Radiation Therapy for Small-Cell Lung Cancer: ASCO Guideline Endorsement of an ASTRO Guideline.

PURPOSE: The American Society for Radiation Oncology (ASTRO) produced an evidence-based guideline on radiation therapy (RT) for small-cell lung cancer (SCLC). Because of the relevance of this topic to ASCO membership, ASCO reviewed the guideline, applying a set of procedures and policies used to critically examine guidelines developed by other organizations. METHODS: The ASTRO guideline on RT for SCLC was reviewed for developmental rigor by methodologists. Then, an ASCO Expert Panel reviewed the content and the recommendations. RESULTS: The ASCO Expert Panel determined that the recommendations from ASTRO guideline on RT for SCLC, published in June 2020, are clear, thorough, and based upon the most relevant scientific evidence. ASCO endorsed ASTRO guideline on RT for SCLC with a few discussion points. RECOMMENDATIONS: Recommendations addressed thoracic radiotherapy for limited-stage SCLC, role of stereotactic body radiotherapy in stage I or II node-negative SCLC, prophylactic cranial radiotherapy, and thoracic consolidation for extensive-stage SCLC.Additional information is available at www.asco.org/thoracic-cancer-guidelines.

Radium-223 (Xofigo) with concurrent abiraterone or enzalutamide: predictive biomarkers of improved overall survival in a clinically advanced cohort.

PURPOSE: Radium-223 (Xofigo) is the first therapy with bone tropism for metastatic castrate-resistant prostate cancer (mCRPC) that has been shown to improve overall survival (OS). Although radium-223 has a positive effect on OS in men with mCRPC, there has been a paucity of reports from community practitioners, especially with regard to concurrent abiraterone and enzalutamide therapy. Significant differences in patient characteristics encountered may exist. PATIENTS AND METHODS: We conducted a retrospective study of men with mCRPC who received at least 1 cycle of radium-223 (n = 35). Baseline pain and ECOG PS as well as concurrent usage of abiraterone or enzalutamide were recorded. Side effect profiles for each patient throughout treatment were noted. RESULTS: Baseline cohort characteristics include a median age of 75 years. 37% had an ECOG PS ≥ 2 and 23% reported severe pain at baseline. 31% received concomitant enzalutamide 31% concomitant abiraterone. Patients treated concurrently with either abiraterone or enzalutamide did not display additional toxicity. Median cohort OS was 10 months. Patients with no or mild pain had longer median OS than those with moderate or severe pain, 14 versus 7 months (P = 0.028). Patients with ECOG PS < 2 had longer median OS than those with ECOG PS ≥ 2, 13 versus 10 months (P = 0.0233). CONCLUSION: This study highlights key differences in patient characteristics encountered by community practitioners. In this population, which presented with clinically advanced disease, there was an improved survival benefit for those treated earlier in their disease. Radium-223 was well tolerated and concurrent treatment with abiraterone or enzalutamide did not add additional toxicity. These 2 points seem to advocate for aggressive and early treatment of patients with radium-223 in the community.

Postoperative Radiation Therapy for Endometrial Cancer: American Society of Clinical Oncology Clinical Practice Guideline Endorsement of the American Society for Radiation Oncology Evidence-Based Guideline.

PURPOSE: To provide guidance on the role of adjuvant radiation therapy in the treatment of endometrial cancer. METHODS: "The Role of Postoperative Radiation Therapy for Endometrial Cancer: An ASTRO Evidence-Based Guideline" by Klopp et al, published in 2014 in Practical Radiation Oncology, was reviewed for developmental rigor by methodologists. The American Society for Radiation Oncology (ASTRO) guideline content and recommendations were further reviewed by the American Society of Clinical Oncology (ASCO) Endorsement Panel. RESULTS: The ASCO Endorsement Panel determined that the recommendations from the ASTRO guideline are clear, thorough, and based on the most relevant scientific evidence. ASCO endorsed the ASTRO guideline with several qualifying statements. RECOMMENDATIONS: Surveillance without adjuvant radiation therapy is a reasonable option for women without residual disease in the hysterectomy specimen and for women with grade 1 or 2 cancer and < 50% myometrial invasion, especially when no other high-risk features are present. For women with grade 1 or 2 cancer and ≥ 50% myometrial invasion or grade 3 cancer and < 50% myometrial invasion, vaginal brachytherapy is as effective as pelvic radiation therapy at preventing vaginal recurrence and is preferred. Patients with grade 3 cancer and ≥ 50% myometrial invasion or cervical stroma invasion may benefit from pelvic radiation to prevent pelvic recurrence. For women with high-risk early-stage disease and advanced disease, the ASCO Endorsement Panel added qualifying statements to the ASTRO recommendations to provide stronger statements in favor of chemotherapy (with or without radiation therapy).

Dose-volume modeling of salivary function in patients with head-and-neck cancer receiving radiotherapy.

PURPOSE: We investigated the factors that affect salivary function after head-and-neck radiotherapy (RT), including parotid gland dose-volume effects, potential compensation by less-irradiated gland tissue, and functional recovery over time. METHODS AND MATERIALS: Sixty-five patients with head-and-neck tumors were enrolled in a prospective salivary function study. RT was delivered using intensity-modulated RT (n = 45), forward-planning three-dimensional conformal RT (n = 14), or three-dimensional conformal RT with an intensity-modulated RT boost (n = 6). Whole salivary flow was measured before therapy and at 6 months (n = 61) and 12 months (n = 31) after RT. A wide variety of dose-volume models to predict post-RT salivary function were tested. Xerostomia was defined according to the subjective, objective, management, analytic (SOMA) criteria as occurring when posttreatment salivary function was < 25% of the pretreatment function. Multivariate logistic regression analysis was used to assess the combined effect of dose-volume, patient-, and treatment-related factors. RESULTS: A significant correlation was observed between the relative quality-of-life scores and relative stimulated saliva values at 6 months after RT (Spearman's correlation coefficient [R(s)] = 0.46, p < 0.001). The dose-volume factors were by far the strongest correlates with stimulated saliva flow, although other factors showed modest significance in multimetric models (chemotherapy, gender, and Karnofsky performance status). Several fitted dose-volume models provided a good mathematical description of the data. Significant noise in the salivary measurements (repeated measurement coefficient of variation was 27% in normal subjects) precluded selection of any one of the models presented solely on the basis of the objective fit criteria. Nevertheless, the mean dose-exponential model, in which each parotid gland's relative salivary gland function equaled exp(-A x mean gland dose), with A equal to 0.054/Gy (68% confidence interval 0.052-0.059), provided a good representation of the data and was incorporated into our multimetric analysis. Using that model, we estimated that a mean parotid dose of 25.8 Gy, on average, was likely to reduce a single parotid gland's flow to 25% of its pretreatment value, regardless of the treatment delivery method. Significant correlations were observed between a logistic multivariate model (incorporating the mean dose-exponential equation, gender, and Karnofsky performance status) and stimulated saliva flow at 6 months (R(s) = 0.73), stimulated saliva flow at 12 months (R(s) = 0.54), and quality-of-life score at 6 months (R(s) = 0.35) after RT. CONCLUSION: Stimulated parotid salivary gland dose-volume models strongly correlated with both stimulated salivary function and quality-of-life scores at 6 months after RT. The mean stimulated saliva flow rates improved from 6 to 12 months after RT. Salivary function, in each gland, appeared to be lost exponentially at a rate of approximately 5%/1 Gy of mean dose. Additional research is necessary to distinguish among the models for use in treatment planning. The incidence of xerostomia was significantly decreased when the mean dose of at least one parotid gland was kept to < 25.8 Gy with conventional fractionation. However, even lower mean doses imply increased late salivary function.