemoradiotherapy Treatment (PCRT) for HER2+ and Triple Negative Breast Cancer Patients: A Feasible Combination.

Primary systemic treatment (PST) downsizes the tumor and improves pathological response. The aim of this study is to analyze the feasibility and tolerance of primary concurrent radio−chemotherapy (PCRT) in breast cancer patients. Patients with localized TN/HER2+ tumors were enrolled in this prospective study. Radiation was delivered concomitantly during the first 3 weeks of chemotherapy, and it was based on a 15 fractions scheme, 40.5 Gy/2.7 Gy per fraction to whole breast and nodal levels I-IV. Chemotherapy (CT) was based on Pertuzumab−Trastuzumab−Paclitaxel followed by anthracyclines in HER2+ and CBDCA-Paclitaxel followed by anthracyclines in TN breast cancers patients. A total of 58 patients were enrolled; 25 patients (43%) were TN and 33 patients HER2+ (57%). With a median follow-up of 24.2 months, 56 patients completed PCRT and surgery. A total of 35 patients (87.5%) achieved >90% loss of invasive carcinoma cells in the surgical specimen. The 70.8% and the 53.1% of patients with TN and HER-2+ subtype, respectively, achieved complete pathological response (pCR). This is the first study of concurrent neoadjuvant treatment in breast cancer in which three strategies were applied simultaneously: fractionation of RT (radiotherapy) in 15 sessions, adjustment of CT to tumor phenotype and local planning by PET. The pCR rates are encouraging.

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.

Postmastectomy radiation therapy in early breast cancer: Utility or futility?

Postmastectomy radiation therapy (PMRT) has been shown to reduce the risk of locoregional recurrence (LRR), in patients with locally advanced breast cancer who are considered of high-risk because of large tumors (>5 cm) or presence of axillary lymph-node involvement, as well as to reduce breast cancer mortality. However, controversy still remains with respect to indication of PMRT in case of early-stages invasive tumors. This review aims to analyze the impact that PMRT has on final results in women with breast tumors in different scenarios that would otherwise be considered as early breast cancer, such as extensive DCIS, tumors without axillary lymph-node involvement or with minimal microscopic nodal-involvement. The existence of risk factors including young age, premenopausal status, and presence of lymphovascular invasion (LVI), high grade or tumor size >2 cm has been associated with an increased risk of LRR in these patients at early-stages and advises to consider PMRT in selected cases.

Radiotherapy for ostheoarticular degenerative disorders: When nothing else works.

Objectives: Show the results in pain and functionality, using low-dose radiotherapy in osteoarticular degenerative disorders (OADD). Review of the evidence. Material and methods: Patients suffering from OADD with no response to other treatments, receive 6Gy in 6 fractions of 1 Gy, each other day, repeating the scheme if necessary. Evaluation of pain based on Visual Analogic Scale, analgesia intake and VonPannewitz score. Results: Results observed in our series of patients treated with low doses of radiotherapy are similar to those previously published and reinforce the consideration of radiotherapy as an useful option for degenerative musculoskeletal disorders. Conclusion: Low dose radiotherapy seems to be a good alternative for aged patients suffering from OADD.

Complete pathological responses in locally advanced rectal cancer after preoperative IMRT and integrated-boost chemoradiation.

BACKGROUND AND PURPOSE: To analyze the efficacy and safety of a new preoperative intensity-modulated radiotherapy (IMRT) and integrated-boost chemoradiation scheme. PATIENTS AND METHODS: In all, 74 patients were treated with IMRT and concurrent standard dose capecitabine. The dose of the planning target volume (PTV) encompassing the tumor, mesorectum, and pelvic lymph nodes was 46 Gy in 23 fractions; the boost PTV, at a dose of 57.5 Gy in 23 fractions, included the macroscopic primary tumor and pathological lymph nodes. The patients underwent surgery 6-8 weeks after chemoradiation. RESULTS: The complete treatment data of 72 patients were analyzed. Tumor downstaging was achieved in 55 patients (76.38 %) and node downstaging in 34 (47.2 %). In 22 patients (30.6 %), there was complete pathological response (ypCR). The circumferential resection margin was free of tumor in 70 patients (97.2 %). The 3-year estimated overall survival and disease-free survival rates were 95.4 and 85.9 % respectively, and no local relapse was found; however, ten patients (13.8 %) developed distant metastases. High pathologic tumor (pT) downstaging was shown as a favorable prognostic factor for disease-free survival. No grade 4 acute radiotherapy-related toxicity was found. CONCLUSIONS: The IMRT and integrated-boost chemoradiation scheme offered higher rates of ypCR and pT downstaging, without a significant increase in toxicity. The circumferential margins were free of tumors in the majority of patients. Primary tumor regression was associated with better disease-free survival.

Institutional experience on the treatment of lung and liver lesions with stereotactic body radiotherapy and Novalis Exactrac Adaptive Gating technique.

INTRODUCTION: Gating technique can improve the accuracy of the treatment of lung and liver lesions with SBRT, by monitoring organ tumor motion and irradiating within a selected area of the respiratory cycle. METHODS: We have treated 75 patients (34 lung and 41 liver) with Novalis LINAC SBRT Adaptive Gating Technique. A total of 130 lesions, 49 lung lesions (11 primary NSCLC and 38 metastases) and 81 liver lesions (10 primary and 71 metastases). Prior to treatment, a fiducial marker is implanted and CT simulation is performed in breatholding with infrared external skin markers. Based on these external markers, internal tumor motion is correlated with the external respiratory signal. The outlined PTV includes (CTV=GTV) + 5 mm margin. The following doses are prescribed: liver (5Gy x 10 or 12-20Gy x 3), peripheral lung lesions (15-20 Gy x 3), and central lung lesions (5Gy x 10 or 10 Gy x5). The dose was delivered with multiple coplanar static beams. During patient setup, infrared markers track the respiratory cycle. Exactrac X-Rays localize the internal marker, quantify the tumor movement, and define the "beam on area" by correlating the external marker motion to the internal marker position. Intrafraction verification of the validity of this model is performed in real time by ExacTrac X-Rays. RESULTS: 130 lesions were evaluated with 90.5% local control at two years [93.8% in lung and 87.3% in liver lesions]. Clinical tolerance was excellent and no lung or liver toxicity grade 3 was observed. CONCLUSION: Our clinical experience with Novalis SBRT Adaptive Gating shows that this technique is safe and efficient for the treatment of lung and liver lesions, while reducing the volume of irradiated healthy tissue. Intrafraction verification improves the treatment accuracy by a real time verification of tumor position.