Toxicity-Related Factors Associated With Use of Services Among Community Oncology Patients.

PURPOSE: Community oncology practices frequently manage chemotherapy-associated toxicities, which may disrupt treatment, impair quality of life, and induce unplanned service use. We sought to understand the patterns and correlates of unplanned health care service use among patients receiving first-cycle chemotherapy at five community-based ambulatory oncology practices. PATIENTS AND METHODS: A survey study examined the dichotomous outcome of unplanned service use, defined as oncologist visits, emergency department visits, and hospitalizations, resulting from toxicity-related factors. Newly diagnosed patients with breast, lung, head and neck, or colorectal cancer or non-Hodgkin lymphoma were recruited during the first chemotherapy cycle. Before beginning the second cycle of chemotherapy, patients completed a questionnaire that measured unplanned service use and overall distress, plus severity of nausea, vomiting, diarrhea, constipation, mouth sores, intravenous catheter problems, pain, fever and chills, extremity edema, and dyspnea on a 5-point scale (1, did not experience; 5, disabling). Medical record reviews captured chemotherapy doses, comorbid conditions, and supportive care interventions. Mixed-effects logistic regression was used to identify factors associated with unplanned service use, with random effects specified for each clinic. RESULTS: Among 106 patients (white, 98%; female, 74.5%; mean age ± standard deviation, 60 ± 11 years), frequently reported toxicities were pain, nausea, diarrhea, and constipation. Thirty-six patients (34%) reported unplanned service use: 29% reported oncologist visits, 14% reported emergency department visits, and 8% reported hospitalizations. Factors significantly associated with unplanned service use were high patient-reported distress and receipt of colony-stimulating factor. CONCLUSION: Service use resulting from toxicity-related factors occurs frequently in community oncology settings. Monitoring toxicity patterns and outcomes can inform proactive symptom management approaches to reduce toxicity burden between scheduled visits.

Laser-induced plasma spectroscopy of hydrogen Balmer series in laboratory air.

Stark-broadened emission profiles for the hydrogen alpha and beta Balmer series lines in plasma are measured to characterize electron density and temperature. Plasma is generated using a typical laser-induced breakdown spectroscopy (LIBS) arrangement that employs a focused Q-switched neodymium-doped yttrium aluminum garnet (Nd : YAG) laser, operating at the fundamental wavelength of 1064 nm. The temporal evolution of the hydrogen Balmer series lines is explored using LIBS. Spectra from the plasma are measured following laser-induced optical breakdown in laboratory air. The electron density is primarily inferred from the Stark-broadened experimental data collected at various time delays. Due to the presence of nitrogen and oxygen in air, the hydrogen alpha and beta lines become clearly discernible from background radiation for time delays of 0.4 and 1.4 µs, respectively.

Measurement and analysis of atomic hydrogen and diatomic molecular AlO, C2, CN, and TiO spectra following laser-induced optical breakdown.

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement is used. Here we operate a Nd:YAG laser at a frequency of 10 Hz at the fundamental wavelength of 1,064 nm. The 14 nsec pulses with anenergy of 190 mJ/pulse are focused to a 50 µm spot size to generate a plasma from optical breakdown or laser ablation in air. The microplasma is imaged onto the entrance slit of a 0.6 m spectrometer, and spectra are recorded using an 1,800 grooves/mm grating an intensified linear diode array and optical multichannel analyzer (OMA) or an ICCD. Of interest are Stark-broadened atomic lines of the hydrogen Balmer series to infer electron density. We also elaborate on temperature measurements from diatomic emission spectra of aluminum monoxide (AlO), carbon (C2), cyanogen (CN), and titanium monoxide (TiO). The experimental procedures include wavelength and sensitivity calibrations. Analysis of the recorded molecular spectra is accomplished by the fitting of data with tabulated line strengths. Furthermore, Monte-Carlo type simulations are performed to estimate the error margins. Time-resolved measurements are essential for the transient plasma commonly encountered in LIBS.