Petr Burkon

Background: In the current era of targeted axillary dissection (TAD), there are still cases where axillary lymph node dissection (ALND) is indicated, but histopathological examination confirms the regression of nodal metastases (ypN0). In this situation, ALND may represent undesirable overtreatment. Methods: A retrospective study at the Comprehensive Cancer Centre was conducted based on a prospectively maintained database. Patients who underwent surgery after neoadjuvant chemotherapy (NAC) between 2020 and 2023 were selected, specifically those for whom ALND was directly indicated after NAC. Subsequently, clinical–pathological characteristics were compared between cases with ypN0 and those with persistent metastases (ypN+). The reasons for indicating ALND in ypN0 cases were extracted from the medical records. Results: ALND was indicated in 118 cases across 117 patients, of which ypN0 was observed in 44 cases (37%). There were significantly more ypN0 cases for inflammatory carcinomas (68%), the non-luminal HER2-positive phenotype (76%), and carcinomas with histopathological regression of the primary tumor (76%) or the persistence of only the non-invasive component of ypTis (67%). Typical reasons for ALND in ypN0 cases included inflammatory carcinoma (n = 13, 29.5%), locally advanced carcinoma (n = 5, 11.4%), occult carcinoma (n = 2, 4.5%), or persistent lymphadenopathy on ultrasound examination after NAC, especially in the tumor phenotypes HER2-positive and triple-negative breast cancer (TNBC) (n = 8, 18.2%). Conclusions: Through real-world evidence data analysis, subgroups of breast cancer patients treated with NAC were identified who may experience surgical overtreatment in the axilla. These include patients with inflammatory carcinoma, locally advanced carcinoma, occult carcinoma, or patients with persistent lymphadenopathy on US examination after NAC, particularly in the tumor phenotypes HER2-positive and TNBC.

Introduction: Primary breast sarcoma is a very rare malignant type of breast tumours with an incidence of 0.1% of all primary breast malignancies. Methods: We present a retrospective analysis of the case series from two hospitals in the Czech Republic with a review of the diagnostic and treatment approach to primary breast sarcomas with an analysis of published prognostic factors. Results: Eleven patients were included in the study, 9 women and 2 men. Statistical evaluation revealed that tumour size (p = 0.1964), grade (p = 0.1667), margin distance (p = 0.5403), mitotic activity (p = 0.8577), or age (p = 0.7822) were not prognostic factors in our cohort. Conclusion: The analysis did not prove any of the factors, such as age, tumour size, grade, or mitotic activity, to be statistically significant prognostic factors. Based on the literature review, the most common published prognostic factors are tumour size, margin status, and grade, but the results are ambiguous.

Pancreatic cancer is the third leading cause of cancer death in the developed world and is predicted to become the second by 2030. A cure may be achieved only with surgical resection of an early diagnosed disease. Surgery for more advanced disease is challenging and can be contraindicated for many reasons. Neoadjuvant therapy may improve the probability of achieving R0 resection. It consists of systemic treatment followed by radiation therapy applied concurrently or sequentially with cytostatics. A novel approach to irradiation, stereotactic body radiotherapy (SBRT), has the potential to improve treatment results. SBRT can deliver higher doses of radiation to the tumor in only a few treatment fractions. It has attracted significant interest for pancreatic cancer patients, as it is completed quickly, requires less time away from full-dose chemotherapy, and is well-tolerated than conventional radiotherapy. In this review, we aim to provide the reader with a basic overview of current evidence for SBRT indications in the treatment of pancreatic tumors. In the second part of the review, we focus on practical information with respect to SBRT treatment plan preparation the performance of such therapy. Finally, we discuss future directions related to the use of magnetic resonance linear accelerators.

Concurrent chemoradiotherapy represents one of the most used strategies in the curative treatment of patients with head and neck (HNC) cancer. Locoregional failure is the predominant recurrence pattern. Tumor hypoxia belongs to the main cause of treatment failure. Positron emission tomography (PET) using hypoxia radiotracers has been studied extensively and has proven its feasibility and reproducibility to detect tumor hypoxia. A number of studies confirmed that the uptake of FMISO in the recurrent region is significantly higher than that in the non-recurrent region. The escalation of dose to hypoxic tumors may improve outcomes. The technical feasibility of optimizing radiotherapeutic plans has been well documented. To define the hypoxic tumour volume, there are two main approaches: dose painting by contour (DPBC) or by number (DPBN) based on PET images. Despite amazing technological advances, precision in target coverage, and surrounding tissue sparring, radiation oncology is still not considered a targeted treatment if the “one dose fits all” approach is used. Using FMISO and other hypoxia tracers may be an important step for individualizing radiation treatment and together with future radiomic principles and a possible genome-based adjusting dose, will move radiation oncology into the precise and personalized era.

Background and Objectives: The treatment of gastroesophageal junction (GEJ) adenocarcinoma consists of either perioperative chemotherapy or preoperative chemoradiotherapy. Radiotherapy (RT) in the neoadjuvant setting is associated with a higher probability of resections with negative margins (R0) and better tumor regression rate, which might be enhanced by incrementing RT dose with potential impact on treatment results. This virtual planning study demonstrates the feasibility of increasing the dose to GEJ tumor and involved nodes using PET/CT imaging. Materials and Methods: 16 patients from the chemoradiotherapy arm of the phase II GastroPET study were treated by a prescribed dose of 45.0 Gray (Gy) in 25 fractions. PET/CT was performed before treatment. The prescribed dose was virtually boosted on PET/CT-positive areas to 54.0 Gy by 9 Gy in 5 fractions. Dose-volume histograms (DVH) were compared, and normal tissue complication (NTCP) modeling was performed for both dose schedules. Results: DVHs were exceeded in mean heart dose in one case for 45.0 Gy and two cases for 54.0 Gy, peritoneal space volume criterion V_45Gy < 195 ccm in three cases for 54.0 Gy and V_15Gy < 825 ccm in one case for both dose schedules. The left lung volume of 25 Gy isodose exceeded 10% in most cases for both schedules. The NTCP values for the heart, spine, liver, kidneys and intestines were zero for both schemes. An increase in NTCP value was for lungs (median 3.15% vs. 4.05% for 25 × 1.8 Gy and 25 + 5 × 1.8 Gy, respectively, p = 0.013) and peritoneal space (median values for 25 × 1.8 Gy and 25 + 5 × 1.8 Gy were 3.3% and 14.25%, respectively, p < 0.001). Conclusion: Boosting PET/CT-positive areas in RT of GEJ tumors is feasible, but prospective trials are needed.

Strategies for preservation of memory function in patients irradiated for brain metastases (BM) are currently widely investigated. Rare presence of BM within hippocampus (Hipp) enabled development of Hipp avoiding (HA) whole brain radiotherapy (WBRT). However, this HA zone are undertreated with increased risk of subsequent BM recurrence. Accumulating data are showing different post-radiotherapy changes in the left and the right hippocampus with a theoretical proposal of only unilateral (dominant - left) hippocampal sparing during WBRT. The aim of this retrospective study is to describe spatial distribution of BM on MRI in a cohort of 260 patients (2595 metastases) and to evaluate distribution separately in the left and right Hipp and in respective HA zones including evaluation of location of centre of metastatic mass (representing spatial location of original seed during metastasis grown). Consecutive patients with BM referred to radiotherapy from 2011 till 2014 were analyzed. For those with BM in proximity to Hipp, both Hipp were contoured (RTOG contouring atlas) and expansion of 5mm was performed to create HA zone. All BM in the proximity were delineated for recording of contact to Hipp or to HA zone. 260 pattients, mean age 57.8, most common primary diagnosis lung cancer, 51.9 % women. Median number of BM per patient was 3 with interquartile range 1–7, most commonly cerebellum and frontal lobes. BM within left and right temporal lobe were described in 23.5 and 23.9 % of patients. Overall, 7.7 % of patients developed BM within Hipp and 18.1 % within HA zone, representing 1.1 and 3.3 % of all BM, respectively. There was no statistically significant difference in the laterality of Hipp or HA BM. Left and right Hipp were involved in 4.6 and 5.6 % of patients (HA involvement in 11.5 and 10.4 % of patients, respectively). Left and right Hipp BM represented 0.5 and 0.6 % of all BM (HA zone BM 1.6 and 1.7 % of all BM). More patients presented with the centre of metastasis within left (15 patients) vs. right (6) HAZ reaching statistical significance. No difference between involvement of left and right hippocampus on MRI was retrospectively observed in large consecutive cohort of 260 patients. Incidence of hippocampal BM in our cohort was higher comparing to previous studies. Superiority of HA WBRT will be evaluated in ongoing phase III clinical trials. Higher presence of BM within left HAZ comparing to the right side, when location of centrum of BM was evaluated is hypothesis generating observation and warrants further research.

In the glioblastoma follow up evaluation, the differentiation between the pseudoprogression and true tumor progression remains challenging. According to the original RANO criteria from 2010, the progression within the first 12 weeks of completion of radiotherapy (RT) can only be determined if the majority of the new enhancement is outside of the high-dose radiation region. However, radiation oncologists do not always report 3 dimensional RT izodoses while ordering follow up imaging, even for patients treated within clinical trials. Thus, we questioned the general awareness of radiologists about the spatial location of high-dose RT region, which is needed for valid differential diagnostics. Four radiologists worked with MR images which were used for RT planning for 8 glioblastoma patients. Radiologists were blinded to RT target volumes which were defined by radiation oncologists according to Radiation Therapy Oncology Group contouring approach (sequential boost, clinical target volume for high dose is defined as the sum of contrast enhancing T1 abnormality and the surgical cavity plus a margin of 2 cm). The aim was to draw target volume for high dose RT fields (that is the region, where they would consider that there may be a psudoprogression in the future MRI scans). Percentage overlap, conformality index (Dice index ranging from 0-no overlap to 1-identical) and median (and maximal - so called Hausdorff distance) distance measurement (of the point on one surface to the nearest point on the second structure′s surface) was analyzed in comparison with original RT target volumes which were used in clinical practice. Eight patients, median age 57, four men, four patients after gross total resection, four after subtotal resection. Median volume for RT high dose filed was 277 ccm as defined by radiation oncologist and 87 ccm (range 32 - 338) as defined by radiologists (median 31%, range 15 - 112%). Median Dice index 0.46 (range 0.14 - 0.78), median distance (mean 11 mm ±6mm) with median Hausdorff distance 25 mm. Large inaccuracy in the awareness of region where pseudoprogression would be considered based on RANO criteria was observed with almost one-third size of estimated volume of target volume. Close collaboration between radiation oncologists and radiologists is needed to correctly evaluate follow up MRI after treatment of glioblastoma patients in daily routine practice as well as in clinical trials.