Coverage of Lateral Lymph Nodes in Rectal Cancer Patients with Routine Radiation Therapy Practice and Associated Locoregional Recurrence Rates.

PURPOSE: Involved internal iliac and obturator lateral lymph nodes (LLNs) are a known risk factor for the occurrence of ipsilateral local recurrences (LLR) in rectal cancer. This study examined coverage of LLNs with routine radiation therapy practice in the Netherlands and associated LLR rates. METHODS AND MATERIALS: Patients with a primary tumor ≤8 cm of the anorectal junction, cT3-4 stage, and at least 1 internal iliac or obturator LLN with short axis ≥5 mm who received neoadjuvant (chemo)radiation therapy, were selected from a national, cross-sectional study of patients with rectal cancer treated in the Netherlands in 2016. Magnetic resonance images and radiation therapy treatment plans were reviewed regarding segmented LLNs as gross tumor volume (GTV), location of LLNs within clinical target volume (CTV), and received proportion of the planned radiation therapy dose. RESULTS: A total of 223 out of 3057 patients with at least 1 LLN ≥5 mm were selected. Of those, 180 (80.7%) LLNs were inside the CTV, of which 60 (33.3%) were segmented as GTV. Overall, 202 LLNs (90.6%) received ≥95% of the planned dose. Four-year LLR rates were not significantly higher for LLNs situated outside the CTV compared with those inside (4.0% vs 12.5%, P = .092) or when receiving <95% versus ≥95% of the planned radiation therapy dose (7.1% vs 11.3%, P = .843), respectively. Two of 7 patients who received a dose escalation of 60 Gy developed an LLR (4-year LLR rate of 28.6%). CONCLUSIONS: This evaluation of routine radiation therapy practice showed that adequate coverage of LLNs was still associated with considerable 4-year LLR rates. Techniques resulting in better local control for patients with involved LLNs need to be explored further.

Patterns of recurrence after surgery alone versus preoperative chemoradiotherapy and surgery in the CROSS trials.

PURPOSE: To analyze recurrence patterns in patients with cancer of the esophagus or gastroesophageal junction treated with either preoperative chemoradiotherapy (CRT) plus surgery or surgery alone. PATIENTS AND METHODS: Recurrence pattern was analyzed in patients from the previously published CROSS I and II trials in relation to radiation target volumes. CRT consisted of five weekly courses of paclitaxel and carboplatin combined with a concurrent radiation dose of 41.4 Gy in 1.8-Gy fractions to the tumor and pathologic lymph nodes with margin. RESULTS: Of the 422 patients included from 2001 to 2008, 418 were available for analysis. Histology was mostly adenocarcinoma (75%). Of the 374 patients who underwent resection, 86% were allocated to surgery and 92% to CRT plus surgery. On January 1, 2011, after a minimum follow-up of 24 months (median, 45 months), the overall recurrence rate in the surgery arm was 58% versus 35% in the CRT plus surgery arm. Preoperative CRT reduced locoregional recurrence (LRR) from 34% to 14% (P < .001) and peritoneal carcinomatosis from 14% to 4% (P < .001). There was a small but significant effect on hematogenous dissemination in favor of the CRT group (35% v 29%; P = .025). LRR occurred in 5% within the target volume, in 2% in the margins, and in 6% outside the radiation target volume. In 1%, the exact site in relation to the target volume was unclear. Only 1% had an isolated infield recurrence after CRT plus surgery. CONCLUSION: Preoperative CRT in patients with esophageal cancer reduced LRR and peritoneal carcinomatosis. Recurrence within the radiation target volume occurred in only 5%, mostly combined with outfield failures.

Target volume delineation variation in radiotherapy for early stage rectal cancer in the Netherlands.

PURPOSE: The aim of this study was to measure and improve the quality of target volume delineation by means of national consensus on target volume definition in early-stage rectal cancer. METHODS AND MATERIALS: The CTV's for eight patients were delineated by 11 radiation oncologists in 10 institutes according to local guidelines (phase 1). After observer variation analysis a workshop was organized to establish delineation guidelines and a digital atlas, with which the same observers re-delineated the dataset (phase 2). Variation in volume, most caudal and cranial slice and local surface distance variation were analyzed. RESULTS: The average delineated CTV volume decreased from 620 to 460 cc (p<0.001) in phase 2. Variation in the caudal CTV border was reduced significantly from 1.8 to 1.2 cm SD (p=0.01), while it remained 0.7 cm SD for the cranial border. The local surface distance variation (cm SD) reduced from 1.02 to 0.74 for anterior, 0.63 to 0.54 for lateral, 0.33 to 0.25 for posterior and 1.22 to 0.46 for the sphincter region, respectively. CONCLUSIONS: The large variation in target volume delineation could significantly be reduced by use of consensus guidelines and a digital delineation atlas. Despite the significant reduction there is still a need for further improvement.

Regional radiotherapy versus an axillary lymph node dissection after lumpectomy: a safe alternative for an axillary lymph node dissection in a clinically uninvolved axilla in breast cancer. A case control study with 10 years follow up.

BACKGROUND: The standard treatment of the axilla in breast cancer used to be an axillary lymph node dissection. An axillary lymph node dissection is known to give substantial risks of morbidity. In recent years the sentinel node biopsy has become common practice. Future randomized study results will determine whether the expected decrease in morbidity can be proven. METHODS: Before the introduction of the sentinel node biopsy, we conducted a study in which 180 women of 50 years and older with T1/T2 cN0 breast cancer were treated with breast conserving therapy. Instead of an axillary lymph node dissection regional radiotherapy was given in combination with tamoxifen (RT-group). The study group was compared with 341 patients, with the same patient and tumour characteristics, treated with an axillary lymph node dissection (S-group). RESULTS: The treatment groups were comparable, except for age. The RT-group was significantly older than the S-group. The median follow up was 7.2 years. The regional relapse rates were low and equal in both treatment groups, 1.1% in RT-group versus 1.5% in S-group at 5 years. The overall survival was similar; the disease free survival was significant better in the RT-group. CONCLUSION: Regional recurrence rates after regional radiotherapy are very low and equal to an axillary lymphnode dissection.