Proton therapy radiation pneumonitis local dose–response in esophagus cancer patients

Abstract

Purpose This study quantifies pulmonary radiation toxicity in patients who received proton therapy for esophagus cancer. Materials/methods We retrospectively studied 100 esophagus cancer patients treated with proton therapy. The linearity of the enhanced FDG uptake vs. proton dose was evaluated using the Akaike Information Criterion (AIC). Pneumonitis symptoms (RP) were assessed using the Common Toxicity Criteria for Adverse Events version 4.0 (CTCAEv4). The interaction of the imaging response with dosimetric parameters and symptoms was evaluated. Results The RP scores were: 0 grade 4/5, 7 grade 3, 20 grade 2, 37 grade 1, and 36 grade 0. Each dosimetric parameter was significantly higher for the symptomatic group. The AIC winning models were 30 linear, 52 linear quadratic, and 18 linear logarithmic. There was no significant difference in the linear coefficient between models. The slope of the FDG vs. proton dose response was 0.022 for the symptomatic and 0.012 for the asymptomatic (p = 0.014). Combining dosimetric parameters with the slope did not improve the sensitivity or accuracy in identifying symptomatic cases. Conclusions The proton radiation dose response on FDG PET/CT imaging exhibited a predominantly linear dose response on modeling. Symptomatic patients had a higher dose response slope.

Gaussian Mixture Models and Model Selection for [18F] Fluorodeoxyglucose Positron Emission Tomography Classification in Alzheimer’s Disease

“…The authors reported that the highest prognostic value appeared with the lowest AIC value, which suggested that AIC can be a guideline in choosing a desired model. In a proton therapy research study [ 16 ], the AIC was used to determine the most appropriate model for the FDG uptake dose response for each patient. A compound-B based PET kinetic modeling study [ 17 ] used AIC to ensure a good kinetic parameter setting.…”

18F-Fluorodeoxyglucose Positron Emission Tomography Can Quantify and Predict Esophageal Injury During Radiation Therapy

“…Previous studies have shown that FDG uptake can quantify normal tissue response in lung for patients with NSCLC and esophageal cancer (15–20)]. Nijkamp et al also examined the use of posttreatment FDG-PET studies to quantify esophageal injury from radiation therapy (23).…”

“…Standard SUV Mean and SUV Max were not able to stratify or predict the progression of esophagitis. The choice of normalization has been utilized in studies of radiation-induced lung toxicity using FDG-PET (15–20). Another study used change in FDG-PET SUV during radiation therapy relative to pre-treatment status (26).…”

“…Previous studies have shown normal tissue FDG-PET uptake is associated with radiation pneumonitis and esophagitis (14–20). However, no study has yet developed localized measures of FDG uptake, attempted to examine how the timing of esophagitis progression relates to mid-treatment FDG uptake, or investigated the ability of FDG uptake to detect or predict esophagitis symptom development, particularly to geometric regions of the esophagus.…”

Clinical outcomes and toxicities of proton radiotherapy for gastrointestinal neoplasms: a systematic review

“…Most (535/582, 92%) patients had adenocarcinoma and all underwent concurrent PBT, proton beam radiotherapy; CGE, cobalt gray equivalent; 5-FU, 5-fluorouracil; AP, anteroposterior; XRT, X-ray (photon) radiotherapy; LC, local control; DSS, disease-specific survival; OS, overall survival; DM, distant metastasis; IMRT, intensity-modulated radiotherapy; PA, posteroanterior; PFS, progression-free survival; RT, radiotherapy; GEJ, gastroesophageal junction; LPO, left posterior oblique; RPO, right posterior oblique; LRC, locoregional control; RFS, recurrence-free survival; DMFS, distant metastasis-free survival; 3DCRT, three-dimensional conformal radiotherapy; MS, median survival; LRR, locoregional recurrence; NS, nonsignificant. Table 1 lists several other articles examining PBT for esophageal cancers (9,(11)(12)(13)16,17). Over a decade of published PBT data point to the safety and efficacy of PBT for esophageal cancers, with or without chemotherapy and/or surgery.…”