Palliative radiotherapy and the introduction of a Rapid Access Palliative Clinic in a national radiation oncology network.

BACKGROUND: Palliative radiotherapy (PRT) is commonly used to treat symptoms of advanced cancer. PRT has been associated with elevated 30-day mortality (30DM). A Rapid Access Palliative Clinic (RAPC) can streamline the treatment process for patients receiving treatment. AIMS: We reviewed the PRT practices in a radiation oncology network in Ireland, and the implementation of a RAPC. Patient outcomes were assessed to inform future treatment decisions. METHODS: A retrospective review of all patients who received PRT over 6 months in 2018 in St. Luke's Radiation Oncology Network (SLRON) was undertaken. We assessed 30DM rates, demographics and referral to specialist palliative care (SPC) services. Subsequently, a retrospective analysis was conducted of a RAPC which ran for 6 months from 2019 to 2020. We assessed treatment data and mortality. RESULTS: Over 6 months, 645 patients commenced PRT in the SLRON. The 30DM for this cohort was 15.8% (n = 102), with most patients having lung primaries. Of the 30DM cohort, only 55% (n = 56) were referred to SPC services and only 26.4% (n = 27) had performance status recorded. Over 6 months, 40 patients attended 28 RAPCs. Of these, 88% (n = 35) received PRT. Single fraction therapy was utilised in 60% and 48% of patients underwent CT simulation and treatment on the same day. Ultimately, 75% of patients received SPC referral. CONCLUSIONS: Referral rates to SPC services and documentation of performance status were low in our 30DM retrospective review cohort. The RAPC facilitated quick treatment turnaround, fewer hospital visits and referral to SPC services.

Off-axis dose distribution with stand-in and stand-off configurations for superficial radiotherapy treatments.

Current practice when delivering dose for superficial skin radiotherapy is to adjust the monitor units so that the prescribed dose is delivered to the central axis of the superficial unit applicator. Variations of source-to-surface distance due to patient's anatomy protruding into the applicator or extending away from the applicator require adjustments to the monitor units using the inverse square law. Off-axis dose distribution varies significantly from the central axis dose and is not currently being quantified. The dose falloff at the periphery of the field is not symmetrical in the anode-cathode axis due to the heel effect. This study was conducted to quantify the variation of dose across the surface being treated and model a simple geometric shape to estimate a patient's surface with stand-in and stand-off. Isodose plots and color-coded dose distribution maps were produced from scans of GAFChromic EBT-3 film irradiated by a Gulmay D3300 orthovoltage x-ray therapy system. It was clear that larger applicators show a greater dose falloff toward the periphery than smaller applicators. Larger applicators were found to have a lower percentage of points above 90% of central axis dose (SA90). Current clinical practice does not take this field variation into account. Stand-in can result in significant dose falloff off-axis depending on the depth and width of the protrusion, while stand-off can result in a flatter field due to the high-dose region near the central axis being further from the source than the peripheral regions. The central axis also received a 7% increased or decreased dose for stand-in or stand-off, respectively.

Human papillomavirus detection and genotyping, by HC2, full-spectrum HPV and molecular beacon real-time HPV assay in an Irish colposcopy clinic.

Cervical screening programmes are moving towards HPV testing as part of the screening process and as a triage for colposcopy. Three HPV detection methods were evaluated using cervical cytology specimens from colposcopy patients. PreservCyt™ liquid based cytology specimens from 241 women attending colposcopy clinics with greater than 2 persistently abnormal smears were recruited through the Coombe Women and Infants University Hospital, Dublin. HPV DNA was detected by Hybrid Capture (HC2) for 13 high-risk HPV types, Full-Spectrum HPV (FS-HPV) for 49 high and low-risk types and Molecular Beacon Real-Time HPV assay (MBRT-HPV) for 16 high and low-risk types. HPV genotyping was performed using Linear Array HPV Assay (LA-HPV). HPV was detected in 83.3% (195/234), 91.9% (217/236) and 80.1% (169/211) of cytology specimens by HC2, FS-HPV and MBRT-HPV, HPV DNA detection assays. The sensitivity of the assays for the detection of high-risk HPV in cytology specimens that had a Cervical Intraepithelial Neoplasia Grade 2+ result by histology were, 98%, 97% and 94% for HC2, FS-HPV and MBRT-HPV assays with positive predictive values of 94.1%, 94.1% and 97.3%. The most common HPV genotypes were HPV 16, 31, 33, 58, 42, 61 and 53, and the most common high-risk HPV genotypes were HPV 16, 31, 33, 58, 18, 45, 59, 51, 56 and 39, with detection of multiple infections in 57.7% of all cases. FS-HPV and MBRT-HPV are highly sensitive and have a similarly high PPV as the HC2 assay for detection of HPV in patients with Cervical Intraepithelial Neoplasia Grade 2+ disease. HPV genotyping of women with persistent abnormalities is warranted prior to the introduction of HPV DNA testing in a colposcopy setting.

Evaluation of type-specific HPV persistence and high-risk HPV viral load quantitation in HPV positive women under 30 with normal cervical cytology.

The persistence of high-risk HPV (HR-HPV) infection is necessary for the development of cervical intraepithelial neoplasia. The aim of this study was to evaluate if HR-HPV typing and HPV16, 18, 31, and 33 quantitation are predictive for type-specific infection persistence and/or the development of CIN in women under 30 with normal cervical cytology. Young women (under 30) attending a family planning clinic who were HPV positive with normal cervical cytology were included. HPV genotyping was assessed by MY09/MY11 PCR, sequencing, phylogenetic analysis, and cloning when necessary. HR-HPV viral load was quantified using duplex real-time PCR. Study patients were offered for a second smear and HR-HPV detection and quantitation after 12 months. HR-HPV was identified in 43 (21.9%) of the 199 included women. Of these, 39 patients had a second cervical sample taken within a mean interval of 11.7 months (8.8-18.3 months). The mean HR-HPV 16, 18, 31, and 33 initial viral load was 1.9 × 10(6) copies/million cells. The level of viral load did not reveal any significant association with type-specific HR-HPV persistence or the subsequent development of cervical intraepithelial neoplasia. Only HPV16 infection was significantly more likely to persist (91.7% vs. 33.1%, P=0.001) and to develop CIN (33.3% vs. 3.7%, P=0.025). In women under 30 with normal cytology, HR-HPV viral load is common and is not predictive of HPV persistence or the development of cervical intraepithelial neoplasia. HPV16 positive women are significantly more likely to have persistent infection and to develop cervical intraepithelial neoplasia.