Primary thoracic aorta angiosarcoma presenting with thromboembolism and progressive claudication despite anticoagulation.

Primary aortic angiosarcomas (PAA) are rare angiosarcomas, frequently diagnosed in advanced stages due to initial misdiagnosis. This case describes a 66-year-old woman, initially presenting with a distal thoracic aorta thrombus and symptomatic bilateral popliteal emboli. Despite initial management and therapeutic anticoagulation, she experienced progressive lower limb claudication and 12 months following initial presentation she re-presented with an obstructing distal thoracic aorta mass and metastatic disease. Histopathology confirmed metastatic epithelioid angiosarcoma. Despite urgent palliative radiotherapy, she died 6 weeks after diagnosis from complications of tumour thromboembolism. Suspicion for PAA should be raised in the case of thrombus in atypical segments (e.g. thoracic aorta) or progressive course despite anticoagulation. Multimodal imaging including MRI and FDG-PET is useful to distinguish from benign aetiologies.

Partially Ablative Body Radiotherapy (PABR): A novel approach for palliative radiotherapy of locally advanced bulky unresectable sarcomas.

BACKGROUND: Locally advanced, bulky, unresectable sarcomas cause significant tumour mass effects, leading to burdensome symptoms. We have developed a novel Partially Ablative Body Radiotherapy (PABR) technique that delivers a high, ablative dose to the tumour core and a low, palliative dose to its periphery aiming to increase overall tumour response without significantly increasing treatment toxicity. AIM: This study aims to report the safety and oncologic outcomes of PABR in patients with bulky, unresectable sarcomas. METHODS AND MATERIALS: A total of 18 patients with histologically proven sarcoma treated with PABR from January 2020 to October 2023 were retrospectively reviewed. The primary endpoints were symptomatic and structural response rates. Secondary endpoints were overall survival, freedom from local progression, freedom from distant progression, and acute and late toxicity rates. RESULTS: All patients had tumours ≥5 cm with a median tumour volume of 985 cc, and the most common symptom was pain. The median age is 72.5 years and 44.5 % were ECOG 2-3. The most common regimen used was 20 Gy in 5 fractions with an intratumoral boost dose of 50 Gy (83.3 %). After a median follow-up of 11 months, 88.9 % of patients exhibited a partial response with a mean absolute tumour volume reduction of 49.5 %. All symptomatic patients experienced symptom improvement. One-year OS, FFLP and FFDP were 61 %, 83.3 % and 34.8 %, respectively. There were no grade 3 or higher toxicities. CONCLUSION: PABR for bulky, unresectable sarcomas appears to be safe and may provide good symptomatic response, tumour debulking, and local control. Further study is underway.

Low rate of severe-end-stage kidney disease after SABR for localised primary kidney cancer.

BACKGROUND: Stereotactic ablative body radiotherapy (SABR) is an emerging treatment for patients with primary renal cell carcinoma (RCC). However, its impact on renal function is unclear. This study aimed to evaluate incidence and clinical factors predictive of severe to end-stage chronic kidney disease (CKD) after SABR for RCC. METHODS AND MATERIALS: This was a Single institutional retrospective analysis of patients with diagnosed primary RCC receiving SABR between 2012-2020. Adult patients with no metastatic disease, baseline estimated glomerular filtration rate (eGFR) of ≥ 30 ml/min/1.73 m2, and at least one post-SABR eGFR at six months or later were included in this analysis. Patients with upper tract urothelial carcinoma were excluded. Primary outcome was freedom from severe to end-stage CKD, determined using the Kaplan-Meier estimator. The impact of baseline CKD, age, hypertension, diabetes, tumor size and fractionation schedule were assessed by Cox proportional hazard models. RESULTS: Seventy-eight consecutive patients were included, with median age of 77.8 years (IQR 70-83), tumor size of 4.5 cm (IQR 3.9-5.8) and follow-up of 42.2 months (IQR 23-60). Baseline median eGFR was 58 mls/min; 55% (n = 43) of patients had baseline CKD stage 3 and the remainder stage 1-2. By last follow-up, 1/35 (2.8%) of baseline CKD 1-2, 7/27 (25.9%) CKD 3a and 11/16 (68.8%) CKD 3b had developed CKD stage 4-5. The estimated probability of freedom from CKD stage 4-5 at 1 and 5 years was 89.6% (CI 83.0-97.6) and 65% (CI 51.4-81.7) respectively. On univariable analysis, worse baseline CKD (p < 0.0001) and multi-fraction SABR (p = 0.005) were predictive for development of stage 4-5 CKD though only the former remained significant in multivariable model. CONCLUSION: In this elderly cohort with pre-existing renal dysfunction, SABR achieved satisfactory nephron sparing with acceptable rates of severe to end-stage CKD. It can be an attractive option in patients who are medically inoperable.

Development of an automated treatment planning approach for lattice radiation therapy.

BACKGROUND: Lattice radiation therapy (LRT) alternates regions of high and low doses within the target. The heterogeneous dose distribution is delivered to a geometrical structure of vertices segmented inside the tumor. LRT is typically used to treat patients with large tumor volumes with cytoreduction intent. Due to the geometric complexity of the target volume and the required dose distribution, LRT treatment planning demands additional resources, which may limit clinical integration. PURPOSE: We introduce a fully automated method to (1) generate an ordered lattice of vertices with various sizes and center-to-center distances and (2) perform dose optimization and calculation. We aim to report the dosimetry associated with these lattices to help clinical decision-making. METHODS: Sarcoma cancer patients with tumor volume between 100 cm3 and 1500 cm3 who received radiotherapy treatment between 2010 and 2018 at our institution were considered for inclusion. Automated segmentation and dose optimization/calculation were performed by using the Eclipse Scripting Application Programming Interface (ESAPI, v16, Varian Medical Systems, Palo Alto, USA). Vertices were modeled by spheres segmented within the gross tumor volume (GTV) with 1 cm/1.5 cm/2 cm diameters (LRT-1 cm/1.5 cm/2 cm) and 2 to 5 cm center-to-center distance on square lattices alternating along the superior-inferior direction. Organs at risk were modeled by subtracting the GTV from the body structure (body-GTV). The prescription dose was that 50% of the vertice volume should receive at least 20 Gy in one fraction. The automated dose optimization included three stages. The vertices optimization objectives were refined during optimization according to their values at the end of the first and second stages. Lattices were classified according to a score based on the minimization of body-GTV max dose and the maximization of GTV dose uniformity (measured with the equivalent uniform dose [EUD]), GTV dose heterogeneity (measured with the GTV D90%/D10% ratio), and the number of patients with more than one vertex inserted in the GTV. Plan complexity was measured with the modulation complexity score (MCS). Correlations were assessed with the Spearman correlation coefficient (r) and its associated p-value. RESULTS: Thirty-three patients with GTV volumes between 150 and 1350 cm3 (median GTV volume = 494 cm3 , IQR = 272-779 cm3 were included. The median time required for segmentation/planning was 1 min/21 min. The number of vertices was strongly correlated with GTV volume in each LRT lattice for each center-to-center distance (r > 0.85, p-values < 0.001 in each case). Lattices with center-to-center distance = 2.5 cm/3 cm/3.5 cm in LRT-1.5 cm and center-to-center distance = 4 cm in LRT-1 cm had the best scores. These lattices were characterized by high heterogeneity (median GTV D90%/D10% between 0.06 and 0.19). The generated plans were moderately complex (median MCS ranged between 0.19 and 0.40). CONCLUSIONS: The automated LRT planning method allows for the efficacious generation of vertices arranged in an ordered lattice and the refinement of planning objectives during dose optimization, enabling the systematic evaluation of LRT dosimetry from various lattice geometries.

Patterns of practice regarding use of radiation therapy following radical prostatectomy: A survey of Radiation Oncologists and Urologists in Australia and New Zealand.

INTRODUCTION: This study aimed to investigate the patterns of practices of radiation oncologists (ROs) and urologists in Australia and New Zealand with respect to the utilisation of post-prostatectomy radiation therapy (RT) and help guide the development of an update to the existing Faculty of Radiation Oncology Genito-Urinary Group post-prostatectomy guidelines. METHODS: ROs and urologists with subspecialty practice in prostate cancer from Australia and New Zealand were invited to participate in an online survey comprised of clinical scenarios regarding post-prostatectomy RT. RESULTS: Sixty-five ROs and 28 urologists responded to the survey. In the setting of low-risk biochemical relapse, the threshold for initiating RT was lower for ROs than urologists. ROs were more likely than urologists to recommend adjuvant RT for node-positive disease. When salvage RT was advised for a pT3N0R1 recurrence, there was no consensus amongst ROs on whether to add either ADT or nodal treatment over prostate bed RT alone. For a solitary PSMA-avid pelvic lymph node recurrence, whole pelvis RT with androgen deprivation therapy was the preferred treatment option (72% ROs, 43% urologists). Most ROs (92%) recommended conventionally fractionated RT to 66-70 Gy, with a boost to any PSMA PET avid recurrent disease. CONCLUSION: This survey highlights the marked discordance in practice for the management of prostate cancer relapse post-prostatectomy. This is seen not only between specialties but also within the radiation oncology community. This emphasises the need for an updated evidence-based guideline to be produced.

Selection of motion management in liver stereotactic body radiotherapy and its impact on treatment time.

Background and purpose: Reduction of respiratory tumour motion is important in liver stereotactic body radiation therapy (SBRT) to reduce side effects and improve tumour control probability. We have assessed the distribution of use of voluntary exhale breath hold (EBH), abdominal compression (AC), free breathing gating (gating) and free breathing (FB), and the impact of these on treatment time. Materials and Methods: We assessed all patients treated in a single institution with liver SBRT between September 2017 and September 2021. Data from pre-simulation motion management assessment using fluoroscopic assessment of liver dome position in repeat breath holds, and motion with and without AC, was reviewed to determine liver dome position consistency in EBH and the impact of AC on motion. Treatment time was assessed for all fractions as time from first image acquisition to last treatment beam off. Results: Of 136 patients treated with 145 courses of liver SBRT, 68 % were treated in EBH, 20 % with AC, 7 % in gating and 5 % in FB. AC resulted in motion reduction < 1 mm in 9/26 patients assessed. Median treatment time was higher using EBH (39 min) or gating (42 min) compared with AC (30 min) or FB (24 min) treatments. Conclusions: Motion management in liver SBRT needs to be assessed per-patient to ensure appropriate techniques are applied. Motion management significantly impacts treatment time therefore patient comfort must also be taken into account when selecting the technique for each patient.

Impact of Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography in the Management of Oligometastatic Renal Cell Carcinoma.

Background: Prostate-specific membrane antigen (PSMA) is overexpressed in the neovasculature of renal cell carcinoma (RCC). However, there remains limited evidence regarding the use of PSMA positron emission tomography/computed tomography (PET/CT) in RCC. Objective: To assess the impact of PSMA PET/CT in the management of metastatic RCC. Design setting and participants: This was a retrospective review of patients who underwent PSMA PET/CT from 2014 to 2020 for restaging or suspected metastatic RCC in a tertiary academic setting. Outcome measurements and statistical analysis: Management plans before and after PSMA PET/CT were recorded. Impact was classified as high (change of treatment intent, modality, or site), medium (change in treatment method), or low. Secondary outcomes included the patient-level detection rate, PSMA PET/CT parameters, sensitivity, and comparison to CT and, if available, fluorodeoxyglucose (FDG) PET/CT. Results and limitations: Sixty-one patients met the inclusion criteria, of whom 54 (89%) had clear cell RCC. PSMA-positive disease was detected in 51 patients (84%). For 30 patients (49%) there was a change in management due to PSMA PET/CT (high impact, 29 patients, 48%). In 15 patients (25%), more metastases were detected on PSMA PET/CT than on CT. The sensitivity of combined PSMA PET/CT and diagnostic CT was 91% (95% confidence interval 77-98%). In a subcohort of 40 patients, the detection rate was 88% for PSMA and 75% for FDG PET/CT (p = 0.17). The maximum standardised uptake value (SUVmax) was higher for PSMA than for FDG PET/CT (15.2 vs 8.0; p = 0.02). Limitations include selection bias due to the retrospective design, and a lack of corresponding histopathology for all patients. Conclusions: PSMA PET/CT is a promising imaging modality in metastatic RCC and led to a change in management in 49% of patients. PSMA PET/CT detected additional metastases compared to CT in 25% of patients and registered a significantly higher SUVmax than FDG PET/CT. Prospective studies are required to further define its role. Patient summary: We report on a group of patients undergoing a new type of imaging for suspected advanced kidney cancer, called PSMA PET/CT. This imaging changed the management plan in 49% of the patients. PSMA PET/CT detected metastases in 84% of our patients and detected more metastases than computed tomography imaging in 25%.

Impact of Medical Operability and Total Metastatic Ablation on Outcomes After SABR for Oligometastases.

PURPOSE: Medical operability is prognostic for survival after SABR in primary malignancies. This study investigated the prognostic significance of medical operability and total versus subtotal ablation of all oligometastatic disease sites. METHODS AND MATERIALS: Consecutive patients with 1 to 5 sites of active extracranial oligometastases had medical operability status and presence of subtotal versus total metastatic ablation recorded prospectively in an institutional database. We retrospectively compared overall survival (OS) and progression-free survival (PFS) for medically operable or inoperable patients and patients undergoing total or subtotal metastatic ablation. Secondary endpoints were patterns of failure, high-grade treatment toxic effects (Common Terminology Criteria for Adverse Events version 4.0), and freedom from systemic therapy. The threshold dose per fraction considered ablative was 8 Gy. RESULTS: A total of 401 patients with 530 treated oligometastases were included, with a median follow-up of 3 years. Three hundred and two and 99 patients had metachronous and synchronous presentations of oligometastatic disease, respectively. Common histologies included prostate (24%), lung (18%), gastrointestinal (19%), and breast (11%). More than 90% of doses delivered were Biologically Effective Dose [BED10]≥60 Gy. Cumulative incidence at 5 years of local-only failure was 6%, local and distant 2%, and distant-only 58%. The 3- and 5-year OS [95% confidence intervals {CIs}] were 68% [62-73] and 54% [47-61], and PFS was 20% [15-25] and 14% [10-20]. The 3- and 5-year freedom from systemic therapy [95% CIs] were 40% [34-46] and 31% [24-37], respectively. Seventy-six patients were inoperable and 325 were operable. Operability status was not prognostic for OS (adjusted hazard ratio [HR], 1.0; 95% CI, 0.6-1.7; P = .9) or for PFS (adjusted HR, 1.1; 95% CI, 0.8-1.6; P = .5). Total metastatic ablation was prognostic for OS (adjusted HR, 0.8; 95% CI, 0.4-0.9; P = .032) and for PFS (adjusted HR, 0.6; 95% CI, 0.4-0.8; P = .003). CONCLUSIONS: Medical operability was not prognostic in patients with oligometastatic disease treated with SABR. Total metastatic ablation was associated with superior OS and PFS compared with subtotal metastatic ablation. Our data support ablation of all sites of oligometastases wherever feasible.

Stereotactic Radiotherapy and Short-course Pembrolizumab for Oligometastatic Renal Cell Carcinoma-The RAPPORT Trial.

BACKGROUND: Stereotactic ablative body radiotherapy (SABR) is an option for oligometastatic clear cell renal cell carcinoma (ccRCC) but is limited by a lack of prospective clinical trial data. OBJECTIVE: The RAPPORT trial evaluated the safety and efficacy of total metastatic irradiation followed by short-course anti-programmed death receptor-1 immunotherapy in patients with oligometastatic ccRCC. DESIGN SETTING, AND PARTICIPANTS: RAPPORT was a single-arm multi-institutional phase I/II trial (NCT02855203). Patients with two or fewer lines of prior systemic therapy and one to five oligometastases from ccRCC were eligible. INTERVENTION: A single fraction of 20 Gy SABR (or if not feasible, ten fractions of 3 Gy) was given to all metastatic sites, followed by pembrolizumab 200 mg administered Q3W for eight cycles. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The endpoints were adverse events (AEs), disease control rate (DCR) for at least 6 mo, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The Kaplan-Meier method was used for time-to-event endpoints. Freedom from local progression (FFLP) was assessed per lesion adding patient as a cluster effect. RESULTS AND LIMITATIONS: Thirty evaluable patients, with a median age of 62 yr, were enrolled. The median follow-up was 28 mo. There were 44% of patients with intermediate-risk and 56% with favorable-risk disease. Eighty-three oligometastases were irradiated (median three per patient): eight adrenal, 11 bone, 43 lung, 12 lymph node, and nine soft tissue. Four patients (13%) had grade 3 treatment-related AEs: pneumonitis (n = 2), dyspnea (n = 1), and elevated alkaline phosphatase/alanine transaminase (n = 1). There were no grade 4 or 5 AEs. FFLP at 2 yr was 92%. ORR was 63% and DCR was 83%. Estimated 1- and 2-yr OS was 90% and 74%, respectively, and PFS was 60% and 45%, respectively. Limitations include a single-arm design and selected patient population. CONCLUSIONS: SABR and short-course pembrolizumab in oligometastatic ccRCC is well tolerated, with excellent local control. Durable responses and encouraging PFS were observed, warranting further investigation. PATIENT SUMMARY: The RAPPORT trial investigated the combination of high-dose precision radiotherapy and a short course of immunotherapy in patients with low-volume metastatic kidney cancer. We found that this treatment regimen was well tolerated, with excellent cancer control in sites of known disease. A proportion of patients were free from cancer relapse in the longer term, and these encouraging findings warrant further investigation.

A phase I/II study of stereotactic radiotherapy and pembrolizumab for oligometastatic renal tumours (RAPPORT): Clinical trial protocol.

BACKGROUND: The management of oligometastatic clear cell renal cell carcinoma (ccRCC) varies widely, ranging from observation to resection or systemic therapies. Prolonged survival has been observed following resection or stereotactic ablative body radiotherapy (SABR). Immunotherapy combinations have shown survival benefits, however, toxicity is higher than that for monotherapy and complete response rates remain less than 10%. The combination of effective local therapies in conjunction with immunotherapy may provide more durable control and pre-clinical models have suggested a synergistic immune-priming effect of SABR. OBJECTIVES: and Methods: RAPPORT is a prospective, single arm, phase I/II study assessing the safety, efficacy and biological effects of single fraction SABR followed by pembrolizumab for oligometastatic ccRCC. The study will include 30 patients with histological confirmed ccRCC and 1-5 oligometastases, one or more of which must be suitable for SABR. Patients can have received prior systemic therapy but not prior immunotherapy. A single 20Gy of SABR is followed 5 days later by 8 cycles of 200 mg pembrolizumab, every 3 weeks. Adverse events are recorded using CTCAE V4.03 and tumour response evaluated by Response Evaluation Criteria in Solid Tumours version 1.1 (RECIST 1.1). Tumour tissue and peripheral blood samples will be collected pre-, during and post-treatment to assess longitudinal changes in immune subsets. OUTCOMES AND SIGNIFICANCE: The RAPPORT study will provide important safety and early efficacy data on the combination of SABR and pembrolizumab in oligometastatic ccRCC and will provide an insight into the underlying biological effects of combination therapy. TRIAL REGISTRATION: clinicaltrials.gov ID NCT02855203.

Results of phase II trial of intensified neoadjuvant treatment with interdigitating radiotherapy and chemotherapy with oxaliplatin, 5-fluorouracil and folinic acid in patients with locally advanced rectal cancer (PROARCT trial).

BACKGROUND AND PURPOSE: The chemotherapy exposure during chemoradiotherapy for rectal cancer is adequate for radiosensitization but suboptimal for treatment of distant micrometastasis. This study aimed to determine tolerability, dose intensity, response, and toxicity of a novel intensified neoadjuvant treatment approach. MATERIALS AND METHODS: Eligible patients were MRI-staged T3-4NxM0 rectal adenocarcinoma. Treatment consisted of FOLFOX chemotherapy given in weeks 1, 6, and 11 with pelvic radiotherapy (25.2 Gy in 3 weeks in 1.8 Gy/fraction with oxaliplatin and 5-FU continuous infusion) given in weeks 3-5, and weeks 8-10. Surgery was performed 4-6 weeks later. The primary endpoint was tolerability defined as the percentage of patients who were able to complete the planned treatment course. Survival rates were estimated using the Kaplan-Meier method. RESULTS: Median age of the 40 patients was 61.5 years. Rectal MRI-stage was T3 in 88%. Overall, 95% completed the regimen. All patients received 50.4 Gy. Relative dose intensity (≥75%) was 92% and 98% for oxaliplatin and 5-FU, respectively. High grade toxicities included neutropenia (25% grade 3; 7.5% grade 4) and diarrhoea (10%). Pathologic CR rate was 20%. Median follow-up was 54 months. The 5-year overall survival, freedom from relapse, locoregional control, and freedom from distant metastasis of the cohort was 82%, 72%, 97% and 72%. CONCLUSIONS: Delivery of intensified neoadjuvant treatment with interdigitating chemotherapy and radiotherapy is feasible with no increase in acute perioperative complications. A larger prospective study is required to further evaluate the potential survival benefit of this design.

Characterising the immune microenvironment in liposarcoma, its impact on prognosis and the impact of radiotherapy.

BACKGROUND AND OBJECTIVES: Limited literature exists examining the immune microenvironment in liposarcoma, particularly with regard to the impact of radiotherapy. A major problem is the lack of scoring system for the tumour-infiltrating lymphocytes (TILs) in sarcoma. This study aims to describe the immune environment pre- and postradiotherapy and identify the optimal immune infiltrate scoring system for sarcoma. METHODS: Thirty-nine paired tissue samples (pre- and postradiotherapy) from patients with liposarcoma were scored by two pathologists for TILs using pre-existing systems (for breast cancer and melanoma) and compared for interobserver reliability. Immunohistochemical staining was performed for various immune markers. RESULTS: The TIL scoring system for breast cancer yielded perfect agreement (κ = 1.000). 21% of patients had increased TILs after radiotherapy, 87.5% of whom had dedifferentiated liposarcoma. Immune suppressor expression was increased frequently after radiotherapy (CD68 increased in 59.4%, PD-L1 increased in 25%). Immune effector expression (CD8) was unchanged in 84.4%. CONCLUSIONS: Breast cancer TIL scoring is reproducible in liposarcoma and has high interobserver reliability. Radiotherapy was observed to have a limited impact on immune effectors but seemed to have more impact in upregulating immune suppressors, suggesting radiotherapy may contribute to disease control through immunomodulatory effects. Dedifferentiated liposarcoma represents a uniquely responsive subtype.

Safety, Efficacy, and Patterns of Failure After Single-Fraction Stereotactic Body Radiation Therapy (SBRT) for Oligometastases.

PURPOSE: Fewer attendances for radiation therapy results in increased efficiency and less foot traffic within a radiation therapy department. We investigated outcomes after single-fraction (SF) stereotactic body radiation therapy (SBRT) in patients with oligometastatic disease. METHODS AND MATERIALS: Between February 2010 and June 2019, patients who received SF SBRT to 1 to 5 sites of oligometastatic disease were included in this retrospective study. The primary objective was to describe patterns of first failure after SBRT. Secondary objectives included overall survival (OS), progression-free survival (PFS), high-grade treatment-related toxicity (Common Terminology Criteria for Adverse Events grade ≥3), and freedom from systemic therapy (FFST). RESULTS: In total, 371 patients with 494 extracranial oligometastases received SF SBRT ranging from 16 Gy to 28 Gy. The most common primary malignancies were prostate (n = 107), lung (n = 63), kidney (n = 52), gastrointestinal (n = 51), and breast cancers (n = 42). The median follow-up was 3.1 years. The 1-, 3-, and 5-year OS was 93%, 69%, and 55%, respectively; PFS was 48%, 19%, and 14%, respectively; and FFST was 70%, 43%, and 35%, respectively. Twelve patients (3%) developed grade 3 to 4 treatment-related toxicity, with no grade 5 toxicity. As the first site of failure, the cumulative incidence of local failure (irrespective of other failures) at 1, 3 and 5 years was 4%, 8%, and 8%, respectively; locoregional relapse at the primary was 10%, 18%, and 18%, respectively; and distant failure was 45%, 66%, and 70%, respectively. CONCLUSIONS: SF SBRT is safe and effective, and a significant proportion of patients remain FFST for several years after therapy. This approach could be considered in resource-constrained or bundled-payment environments. Locoregional failure of the primary site is the second most common pattern of failure, suggesting a role for optimization of primary control during metastasis-directed therapy.

Utilization of a Transanal TME Platform to Enable a Distal TME Dissection En Bloc with Presacral Fascia and Pelvic Sidewall with Intraoperative Radiotherapy Delivery in a Locally Advanced Rectal Cancer: Advanced Application of taTME.

Introduction: The safe introduction of transanal total mesorectal excision (taTME) has been documented by the Australasian group previously. The most important prognostic indicator for rectal cancer is the ability to achieve a clear resection margin. By utilizing false planes for taTME surgery, the endopelvic fascia and or presacral fascia can be resected en bloc. Technique: This case highlights the utilization of a taTME platform to perform a distal taTME with presacral fascial stripping and a lateral pelvic sidewall transanal-assisted dissection in a 53-year-old otherwise healthy woman with a mid-rectal tumor. Radiologically the tumor was staged as a T3c/T4 rectal cancer with an N1c deposit extending beyond mesorectal fascia abutting the left piriformis muscle. An extramural venous invasion positive tumor was evident with a positive circumferential resection margin at 4 o' clock. In addition, the taTME platform was used to allow transanal intraoperative radiotherapy (IORT) delivery to the sacrum. An R0 resection was achieved and the patient recovered well without incident. Results: Total operative time was 250 minutes with the patient being discharged on day 7 postoperatively without complication. Macroscopic evaluation revealed a grade III mesorectal excision with en bloc removal of presacral fascia. On microscopic evaluation, revealed a T3N1b tumor with 2 of 14 positive lymph nodes (0/5 pelvic sidewall nodes). Conclusion: The case highlights a novel application of taTME and is to the authors' best knowledge the first described use of a transanal platform to deliver intraoperative radiation therapy in the literature.

Australasian Gastrointestinal Trials Group (AGITG) and Trans-Tasman Radiation Oncology Group (TROG) Guidelines for Pancreatic Stereotactic Body Radiation Therapy (SBRT).

PURPOSE: Nonrandomized data exploring pancreas stereotactic body radiation therapy (SBRT) has demonstrated excellent local control rates and low toxicity. Before commencing a randomized trial investigating pancreas SBRT, standardization of prescription dose, dose constraints, simulation technique, and clinical target volume delineation are required. METHODS AND MATERIALS: Specialists in radiation oncology, medical oncology, hepatobiliary surgery, and gastroenterology attended 2 consecutive Australasian Gastrointestinal Trials Group workshops in 2017 and 2018. Sample cases were discussed during workshop contact with specifically invited international speakers highly experienced in pancreas SBRT. Furthermore, sample cases were contoured and planned between workshop contact to finalize dose constraints and clinical target volume delineation. RESULTS: Over 2 separate workshops, consensus was reached on dose and simulation technique. The working group recommended a dose prescription of 40 Gy in 5 fractions. Treatment delivery during end-expiratory breath hold with triple-phase contrast enhanced computed tomography was recommended. In addition, dose constraints, stepwise contouring guidelines, and an anatomic atlas for pancreatic SBRT were developed. CONCLUSIONS: Pancreas SBRT is emerging as a promising treatment modality requiring prospective evaluation in randomized studies. This work attempts to standardize dose, simulation technique, and volume delineation to support the delivery of high quality SBRT in a multicenter study.

NaF PET/CT for response assessment of prostate cancer bone metastases treated with single fraction stereotactic ablative body radiotherapy.

INTRODUCTION: In prostate cancer patients, imaging of bone metastases is enhanced through the use of sodium fluoride positron emission tomography (18F-NaF PET/CT). This imaging technique shows areas of enhanced osteoblastic activity and blood flow. In this work, 18F-NaF PET/CT was investigated for response assessment to single fraction stereotactic ablative body radiotherapy (SABR) to bone metastases in prostate cancer patients. METHODS: Patients with bone metastases in a prospective trial treated with single fraction SABR received a 18F-NaF PET/CT scan prior to and 6 months post-SABR. The SUVmax in the tumour was determined and the difference between before and after SABR determined. The change in uptake in the non-tumour bone was also measured as a function of the received SABR dose. RESULTS: Reduction in SUVmax was observed in 29 of 33 lesions 6 months after SABR (mean absolute decrease in SUVmax 17.7, 95% CI 25.8 to - 9.4, p = 0.0001). Of the three lesions with increased SUVmax post-SABR, two were from the same patient and located in the vertebral column. Both were determined to be local progression in addition to one fracture. The third lesion (in a rib) was shown to be controlled locally but suffered from a fracture at 24 months. Progression adjacent to the treated volume was observed in two patients. The non-tumour bone irradiated showed increased loss in uptake with increasing dose, with a median loss in uptake of 23.3% for bone receiving 24 Gy. CONCLUSION: 18F-NaF PET/CT for response assessment of bone metastases to single fraction SABR indicates high rates of reduction of osteoblastic activity in the tumour and non-tumour bone receiving high doses. The occurrence of marginal recurrence indicates use of larger clinical target volumes may be warranted in treatment of bone metastases. TRIAL REGISTRATION: POPSTAR, 'Pilot Study of patients with Oligometastases from Prostate cancer treated with STereotactic Ablative Radiotherapy', Universal Trial Number U1111-1140-7563 , Registered 17th April 2013.

Metastasis-directed Therapy in Treating Nodal Oligorecurrent Prostate Cancer: A Multi-institutional Analysis Comparing the Outcome and Toxicity of Stereotactic Body Radiotherapy and Elective Nodal Radiotherapy.

BACKGROUND: Stereotactic body radiotherapy (SBRT) and elective nodal radiotherapy (ENRT) are being investigated as metastasis-directed treatments in oligorecurrent prostate cancer (PC); however, comparative data are still lacking. OBJECTIVE: To compare outcome and toxicity between both treatments. Primary endpoint was metastasis-free survival, adjusted for selected variables (aMFS). DESIGN, SETTING, AND PARTICIPANTS: This was a multi-institutional, retrospective analysis of 506 (SBRT: 309, ENRT: 197) patients with hormone-sensitive nodal oligorecurrent PC (five or fewer lymph nodes (LNs; N1/M1a), treated between 2004 and 2017. Median follow-up was 36 mo (interquartile range 23-56). INTERVENTION: SBRT was defined as a minimum of 5 Gy per fraction to each lesion with a maximum of 10 fractions. ENRT was defined as a minimum dose of 45 Gy in up to 25 fractions to the elective nodes, with or without a simultaneous boost to the suspicious node(s). The choice of radiotherapy (RT) was at the discretion of the treating physician, with treatments being unbalanced over the centers. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: In total, 506 patients from 15 different treatment centers were included. Primary treatment was radical prostatectomy, RT, or their combination. Nodal recurrences were detected by positron emission tomography/computer tomography (97%) or conventional imaging (3%). Descriptive statistics was used to summarize patient characteristics. RESULTS AND LIMITATIONS: ENRT was associated with fewer nodal recurrences compared with SBRT (p < 0.001). In a multivariable analysis, patients with one LN at recurrence had longer aMFS after ENRT (hazard ratio: 0.50, 95% confidence interval 0.30-0.85, p = 0.009). Late toxicity was higher after ENRT compared with that after SBRT (16% vs. 5%, p < 0.01). Limitations include higher use of hormone therapy in the ENRT cohort and nonstandardized follow-up. CONCLUSIONS: ENRT reduces the number of nodal recurrences as compared with SBRT, however at higher toxicity. Our findings hypothesize that ENRT should be preferred to SBRT in the treatment of nodal oligorecurrences. This hypothesis needs to be evaluated in a randomized trial. PATIENT SUMMARY: This study investigated the difference between stereotactic and elective nodal radiotherapy in treating limited nodal metastatic prostate cancer. Nodal relapse was less frequent following elective nodal radiotherapy than following stereotactic body radiotherapy, and thus elective nodal radiotherapy might be the preferred treatment.

A clinical trial with protracted infusion 5-fluorouracil and mitomycin C for localized squamous cell carcinoma of the anus.

PURPOSE: Mitomycin C (MMC) plus standard 5-fluorouracil (FU) infusion in weeks 1 and 5 often contributes to radiotherapy interruptions and possibly less-than-ideal outcomes in anal cancer. This study was to evaluate alternative strategies for chemotherapy delivery that might be less toxic or more efficacious, and outcomes of patient-initiated treatment interruption for severe acute toxicity. MATERIALS AND METHODS: This was a prospective, nonrandomized study for patients with T1-4N0-3M0 anal squamous carcinoma. Radiotherapy of 54 Gy in 30 fractions over 6 weeks was given with infusion FU 300 mg/m2 /day for 96 hours/week for 6 weeks plus bolus MMC at 10 mg/m2 on D1. RESULTS: Fifty patients were recruited (72% female). Median age was 60.5 years (35-84). Forty-seven patients (94%) received 54 Gy. Median duration of chemoradiation was 39 days (37-105). Grade 3 and 4 acute toxicity were observed in 66%. Thirty-one percent with severe acute toxicity developed severe late toxicity. Of those who experienced severe late skin toxicity, 29% did not have severe acute toxicity. Disease-free survival at 5 years was 74% (95% confidence interval [CI], 60-84), and at 9 years 61% (95% CI, 46-74). Overall survival at 5 years was 84% (95% CI, 71-92), and at 9 years 67% (95% CI, 50-81). Colostomy-free survival at 5 years was 70% (95% CI, 56-81), and at 9 years 57% (95% CI, 40-72). CONCLUSION: It is feasible to deliver chemoradiation with bolus MMC and protracted infusion FU for anal cancer. Efficacy and toxicity of this regimen seem similar to conventional chemoradiation with FU/MMC. Acute skin toxicity is not a reliable predictor of severe late skin toxicity.

Treatment of patients with primary retroperitoneal sarcoma: predictors of outcome from an Australian specialist sarcoma centre.

BACKGROUND: Several unanswered questions surround the management of retroperitoneal sarcoma (RPS). Guidelines recommend treatment by a multidisciplinary team at a specialized referral centre. The objective of this study was to describe the management of RPS at an Australian specialist sarcoma centre, comparing outcomes to international standards and analysing for predictors of local failure. METHODS: A retrospective review of a prospectively maintained database was performed on patients with RPS treated between 2008 and 2016. A 5-year outcome analyses focussed on patients undergoing curative-intent surgery for primary, non-metastatic RPS. RESULTS: Eighty-eight patients underwent surgery for primary RPS. Five-year overall survival was 66%, 5-year freedom from local recurrence was 65% and 5-year freedom from distant metastasis was 71%. Overall survival was associated with tumour grade (hazard ratio (HR) 6.1, P < 0.001) and histologic organ invasion (HR 5.7, P < 0.001). Variables associated with improved freedom from local recurrence were macroscopically complete resection (HR 0.14, P < 0.001) and neoadjuvant radiotherapy (HR 0.33, P = 0.014). Treatment at a specialist sarcoma centre was associated with a higher rate of preoperative biopsy and neoadjuvant radiotherapy (both with P < 0.001). There was a trend towards improved local control for patients undergoing surgery at a specialist centre (P = 0.055). CONCLUSION: This is the largest Australian series of RPS and outcomes are comparable to major international sarcoma centres. Patients treated at a specialist centre had higher rates of preoperative diagnosis and tailored therapy which was associated with improved outcomes. Patients with suspected RPS should be referred to a specialist centre for optimal preoperative evaluation and multidisciplinary management.