American Radium Society (ARS) Appropriate Use Criteria (AUC) for Locoregional Gastric Adenocarcinoma: Systematic Review and Guidelines.

OBJECTIVE: The objective of this study was to systematically evaluate the data regarding the use of neoadjuvant, perioperative, surgical, and adjuvant treatment options in localized gastric cancer patients and to develop Appropriate Use Criteria recommended by a panel of experts convened by the American Radium Society. METHODS: Preferred reporting items for systematic reviews and meta-analyses methodology was used to develop an extensive analysis of peer-reviewed phase 2/2R/3 trials, as well as meta-analyses found within the Ovid Medline database between 2010 and 2020. The expert panel then rated the appropriateness of various treatments in 5 representative clinical scenarios through a well-established consensus methodology (modified Delphi). RESULTS: For patients with medically operable locally advanced gastric cancer, the strongest recommendation was for perioperative chemotherapy based on high-quality data. Acceptable alternatives included surgery followed by either chemotherapy or concurrent chemoradiotherapy (CRT). For patients with upfront resection of stages I to III gastric cancer (no neoadjuvant therapy), the group strongly recommended adjuvant therapy with either chemotherapy alone or CRT, based on high-quality data. For patients with locally advanced disease who received preoperative chemotherapy without tumor regression, the group strongly recommended postoperative chemotherapy or postoperative CRT. Finally, for medically inoperable gastric cancer patients, there was moderate consensus recommending definitive concurrent CRT. CONCLUSIONS: The addition of chemotherapy and/or radiation, either in the neoadjuvant, adjuvant, or perioperative setting, results in improved survival rates for patients compared with surgery alone. For inoperable patients, definitive CRT is a reasonable treatment option, though largely palliative.

Defining the rectal dose constraint for permanent radioactive seed implantation of the prostate.

PURPOSE: This study was performed to define the rectal dose constraint that would predict late rectal bleeding requiring argon plasma coagulation (APC) following prostate brachy mono-therapy. METHODS AND MATERIALS: Between February 1999 and April 2002, 91 patients with low risk prostate cancer underwent permanent I(125) radioactive seed implantation without the use of supplemental external beam radiation or androgen suppression therapy. Patients received both CT and MRI scans 6 weeks postimplant for evaluation of dosimetry. The CT and MRI scans were fused. Rectal volumes were contoured on the T2 weighted MR images. For those patients requiring APC, the date on which a patient reported rectal bleeding was recorded. A Cox regression analysis was performed to assess whether there was a significant association between the rectal volume (continuous) exceeding 100 Gy time rectal bleeding. Comparisons of estimates of rectal bleeding requiring APC were made using a 2-sided log rank test. RESULTS: There was a significant association (hazard ratio = 5.6 [95% confidence interval: 1.3, 23.8]; P = 0.002) between the rectal volume exceeding 100 Gy and rectal bleeding requiring APC. After a median follow-up of 4.25 (1-6) years, no patient with less than a median value of 8 cc of rectum exceeding 100 Gy required APC, whereas 20% (P = 0.004) were estimated to require APC within 3 years following treatment. CONCLUSIONS: Keeping the rectal volume receiving more than 100 Gy below 8 cc will minimize the risk of rectal bleeding requiring APC following I(125) permanent prostate brachy mono-therapy.