Derfel ap Dafydd

Renal cell carcinoma (RCC) is increasingly managed with a broad range of systemic and local therapies, creating new challenges for imaging-based response assessment in metastatic disease. While conventional size-based criteria such as RECIST v1.1 remain widely used, they incompletely capture the diverse morphologic and functional changes induced by modern treatment. Targeted therapies, including vascular endothelial growth factor receptor tyrosine kinase inhibitors and other pathway-directed agents, may produce necrosis, devascularisation, and prolonged disease stability without substantial tumour shrinkage. Immune checkpoint inhibitors introduce additional atypical response patterns, including pseudoprogression, mixed response, and rarely hyperprogression, which can complicate early interpretation of surveillance imaging. Combination regimens may demonstrate features of both targeted and immune-mediated response. In parallel, stereotactic body radiotherapy has emerged as an important treatment for oligometastatic and oligoprogressive RCC, with imaging appearances that may include lesion shrinkage, stability, or transient enlargement following treatment. This review summarises the current treatment landscape for metastatic RCC and the imaging manifestations of response across chemotherapy, targeted therapy, immunotherapy, combination systemic therapy, and stereotactic radiotherapy. It discusses the strengths and limitations of conventional and modified response criteria, including RECIST v1.1, iRECIST, attenuation-based CT criteria, and morphology-based approaches. The review also highlights the evolving role of functional and novel imaging techniques, including diffusion-weighted whole-body MRI, dual-energy and spectral CT, and PET/CT, as potential tools for improving response assessment beyond size alone. In addition, key imaging features of treatment-related toxicity are reviewed. Familiarity with these response patterns and complications is essential for radiologists involved in the care of patients with metastatic RCC, particularly as treatment strategies become increasingly multimodal and biologically complex.

Stereotactic radiotherapy (SBRT) and radiofrequency ablation (RFA) are common ablative techniques for lung metastases. A retrospective review of all patients treated with either modality at a single institution between 2011 and 2019 was conducted. Baseline characteristics and outcomes were compared. Local and distant progression, and overall survival were estimated using the Kaplan–Meier method. Univariable analysis was carried out using Cox regression; this was followed by multivariable modelling. In total, 106 patients treated with RFA and 70 treated with SBRT were identified. Tumours treated with SBRT were larger (median size 18 mm vs. 11 mm) and primarily oligometastatic (91.4% vs. 20%). Median progression-free survival (PFS) was 12.5 months for SBRT and 7.9 months for RFA (p = 0.009). Median OS was similar (p = 0.66). In multivariable analysis, lesion size > 20 mm was predictive of adverse local PFS (p = 0.001), PFS (p = 0.0034) and OS (p = 0.001). A statistically significant interaction effect suggested that RFA was associated with better local PFS within colorectal primary patients (p = 0.035). This study highlights differences in patient selection and outcomes for RFA or SBRT in the treatment of lung metastases at our institution. Future studies for SBRT should focus on the optimum dose schedules required for different histologies. For less-radiosensitive tumours, RFA may offer a superior alternative where dose-escalated SBRT is not possible.

Stereotactic radiotherapy (SBRT) and radiofrequency ablation (RFA) are common ablative techniques for lung metastases. Retrospective review of all patients treated with either modality at a single institution between 2011 and 2019 was conducted. Baseline characteristics and outcomes were compared. Local and distant progression, and overall survival were estimated using the Kaplan Meier method. Univariable analysis was carried out using Cox regression followed by multivariable modeling. 106 patients treated with RFA and 70 treated with SBRT were identified. Tumours treated with SBRT were larger (median size 18 vs 11mm) and primarily oligometastatic (91.4% vs 20%). Median progression-free survival (PFS) was 12.5 months for SBRT and 7.9 months for RFA (p=0.009). Median OS was similar (p=0.66). In multivariable analysis, lesion size >20mm was predictive of adverse local PFS (p=0.001), PFS (p=0.0034) and OS (p=0.001). Statistically significant interaction effect suggested RFA offered better local PFS compared to SBRT within colorectal primary patients (p=0.035). This study highlights differences in patient baseline characteristics, selection and outcomes for RFA or SBRT in the treatment of lung metastases at our institution. Future studies for SBRT should focus on the radiosensitivites of individual tumour types and the optimum dose schedules required for differing histologies. For less radiosensitive tumours, RFA may offer a superior alternative.

Background: Traditional head and neck cancer treatment involves open surgery, cytotoxic chemotherapy, and conventional radiotherapy planning. Emerging techniques aim to improve precision and reduce associated toxicity and functional impairment in current practice. This review article describes four such adaptations in image guidance, tailored to next generation therapies.Methods: This is a review of current literature, including feasibility studies from our cancer center, relating to: saline‐aided intra‐oral ultrasound‐guided retropharyngeal biopsy; intra‐oral ultrasound guided trans‐oral robotic surgery (TORS); ultrasound‐guided injection of “directly injected therapies”; and magnetic resonance imaging‐guided radiotherapy.Results: Presented within the context of the wider literature, initial local experience and data indicate good technical outcomes and patient tolerance, and low technical complications in all four image guidance techniques.Conclusion: Initial findings suggest a potentially important future role for these four image guidance techniques, on which next generation therapies are reliant. The broader implications on cross‐disciplinary collaboration are also explored herein.

Background: Directly-injected therapies (DIT) include a broad range of agents within a developing research field in cancer immunotherapy, with encouraging clinical trial results in various tumour subtypes. Currently, the majority of such therapies are only available within clinical trials; however, more recently, talimogene laherparepvec (T-VEC, Imlygic) has been approved as the first oncolytic virus therapy in the USA and Europe. Our institution contributes to multiple different trials exploring the efficacy of DIT, the majority of which are performed by oncologists in clinic. However, specific, challenging cases – mainly neck tumours – require image-guided administration. Main body: This review article addresses the technical and logistical factors relevant to the incorporation of image-guided DIT into an established ultrasound service. Image-guidance (usually with ultrasound) is frequently needed for certain targets that cannot be palpated or are in high-risk locations, e.g. adjacent to blood vessels. A multi-disciplinary approach is essential to facilitate a safe and efficient service, including careful case-selection. Certain protocols and guidance need to be followed when incorporating such a service into an established ultrasound practice to enhance efficiency and optimise safety. Key learning points are drawn from the literature and from our early experience at a tertiary cancer centre following image guided DIT for an initial cohort of 22 patients (including 11 with a neck mass), addressing trial protocols, pre-procedure work-up, organisation, planning, consent, technical aspects, procedure tolerability, technical success, and post-procedure considerations. Conclusion: With appropriate planning and coordination, and application of the learning points discussed herein, image-guided administration of DIT can be safely and efficiently incorporated into an established procedural ultrasound list. This has relevance to cancer centres, radiology departments, individual radiologists, and other team members with a future role in meeting the emerging need for these procedures. This paper provides advice on developing such an imaging service, and offers certain insights into the evolving remit of radiologists within cancer care in the near future.

Background: The purpose of this study was to determine the feasibility of the novel technique of intra‐cavitary saline‐aided ultrasound (US) guided transoral biopsy or excision of retropharyngeal nodes.Methods: We followed the IDEAL 2a framework to develop this technique. Procedures were performed between July 2020 and July 2022 at a tertiary head and neck center.Results: Five patients in total underwent an ultrasound‐guided biopsy of a retropharyngeal node. They underwent seven procedures between them: three transoral robotic surgery (TORS) procedures, three fine needle aspirations (FNA) and/or core biopsy procedures, and one US assessment under general anesthetic. The six patients with histology taken (three TORS and three FNA/core biopsies) all had diagnostically adequate samples enabling appropriate treatment planning. There were no significant complications from the procedure.Conclusion: Saline‐aided US‐guided biopsy of a retropharyngeal node is a safe and useful tool enabling accurate tissue sampling and tumor excision and ongoing appropriate treatment planning.

Purpose Awareness of head and neck mucosal melanoma (HNMM) is important, as incorrect work-up can impact on the investigation and management of this rare and aggressive cancer. Following on from the 2020 HNMM UK guidelines, we set out the imaging recommendations and their rationale. To illustrate the key imaging characteristics, we also include a case series from our centre. Methods All HNMM cases managed at our institution from January 2016 to January 2021 were identified, and the available imaging for each patient was reviewed. For each patient, the age, gender and location of primary tumour was recorded together with key staging and diagnostic imaging parameters. Results A total of 14 patients were identified. The median age was 65 years with a female to male ratio of 1.33:1. Primary tumours were sinonasal in location in 93% of cases, with 7% of patients having metastatic neck nodes at presentation and 21% of cases having distant metastatic disease at presentation. Conclusion This data set is in general concordance with other published series regarding the sinonasal origin of the vast majority of HNMM tumours along with the proportion of patients with metastatic neck nodes and distant metastases at presentation. We recommend dual-modality imaging with computed tomography (CT) and magnetic resonance imaging (MRI) of primary tumours whenever possible. In the systematic staging of HNMM, positron emission tomography (PET)-CT should be strongly considered, together with MRI of the brain. Pre-biopsy imaging of HNMM tumours is advisable whenever possible.

Purpose Awareness of head and neck mucosal melanoma (HNMM) is important, as incorrect work-up can impact on the investigation and management of this rare and aggressive cancer. Following on from the 2020 HNMM UK guidelines, we set out the imaging recommendations and their rationale. To illustrate the key imaging characteristics, we also include a case series from our centre. Methods All HNMM cases managed at our institution from January 2016 to January 2021 were identified and the available imaging for each patient was reviewed. For each patient, the age, gender and location of primary tumour was recorded together with key staging and diagnostic imaging parameters. Results A total of 14 patients were identified. The median age was 65 years with a female to male ratio of 1.33:1. Primary tumours were sinonasal in location in 93% of cases, with 7% of patients having metastatic neck nodes at presentation and 21% of cases having distant metastatic disease at presentation. Conclusion This data set is in general concordance with other published series regarding the sinonasal origin of the vast majority of HNMM tumours along with the proportion of patients with metastatic neck nodes and distant metastases at presentation. We recommend dual-modality imaging with computed tomography (CT) and magnetic resonance imaging (MRI) of primary tumours whenever possible. In the systematic staging of HNMM, positron emission tomography (PET)-CT should be strongly considered, together with MRI of the brain. Pre-biopsy imaging of HNMM tumours is advisable whenever possible.

Objective: We determined the sensitivity and specificity of multiparametric magnetic resonance imaging (MP-MRI) in detection of locally recurrent prostate cancer and extra prostatic extension in the post-radical radiotherapy setting. Histopathological reference standard was whole-mount prostatectomy specimens. We also assessed for any added value of the dynamic contrast enhancement (DCE) sequence in detection and staging of local recurrence. Methods: This was a single centre retrospective study. Participants were selected from a database of males treated with salvage prostatectomy for locally recurrent prostate cancer following radiotherapy. All underwent pre-operative prostate-specific antigen assay, positron emission tomography CT, MP-MRI and transperineal template prostate mapping biopsy prior to salvage prostatectomy. MP-MRI performance was assessed using both Prostate Imaging-Reporting and Data System v. 2 and a modified scoring system for the post-treatment setting. Results: 24 patients were enrolled. Using Prostate Imaging-Reporting and Data System v. 2, sensitivity, specificity, positive predictive value and negative predictive value was 64%, 94%, 98% and 36%. MP-MRI under staged recurrent cancer in 63%. A modified scoring system in which DCE was used as a co-dominant sequence resulted in improved diagnostic sensitivity (61%–76%) following subgroup analysis. Conclusion: Our results show MP-MRI has moderate sensitivity (64%) and high specificity (94%) in detecting radio-recurrent intraprostatic disease, though disease tends to be under quantified and under staged. Greater emphasis on dynamic contrast images in overall scoring can improve diagnostic sensitivity. Advances in knowledge: MP-MRI tends to under quantify and under stage radio-recurrent prostate cancer. DCE has a potentially augmented role in detecting recurrent tumour compared with the de novo setting. This has relevance in the event of any future modified MP-MRI scoring system for the irradiated gland.