It is unclear whether laparoscopic distal gastrectomy for locally advanced gastric cancer is oncologically equivalent to open distal gastrectomy. The noninferiority of laparoscopic subtotal ...gastrectomy with D2 lymphadenectomy for locally advanced gastric cancer compared with open surgery in terms of 3-year relapse-free survival rate was evaluated.
A phase III, open-label, randomized controlled trial was conducted for patients with histologically proven locally advanced gastric adenocarcinoma suitable for distal subtotal gastrectomy. The primary end point was the 3-year relapse-free survival rate; the upper limit of the hazard ratio (HR) for noninferiority was 1.43 between the laparoscopic and open distal gastrectomy groups.
From November 2011 to April 2015, 1,050 patients were randomly assigned to laparoscopy (n = 524) or open surgery (n = 526). After exclusions, 492 patients underwent laparoscopic surgery and 482 underwent open surgery and were included in the analysis. The laparoscopy group, compared with the open surgery group, suffered fewer early complications (15.7%
23.4%, respectively;
= .0027) and late complications (4.7%
9.5%, respectively;
= .0038), particularly intestinal obstruction (2.0%
4.4%, respectively;
= .0447). The 3-year relapse-free survival rate was 80.3% (95% CI, 76.0% to 85.0%) for the laparoscopy group and 81.3% (95% CI, 77.0% to 85.0%; log-rank
= .726) for the open group. Cox regression analysis after stratification by the surgeon revealed an HR of 1.035 (95% CI, 0.762 to 1.406; log-rank
= .827;
for noninferiority = .039). When stratified by pathologic stage, the HR was 1.020 (95% CI, 0.751 to 1.385; log-rank
= .900;
for noninferiority = .030).
Laparoscopic distal gastrectomy with D2 lymphadenectomy was comparable to open surgery in terms of relapse-free survival for patients with locally advanced gastric cancer. Laparoscopic distal gastrectomy with D2 lymphadenectomy could be a potential standard treatment option for locally advanced gastric cancer.
In this study, some confusing points about electron film dosimetry using white polystyrene suggested by international protocols were verified using a clinical linear accelerator (LINAC). According to ...international protocol recommendations, ionometric measurements and film dosimetry were performed on an SP34 slab phantom at various electron energies. Scaling factor analysis using ionometric measurements yielded a depth scaling factor of 0.923 and a fluence scaling factor of 1.019 at an electron beam energy of <10 MeV (i.e., R.sub.50 < 4.0 g/cm.sup.2). It was confirmed that the water-equivalent characteristics were similar because they have values similar to white polystyrene (i.e., depth scaling factor of 0.922 and fluence scaling factor of 1.019) presented in international protocols. Furthermore, percentage depth dose (PDD) curve analysis using film dosimetry showed that when the density thickness of the SP34 slab phantom was assumed to be water-equivalent, it was found to be most similar to the PDD curve measured using an ionization chamber in water as a reference medium. Therefore, we proved that the international protocol recommendation that no correction for measured depth dose is required means that no scaling factor correction for the plastic phantom is necessary. This study confirmed two confusing points that could occur while determining beam characteristics using electron film dosimetry, and it is expected to be used as basic data for future research on clinical LINACs.
Background
With improved short-term surgical outcomes, laparoscopic distal gastrectomy has rapidly gained popularity. However, the safety and feasibility of laparoscopic total gastrectomy (LTG) has ...not yet been proven due to the difficulty of the technique. This single-arm prospective multi-center study was conducted to evaluate the use of LTG for clinical stage I gastric cancer.
Methods
Between October 2012 and January 2014, 170 patients with pathologically proven, clinical stage I gastric adenocarcinoma located at the proximal stomach were enrolled. Twenty-two experienced surgeons from 19 institutions participated in this clinical trial. The primary end point was the incidence of postoperative morbidity and mortality at postoperative 30 days. The severity of postoperative complications was categorized according to Clavien–Dindo classification, and the incidence of postoperative morbidity and mortality was compared with that in a historical control.
Results
Of the enrolled patients, 160 met criteria for inclusion in the full analysis set. Postoperative morbidity and mortality rates reached 20.6% (33/160) and 0.6% (1/160), respectively. Fifteen patients (9.4%) had grade III or higher complications, and three reoperations (1.9%) were performed. The incidence of morbidity after LTG in this trial did not significantly differ from that reported in a previous study for open total gastrectomy (18%).
Conclusions
LTG performed by experienced surgeons showed acceptable postoperative morbidity and mortality for patients with clinical stage I gastric cancer.
The advantages of laparoscopic resection over open surgery in the treatment of gastric gastrointestinal stromal tumor (GIST) are not conclusive. This study aimed to evaluate the postoperative and ...oncologic outcome of laparoscopic resection for gastric GIST, compared to open surgery. We retrospectively reviewed the prospectively collected database of 1019 patients with gastric GIST after surgical resection at 13 Korean and 2 Japanese institutions. The surgical and oncologic outcomes were compared between laparoscopic and open group, through 1:1 propensity score matching (PSM). The laparoscopic group (N = 318) had a lower rate of overall complications (3.5% vs. 7.9%, P = 0.024) and wound complications (0.6% vs. 3.1%, P = 0.037), shorter hospitalization days (6.68 ± 4.99 vs. 8.79 ± 6.50, P < 0.001) than the open group (N = 318). The superiority of the laparoscopic approach was also demonstrated in patients with tumors larger than 5 cm, and at unfavorable locations. The recurrence-free survival was not different between the two groups, regardless of tumor size, locational favorableness, and risk classifications. Cox regression analysis revealed that tumor size larger than 5 cm, higher mitotic count, R1 resection, and tumor rupture during surgery were independent risk factors for recurrence. Laparoscopic surgery provides lower rates of complications and shorter hospitalizations for patients with gastric GIST than open surgery.
Background
Recently, the number of laparoscopic procedures for gastric cancer has increased rapidly. Laparoscopic surgery is reported to have many advantages over open gastrectomy with oncologic ...safety in early gastric cancer. However, there were few reports on long-term outcomes of laparoscopy-assisted gastrectomy (LAG) for advanced gastric cancer (AGC). The aim of this study was to investigate long-term survival outcomes after LAG for AGC.
Methods
The data of 1,485 patients who underwent LAG between April 1998 and December 2005 by ten surgeons at ten hospitals were collected retrospectively. Among them, 239 patients who were diagnosed with AGC on final pathologic examination were enrolled in the present study to investigate long-term clinical outcomes.
Results
The ratio of male to female patients was 151:88 and the mean age was 57.1 years. One hundred ninety-three subtotal gastrectomies, 41 total gastrectomies, and 5 proximal gastrectomies were performed. D1 + α, D1 + β, and D2 lymph node dissections were performed for 14, 62, and 163 cases, respectively. The median follow-up period was 55.4 months. The overall 5-year survival rate of the 239 AGC patients was 78.8% and the disease-specific 5-year survival rate was 85.6%. The 5-year survival rates of the TNM staging system’s (7th ed.) stages were 90.5% (stage Ib,
n
= 86), 86.4% (stage IIa,
n
= 53), 78.3% (stage IIb,
n
= 44), 52.8% (stage IIIa,
n
= 24), 52.9% (stage IIIb,
n
= 24), and 37.5% (stage IIIc,
n
= 8) (
p
< 0.001).
Conclusion
The long-term survival outcome rates of LAG for AGC in the present study were comparable to those previously reported for open gastrectomy. Based on the present results, a well-designed phase III trial comparing LAG and open gastrectomy for AGC will be needed to affirm the validity of LAG for AGC.
The oncologic outcomes of laparoscopy-assisted gastrectomy for the treatment of gastric cancer have not been evaluated. The aim of this study is to validate the efficacy and safety of laparoscopic ...gastrectomy for gastric cancer in terms of long-term survival, morbidity, and mortality retrospectively.
The study group comprised 2,976 patients who were treated with curative intent either by laparoscopic gastrectomy (1,477 patients) or open gastrectomy (1,499 patients) between April 1998 and December 2005. The long-term 5-year actual survival analysis in case-control and case-matched population was conducted using the Kaplan-Meier method. The morbidity and mortality and learning curves were evaluated.
In the case-control study, the overall survival, disease-specific survival, and recurrence-free survival (median follow-up period, 70.8 months) were not statistically different at each cancer stage with the exception of an increased overall survival rate for patients with stage IA cancer treated via laparoscopy (laparoscopic group; 95.3%, open group: 90.3%; P < .001). After matching using a propensity scoring system, the overall survival, disease-specific survival, and recurrence-free survival rates were not statistically different at each stage. The morbidity of the case-matched group was 15.1% in the open group and 12.5% in the laparoscopic group, which also had no statistical significance (P = .184). The mortality rate was also not statistically significant (0.3% in the open group and 0.5% in the laparoscopic group; P = 1.000). The mean learning curve was 42.
The long-term oncologic outcomes of laparoscopic gastrectomy for patients with gastric cancer were comparable to those of open gastrectomy in a large-scale, multicenter, retrospective clinical study.
The aim of this study was to evaluate the safety of this trial with respect to morbidity and mortality.
Laparoscopic-assisted distal gastrectomy (LADG) is rapidly gaining popularity. However, there ...is limited evidence regarding its oncologic safety. We therefore conducted a phase III multicenter, prospective, randomized study comparing LADG with open gastrectomy (ODG).
Patient eligibility criteria were pathologically-proven adenocarcinoma, 20 to 80 years of age, preoperative stage I, no history of other cancer, chemotherapy, or radiotherapy. The primary end point was to determine whether there is a difference in overall survival between 2 groups. The morbidity and mortality were compared to evaluate the safety of this trial. The time was decided on the hypothesis that the morbidity of this trial was not significantly different from that of previous reports on open gastric cancer surgeries (17%-20%). This study is registered at ClinicalTrials.gov and carries the following ID number: NCT00452751.
A total of 342 patients were randomized (LADG, 179 patients; ODG, 161 patients) between January 1, 2006 and July 19, 2007. There were no significant differences between the 2 groups in age, gender, and comorbidities. The postoperative complication rates of the LADG and ODG groups were 10.5% (17/179) and 14.7% (24/163), respectively (P = 0.137). Reoperations were required in 3 cases each group. The postoperative mortality was 1.1% (2/179) and 0% (0/163) in the LADG and ODG groups (P = 0.497), respectively.
There was no significance difference in the morbidity and mortality between the 2 groups. Therefore, we conclude that this trial is safe and is thus ongoing.
Background
The aim of this study is to identify an indicator to predict the overcoming of the learning curve of distal gastrectomy in gastric cancer surgery.
Method
A retrospective multicenter cohort ...study was conducted in 2100 patients who underwent radical distal gastrectomy performed by nine surgeons in eight hospitals between 2001 and 2006. For each surgeon, an individual CUSUM chart was formulated in terms of operation time or clinical outcomes, including severe complications, number of retrieved lymph nodes, positive resection margin, and hospital stay. The actual changing points (CPs) of the CUSUM charts were analyzed. Based on the CP, patients were divided into pre-CP and post-CP groups, and the clinicopathologic outcomes and survival data were compared between the groups.
Results
CP determined by operation time was more reliable than CP determined by a combination of clinical outcomes, as the former was correlated not only with short-term outcomes but also with survival. The outcomes were superior in the post-CP group in terms of numbers of harvested lymph nodes, sufficient lymph node harvesting (> 15), and negative proximal margins. In a survival analysis, the post-CP group showed better survival than the pre-CP group in stage II (76% vs 86.1%
p
= 0.010) and stage III (51.5% vs 60.6%
p
= 0.042).
Conclusion
Overcoming the learning curve of distal gastrectomy for gastric cancer can be better predicted by operation time rather than by a combination of postoperative clinical parameters. It is recommended that surgeons initially operate on early stage cancer patients before overcoming the learning curve.
After a gastrectomy, the nutritional status of patients with gastric cancer has great effect on the treatment outcome and patients' quality of life. We investigated the changes in body composition ...and nutrient intake after gastrectomy in 288 gastric cancer patients. A multiple linear regression analysis was used for each time period to verify the effects of nutritional and clinical factors on weight and fat-free mass loss rates. Gastric cancer patients who underwent a gastrectomy continued to experience weight and fat-free mass loss until three months after surgery and became stagnant at six months. The marginal mean of calorie intake per weight was 24.5, 26.8, and 29.4 kcal at one, three, and six months. The protein intake per kg lean mass was 1.14, 1.14, and 1.16 g at one, three, and six months, respectively. One month after surgery, the rate of weight loss increased significantly in females who received chemotherapy (
< 0.001). At one to three months postoperative, females who had undergone chemotherapy tended to significantly lose weight (
= 0.016). Females with a history of chemotherapy also showed a reduction in fat-free mass for one to three months (
= 0.036). Calorie intake was a significant factor in preventing fat-free mass weight loss at one month after surgery. Chemotherapy was an independent factor affecting the weight and fat-free mass loss rate up to six months after gastrectomy. Careful monitoring of weight and muscle mass changes following active nutritional intervention for sufficient nutrition support could be helpful for patients after gastrectomy.
Radiation therapy technology has been advancing with a focus on enhancing treatment efficiency based on state-of-the-art medical physics technologies. The rapid increase in the use of medical ...radiation and technological advancements that aim to achieve high-performance and high-precision radiotherapy necessitates the evaluation of existing technologies and the development of regulatory technologies for the safe use of medical radiation. In this study, we conducted a national postal dosimetry audit for the output dose and mechanical accuracy of clinical radiotherapy at medical institutions between 2017 and 2020; the audit was performed on the output dose and mechanical accuracy of photon beams (385 beams) for 200 linear accelerators (LINACs) from 92 institutions. As a result of corrective action and re-execution, it was confirmed that the energy in the LINACs met acceptable standards. These results confirm the quality management status of the LINACs used in radiotherapy in South Korea. This audit can aid in the establishment of a national quality control system for radiotherapy according to the proposed quality control standard procedures. Finally, through the independent national quality audits at the secondary standard dosimetry laboratory level, stable use of high-energy radiation for radiation therapy can be achieved.
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