Solitary Extramedullary Plasmacytoma of the Head and Neck: A Report of Three Cases Treated With Curative Radiotherapy and a Review of the Dose-Control Relationship.

Solitary plasmacytoma is an uncommon hematologic malignancy characterized by the monoclonal proliferation of abnormal plasma cells in the bone or extramedullary tissues and the absence of other multiple myeloma-defining clinical characteristics. Mostly, solitary extramedullary plasmacytoma (SEP) occurs in the head and neck region, also called solitary extramedullary plasmacytoma of the head and neck (SEPHN). Although the standard of care for SEPHN is not well established, either a surgical approach or localized external beam radiotherapy (EBRT) can be used as a definitive treatment. Due to the high radiosensitivity of SEPHN, EBRT has been associated with adequate therapeutic effects in the management of SEP, with the advantage of being a noninvasive modality that yields high rates of local control with a reasonable toxicity profile. We present a case series of three patients with SEPHN treated with EBRT at our institution with clinical outcomes.

Laser Light Trapping Phenomenon in a 3D Radiotherapy Polymer Gel Dosimeter.

This paper aims to explain the phenomenon of laser light trapping (LLT) in a 3D polymer gel dosimeter. A VIC-T polymer gel dosimeter containing 17% N-vinylpyrrolidone, 8% N,N'-methylenebisacrylamide, 12% tert-butyl alcohol, 5% gelatine, 0.02% hydroquinone and 14 mM tetrakis(hydroxymethyl)phosphonium chloride was used in this study. It was exposed to green laser light with a wavelength of 532 nm. A film was recorded during the exposure. After exposure, Raman spectroscopy was used to study the reactions taking place inside the dosimeter. The obtained results were used to explain what the LLT phenomenon is, what are the consequences for the dosimeter in which such a phenomenon occurs, and what dosimeter components play an important role in the occurrence of LLT. In addition, the conditions under which 3D polymer gel dosimeters can be measured using optical computed tomography at short wavelengths of visible laser light are indicated.

Frequency of Mucositis Among Head and Neck Cancer Patients Receiving Three-Dimensional (3D) Radiotherapy.

Background and objective Head and neck cancer can arise from any site like hypo-pharynx, oro-pharynx, lip, oral cavity, or larynx. Almost 90% of them are head and neck squamous cell carcinomas (HNSCC). In the current project, the goal was to determine the frequency of acute side effects in terms of mucositis during and immediately post-irradiation period in patients receiving concurrent three-dimensional (3D) radiotherapy in a tertiary care hospital.  Methodology This descriptive case series with 106 enrolled patients was carried out from December 2019 to May 2020 at the Department of Radiation Oncology following approval. All patients were given radiotherapy or chemo-radio-therapy as per the clinician's advice and hospital protocol. All patients were evaluated at pre radiation time, at weekly intervals during treatment and at 11 weeks from 1st radiation fraction. Data was entered and analyzed by Statistical Package for Social Sciences, version 20 (SPSS Inc., Chicago, IL). Chi-square and Fisher's exact test was applied as p-value ≤ 0.05 was considered significant.  Results In the present study, all patients (n=106) showed a mean age of 57.8 ± 8.3 years. There was a gradual increase in grades of mucositis in all patients after treatments until seven weeks. After one month of post-treatment, a decrease in grades of mucositis was observed in all patients.  Conclusion Acute side effects appeared in all patients receiving 3D radiation therapy (RT) although the treatment response was good. Hence, we concluded it has a high incidence of treatment-related toxicities but it is safe.

Clinical radiotherapy application of N-vinylpyrrolidone-containing 3D polymer gel dosimeters with remote external MR-reading.

PURPOSE: Advanced 3D dosimetry is required for verifications of complex dose distributions in modern radiotherapy. Two 3D polymer gel dosimeters, coupled with magnetic resonance (MR) imaging (3 T MRI) readout and data processing with polyGeVero® software, were tested for the verification of calculated 3D dose distributions by a treatment planning system (TPS) and ArcCHECK®-3DVH®, related to eradication of a lung tumour. METHODS: N-vinylpyrrolidone-containing 3D polymer gel dosimeters were used: VIC (containing ascorbic acid and copper sulfate pentahydrate) and VIC-T (containing tetrakis(hydroxymethyl)phosphonium chloride). Three remote centers were involved in the dosimeters preparation and irradiation (Poland), and MRI (Austria). Cross beam calibration of the dosimeters and verification of a 3D dose distribution calculated with an Eclipse External Beam TPS and ArcCHECK®-3DVH® were performed. The 3D-to-3D comparisons of the VIC and VIC-T with TPS and ArcCHECK®-3DVH® along with ArcCHECK®-3DVH® versus TPS dose matrixes were performed with the aid of the polyGeVero® by analyzing dose profiles, isodoses lines, gamma index, gamma angle, dose difference, and related histograms. RESULTS: The measured MR-relaxation rate (R2 = 1/T2) for the dosimeters relates to the dose, as follows: R2 = 0.0928 ± 0.0008 [Gy-1 s-1] × D [Gy] + 2.985 ± 0.012 [s-1] (VIC) and 0.1839 ± 0.0044 [Gy-1 s-1] × D [Gy] + 2.519 ± 0.053 [s-1] (VIC-T). The 3D-to-3D comparisons revealed a good agreement between the measured and calculated 3D dose distributions. CONCLUSIONS: VIC and VIC-T with 3T MRI readout and polyGeVero® showed potential for verifications of calculated irradiation plans. The results obtained suggest the implementation of the irradiation plan for eradication of the lung tumour.

Prevalence and characterization of breakthrough pain in cancer patients with proctalgia treated with 3D pelvic radiotherapy.

PURPOSE: Radiotherapy-induced dysfunction of the gastrointestinal tract is common in cancer patients and has a significant impact on their quality of life. In this study, we investigated the prevalence of breakthrough cancer pain (BTcP) in patients undergoing 3D pelvic radiotherapy and who had proctalgia. METHODS: This observational, multicenter, cross-sectional epidemiological study was performed in 13 Spanish hospitals. Data were obtained on the presence and characteristics of BTcP, demographics, common comorbidities, and treatments prescribed to the patients. RESULTS: The prevalence of BTcP in patients undergoing pelvic 3D external radiotherapy with proctalgia (N = 105) was 48.6% (95% CI 39.0-58.1%). BTcP was further characterized in 59 patients. The mean (± SD) intensity of the BTcP episodes was 7.45 ± 1.47 in a visual analog scale. We found several statistically significant associations between the descriptive variables of BTcP with demographic and clinical variables associated with the tumor or the patient, such as an increased number of BTcP episodes per day depending on the presence or absence of diabetes (p = 0.001, Chi-square) or time to the onset of pain relief depending on the location of the tumor (p = 0.019, Chi-square). Fentanyl was the drug of choice in BTcP episodes for 95% of the patients. CONCLUSIONS: This study demonstrated a high prevalence of BTcP prevalence in cancer patients undergoing pelvic 3D radiotherapy and with proctalgia. Although the variables determining the onset of BTcP are still unclear, our results could help in the design of future clinical studies addressing the treatment of BTcP in these patients.

Long-Term Results of a Trial of Concurrent Chemotherapy and Escalating Doses of Radiation for Unresectable Non-Small Cell Lung Cancer: NCCTG N0028 (Alliance).

INTRODUCTION: This phase I/II trial was designed to determine the maximally tolerated dose of thoracic radiotherapy as part of a combined modality approach. This report includes the long-term outcomes of patients treated on this study. The phase II portion was never completed, as RTOG-0617 opened before it was concluded. METHODS: In this study, the maximally tolerated dose was defined as 74 Gy of radiation in 37 fractions. Twenty-five patients with unresectable NSCLC were treated with 2-Gy daily fractions and concurrent weekly carboplatin and paclitaxel. Of these patients, 20 had stage III disease and five had stage I or II disease. RESULTS: Patients were followed until death or for a minimum of 5 years in the case of survivors. The median and 5-year survivals were 42.5 months and 20% for all patients, 52.9 months and 40% in patients with stages I or II disease, and 39.8 months and 15% in patients with stage III disease. CONCLUSIONS: The median survival of the stage III patients was quite favorable. We believe that this may have been due to a robust central review program of radiotherapy plans before treatment, ensuring compliance with protocol guidelines along with very low exposure of the heart to radiotherapy. Further improvements in 5-year survival will likely require research on both systemic therapy and thoracic radiotherapy. Potential therapeutic modalities that may aid in these efforts include immunotherapy, targeted therapy, improved imaging, adaptive radiotherapy, simultaneous integrated boost techniques, novel dose fractionation regimens, and charged particle therapy.

IMRT delivers lower radiation doses to dental structures than 3DRT in head and neck cancer patients.

BACKGROUND: Radiotherapy (RT) is frequently used in the treatment of head and neck cancer, but different side-effects are frequently reported, including a higher frequency of radiation-related caries, what may be consequence of direct radiation to dental tissue. The intensity-modulated radiotherapy (IMRT) was developed to improve tumor control and decrease patient's morbidity by delivering radiation beams only to tumor shapes and sparing normal tissue. However, teeth are usually not included in IMRT plannings and the real efficacy of IMRT in the dental context has not been addressed. Therefore, the aim of this study is to assess whether IMRT delivers lower radiation doses to dental structures than conformal 3D radiotherapy (3DRT). MATERIAL AND METHODS: Radiation dose delivery to dental structures of 80 patients treated for head and neck cancers (oral cavity, tongue, nasopharynx and oropharynx) with IMRT (40 patients) and 3DRT (40 patients) were assessed by individually contouring tooth crowns on patients' treatment plans. Clinicopathological data were retrieved from patients' medical files. RESULTS: The average dose of radiation to teeth delivered by IMRT was significantly lower than with 3DRT (p = 0.007); however, only patients affected by nasopharynx and oral cavity cancers demonstrated significantly lower doses with IMRT (p = 0.012 and p = 0.011, respectively). Molars received more radiation with both 3DRT and IMRT, but the latter delivered significantly lower radiation in this group of teeth (p < 0.001), whereas no significant difference was found for the other dental groups. Maxillary teeth received lower doses than mandibular teeth, but only IMRT delivered significantly lower doses (p = 0.011 and p = 0.003). Ipsilateral teeth received higher doses than contralateral teeth with both techniques and IMRT delivered significantly lower radiation than 3DRT for contralateral dental structures (p < 0.001). CONCLUSION: IMRT delivered lower radiation doses to teeth than 3DRT, but only for some groups of patients and teeth, suggesting that this decrease was more likely due to the protection of other high risk organs, and was not enough to remove teeth from the zone of high risk for radiogenic disturbance (>30Gy).

Prostate cancer radiation therapy: A physician's perspective.

Prostate cancer is the second most common cancer in men and a major cause of cancer deaths worldwide. Ionizing radiation has played a substantial role in the curative treatment of this disease. The historical evolution of radiotherapy techniques through 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and image-guided radiotherapy (IGRT) has allowed more accurate and precise treatments toward significant improvements in the therapeutic ratio. The addition of androgen deprivation therapy has significantly improved overall survival becoming the standard therapy for intermediate- and high-risk disease. Many randomized controlled trials have shown improved local control with dose escalation, and hypofractionated RT has been consolidated with proven efficacy and safe clinical results. However, several questions remain open in the radiotherapeutic management of prostate cancer patients and hopefully ongoing studies will shed light on these uncertainties. More individualized approaches are essential through better prognostic and novel predictive biomarkers of prostate radiotherapy response. Clinicians should critically interpret the evolving technologies in prostate cancer radiotherapy with important optimism but balancing the costs and the actual magnitude of clinical benefit. This article provides an overview of the basic aspects of radiotherapy treatment in localized prostate cancer from a physician's perspective.

Proton beam therapy for locally advanced lung cancer: A review.

Protons interact with human tissue differently than do photons and these differences can be exploited in an attempt to improve the care of lung cancer patients. This review examines proton beam therapy (PBT) as a component of a combined modality program for locally advanced lung cancers. It was specifically written for the non-radiation oncologist who desires greater understanding of this newer treatment modality. This review describes and compares photon (X-ray) radiotherapy (XRT) to PBT. The physical differences of these beams are described and the clinical literature is reviewed. Protons can be used to create treatment plans delivering significantly lower doses of radiation to the adjacent organs at risk (lungs, esophagus, and bone marrow) than photons. Clinically, PBT combined with chemotherapy has resulted in low rates of toxicity compared to XRT. Early results suggest a possible improvement in survival. The clinical results of proton therapy in lung cancer patients reveal relatively low rates of toxicity and possible survival benefits. One randomized study is being performed and another is planned to clarify the clinical differences in patient outcome for PBT compared to XRT. Along with the development of better systemic therapy, newer forms of radiotherapy such as PBT should positively impact the care of lung cancer patients. This review provides the reader with the current status of this new technology in treating locally advanced lung cancer.