Background:Biaxially rotating O-ring linear accelerators equipped with biaxially rotating gantry-ring mechanics enable non-coplanar arc delivery without the need for couch rotation. This architecture is intended to achieve conformal dose distributions and enable efficient non-coplanar delivery compared with couch-rotated techniques. However, clinical implementation requires dosimetric verification to confirm delivery accuracy. This study aimed to validate the dosimetric accuracy and treatment efficiency of a biaxially rotating O-ring linac using AAPM Task Group (TG)-119 and TG-244 test cases, with reference to TG-218 acceptance criteria. Materials and methods:In this retrospective phantom-based dosimetric validation study, 26 treatment plans were generated in RayStation based on TG-119 and TG-244 and delivered as coplanar VMAT (cVMAT) or non-coplanar VMAT [dynamic swing arc (DSA)]. Point dose measurements were performed with an A1SL ionisation chamber, and dose distribution verification was conducted using the Delta4 Phantom+. Monitor units (MU) and beam-on time (BOT) were compared between cVMAT and DSA. Results:All plans met the ±3% tolerance for absolute point-dose error (measured vs. calculated), with a mean error of -0.21% ± 1.09%. Gamma analysis (3%/2 mm, 10% threshold) showed a mean pass rate of 99.3%, exceeding the 95% threshold. Significant differences were observed in MU and BOT between cVMAT (median 862.4 MU, 104.0 s) and DSA (median 740.5 MU, 136.5 s). Conclusions:This study demonstrated dosimetric validation of a biaxially rotating O-ring linear accelerator using TG-119 and TG-244 test cases. The system achieved high accuracy in both cVMAT and DSA deliveries, supporting the dosimetric readiness for clinical implementation.
Background:This study aimed to evaluate the effects of systemic treatment on the overall survival (OS) of patients with superior vena cava (SVC) syndrome caused by neoplasms other than lung and haematological cancers. Materials and methods:Patient data were collected retrospectively. Cox proportional hazards regression was used to analyse the associations between variables and time to death. Results:Twenty-four patients were identified. The median follow-up time was 36 months. The median OS of patients receiving upfront systemic treatment and radiotherapy were 252 and 150 days (p = 0.298), and the 1-year OS rates were 20% and 22.7%, respectively. Patients treated with and without steroids had 1-year OS rates of 30.8% and 10.1% and median OS of 154 and 224 days, respectively (p = 0.426). The median OS of patients treated with and without loop diuretics was 114 and 252 days (p = 0.004), and the 1-year OS rates were 0% and 33.6%, respectively. In multivariable analysis, significant independent factors included upfront systemic therapy [hazard ratio (HR) = 0.022; 95% confidence interval (CI): 0.001-0.413], loop diuretics (HR = 12.364; 95% CI: 2.093-73.032), male sex (HR = 9.746; 95% CI: 1.478-64.276), visceral metastases (HR = 96.265; 95% CI: 5.437-1704.39), and previous systemic treatment for nonmetastatic disease (HR = 0.072; 95% CI: 0.005-0.955). Conclusions:In multivariable analysis, systemic treatment was associated with improved survival. However, this finding remains exploratory because of the small sample size and model instability. Loop diuretics were associated with increased mortality, and steroids showed no benefit in improving survival.
Background:Uveal melanoma is the most common primary intraocular malignancy in adults. Current management emphasises local tumour control and globe preservation, while survival remains largely determined by metastatic disease. Several eye-preserving radiotherapy modalities have replaced enucleation in many cases. This narrative review summarises indications, outcomes, and toxicity profiles of definitive local treatment strategies for primary uveal melanoma. Materials and methods:A nonsystematic literature review was conducted in accordance with SANRA guidelines. Publications from 2015-2025 were identified via PubMed using keywords related to uveal melanoma and radiotherapy. Landmark data from the COMS and recommendations from the National Comprehensive Cancer Network (NCCN) were included to provide clinical context. Studies addressing primary tumour management were eligible, while those focusing exclusively on metastatic disease were excluded. Results:Five-year local control rates exceed 90% across modalities for tumours of comparable size. Plaque brachytherapy remains the most widely used technique, offering survival outcomes equivalent to enucleation, with isotope selection varying by region. fSRT provides excellent local control for posterior or large tumours unsuitable for plaque placement, particularly with hypofractionated regimens such as 50 Gy in 5 fractions. PBT offers highly conformal dose distribution and is advantageous for large or posterior tumours, although access is limited. Despite improved local control, metastatic outcomes remain poor; ongoing trials of adjuvant tebentafusp may influence future systemic strategies. Conclusions:Treatment should be individualised within a multidisciplinary setting. Brachytherapy remains the standard for small and medium tumours, while fSRT and PBT are effective alternatives when plaque therapy is not feasible.
Background:Sentinel lymph node biopsy (SLNB) is an established alternative to systematic lymphadenectomy in endometrial cancer (EC). However, the anatomical variability of sentinel lymph node (SLN) locations remains incompletely characterised. This study assessed SLN distribution in a single-centre cohort and compared findings with published data. Materials and methods:We retrospectively analysed 292 patients with EC treated at the Maria Sklodowska-Curie National Research Institute of Oncology, Krakow Branch (2016-2025). All underwent SLN mapping using technetium-99m (Tc-99m), indocyanine green (ICG), Patent Blue, or their combinations. Bilateral detection failures were managed according to an established intraoperative algorithm. SLNs were classified anatomically, and outcomes were compared across mapping techniques. Histopathological assessment included ultrastaging. Results:A total of 526 SLNs were identified (mean 1.8 per patient). The most common locations were the obturator (48.7%) and internal iliac (25.1%) regions. Bilateral detection was achieved in 87.0% of patients, unilateral in 12.0%, and no detection in 1.0%. Metastases were found in 41 SLNs (7.8%) from 34 patients (11.6%), most frequently in obturator (41.5%) and internal iliac (14.6%) nodes. The use of tracer combinations (ICG + Tc-99m or Tc-99m + Patent Blue) improved detection when preoperative Tc-99m mapping was incomplete. Para-aortic SLNs were rare (1.5%) but carried a significantly higher risk of metastasis. Conclusions:Sentinel lymph node biopsy is an effective and safe method for nodal assessment in EC, with the obturator and internal iliac regions being the most frequent SLN sites. Variability in SLN locations appears to depend on mapping technique, tracer type, and surgical access. Standardization of procedures and prospective comparative studies are essential to further optimise SLNB in gynaecological oncology.
BACKGROUND: Radiotherapy is a cornerstone in cancer treatment, but is frequently correlated with acute cutaneous toxicity, particularly in patients with head, neck, and breast cancers. This systematic review evaluates the efficacy of interventions for managing grade III moist desquamation among various cancer patients receiving radiotherapy. MATERIALS AND METHODS: A total of 676 studies were screened, and 10 randomised controlled trials were analysed based on inclusion criteria. RESULTS: Interventions such as Mepitel Film, boron-based gel, and 0.1% Mometasone Furoate demonstrated significant efficacy in reducing the incidence and severity of moist desquamation compared to standard creams or placebo. Hydroactive colloid gels and aloe vera showed promise in alleviating symptoms and improving treatment adherence. Betamethasone effectively reduced grade 2 dermatitis but limitedly impacted severe grade 3 reactions. CONCLUSIONS: The findings highlight the importance of tailoring interventions to individual patient needs and emphasize the need for further studies to validate treatments, explore long-term outcomes, and improve patient quality of life during radiotherapy.
BACKGROUND: HPV-negative head and neck squamous cell carcinoma (HNSCC) has a poorer prognosis than HPV-positive tumours, yet real-world outcomes remain understudied. This study analyses a multicentre cohort of HPV-negative HNSCC patients, including those over 65 years of age. MATERIALS AND METHODS: This retrospective study included HPV-negative HNSCC patients treated with definitive radiotherapy (RT) or chemoradiotherapy (CRT) between 2015 and 2020. RT protocols included standard fractionation (70 Gy, 35 fractions), simultaneous integrated boost (69.96 Gy, 33 fractions), or concomitant boost (72.5 Gy, 50 fractions). RESULTS: Among 225 patients (62 over 65 years), 138 (61%) received CRT. Local progression occurred in 83 (37%), and 177 (79%) died. Median overall survival (OS) was 23.1 months, with 3-year OS and local control (LC) rates of 37% and 35%, respectively. ECOG predicted outcomes (p < 0.001 for OS, p = 0.040 for LC), while comorbidity burden and disease stage were significant only for OS (p < 0.001 and p = 0.006). CRT improved OS over RT alone (p = 0.059). Older patients more often had hypopharyngeal/laryngeal tumours (p = 0.033), received CRT less frequently (29% vs. 74%, p < 0.001), and chemotherapy did not affect outcomes. CONCLUSIONS: Real-world outcomes for inoperable HPV-negative HNSCC remain poor. Personalized approaches are needed to improve care for this challenging population.
Background:The smoothing factor is a key planning parameter in intensity-modulated radiotherapy that affects both plan quality and deliverability. This study investigates the dosimetric impact of SF in breast radiotherapy and introduces a logistic regression-based model to predict plan acceptability. Materials and methods:IMRT plans were generated for 21 breast cancer patients using SF values from 10 to 300 (126 plans total). Dosimetric parameters included monitor units, ipsilateral lung dose (V17 Gy), planning target volume coverage, and complexity (modulation complexity score). A logistic regression model was trained using six key features to classify plan quality. Results:Plans with SF values between 100 and 150 provided the best compromise between monitor units, PTV coverage, and modulation complexity. The predictive model performed well (AUC = 0.88), with conformity index, maximum dose, and modulation complexity score emerging as the most influential predictors. It enables automated classification and supports smoothing factor selection. Conclusions:The smoothing factor strongly influences the performance of intensity-modulated radiotherapy plans. Our predictive model provides a robust tool for plan evaluation, supporting clinical decision-making and optimisation of smoothing factor in breast radiotherapy.
BACKGROUND: Radiotherapy is a technically precise yet deeply human medical specialty, often underrepresented in narrative depictions of oncology. Like modern superhero stories, radiotherapy practice blends idealism, responsibility, moral ambiguity, and human limitation. This work explores the professional behaviours, cultural identities, and interpersonal dynamics within radiotherapy departments through a satirical but recognisable framework. MATERIALS AND METHODS: We conducted a qualitative, narrative-based observational study informed by long-term clinical experience in radiotherapy practice. Using thematic synthesis, reflective ethnography, and humour as analytical tools, recurrent professional behaviours and attitudes were identified and distilled into archetypal personas representing common patterns within the radiotherapy workforce. RESULTS: Seven archetypal radiotherapy phenotypes emerged, each embodying characteristic strengths, flaws, and decision- making styles. These personas illustrate tensions between evidence and action, precision and pragmatism, idealism and compromise, as well as the balance between technical excellence and human factors. Collectively, they provide an accessible framework to describe the social and cognitive ecology of contemporary radiotherapy practice. CONCLUSIONS: This satirical taxonomy highlights the diversity, complexity, and humanity of professionals working in radiotherapy. By framing the specialty as a “multiverse” of flawed yet committed heroes, the study offers an engaging perspective on clinical culture, professional identity, and self-awareness. Ultimately, it argues that maintaining humour and humility may be as essential to radiotherapy practice as technical precision.
BACKGROUND: Interstitial brachytherapy enables highly conformal tumor irradiation while limiting exposure of surrounding tissues, but its successful execution requires advanced spatial orientation and manual precision. Augmented reality (AR) may support these procedures by providing three-dimensional visualisation of treatment planning data within the procedural environment. This study presents a prospective, phantom-based protocol with preliminary results evaluating the impact of AR guidance on implantation accuracy and procedure duration in interstitial brachytherapy. MATERIALS AND METHODS: A total of 136 implantation procedures are planned using 34 custom-made, tissue-equivalent phantoms. Each phantom undergoes CT imaging and treatment planning with the Oncentra Brachy system. Implantations are performed using a conventional freehand technique and an AR-assisted approach. The AR system, based on Microsoft HoloLens 2 and the HOLO BR platform, enables visualisation of DICOM RT data, including three-dimensional anatomical structures and applicator trajectories. Primary endpoints are implantation accuracy, defined as spatial deviation from the planned needle position, and total procedure time. This manuscript additionally reports preliminary results from a pilot phase comprising 12 AR-assisted and 12 conventional procedures, analysed using non-parametric statistical tests. RESULTS: All pilot procedures were completed successfully. Implantation accuracy was numerically improved with AR guidance compared to the conventional technique, while procedure time was longer in the AR-assisted arm; however, neither difference reached statistical significance. CONCLUSIONS: This study provides an experimental framework and initial quantitative data on AR-guided interstitial brachytherapy under controlled conditions. The preliminary results support the feasibility of AR-assisted implantation and justify completion of the full experimental protocol and subsequent clinical validation.
BACKGROUND: Head and neck cancer with synchronous primary cancers is rare. There is a paucity of data on HNC with SPC regarding treatment modalities, outcomes, and combined treatment toxicities, creating a challenge for treating clinicians. MATERIALS AND METHODS: We retrospectively screened patients who received head and neck cancer radiotherapy in the Saint Luke’s Radiation Oncology Network from July 2017 to July 2024. A synchronous primary cancer was defined as anatomically separate, not a possible metastasis of the first primary cancer and diagnosed within six months of the first primary cancer. RESULTS: We screened 2,971 HNC patients who underwent radiotherapy of which 48 (2%) patients met the inclusion criteria. The median follow-up was 21.9 months and median age was 65 years. The most common SPC sites were lung (46%), oesophageal (13%), then prostate, colon and thyroid (all 6%). The median overall survival for all patients was 28 months. Forty-two (88%) patients completed definitive treatment for both cancers. The median overall survival of patients who completed definitive treatment for both cancers was 30.2 months vs. 5.5 months among patients who did not (p < 0.001). Ten patients had simultaneous radiotherapy to both cancers with overlapping radiotherapy fields and nine of them finished definitive treatment to both cancers. CONCLUSIONS: Patients with HNC and a synchronous primary can be treated curatively to both cancers with a median overall survival of over 2 years. Simultaneous radiotherapy for both cancers can be completed with acceptable toxicity rates even in the setting of overlapping radiation fields.
