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R0 Resection (r0 + resection)

Distribution by Scientific Domains

Medical Sciences	100%

Distribution within Medical Sciences

Surgery & Surgical Specialties	52%
Oncology & Radiotherapy	29%

Terms modified by R0 Resection

r0 resection rate

Selected Abstracts

Toxicity of two cisplatin-based radiochemotherapy regimens for the treatment of patients with stage III/IV head and neck cancer

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 2 2008
Dirk Rades MD
Abstract Background. This nonrandomized study compared 2 radiochemotherapy regimens for toxicity in 128 patients with stage III/IV head and neck cancer. Methods. Patients received conventionally fractionated radiotherapy. The total dose to primary tumor and involved lymph nodes did depend on preceding surgery. Patients received 66 to 70 Gy if surgery was not performed, 60 to 66 Gy after R0 resection, 66 Gy after R1 resection, and 70 to 72 Gy after R2 resection. Concurrent chemotherapy consisted of 3 courses cisplatin (100 mg/m2/d1,22,43) (group A, N = 61) or 2 courses cisplatin (20 mg/m2/d1,5 + 29,33)/5-fluorouracil (5-FU) (600 mg/m2/d1,5 + 29,33) (group B, N = 67). Results. Acute toxicity was more severe in group A, especially nausea/vomiting (p = .002), nephrotoxicity (p = .001), ototoxicity (p = .034), and hematotoxicity (p = .049). Forty-eight percent of group A and 10% of group B patients could not complete chemotherapy due to toxicity (p = .018). Late toxicity was similar (p = .99). Conclusion. Two courses of fractionated cisplatin (20 mg/m2/d) and 5-FU were associated with significantly less acute toxicity than were 3 courses cisplatin (100 mg/m2/d). © 2007 Wiley Periodicals, Inc. Head Neck 2008 [source]

Practical questions in liver metastases of colorectal cancer: general principles of treatment

HPB, Issue 4 2007
Héctor Daniel González
Abstract Liver metastases of colorectal cancer are currently treated by multidisciplinary teams using strategies that combine chemotherapy, surgery and ablative techniques. Many patients classically considered non-resectable can now be rescued by neoadjuvant chemotherapy followed by liver resection, with similar results to those obtained in initial resections. While many of those patients will recur, repeat resection is a feasible and safe approach if the recurrence is confined to the liver. Several factors that until recently were considered contraindications are now recognized only as adverse prognostic factors and no longer as contraindications for surgery. The current evaluation process to select patients for surgery is no longer focused on what is to be removed but rather on what will remain. The single most important objective is to achieve a complete (R0) resection within the limits of safety in terms of quantity and quality of the remaining liver. An increasing number of patients with synchronous liver metastases are treated by simultaneous resection of the primary and the liver metastatic tumours. Multilobar disease can also be approached by staged procedures that combine neoadjuvant chemotherapy, limited resections in one lobe, embolization or ligation of the contralateral portal vein and a major resection in a second procedure. Extrahepatic disease is no longer a contraindication for surgery provided that an R0 resection can be achieved. A reverse surgical staged approach (liver metastases first, primary second) is another strategy that has appeared recently. Provided that a careful selection is made, elderly patients can also benefit from surgical treatment of liver metastases. [source]

Distant nodal metastases from intrathoracic esophageal squamous cell carcinoma: Characteristics of long-term survivors after chemoradiotherapy

JOURNAL OF SURGICAL ONCOLOGY, Issue 2 2010
Yin-Kai Chao MD
Abstract Background Non-regional lymph node metastasis in intrathoracic esophageal cancer is classified as M1 lesion with poor prognosis following surgery alone. We studied the controversial question of whether chemoradiotherapy (CRT) improves survival of these patients. Methods A cohort of patients with clinically overt nodal M1 disease, which could be encompassed by a tolerable radiation therapy port, was selected from the database of the Chang Gung Memorial Hospital. Results From 1994 to 2005, 54 nodal stage IV intrathoracic esophageal squamous cell carcinoma (SCC) patients received neoadjuvant CRT. Significant response occurred in 24 patients. Scheduled esophagectomy was performed in 26 patients. The 3-year overall survival (OS) and disease-free survival (DFS) for the whole group were 27% (median: 14.2 months) and 22% (median: 14.7 months), respectively. Multivariate analysis identified pretherapy lymph nodes classified as M1a and R0 resection after CRT as independent favorable prognosticators. Median survival reached 36.9 months in the pretherapy M1a subgroup as opposed to 12.5 months in the M1b subgroup (3-year-DFS: 40% vs. 10%, P,=,0.0117). Scheduled surgery after CRT benefits only after R0 resection (3-year-DFS: 36%, median survival: 45 months). The group with incomplete resection had a high surgical risk and dismal survival compared to the non-surgery group (3-year-DFS: 0% vs. 9%, 9.5 vs. 10.5 months). Conclusions Pretherapy M1a disease had a significantly better survival than nodal M1b disease after CRT in SCC. Aggressive surgical treatment after CRT is reserved for cases when complete resection is anticipated. J. Surg. Oncol. 2010;102:158,162. © 2010 Wiley-Liss, Inc. [source]

The survival outcome and prognostic factors for middle and distal bile duct cancer following surgical resection

JOURNAL OF SURGICAL ONCOLOGY, Issue 6 2009
Sae Byeol Choi MD
Abstract Background and Objectives The objective of this study was to analyze the survival outcome and the clinicopathological factors that influence survival and recurrence of middle and distal bile duct cancer after surgical resection. Methods From January 2000 to June 2007, 125 patients underwent surgical resection for middle and distal bile duct cancer. The clinicopathological characteristics and survival outcomes were reviewed retrospectively. Results Of the 125 patients, 31 patients underwent segmental resection of the bile duct, and 94 patients underwent pancreaticoduodenectomy (PD). Overall survival rates were 85.8% at 1 year and 38.3% at 5 years. Lymph node metastasis, noncurative resection, poorly differentiated tumor, and preoperative bilirubin level greater than 5.0 mg/dl were significant independent predictors of poor prognosis by multivariate analysis. The number of metastatic lymph nodes did not significantly affect survival. Recurrence occurred in 72 patients (61.0%). Disease-free survival rates were 74.1% at 1 year and 42.0% at 3 years. Lymph node and distant metastases and poorly differentiated tumors were found to be significant independent predictors of recurrence by multivariate analysis. Conclusions R0 resection confers a survival benefit, thus the surgeon should make an effort to achieve R0 resection. The presence of lymph node metastasis was a significant prognostic factor. J. Surg. Oncol. 2009;99:335,342. © 2009 Wiley-Liss, Inc. [source]

The performance of a novel ball-tipped Flush knife for endoscopic submucosal dissection: a case,control study

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 7 2010
T. Toyonaga
Aliment Pharmacol Ther 2010; 32: 908,915 Summary Background, Endoscopic submucosal dissection (ESD) using short needle knives is safe and effective, but bleeding is a problem due to low haemostatic capability. Aim, To assess the performance of a novel ball-tipped needle knife (Flush knife-BT) for ESD with particular emphasis on haemostasis. Methods, A case,control study to compare the performance for ESD of 30 pairs of consecutive early gastrointestinal lesions (oesophagus: 12, stomach: 32, colorectum: 16) with standard Flush knife (F) vs. Flush knife-BT (BT). Primary outcome was efficacy of intraprocedure haemostasis. Secondary outcomes included procedure time, procedure speed (dividing procedure time into the area of resected specimen), en bloc resection rate and recurrence rate. Results, Median intraoperative bleeding points and bleeding points requiring haemostatic forceps were smaller in the BT group than in the F group (4 vs. 8, P < 0.0001, 0 vs. 3, P < 0.0001). There was no difference between groups for procedure time; however, procedure speed was shorter in the BT group (P = 0.0078). En bloc and en bloc R0 resection rates were 100%, with no perforation or post-operative bleeding. No recurrence was observed in either group at follow-up 1 year postprocedure. Conclusions, Ball-tipped Flush knife (Flush knife-BT) appears to improve haemostatic efficacy and dissection speed compared with standard Flush knife. [source]

A confusing world: what to call histology of three-dimensional tumour margins?

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 5 2007
M Moehrle
Abstract Complete three-dimensional histology of excised skin tumour margins has a long tradition and, unfortunately, a multitude of names as well. Mohs, who introduced it, called it ,microscopically controlled surgery'. Others have described it as ,micrographic surgery', ,Mohs' micrographic surgery', or simply ,Mohs' surgery'. Semantic confusion became truly rampant when variant forms, each useful in its own way for detecting subclinical outgrowths of malignant skin tumours, were later introduced under such names as histographic surgery, systematic histologic control of the tumour bed, histological control of excised tissue margins, the square procedure, the perimeter technique, etc. All of these methods are basically identical in concept. All involve complete, three-dimensional histological visualization and evaluation of excision margins. Their common goal is to detect unseen tumour outgrowths. For greater clarity, the authors of this paper recommend general adoption of ,3D histology' as a collective designation for all the above methods. As an added advantage, 3D histology can also be used in other medical disciplines to confirm true R0 resection of, for example, breast cancer or intestinal cancer. [source]

Major liver resections for hepatocellular carcinoma on cirrhosis: Early and long-term outcomes

LIVER TRANSPLANTATION, Issue S2 2004
Lorenzo Capussotti
Since the lack of donors, liver resections continue to be the treatment of choice for cirrhotic patients with good liver function and resectable hepatocellular carcinoma (HCC). Moreover, over the past 2 decades, an increasing number of major hepatic resections have been performed. The aim of this study is to evaluate short- and long-term outcomes of 55 cirrhotic patients undergoing major hepatic resection with particular attention to the survival of the patients with gross portal vein invasion or large size tumors. Twenty-two patients (40%) required intra- or post-operative blood transfusion. Medium tumor size was 66.6±29.2 mm; 7 patients had large size (> 10 cm) HCCs. A single node was present in 38 cases (69.1%). There was a gross portal vein tumor thrombus (PVTT) in 13 patients (23.6%). Resection was non-curative in 4 cases. In-hospital mortality and morbidity rates were 5.5% and 30.9%, respectively. The overall and disease-free survival rates were 36.2% and 42.8%, respectively. Overall 5-year survival rates of patients with large size tumors was 17.1%. Ten patients with a gross PVTT had an R0 resection with a 26.6% 5-year survival rate. In conclusion, major hepatic resections for HCC can be performed with low mortality and morbidity rates. HCCs with PVTT or greater than 10 cm in size have very limited options of treatment; the favorable long-term results of our study suggest that they should undergo surgery if a radical resection can be achieved. (Liver Transpl 2004;10:S64,S68.) [source]

Oesophagectomy for tumours and dysplasia of the oesophagus and gastro-oesophageal junction

ANZ JOURNAL OF SURGERY, Issue 4 2009
Krishna Epari
Abstract Background:, Neoadjuvant therapy, radical lymphadenectomy and treatment in high-volume centres have been proposed to improve outcomes for resectable oesophageal tumours. The aim of the present study was to review the oesophagectomy experience of a single surgeon with a moderate caseload who uses neoadjuvant therapy selectively and performs a conservative lymphadenectomy. Methods:, A retrospective review of prospectively collected data was performed. The study included 125 consecutive attempted oesophageal resections performed by a single surgeon (RC) from 1993 to 2006. Results:, All patients were staged with computed tomography and also laparoscopy for lower third and junctional tumours. Endoscopic ultrasound was used in 69%. Seventy-seven per cent were adenocarcinomas. Neoadjuvant therapy was used selectively in 23%. One hundred and twenty-one resections were carried out, giving an overall resection rate of 97% with an R0 resection in 82%. In-hospital mortality was 0.8%, clinical anastomotic leak 1.7% and median length of stay 14 days. Overall median and 5-year survival were 46 months and 47%. Stage-specific 5-year survival was 100%, 71%, 41% and 21% for stages 0, I, II and III, respectively. Isolated local recurrence occurred in 8%. Conclusions:, A moderate volume surgeon with specialist training in oesophageal resectional surgery can achieve a low mortality and anastomotic leak rate with good survival outcomes. The role for neoadjuvant therapy and radical lymphadenectomy is controversial and remains to be clearly defined. Accurate preoperative staging is essential for selection of patients for curative surgery with or without neoadjuvant therapy and for comparison of results. [source]

Endoscopic ultrasonography-detected low-volume ascites as a predictor of inoperability for oesophagogastric cancer

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2008
J. Sultan
Background: Endoscopic ultrasonography (EUS) can detect low-volume ascites (LVA) not apparent on computed tomography. The aim of this study was to assess the importance of LVA for management of patients with oesophagogastric (OG) cancer. Methods: Patients with LVA were identified from a prospective OG cancer unit database between January 2002 and January 2006. Results: Of 1118 patients staged with OG cancer, 802 had EUS. The incidence of LVA was 8·4 per cent overall but fell to 6·5 per cent when those with metastases on computed tomography were excluded. Only patients with gastric and OG junction carcinoma had LVA. Staging laparoscopy in the 21 patients with LVA revealed that 11 (52 per cent) were inoperable. The remainder had laparotomy and complete (R0) resection was possible in only five (50 per cent). In 106 patients who had staging laparoscopy after EUS without LVA, 37 (34·9 per cent) were inoperable and 56 of the remaining 69 (81 per cent) had R0 resection. Conclusion: The presence of LVA on EUS is uncommon in patients with OG cancer but very important, being indicative of incurable disease in 76 per cent. This information will be helpful in counselling patients regarding management options and the low likelihood of potentially curative treatment. Copyright © 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]

Image-guided surgery of liver metastases by three-dimensional ultrasound-based optoelectronic navigation

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 7 2007
S. Beller
Background: Vessel-oriented surgery and tumour-free resection margins are essential for resection of liver metastases to preserve liver parenchyma and improve oncological outcome. Preoperative three-dimensional models reconstructed from imaging data could facilitate surgical planning with the use of navigation technology. Methods: Thirty-three patients with central and/or impalpable liver metastases were scheduled for navigated hepatic resection. Intraoperative three-dimensional ultrasonography and an infrared-based optical tracking system were used for data registration and image-guided surgery. Postoperative three-dimensional data were compared with the preoperative virtual surgical plan to assess the accuracy of navigation, and clinical results were compared with those of a matched control group of 32 patients. Results: Navigation was successful in 32 of 33 patients. Realization of the preoperative plan and R0 resection was achieved in 30 of these 32 patients. The median discrepancy between the planned and actual vascular dissection level was 6 (range 0,11) mm. There was a reduced rate of R1 resection in the navigated group compared with the control group (two versus four patients), and more parenchyma was preserved. Conclusion: Three-dimensional ultrasound-based optoelectronic navigation technology improves intraoperative orientation and enables parenchyma-preserving surgery with high precision. Copyright © 2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]

Impact of preoperative radiochemotherapy on postoperative course and survival in patients with locally advanced squamous cell oesophageal carcinoma,

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2006
C. Mariette
Background: The aim of this study was to determine the effect of neoadjuvant radiochemotherapy (RCT) on postoperative complications and survival after surgery for locally advanced oesophageal squamous cell carcinoma. Methods: Postoperative course and survival were compared in 144 patients who had neoadjuvant RCT and 80 control patients who had surgery alone for locally advanced oesophageal squamous cell carcinoma (radiological stage T3, N0 or N1, M0). Results: The two groups were comparable in terms of American Society of Anesthesiologists grade, age, sex, weight loss, tumour location, presence of lymph node metastasis and surgical approach. Postoperative mortality rates were 6·3 and 9 per cent (P = 0·481), with morbidity rates of 40·3 and 41 per cent (P = 0·887) in the RCT and control group respectively. Complete resection (R0) rates were 74·3 and 48 per cent respectively (P < 0·001). Significant downstaging was observed in the RCT group (P < 0·001), with 16·0 per cent of patients having a complete pathological response. Median survival was 29 versus 15 months, and the 5-year survival rate 37 versus 17 per cent (P = 0·002) in RCT and control groups respectively. Conclusion: Neoadjuvant RCT significantly enhanced R0 resection and survival rates in patients with stage T3 oesophageal squamous cell carcinoma, with no increase in postoperative mortality and morbidity rates. Copyright © 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]

Curative resection is the single most important factor determining outcome in patients with pancreatic adenocarcinoma

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 5 2004
M. Wagner
Background: Mortality rates associated with pancreatic resection for cancer have steadily decreased with time, but improvements in long-term survival are less clear. This prospective study evaluated risk factors for survival after resection for pancreatic adenocarcinoma. Methods: Data from 366 consecutive patients recorded prospectively between November 1993 and September 2001 were analysed using univariate and multivariate models. Results: Fifty-eight patients (15·8 per cent) underwent surgical exploration only, 97 patients (26·5 per cent) underwent palliative bypass surgery and 211 patients (57·7 per cent) resection for pancreatic adenocarcinoma. Stage I disease was present in 9·0 per cent, stage II in 18·0 per cent, stage III in 68·7 per cent and stage IV in 4·3 per cent of patients who underwent resection. Resection was curative (R0) in 75·8 per cent of patients. Procedures included pylorus-preserving Whipple resection (41·2 per cent), classical Whipple resection (37·0 per cent), left pancreatic resection (13·7 per cent) and total pancreatectomy (8·1 per cent). The in-hospital mortality and cumulative morbidity rates were 2·8 and 44·1 per cent respectively. The overall actuarial 5-year survival rate was 19·8 per cent after resection. Survival was better after curative resection (R0) (24·2 per cent) and in lymph-node negative patients (31·6 per cent). A Cox proportional hazards survival analysis indicated that curative resection was the most powerful independent predictor of long-term survival. Conclusion: Resection for pancreatic adenocarcinoma can be performed safely. The overall survival rate is determined by the radicality of resection. Patients deemed fit for surgery who have no radiological signs of distant metastasis should undergo surgical exploration. Resection should follow if there is a reasonable likelihood that an R0 resection can be obtained. Copyright © 2004 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]

Adjuvant therapy and survival after resection of pancreatic adenocarcinoma

CANCER, Issue 12 2010
A population-based analysis
Abstract BACKGROUND: The use of adjuvant chemoradiation for pancreatic adenocarcinoma (PAC) is accepted in North America, but there is a paucity of data to support this practice. The relation between adjuvant therapy and survival was assessed in a population-based cohort of patients with PAC. METHODS: A review was conducted of all cases of resected PAC from 1996 to 2003 using data from the state cancer registry augmented with data from primary medical record review. Use of adjuvant therapy was ascertained from registry data. Survival was assessed using the Kaplan-Meier method, and a Cox proportional hazards model was developed for multivariate analysis. RESULTS: A total of 298 patients from 27 hospitals met criteria for inclusion. There were 228 patients (76.5%) who were resected with curative intent, with a median overall survival of 12 months. The 6-month, 1-year, and 5-year survival rates were 80.2%, 58.4%, and 6.7%, respectively. Of the 228 patients resected, 122 (53.5%) received adjuvant treatment and had a median survival of 13.0 months versus 11.0 months for those with no adjuvant treatment (P = .16). After adjustment for surrogates of performance status, significant predictors of overall survival included no weight loss, T1/T2 pathologic stage, a microscopically complete resection (R0), and receipt of adjuvant therapy. CONCLUSIONS: An R0 resection and adjuvant therapy were found to be independently associated with an increase in overall survival in patients with resected PAC. These data underscore the importance of adjuvant therapy in resected PAC and the need for ongoing clinical trials to refine the efficacy and timing of adjuvant therapy in this disease. Cancer 2010. © 2010 American Cancer Society. [source]

Treatment of thoracic esophageal carcinoma invading adjacent structures

CANCER SCIENCE, Issue 7 2007
Yasuyuki Seto
T4 esophageal cancer is defined as the tumor invading adjacent structures, using tumor,node,metastasis (TNM) staging. For clinically T4 thoracic esophageal carcinoma, multimodality therapy, that is, neoadjuvant chemoradiotherapy (CRT) followed by surgery or definitive CRT, has generally been performed. However, the prognosis of patients with these tumors remains poor. Another strategy is needed to achieve curative treatment. In the present article, the treatment strategies employed to date are reviewed. Furthermore, the strategies for these malignancies are reassessed, based on our experiences. R1/2 and R0 resections are regarded as those with residual and no tumor after surgery. The present data show that patients who underwent R1/2 resection after neoadjuvant CRT experienced little survival benefit, while complete response (CR) cases after definitive CRT had comparatively better results. Therefore, curative surgery should not be attempted without down-staging, and definitive CRT should be the initial treatment. Then surgery is indicated for the eradication of residual cancer cells. Close surveillance is essential for early detection of relapse even after CR, because the operation will gradually become increasingly difficult due to post-CRT fibrosis. In conclusion, multimodality therapy consists of definitive CRT followed by R0 resection, which can be the treatment of choice for T4 esophageal carcinoma. These challenging treatments have the potential to constitute the most effective therapeutic strategy. (Cancer Sci 2007; 98: 937,942) [source]

A national cohort study of long-course preoperative radiotherapy in primary fixed rectal cancer in Denmark

COLORECTAL DISEASE, Issue 7Online 2010
S. Bülow
Abstract Objective, Preoperative radiotherapy has been shown to enable a fixed rectal cancer to become resectable which in turn may result in long-time survival. In this study, we analysed the outcome of long-course preoperative radiotherapy in fixed rectal cancer in a national cohort including all Danish patients registered with primary inoperable rectal cancer and treated in the period May 2001 to December 2005. Method, The study was based on surgical and demographic data from a continuously updated and validated national database. In addition, retrospective data were retrieved from all departments of radiotherapy concerning technique of radiotherapy, dose and fractionation and use of concomitant chemotherapy. Outcome was determined by actuarial analysis of local control, disease-free survival and overall survival. Results, A total of 258 patients with fixed rectal cancer received long-course radiotherapy (> 45 Gy). The median age at diagnosis was 66 years (range: 32,85) and 185 (72%) patients were male. The resectability rate was 80%, and a R0 resection was obtained in 148 patients (57% of all patients and 61% of those operated). The 5-year local recurrence rate for all patients was 5% (95% CI: 3,7%), and the actuarial distant recurrence rate was 41% (95% CI: 35,47%). The cumulative 5-year disease-free survival was 27% (95% CI: 22,32%) and overall 5-year survival was 34% (95% CI: 29,39%). Conclusions, This study is the first population-based report on outcome of preoperative long-course radiotherapy in a large unselected patient group with clinically fixed rectal cancer. Most patients could be resected with the intention of cure and one in three was alive after 5 years. [source]

B001 Multicentre Randomized Trial of Sphincter Preserving Surgery for Ultra-Low Rectal Carcinoma

COLORECTAL DISEASE, Issue 2006
E. Rullier
Objective, This randomized study compared two neoadjuvant treatments in patients with a low rectal cancer less than 2 cm from the anal verge that would have required APR before radiotherapy. Method, A total of 207 patients (71% uT3) with a rectal carcinoma at 0.5 cm from the anal verge were randomized in two groups. The group HDR received a high dose of radiotherapy (45 Gy + boost 18 Gy). The group RCT received 45 Gy with concomitant chemotherapy (5FU). Surgery was performed 6 weeks after treatment, surgeons were trained with TME, APR and intersphincteric resection. Results, The rate of sphincter preserving surgery was 83% after HDR and 86% after RCT (P = 0.69). There was no difference in morbidity, clinical tumour regression (80% vs. 87%) and complete pathological response (8% vs. 15%) between HDR and RCT. Overall, the rate of R0 resection was 78%. After a follow-up of 23 months, the rates of local and distant recurrence were 6% and 19% respectively and the disease-free survival was 77%. Survival was better after sphincter preservation than after APR. Conclusion, Sphincter preservation was achieved in 85% of ultra-low rectal carcinomas without compromising oncological prinicples. No difference was observed between HDR and RCT. Further follow-up is necessary to confirm this conservative approach. [source]