Prognostication methods for patients treated with palliative radiotherapy: a narrative review.

BACKGROUND AND OBJECTIVE: Palliative radiotherapy (PRT) practice patterns among radiation oncologists are heterogeneous. Appropriate selection of PRT regimen must balance symptom/disease control with patient quality of life. The aim of this review is to summarize prognostic scoring systems for PRT in order to help guide clinical decision making and selection of appropriate PRT regimens. METHODS: A PubMed search was conducted for articles published between 01/2000 and 07/2023. Standardized search terms including "palliative", "radiotherapy" and "survival" were used. Only English-language, peer-reviewed articles that presented a prognostic scoring system of PRT were included in this review. KEY CONTENT AND FINDINGS: In this study, we review the published literature on prognostic scoring systems for patients treated with PRT. Multiple models have been developed and each pertains to a specific patient population or primary tumor type. While they are specific to a particular patient population, all models incorporate patients' clinical characteristics such as primary site, performance status, location of metastatic disease, and indication for PRT to estimate overall survival (OS) after PRT. For each model, the salient points of the scoring system are described. Based on survival estimates from each prognostic system, different PRT regimens are recommended. CONCLUSIONS: PRT scoring systems can be used to help clinicians assess patient prognosis. With the information provided by the included studies, radiation oncologists will be better prepared to formulate an optimal, individualized treatment plan for patients to be treated with PRT.

Isoform Switching Regulates the Response to Ionizing Radiation Through SRSF1.

PURPOSE: This study investigated how isoform switching affects the cellular response to ionizing radiation (IR), an understudied area despite its relevance to radiation therapy in cancer treatment. We aimed to identify changes in transcript isoform expression post-IR exposure and the proteins mediating these changes, with a focus on their potential to modulate radiosensitivity. METHODS AND MATERIALS: Using RNA sequencing, we analyzed the B-cell lines derived from 10 healthy individuals at 3 timepoints, applying the mixture of isoforms algorithm to quantify alternative splicing. We examined RNA binding protein motifs within the sequences of IR-responsive isoforms and validated the serine/arginine-rich splicing factor 1 (SRSF1) as a predominant mediator through RNA immunoprecipitation. We further investigated the effects of SRSF1 on radiosensitivity by RNA interference and by analyzing publicly available data on patients with cancer. RESULTS: We identified ∼1900 radiation-responsive alternatively spliced isoforms. Many isoforms were differentially expressed without changes in their overall gene expression. Over a third of these transcripts underwent exon skipping, while others used proximal last exons. These IR-responsive isoforms tended to be shorter transcripts missing vital domains for preventing apoptosis and promoting cell division but retaining those necessary for DNA repair. Our combined computational, genetic, and molecular analyses identified the proto-oncogene SRSF1 as a mediator of these radiation-induced isoform-switching events that promote apoptosis. After exposure to DNA double-strand break-inducing agents, SRSF1 expression decreased. A reduction in SRSF1 increased radiosensitivity in vitro and among patients with cancer. CONCLUSIONS: We establish a pivotal role for isoform switching in the cellular response to IR and propose SRSF1 as a promising biomarker for assessing radiation therapy effectiveness.

Radiotherapy for Advanced Hodgkin Lymphoma with Initial Bulk: A Combined Analysis of Two Randomized Trials.

Purpose: The role of consolidative radiation therapy (RT) in patients with advanced Hodgkin lymphoma with initial bulk is unclear. GITIL/FIL HD0607 and FIL HD0801, 2 randomized controlled trials with similar design and methodologies, did not identify a benefit to consolidative RT after a metabolic complete response to 6 cycles of doxorubicin, bleomycin, vinblastine and dacarbazine. However, their limited sample sizes reduced statistical power to detect a small but clinically meaningful benefit to RT. Methods and Materials: In a secondary analysis of these 2 phase 3 trials, reconstructed patient data were used to compare outcomes for early and complete responders randomized to no RT or RT to the site(s) of initial bulk. Estimates of progression-free survival (PFS) in the intent-to-treat (ITT) and per-protocol (PP) analyses were generated using the combined data and compared between groups using the log-rank test. Results: A total of 412 patients were included in the ITT analysis, and 373 patients were included in the PP analysis. Median age was 30 to 32 years, 42% of patients were stage IIB, and 73% of bulky sites were located in the mediastinum. For the no RT versus RT groups, 5-year ITT PFS estimates were 90.1% versus 90.1%, respectively (P = .81). Five-year PP PFS rates were 90.9% versus 92.9%, respectively (P = .31). There was no observed difference between no RT and RT groups in subgroups according to size of bulky disease: 5 to 7 cm (P = .78), 7 to 10 cm (P = .25), and >10 cm (P = .69). Conclusions: In this combined analysis of 2 randomized phase 3 clinical trials, consolidative RT to initial sites of bulky nodal involvement was not associated with a PFS benefit in patients with advanced Hodgkin lymphoma in metabolic complete response after 2 and 6 cycles of doxorubicin, bleomycin, vinblastine and dacarbazine.