Long-term outcomes of definitive radiation with volumetric modulated arc therapy and concurrent chemotherapy for squamous cell carcinoma of the anus in a regional Australian cancer centre.

INTRODUCTION: Concurrent chemoradiotherapy is the standard of care in the curative intent treatment of squamous cell carcinoma (SCC) of the anus. Volumetric arc therapy (VMAT) is a highly conformal radiation therapy technique that has been implemented to reduce toxicity for these patients. However, there are few reports evaluating the long-term outcomes of VMAT. Thus, we evaluated the survival and toxicity outcomes of anal cancer patients treated in our regional cancer centre undergoing curative intent chemoradiotherapy using VMAT and following the Australian EviQ guidelines. METHODS: All consecutive patients treated with the VMAT technique for curative-intent definitive chemoradiotherapy for anal SCC at our institution from 2013 until 2022 were retrospectively reviewed for survival and toxicity outcomes. Kaplan-Meier estimates of locoregional control, distant metastasis-free survival, disease-free survival, anal cancer-specific survival and overall survival were obtained. RESULTS: In total, 44 patients were analysed. The median follow-up was 48.9 months (Range 7.8-107). 97.7% of patients completed the prescribed radiation therapy and 88.6% chemotherapy. Five patients (11.4%) recurred. Four (9.1%) had isolated local failures, and one (2.3%) had an isolated distant failure. There were no regional nodal failures. The Kaplan-Meier estimates for locoregional control, distant metastasis-free survival, disease-free survival, anal cancer-specific survival and overall survival were 90.3%, 97.7%, 88.1%, 97.1% and 87% at 3 years, and 90.3%, 97.7%, 88.1%, 93.0% and 72.3% at 5 years, respectively. Acute grade 3 genitourinary (GU), gastrointestinal (GI) and skin toxicities occurred in 2.2%, 6.8% and 13.6% of patients, respectively. There were no acute grade 4 toxicities. Late grade 2 GU and GI toxicities occurred in 6.8% and 11.3% of patients, respectively. There were no late grade 3 or 4 toxicities or treatment-related deaths. The 5 -year colostomy-free survival rate was 86.4%. CONCLUSION: Outcomes for anal SCC after definitive chemoradiotherapy using VMAT in our regional cancer centre results in low rates of grade 3/4 toxicity, high rates of organ preservation and excellent survival outcomes.

Prostate-specific membrane antigen positron emission tomography detected local failure after post-prostatectomy radiation therapy: Low rates of out-of-field recurrence validates current Australian prostate bed contouring guidelines.

INTRODUCTION: The Australian Faculty of Radiation Oncology Genitourinary Group (FROGG) developed prostate bed clinical target volume (CTV) contouring guidelines which were subsequently used to develop the National EviQ guidelines for adjuvant and salvage post-prostatectomy radiotherapy (PPRT). These guidelines were based mainly upon consensus agreement. With the advent of prostate-specific membrane antigen (PSMA) positron emission tomography (PET), sites of recurrence can now be detected with low prostate-specific antigen (PSA) levels following radical prostatectomy. We evaluated sites of recurrence in patients treated with FROGG/EviQ CTVs to inform upcoming modifications of these guidelines. METHODS: At our institution, we use the FROGG/EviQ guidelines for PPRT. From 2015, patients with PSA failure following PPRT have been re-staged using PSMA PET imaging. We identified patients with PET-avid local, nodal, and distant recurrences, fusing them with original treatment plans to determine whether recurrences were within or outside the prostate bed CTV. Regional nodal failures were reviewed to determine if they were within current elective node contouring guidelines. RESULTS: Ninety-four patients had positive PSMA PET following PPRT. Nine (9.6%) recurrences were local, seven being local-only. One local recurrence (1.1%) was just superior to the contoured prostate bed CTV, located within the vas deferens. Seventy-three (77.7%) patients had a component of node failure, with 56 (59.6%) having node-only failure. Sites of nodal relapses were covered by standard contouring guidelines 60.3% of the time. CONCLUSION: The low recurrence rate outside of current prostate bed CTV contouring guidelines is consistent with other studies using contemporary contouring, and validates the efficacy of the current FROGG/EviQ prostate bed CTV definition.

PSMA-PET-guided dose-escalated volumetric arc therapy for newly diagnosed lymph node-positive prostate cancer: 5 Year outcomes following the FROGG and EviQ node-positive guidelines.

INTRODUCTION: The Royal Australian and New Zealand College of Radiologists (RANZCR) Faculty of Radiation Oncology Genitourinary Group (FROGG) guidelines and online EviQ protocols incorporate prostate-specific membrane antigen (PSMA) positron emission tomography (PET)-guided dose-escalated intensity-modulated radiation therapy (DE-IMRT) for newly diagnosed lymph node (LN) positive prostate cancer. We evaluated late toxicity and efficacy outcomes following the FROGG and EviQ approach. METHODS: Patients with LN-positive-only metastases on PSMA-PET imaging were offered curative therapy with 3 months neoadjuvant androgen deprivation therapy (ADT) followed by DE-IMRT and 3 years adjuvant ADT. IMRT was delivered via volumetric arc therapy (VMAT). We aimed to deliver 81 Gy in 45 fractions (Fx) to the prostate and PET-positive LNs, and 60 Gy in 45 Fx to elective pelvic nodes, contoured using the PIVOTAL guidelines. RESULTS: Forty-five patients were included. The median number of PET-positive nodes boosted was 2 (range 1-6) and median boost volume 1.16 cc (range 0.15-4.14). Seventeen (38%) patients had PET-positive nodes outside of PIVOTAL contouring guidelines. With 60 months median follow-up, disease-free, metastasis-free, prostate cancer-specific and overall survival were 88.1%, 95.3%, 100% and 91.5%. There were no in-field nodal failures. Late grade 1, 2 and 3 gastrointestinal toxicities occurred in 4%, 2% and 0% of patients, and genitourinary toxicity in 18%, 18% and 4%. Lower limb grade 2 lymphoedema occurred in three patients (7%). CONCLUSION: Outcomes following FROGG guidelines and EviQ are promising, with high long-term disease control and low toxicity. Contouring guidelines require modification due to the high rate of PET-positive nodes demonstrated beyond recommended coverage.

Pelvic MRI staging of endometriosis at 3 T without patient preparation or anti-peristaltic: Diagnostic performance outcomes.

PURPOSE: Endometriosis is a disease of significant burden among pre-menopausal women characterised by the appearance of functional endometrial tissue in locations outside the uterus. Deep infiltrating endometriosis (DIE) is an invasion of the endometriotic lesion that exceeds 5 mm in depth into the peritoneum. In most cases, pelvic MRI is the imaging modality of choice for the pre-operative workup for DIE to guide surgery. The recommended standard for pelvic MRI images is at 1.5 T with patient preparations in the form of laxatives, anti-spasmodics and/or rectal contrast. However, there appears to be equally diagnostic quality imaging obtainable with a 3 T system using fast imaging acquisition without any patient preparation. This reduces imaging time, movement artefacts, is more comfortable for the patient and is easier for workflow coordination. This study aims to confirm that this approach reaches diagnostic performance outcomes comparable to reported international standards, particularly in the detection of endometriotic bowel lesions, in order to guide surgical pre-operative planning. METHODS AND MATERIALS: Pre-operative diagnostic radiology reports were identified by a search of the Radiology Information System (RIS) for all pelvic MRI studies performed at a tertiary referral centre, King Edward Memorial Hospital for Women, between January 2015 to April 2017 that contained the keyword "endometriosis". Reported sites of endometriotic deposits at MRI findings were tallied based on anatomical location and correlated to laparoscopic surgical report findings and/or pathology report as a reference standard. Pooled sensitivities and specificities were then calculated and compared with established studies. RESULTS: Ninety-eight MRI studies were identified, of which 76 identified DIE and 22 were normal studies. Sixty-one patients did not have a surgical or pathology record. Of the remainder who underwent laparoscopy, operative and/or pathology reports were obtainable in 37 female patients, with a median age of 35 years (range: 24 to 49 years). The average time interval from MRI report to surgical operation was 195 days (range: 5 to 563 days). Middle compartment estimated sensitivity was 79.4% (95% CI = (69.4%, 89.4%)), specificity 95.1% (95% CI = (91.2%, 98.9%)). Posterior compartment estimated sensitivity was 76.5% (95% CI = (66.4%, 86.6%)), specificity 99.4% (95% CI = (98.1%, 100%)). Overall sensitivity 76.9% (95% CI = (69.7%, 84.0%)), specificity 98.5% (95% CI = (97.3%, 99.6%)). Sensitivity and specificity of detecting bowel endometriosis were estimated to be 94.4% (95% CI = (83.9%, 100%) and 94.7% (84.7%, 100%)) respectively. CONCLUSION: Using a 3 T MRI system without patient preparation is feasible and achieves benchmark diagnostic performance outcomes in the pre-operative assessment for DIE, especially in detecting posterior compartment lesions and bowel DIE to correctly guide surgical planning.