Modern Techniques in Re-Irradiation for Locally Recurrent Rectal Cancer: A Systematic Review.

BACKGROUND: Radiotherapy (RT) plays an important role in the treatment of patients with previously irradiated locally recurrent rectal cancer (LRRC). Over the years, numerous technologies and different types of RT have emerged. The aim of our systematic literature review was to determine whether the new techniques have led to improvements in both outcomes and toxicities. METHODS: A computerized search was performed by MEDLINE and the Cochrane database. The studies reported data from patients treated with carbon ion radiotherapy (CIRT), intensity-modulated photon radiotherapy (IMRT), and stereotactic radiotherapy (SBRT). RESULTS: Seven publications of the 126 titles/abstracts that emerged from our search met the inclusion criteria and presented outcomes of 230 patients. OS was reported with rates of 90.0% and 73.0% at 1 and 2 years, respectively; LC was 89.0% and 71.6% at 1 and 2 years after re-RT, respectively. Toxicity data vary widely, with emphasis on acute and chronic gastrointestinal and urogenital toxicity, even with modern techniques. CONCLUSION: data on toxicity and outcomes of re-RT for LRRC with new technologies are promising compared with 3D techniques. Comparative studies are needed to define the best technique, also in relation to the site of recurrence.

The Potential Role of Adjuvant Chemoradiotherapy in Patients with Microscopically Positive (R1) Surgical Margins after Resection of Cholangiocarcinoma.

(1) Background: Biliary tract cancers (BTCs) are a heterogeneous group of neoplasms with dismal prognosis and the role of adjuvant chemoradiotherapy in high-risk resected patients is unclear. (2) Methods: We retrospectively analyzed the outcomes of BTC patients who received curative intent surgery with microscopically positive resection margins (R1) and adjuvant chemoradioradiotherapy (CCRT) or chemotherapy (CHT) from January 2001 to December 201. (3) Results: Out of 65 patients who underwent R1 resection, 26 received adjuvant CHT and 39 adjuvant CCRT. The median recurrence-free survival (RFS) in the CHT and CHRT groups was 13.2 and 26.8 months, respectively (p = 0.41). Median overall survival (OS) was higher in the CHRT group (41.9 months) as compared to the CHT group (32.2 months), but the difference was not statistically significant (HR 0.88; p = 0.7). A promising trend in favor of CHRT was observed in N0 patients. Finally, no statistically significant differences were observed between patients undergoing adjuvant CHRT after R1 resection and patients treated with chemotherapy alone after R0 surgery. (4) Conclusions: Our study did not show a significant survival benefit with adjuvant CHRT over CHT alone in BTC patients with positive resection margins, while a promising trend was observed.

Stereotactic Arrhythmia Radioablation (STAR): A Multidisciplinary Narrative Minireview of Preclinical Studies.

The aim of this narrative review of the literature was to collect and analyze the results of the published preclinical studies on stereotactic arrhythmia radioablation (STAR) in the treatment of refractory cardiac arrhythmias. A literature search was conducted on PubMed using the following terms: ("stereotactic" OR "SBRT" OR "SABR" OR "radioablation" OR "radiosurgery") AND ("arrhythmia" OR "tachycardia"). Preclinical and pathological reports published in English without time limit, comprising studies of STAR in animal models and histological analyzes of explanted animal and human hearts were included. The analyzed studies confirm that doses lower than 25 Gy seem to produce sub-optimal therapeutic results whereas doses >35 Gy are less safe in terms of radiation-induced toxicity. However, long-term results (>1 year) are still missing and reporting outcomes based on low dose irradiation (≤15 Gy). Finally, STAR proved to be an effective therapy in the analyzed studies despite the irradiation of rather different cardiac targets. Therefore, additional studies are needed to: 1) compare the outcomes of STAR at doses of 25 Gy versus 30 Gy; 2) evaluate the long-term results (>1 year) in animal models irradiated at doses similar to those used in the clinic; 3) define the optimal target.

How smart is artificial intelligence in organs delineation? Testing a CE and FDA-approved Deep-Learning tool using multiple expert contours delineated on planning CT images.

Background: A CE- and FDA-approved cloud-based Deep learning (DL)-tool for automatic organs at risk (OARs) and clinical target volumes segmentation on computer tomography images is available. Before its implementation in the clinical practice, an independent external validation was conducted. Methods: At least a senior and two in training Radiation Oncologists (ROs) manually contoured the volumes of interest (VOIs) for 6 tumoral sites. The auto-segmented contours were retrieved from the DL-tool and, if needed, manually corrected by ROs. The level of ROs satisfaction and the duration of contouring were registered. Relative volume differences, similarity indices, satisfactory grades, and time saved were analyzed using a semi-automatic tool. Results: Seven thousand seven hundred sixty-five VOIs were delineated on the CT images of 111 representative patients. The median (range) time for manual VOIs delineation, DL-based segmentation, and subsequent manual corrections were 25.0 (8.0-115.0), 2.3 (1.2-8) and 10.0 minutes (0.3-46.3), respectively. The overall time for VOIs retrieving and modification was statistically significantly lower than for manual contouring (p<0.001). The DL-tool was generally appreciated by ROs, with 44% of vote 4 (well done) and 43% of vote 5 (very well done), correlated with the saved time (p<0.001). The relative volume differences and similarity indexes suggested a better inter-agreement of manually adjusted DL-based VOIs than manually segmented ones. Conclusions: The application of the DL-tool resulted satisfactory, especially in complex delineation cases, improving the ROs inter-agreement of delineated VOIs and saving time.

Dose-Volume Constraints fOr oRganS At risk In Radiotherapy (CORSAIR): An "All-in-One" Multicenter-Multidisciplinary Practical Summary.

BACKGROUND: The safe use of radiotherapy (RT) requires compliance with dose/volume constraints (DVCs) for organs at risk (OaRs). However, the available recommendations are sometimes conflicting and scattered across a number of different documents. Therefore, the aim of this work is to provide, in a single document, practical indications on DVCs for OaRs in external beam RT available in the literature. MATERIAL AND METHODS: A multidisciplinary team collected bibliographic information on the anatomical definition of OaRs, on the imaging methods needed for their definition, and on DVCs in general and in specific settings (curative RT of Hodgkin's lymphomas, postoperative RT of breast tumors, curative RT of pediatric cancers, stereotactic ablative RT of ventricular arrythmia). The information provided in terms of DVCs was graded based on levels of evidence. RESULTS: Over 650 papers/documents/websites were examined. The search results, together with the levels of evidence, are presented in tabular form. CONCLUSIONS: A working tool, based on collected guidelines on DVCs in different settings, is provided to help in daily clinical practice of RT departments. This could be a first step for further optimizations.

CARE-compliant stereotactic radiotherapy of urothelial nodal metastases: A case report.

The aim of the present study was to report the case of a 58-year-old male patient with ureteral carcinoma who underwent ureteroileostomy treatment. At 2 years following surgery, six lymph node metastases (LNMs) were detected in the patient's para-aortic and pelvic regions using 18F-labeled fluoro-2-deoxyglucose (FDG) positron emission tomography (PET)/CT. All LNMs were treated using stereotactic body radiotherapy (SBRT; 35-40 Gy/5 fractions). At 3 months after radiotherapy, 18F-FDG-PET/CT examination revealed a complete radiological and metabolic response of all targeted treatment sites in the patient. In the 2 years following radiotherapy, another three same-dose SBRT treatments were performed on single or multiple LNMs, which were all detected in the abdomen and pelvis of the patient. Overall, a total of 11 LNMs were targeted in the patient and all exhibited complete radiological and metabolic response following treatment. The only treatment side effect reported by the patient was a slight and temporary loss of appetite. In patients with lymph node oligometastases there are two options for radiotherapy: i) Irradiation focusing on LNMs alone; and ii) prophylactic irradiation of the entire lymph node area combined with a boost on macroscopic lesions. In the patient discussed in the present study, the choice of irradiation focusing on LNMs alone made it possible to postpone systemic therapies and instead use an optimally tolerated treatment. The treatment outcome in this patient indicated that there was no radioresistance of urothelial LNMs.

Definition of Local Recurrence Site in Resected Pancreatic Adenocarcinoma: A Multicenter Study (DOLORES-1).

The study aimed to generate a local failure (LF) risk map in resected pancreatic cancer (PC) and validate the results of previous studies, proposing new guidelines for PC postoperative radiotherapy clinical target volume (CTV) delineation. Follow-up computer tomography (CT) of resected PC was retrospectively reviewed by two radiologists identifying LFs and plotting them on a representative patient CT scan. The percentages of LF points randomly extracted based on CTV following the RTOG guidelines and based on the LF database were 70% and 30%, respectively. According to the Kernel density estimation, an LF 3D distribution map was generated and compared with the results of previous studies using a Dice index. Among the 64 resected patients, 59.4% underwent adjuvant treatment. LFs closer to the root of the celiac axis (CA) or the superior mesenteric artery (SMA) were reported in 32.8% and 67.2% cases, respectively. The mean (± standard deviation) distances of LF points to CA and SMA were 21.5 ± 17.9 mm and 21.6 ± 12.1 mm, respectively. The Dice values comparing our iso-level risk maps corresponding to 80% and 90% of the LF probabilistic density and the CTVs-80 and CTVs-90 of previous publications were 0.45-0.53 and 0.58-0.60, respectively. According to the Kernel density approach, a validated LF map was proposed, modeling a new adjuvant CTV based on a PC pattern of failure.

Stereotactic radiotherapy in intrahepatic cholangiocarcinoma: A systematic review.

Among biliary tract cancers, intrahepatic cholangiocarcinoma (ICC) has different characteristics compared with those in other sites. Current guidelines suggest several treatment options for ICC, including stereotactic body radiation therapy (SBRT). However, the role of SBRT in locally advanced ICC is unclear. The aim of the present study was to present a systematic review on the efficacy and safety of SBRT in ICC. A systematic review based on the PRISMA methodology was performed. Only papers reporting outcomes in terms of overall survival (OS) after SBRT in inoperable patients with ICC were included. Secondary aims were local control (LC), progression-free survival (PFS) and treatment-related toxicity. Six papers (145 patients) were included in the present analysis. SBRT was frequently used as a salvage treatment, since 28.6-66.7% of patients received previous systemic or local treatments. The median SBRT dose was 45 Gy delivered in 3-5 fractions. The median follow-up was 16 months, and median OS time was 14 months (range, 10-48 months). In one of the included studies, SBRT was significantly superior in terms of OS compared with both chemoradiation and trans-arterial-radio-embolization. The 1-year LC rate was 85% in one study, and 1-year PFS rates were 50 and 68% in two studies, respectively. Toxicity was generally not reported in detail or was reported including other sites of biliary cancers. Overall, limited evidence was available on the efficacy of SBRT in ICC, which should be further investigated in prospective studies with a larger number of patients. However, based on the available data, SBRT seems to produce similar results compared with other ICC treatments, with the advantage of being a very short and non-invasive therapy. Therefore, SBRT should be considered in selected patients with ICC.

Radiotherapy of Prostate Carcinoma: A Comparison of the Predictive Role of EAU Versus NCCN Risk Stratification Systems.

BACKGROUND/AIM: To compare the predictive efficacy of National Comprehensive Cancer Network (NCCN) and European Association of Urology (EAU) risk stratification systems in radiotherapy of prostate cancer. PATIENTS AND METHODS: One-thousand-nine-hundred-nine patients treated with definitive (1,074), adjuvant (381), and salvage radiotherapy (454) were analysed. RESULTS: Both systems significantly predicted biochemical-relapse-free-survival, metastasis-free-survival, and disease-free-survival, while only the NCCN system correlated with local-control in the definitive radiotherapy group. In the adjuvant setting, both systems failed to predict all outcomes. In the salvage setting, only the NCCN system significantly predicted biochemical-relapse-free-survival, metastasis-free-survival and disease-free-survival. CONCLUSION: This analysis confirms the efficacy of both systems in definitive radiotherapy and suggests the utility of the NCCN also in salvage radiotherapy.

Radiotherapy of prostate cancer: impact of treatment characteristics on the incidence of second tumors.

BACKGROUND: It has been hypothesized that radiotherapy (RT) techniques delivering radiations to larger volumes (IMRT, VMAT) are potentially associated with a higher risk of second primary tumors. The aim of this study was to analyse the impact of RT technique (3D-CRT vs IMRT/VMAT) on the incidence of second tumors in prostate cancer (PCa) patients. METHODS: A retrospective study on 2526 previously irradiated PCa patients was performed. Patients were treated with 3D-CRT (21.3%), IMRT (68.1%), or VMAT (10.6%). Second tumors incidence was analysed in 3 categories: pelvic, pelvic and abdominal, and "any site". The correlation with RT technique was analysed using log-rank test and Cox's proportional hazard method. RESULTS: With a median follow-up of 72 months (range: 9-185), 92 (3.6%) cases of second tumors were recorded with 48 months (range: 9-152) median interval from RT. Actuarial 10-year second tumor free survival (STFS) was 87.3%. Ten-year STFS in patients treated with 3D-CRT and IMRT/VMAT was 85.8 and 84.5%, respectively (p: .627). A significantly higher 10-year cumulative incidence of second tumors in the pelvis was registered in patients treated with IMRT/VMAT compared to 3D-CRT (10.7% vs 6.0%; p: .033). The lower incidence of second pelvic cancers in patients treated with 3D-CRT was confirmed at multivariable analysis (HR: 2.42, 95%CI: 1.07-5.47, p: .034). CONCLUSIONS: The incidence of second pelvic tumors after RT of PCa showed a significant correlation with treatment technique. Further analyses in larger series with prolonged follow-up are needed to confirm these results.

Radiotherapy Plus GnRH Analogue Versus High Dose Bicalutamide: A Case Control Study.

BACKGROUND/AIM: Radiotherapy (RT) with adjuvant hormone therapy (HT) improves prognosis in prostate cancer (PC) patients. Gonadotrophin-releasing hormone agonist (GnRHa) with luteinizing hormone-releasing hormone (LH-RH) analogues is the standard HT. High-dose antiandrogen therapy also improves survival in patients with locally advanced PC. The aim of this study was to compare the results of patients treated with RT plus GnRHa and patients treated with RT plus bicalutamide. PATIENTS AND METHODS: Our institutional PC database was used to identify patients treated with definitive or postoperative RT +/- HT which were included in this study. RESULTS: Three hundred and eighteen patients were retrospectively reviewed (median follow-up=56 months). Five-year biochemical relapse-free survival was 85.5% and 88.3% in patients treated with GnRHa and bicalutamide, respectively (p=0.712). CONCLUSION: Bicalutamide may be offered as an adjuvant treatment to RT in patients who refuse GnRHa because of related side effects. Furthermore, our study justifies randomized trials comparing RT plus GnRHa and RT plus bicalutamide.

Radiotherapy or Chemoradiation in Unresectable Biliary Cancer: A Retrospective Study.

BACKGROUND/AIM: To retrospectively evaluate the outcome of patients with unresectable biliary cholangiocarcinoma (CC) treated with radiotherapy (RT) plus/minus chemotherapy (CHT). MATERIALS AND METHODS: Data of patients with intrahepatic CC (ICC), Klatskin's tumor (KT), distal extrahepatic CC (ECC), and gallbladder cancer (GBC) diagnosed from 1991 to 2017 were retrospectively analyzed. The treatment was mainly based on RT plus concurrent CHT +/- brachytherapy (BRT) boost. The Kaplan-Meier method was used to calculate survival curves that were compared using the log-rank test. RESULTS: Seventy-six patients were included in this analysis (males: 59%; females: 41%; median age: 66.5 years). A minority of patients (7.9%) were treated for disease recurrence after surgery. According to TNM, 78.5% of patients had T stage >3 and 77.6% of patients were treated with concurrent CHT-RT while 22.3% received RT followed by sequential CHT. Median RT dose was 50 Gy (range: 16-75 Gy) delivered with conventional fractionation. CHT was based on Gemcitabine or 5-fluorouracil. BRT was prescribed to 51.3% of patient with a median dose of 14 Gy. Reported Grade ≥3 acute GI and hematological toxicity were 13.2% and 8.1%, respectively. No other severe acute toxicities were reported. One- and 2-year overall survival (OS) were 58.1% and 25.8%, respectively (median: 13.5 months), while 1- and 2-year progression-free survival (PFS) were 43.4% and 9.4%, respectively. None of the following variables had a significant impact on OS and PFS: BRT boost, tumor site, concurrent CHT, and the drugs used in concurrent CHT. In contrast, patients receiving RT with 2D technique showed a PFS significantly higher compared to patients treated with the 3D technique (median: 15.5 vs. 8.5 months; p=0.02). CONCLUSION: Combined modality treatment (RT+CHT±BRT) in unresectable biliary cancer was associated with acceptable toxicity and OS comparable to the actual standard treatment (CHT). The significantly improved PFS in patients undergoing 2D-RT raises doubts regarding the adequacy of target delineation in these neoplasms.

Stereotactic body radiation therapy in cholangiocarcinoma: a systematic review.

OBJECTIVE: Stereotactic body radiation therapy (SBRT) has been used in the treatment of cholangiocarcinoma (CC) but toxicity and clinical results of SBRT in CC are still limited and sparse. Therefore, the aim of this systematic review was to analyze the results of SBRT in the setting of advanced CC. METHODS: A systematic literature search was conducted on PubMed, Scopus, and Cochrane library using the PRISMA methodology. Studies including at least 10 patients with diagnosis of advanced CC regardless of tumor site and other treatments were included. The primary outcome was overall survival (OS) and secondary endpoints were local control (LC) and toxicity rates. The ROBINS-I risk of bias tool was used. RESULTS: 10 studies (231 patients) fulfilled the selection criteria and were included in this review. All but one study showed moderate to serious risk of bias. Median follow up was 15 months (range: 7.8-64.0 months). Pooled 1 year OS was 58.3% (95% CI: 50.2-66.1%) and pooled 2 year OS was 35.5% (95% CI: 22.1-50.1%). Pooled 1 year LC was 83.4%, (95% CI: 76.5-89.4%). The reported toxicities were acceptable and manageable with only one treatment-related death. CONCLUSION: The role of SBRT in CC is not yet supported by robust evidence in literature. However, within this limit, preliminary results seem almost comparable to the ones of standard chemotherapy or chemoradiation. ADVANCES IN KNOWLEDGE: SBRT seems effective in terms of LC with acceptable treatment-related toxicities. Therefore, SBRT can be considered a therapeutic option at least in selected patients with CC, possibly combined with adjuvant chemotherapy (CHT).

An atlas for clinical target volume definition, including elective nodal irradiation in definitive radiotherapy of biliary cancer.

Radiotherapy (RT) is a treatment option for advanced biliary tract cancer (BTC), often combined with sequential and/or concurrent chemotherapy. The use of modern RT techniques requires accurate clinical target volume (CTV) definition and delineation. However, guidelines for CTV delineation in BTC are lacking. Therefore, the aim of this study was to propose a computer tomography (CT) atlas for CTV definition of BTC. We previously proposed guidelines to define the nodal CTV (CTV-N) in BTC. In this study, based on a literature analysis, we defined the margins to be added to the gross tumor volume (GTV; subclinical and microscopic disease) to define the primary tumor CTV (CTV-T). An abdominal contrast enhanced planning CT scan was performed on three different patients with unresectable intrahepatic cholangiocarcinoma (CC), extrahepatic CC and gallbladder cancer. The GTV and anatomical reference structures were outlined on CT images. Then, based on our guidelines, the CTV-T and CTV-N were delineated and merged to define the final CTV in the three patients. An atlas, showing the defined CTV, was generated from the reference CT images to illustrate the CTV for intra-hepatic CC, extra-hepatic CC and gallbladder cancer. This atlas can be used as an aid for CTV definition in patients with BTC treated with modern RT techniques.