Lumbosacral Plexopathy After Carbon-ion Radiation Therapy for Postoperative Pelvic Recurrence of Rectal Cancer: Subanalysis of a Prospective Observational Study (GUNMA 0801)

IF 2.2 Q3 ONCOLOGY

Advances in Radiation Oncology Pub Date : 2025-02-07 DOI:10.1016/j.adro.2024.101711

Takuya Kumazawa MD, PhD , Shintaro Shiba MD, PhD , Yuhei Miyasaka MD, PhD , Masahiko Okamoto MD, PhD , Daijiro Kobayashi MD, PhD , Tatsuya Ohno MD, PhD

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引用次数: 0

Abstract

Purpose

Data are lacking on the risk factors for radiation-induced lumbosacral plexopathy (RILSP) after carbon-ion radiation therapy (CIRT) for pelvic tumors, such as postoperative recurrence of rectal cancer. We investigated the incidence of RILSP and the associated dosimetric parameters using data from a prospective study of CIRT for postoperative pelvic recurrence of rectal cancer (GUNMA 0801).

Methods and Materials

The GUNMA 0801 study included 28 patients, of which we analyzed 20 without lumbosacral plexopathy prior to CIRT. The total dose of CIRT was 73.6 Gy (relative biological effectiveness [RBE]) in 16 fractions. The incidence of RILSP and parameters of the dose-volume histogram were evaluated for the lumbosacral plexuses. RILSP was graded according to the Common Terminology Criteria for Adverse Events version 4.0.

Results

Median follow-up was 24 months. The incidence of all RILSP (grades 1 and 2) and grade 2 RILSP was 22.5% (9/40) and 10% (4/40) of 40 lumbosacral plexuses in 20 patients, respectively, and no grade ≥ 3 toxicity was observed. Throughout the dose range, the volumes of the irradiated lumbosacral plexuses were significantly higher in patients with RILSP than in patients without RILSP (P < .001 for Dmax, D0.5 cm³ − D2 cm³, V20 Gy(RBE) − V70 Gy(RBE)). D2 cm³ and V50 Gy(RBE) were considered useful for receiver operating characteristic analysis. Cutoff values for RILSP were 73.82 Gy(RBE) and 33.2% for D2 cm³ and V50 Gy(RBE), respectively.

Conclusions

We demonstrated the incidence and predictive dosimetric parameters for RILSP after CIRT and showed that D2 cm³ ≥ 73.82 Gy(RBE) and V50 Gy(RBE) = 33.2% are cutoff values for predicting RILSP. These results would improve treatment plans using CIRT for patients with pelvic recurrences of rectal cancer.

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来源期刊

Advances in Radiation Oncology Medicine-Radiology, Nuclear Medicine and Imaging

CiteScore

4.60

自引率

4.30%

发文量

208

审稿时长

98 days

期刊介绍： The purpose of Advances is to provide information for clinicians who use radiation therapy by publishing: Clinical trial reports and reanalyses. Basic science original reports. Manuscripts examining health services research, comparative and cost effectiveness research, and systematic reviews. Case reports documenting unusual problems and solutions. High quality multi and single institutional series, as well as other novel retrospective hypothesis generating series. Timely critical reviews on important topics in radiation oncology, such as side effects. Articles reporting the natural history of disease and patterns of failure, particularly as they relate to treatment volume delineation. Articles on safety and quality in radiation therapy. Essays on clinical experience. Articles on practice transformation in radiation oncology, in particular: Aspects of health policy that may impact the future practice of radiation oncology. How information technology, such as data analytics and systems innovations, will change radiation oncology practice. Articles on imaging as they relate to radiation therapy treatment.