Dosimetric Comparative Study of 3 Different Postoperative Radiotherapy Techniques (3D-CRT,IMRT, and RapidArc) for II–III Stage Rectal Cancer

Postoperative radiotherapy is critical for reducing local relapse for advanced rectal carcinoma but has many side effects. Our study compared the dose distribution of target volumes, protection of normal organs at risk (OAR), and monitor unit (MU) for 3 radiotherapy techniques (3-dimensional conformal radiation therapy [3D-CRT], intensity-modulated radiation therapy [IMRT], and RapidArc (Varian Medical Systems, Inc., Palo Alto, CA, USA)). The results advocate for the clinical application of RapidArc technique in the future.Thirty postoperative patients with rectal cancer were enrolled. The 3 radiotherapy plans mentioned above were designed for each patient. The target volume coverage indicators included average dose, conformity index (CI), and homogeneity index (HI) of planning tumor volume (PTV). OAR included the bladder, small intestine, colon, and bilateral proximal femurs. The 30 patients were divided into 3 groups (10 cases in each group) for postoperative radiotherapy with the 3D-CRT, IMRT, or RapidArc technique, respectively.Both the IMRT and RapidArc plans have a significantly higher average PTV dose and better CI and HI (P < 0.01) than 3D-CRT. IMRT and RapidArc result in significantly lower doses of irradiation for all the OAR examined. Both the IMRT and RapidArc plans have a significantly lower V40 of the bladder, small intestine, and colon than 3D-CRT (P < 0.01). The IMRT and RapidArc plans can also reduce the maximum dose (Dmax) for the left proximal femur, V30, and V40 of bilateral proximal femurs compared with 3D-CRT (P < 0.01). Compared with IMRT, RapidArc can further reduce the Dmax of the small intestine, the Dmax and V30 of the bilateral proximal femurs, and the V40 of the right proximal femur (P < 0.01). RapidArc reduces MU remarkably compared with IMRT (P < 0.01). Regarding acute side effects, IMRT and RapidArc can greatly reduce the incidence of grade 3 radiation-induced cystitis and grade 2 enteritis.Both IMRT and RapidArc are better than 3D-CRT regarding PTV coverage and OAR protection. Furthermore, RapidArc is superior to IMRT regarding protection of the small intestine and bilateral proximal femurs and requires a reduced treatment time. RapidArc could be widely applied for postoperative radiotherapy for patients with ΙΙ–ΙΙΙ stage rectal cancer.     

Intensity-modulated radiotherapy with a belly board for rectal cancer

Background and aim Intensity-modulated radiotherapy (IMRT) techniques can reduce the irradiated small bowel volume in rectal cancer patients, but combined use of IMRT and a belly board is yet to be reported on for rectal cancer patients. The aim of this study was to determine whether additional use of a belly board reduced the irradiated small bowel volume observed using IMRT alone in rectal cancer patients. Materials and methods Twenty patients scheduled to receive preoperative radiotherapy for rectal cancer underwent two series of CT scans, with and without a belly board. IMRT planning was performed using 6-MV photon beams and seven equispaced fields. The bladder, small bowel, and planning target volume (PTV) were analyzed for doses between 10% and 100% of the prescribed dose at 10% intervals. Data were analyzed using Wilcoxon signed rank tests. Results There were no significant differences between patients undergoing IMRT with a belly board and those without a belly board in terms of total small bowel volumes, bladder, and PTV (p=0.571, p=0.841, and p=0.870, respectively). Statistical analysis showed that the irradiated small bowel volume with a belly board was smaller than that without a belly board (p<0.05 at 20–100% dose levels), with the mean relative reduction in the irradiated small bowel volume being 37.8±32.8%. Conclusion IMRT with a belly board is more effective than IMRT alone in reducing the irradiated small bowel volume. These findings suggest that the use of a belly board with IMRT may reduce small bowel complications in preoperative radiotherapy.     

Estimating Cardiac Substructures Exposure From Diverse Radiotherapy Techniques in Treating Left-Sided Breast Cancer

The study compares the physical and biologically effective doses (BED) received by the heart and cardiac substructures using three-dimensional conformal RT (3D-CRT), intensity-modulated radiotherapy (IMRT), and simple IMRT (s-IMRT) in postoperative radiotherapy for patients with left-sided breast cancer.From October 2008 to February 2009, 14 patients with histologically confirmed left-sided breast cancer were enrolled and underwent contrast-enhanced computed tomography (CT) simulation and 18F-FDG positron emission tomography-CT to outline the left cardiac ventricle (LV) and other substructures. The linear-quadratic model was used to convert the physical doses received by critical points of inner heart to BED.The maximal dose, minimum dose, dose received by 99% of volume (D₉₉) and dose received by 95% of volume (D₉₅) in target areas were significantly better using IMRT and s-IMRT when compared with 3D-CRT (P < 0.05). IMRT and s-IMRT significantly reduced the maximal cardiac dose (5038.98 vs 5346.47 cGy, P = 0.002; 5146.66 vs 5346.47 cGy, P = 0.03). IMRT reduced the maximal dose to LV by 4% (P = 0.05) in comparison with 3D-CRT. The average doses to heart and LV in 3D-CRT plan were significantly lower than those in IMRT plan (P < 0.05). The average cardiac volumes receiving ≥25 Gy (V_25 Gy) in IMRT, s-IMRT, and 3D-CRT plans were 73.98, 76.75, and 60.34 cm³, respectively. The average LV volumes receiving ≥25 Gy (V_25 Gy) in IMRT, s-IMRT and 3D-CRT plans were 23.37, 24.68, and 17.61 cm³, respectively. In the IMRT plan, the mean BED to the critical points of inner heart located within the high physical dose area were substantially lower than in 3D-CRT or s-IMRT.Compared with 3D-CRT technique, IMRT and s-IMRT had superior target dose coverage and dose uniformity. IMRT significantly reduced the maximal RT dose to heart and LV. IMRT and s-IMRT techniques did not reduce the volume of heart and LV receiving high doses.     

食管癌三维适形和调强放疗剂量学对比研究

目的 应用三维治疗计划系统分析食管癌三维适形放疗(3 D-CRT)及调强放疗(IMRT)中肿瘤靶区和危及器官的剂量分布.方法 对20例胸段食管鳞癌患者行CT模拟定位.每例分别设计3D-CRT和IMRT两份计划,以95％ PTV60体积获得60Gy处方剂量进行归一,分析靶区剂量和危及器官受量.结果 IMRT的PTV50剂量参数D100和D95、PTV50体积参数V100均优于3D-CRT计划(P均＜0.01),PTV50剂量参数最大剂量、最小剂量和平均剂量均优于3D-CRT计划(P均＜0.01).IMRT的PTV60参数D100、D95、V100较3D-CRT无优势,Dmean低于3D-CRT(P ＜0.01).IMRT的PTV50和PTV60适形指数均优于3D-CRT(P均＜0.01).IMRT的全肺V5、V10、V15、V20和平均剂量均低于3D-CRT(P均＜0.01).IMRT和3D-CRT的心脏平均剂量相似,IMRT的脊髓剂量较3D-CRT显著增加,但未超过耐受量.结论 IMRT放疗技术能够更好实现食管癌的肿瘤靶区均匀的剂量分布,并降低肺部的照射剂量.     

The comparison of radiotherapy techniques for treatment of the prostate cancer: the three-field vs. the four-field

Our purpose was to compare the three-field and the four-field planning techniques in patients with localized prostate cancer. Twenty patients with localized prostate cancer stage (T1-T2N0M0) were chosen for the analysis of treatment plans. Simulation and CT planning were performed in all cases in the supine position with a "comfortably" full bladder. The planning treatment volume (PTV) was defined as the prostate gland with a 10 mm margins around the clinical target volume (CTV), except for the posterior margin (prostate gland - the anterior part of rectum wall), where a 5 mm margin was applied. The clinical target volume (CTV) was defined as prostate gland. For each patient the following organs at risk (OAR) were outlined: rectum, bladder, and right femoral head. The following three-field and four-field plans were made: 3 field techniques with beam angles orientations 0 degree, 120 degrees, 240 degrees and 0 degree, 90 degrees, 270 degrees, and 4 field technique (0 degree, 90 degrees, 180 degrees, 270 degrees). Two versions of treatment plans were also made including different range of applied energy of photons (6 MV or 20 MV) for the therapeutic machine - Clinac 2300 CD. Beam portals were conformal by shaped by a multileaf collimator (MLC). The daily fractionation dose 1.8 Gy and the total dose 73.8 Gy were applied in each case. One hundred and twenty treatment plans were made and compared according to the following parameters: the mean total dose (MTD) in the target, the tumor control probability (TCP), the mean total dose (MTD) in the OAR (rectum, bladder, and right femoral head), the normal tissue complication probabilities (NTCP), and the volume of OARs which received arbitrary chosen fraction (%) of the total prescribed dose (73.8 Gy=100%). ANOVA statistical methods to verify the significance of differences between the treatment plans were used. There were no significant differences in the distribution of MTD and TCP in the PTV for the evaluated treatment plans. There were no significant differences in the MTD, NTCP, V80, and V90 distribution in bladder. The distribution of MTD, NTCP, and V80 for rectum indicated that lower parameters were achieved in the case of the three-field technique with the orientation of beams 0 degree, 90 degrees, 270 degrees. The distribution of MTD, NTCP, and V70 in right femoral head for each treatment plan was below the tolerance dose. The study has shown that the three-field technique (an anterior and two opposing lateral fields with the portals orientation 0 degree, 90 degrees, 270 degrees) and applied energy photons 20 MV, provides the best rectal protection. All evaluated plans according to the dose distribution in the target (PTV) have not indicated any significant differences. None of the techniques has shown any significant advantages in sparing bladder. The risk of morbidity in the femoral heads for all the applied techniques, in a dose up to 73.8 Gy was not a therapeutic problem. However, the three-field technique with beams orientation 0 degree, 120 degrees, 240 degrees gave the best sparing effect for femoral heads.     

食管癌三维适形和调强放疗中肺损伤的剂量学研究

目的应用三维治疗计划比较食管癌三维适形放疗（3DCRT）、diding window调强（SMLC—IMRT）中肺组织受量上的情况，探讨食管癌放射治疗理想的计划模式。方法采用Varian公司Eclipse三维治疗计划系统对10例食管癌病人设计放射治疗计划，每例均做4个计划5野适形、7野适形和5野SMLC调强、7野SMLC调强，在规定PTV至少达到95％处方剂量前提下．用剂量体积直方图（DVH）比较肺组织受照射剂量的差异。结果（1）采用3DCRT技术时，肺所受的剂量在5野与7野照射技术中基本相同。（2）采用SMLC—IMRT技术时肺所受的剂量在5野与7野照射技术中基本相同。（3）3DCRT和SMLC—IMRT相比较，SMLC—IMRT组肺的平均剂量、V20、V30低于3DCRT，两组有差异（P〈0．01），其余无差异。结论采用3DCRT和SMLC—IMRT技术时，5野和7野在肺组织保护上无明显差异；SMLC—IMRT与3DCRT相比可减少肺平均剂量，有利于肺组织的保护.     

Comparison of conformal and intensity-modulated techniques for simultaneous integrated boost radiotherapy of upper esophageal carcinoma

AIM: To compare intensity-modulated radiotherapy (IMRT) with conformal radiotherapy (CRT) by investigating the dose profiles of primary tumors, electively treated regions, and the doses to organs at risk. METHODS: CRT and IMRT plans were designed for five patients with upper esophageal carcinoma. For each patient, target volumes for primary lesions (67.2 Gy) and electively treated regions (50.4 Gy) were predefined. An experienced planner manually designed one CRT plan. Four IMRT plans were generated with the same dose-volume constraints, but with different beam arrangements. Indices including dose distributions, dose volume histograms (DVHs) and conformity index were compared. RESULTS: The plans with three intensity-modulated beams were discarded because the doses to spinal cord were lager than the tolerable dose 45Gy, and the dose on areas near the skin was up to 50Gy. When the number of intensity beams increased to five, IMRT plans were better than CRT plans in terms of the dose conformity and homogeneity of targets and the dose to OARs. The dose distributions changed little when the beam number increased from five to seven and nine. CONCLUSION: IMRT is superior to CRT for the treatment of upper esophageal carcinoma with simultaneous integrated boost (SIB). Five equispaced coplanar intensity-modulated beams can produce desirable dose distributions. The primary tumor can get higher equivalent dose by SIB technique. The SIB-IMRT technique shortens the total treatment time, and is an easier, more efficient, and perhaps a less error-prone way in delivering IMRT.     

Three-dimensional conformal radiotherapy in localized carcinoma of prostate: preliminary reports of toxicity in dose-escalation treatment

PURPOSE. Many studies confirmed the evidence of a dose-response relationship in prostate cancer. Escalation of dose using conventional techniques is however limited by rectal tolerance. IMRT and 3D-CRT have been designed to allow dose escalation while not exceeding rectal tolerance. We evaluated the acute and early late tolerance to surrounding organs upon dose escalation from 70 to 78 Gy in 3D-CRT setting, in order to introduce the IMRT process as a routine practice in prostate cancer treatment. MATERIALS AND METHODS. We compared clinical data from 35 patients with localized adenocarcinoma of the prostate, who received 70 Gy within a traditional reconstructed three-dimensional treatment planning, and data from 72 patients who received 78 Gy within a threedimensional conformal setting. In order to respect rectal tolerance in the higher dose group, limits were set for rectum doses, and simulation procedures were standardized. We evaluated radiation morbidity (acute and late gastrointestinal and genitourinary toxicity) using the Radiation Therapy Oncology Group scoring criteria (RTOG scale). RESULTS. Increasing doses from 70 Gy to 78 Gy resulted in no significant difference for acute and late effects. CONCLUSION. A procedural standardization aiming at minimizing day-by-day variation, as well as a more consistent dose distribution to critical organs may significantly reduce the risk of increased toxicity in dose-escalation setting.     

Volumetric-modulated arc therapy vs c-IMRT in esophageal cancer: A treatment planning comparison

AIM: To compare the volumetric-modulated arc therapy (VMAT) plans with conventional sliding window intensity-modulated radiotherapy (c-IMRT) plans in esophageal cancer (EC).METHODS: Twenty patients with EC were selected, including 5 cases located in the cervical, the upper, the middle and the lower thorax, respectively. Five plans were generated with the eclipse planning system: three using c-IMRT with 5 fields (5F), 7 fields (7F) and 9 fields (9F), and two using VMAT with a single arc (1A) and double arcs (2A). The treatment plans were designed to deliver a dose of 60 Gy to the planning target volume (PTV) with the same constrains in a 2.0 Gy daily fraction, 5 d a week. Plans were normalized to 95% of the PTV that received 100% of the prescribed dose. We examined the dose-volume histogram parameters of PTV and the organs at risk (OAR) such as lungs, spinal cord and heart. Monitor units (MU) and normal tissue complication probability (NTCP) of OAR were also reported.RESULTS: Both c-IMRT and VMAT plans resulted in abundant dose coverage of PTV for EC of different locations. The dose conformity to PTV was improved as the number of field in c-IMRT or rotating arc in VMAT was increased. The doses to PTV and OAR in VMAT plans were not statistically different in comparison with c-IMRT plans, with the following exceptions: in cervical and upper thoracic EC, the conformity index (CI) was higher in VMAT (1A 0.78 and 2A 0.8) than in c-IMRT (5F 0.62, 7F 0.66 and 9F 0.73) and homogeneity was slightly better in c-IMRT (7F 1.09 and 9F 1.07) than in VMAT (1A 1.1 and 2A 1.09). Lung V30 was lower in VMAT (1A 12.52 and 2A 12.29) than in c-IMRT (7F 14.35 and 9F 14.81). The humeral head doses were significantly increased in VMAT as against c-IMRT. In the middle and lower thoracic EC, CI in VMAT (1A 0.76 and 2A 0.74) was higher than in c-IMRT (5F 0.63 Gy and 7F 0.67 Gy), and homogeneity was almost similar between VMAT and c-IMRT. V20 (2A 21.49 Gy vs 7F 24.59 Gy and 9F 24.16 Gy) and V30 (2A 9.73 Gy vs 5F 12.61 Gy, 7F 11.5 Gy and 9F 11.37 Gy) of lungs in VMAT were lower than in c-IMRT, but low doses to lungs (V5 and V10) were increased. V30 (1A 48.12 Gy vs 5F 59.2 Gy, 7F 58.59 Gy and 9F 57.2 Gy), V40 and V50 of heart in VMAT was lower than in c-IMRT. MUs in VMAT plans were significantly reduced in comparison with c-IMRT, maximum doses to the spinal cord and mean doses of lungs were similar between the two techniques. NTCP of spinal cord was 0 for all cases. NTCP of lungs and heart in VMAT were lower than in c-IMRT. The advantage of VMAT plan was enhanced by doubling the arc.CONCLUSION: Compared with c-IMRT, VMAT, especially the 2A, slightly improves the OAR dose sparing, such as lungs and heart, and reduces NTCP and MU with a better PTV coverage.     

Dosimetric and efficiency comparison of high‐dose radiotherapy for esophageal cancer: volumetric modulated arc therapy versus fixed‐field intensity‐modulated radiotherapy

The aim of this study was to compare high‐dose volumetric modulated arc therapy (VMAT) and fixed‐field intensity‐modulated radiotherapy (ff‐IMRT) plans for the treatment of patients with middle‐thoracic esophageal cancer. Eight patients with cT2‐3N0M0 middle‐thoracic esophageal cancer were enrolled. The treatment planning system was the version 9 of the Pinnacle³ with SmartArc (Philips Healthcare, Fitchburg, WI, USA). VMAT and ff‐IMRT treatment plans were generated for each case, and both techniques were used to deliver 50 Gy to the planning target volume (PTV₅₀) and then provided a 16‐Gy boost (PTV₆₆). The VMAT plans provided superior PTV₆₆ coverage compared with the ff‐IMRT plans (P = 0.034), whereas the ff‐IMRT plans provided more appropriate dose homogeneity to the PTV₅₀ (P = 0.017). In the lung, the V₅ and V₁₀ were lower for the ff‐IMRT plans than for the VMAT plans, whereas the V₂₀ was lower for the VMAT plans. The delivery time was significantly shorter for the VMAT plans than for the ff‐IMRT plans (P = 0.012). In addition, the VMAT plans delivered fewer monitor units. The VMAT technique required a shorter planning time than the ff‐IMRT technique (3.8 ± 0.8 hours vs. 5.4 ± 0.6 hours, P = 0.011). The major advantages of VMAT plans are higher efficiency and an approximately 50% reduction in delivery time compared with the ff‐IMRT plans, with comparable plan quality. Further clinical investigations to evaluate the use of high‐dose VMAT for the treatment of esophageal cancer are warranted.     

A Comparison of Gastrointestinal Toxicities between Intensity-Modulated Radiotherapy and Three-Dimensional Conformal Radiotherapy for Pancreatic Cancer

Background/Aims

Concurrent chemoradiotherapy (CCRT) is considered the treatment option for locally advanced pancreatic cancer, but accompanying gastrointestinal toxicities are the most common complication. With the introduction of three-dimensional conformal radiotherapy (3-D CRT) and intensity-modulated radiotherapy (IMRT), CCRT-related adverse events are expected to diminish. Here, we evaluated the benefits of radiation modalities by comparing gastrointestinal toxicities between 3-D CRT and IMRT.

Methods

Patients who received CCRT between July 2010 and June 2012 in Severance Hospital, Yonsei University College of Medicine, were enrolled prospectively. The patients underwent upper endoscopy before and 1 month after CCRT.

Results

A total of 84 patients were enrolled during the study period. The radiotherapy modalities delivered included 3D-CRT (n=40) and IMRT (n=44). The median follow-up period from the start of CCRT was 10.6 months (range, 3.8 to 29.9 months). The symptoms of dyspepsia, nausea/vomiting, and diarrhea did not differ between the groups. Upper endoscopy revealed significantly more gastroduodenal ulcers in the 3-D CRT group (p=0.003). The modality of radiotherapy (3D-CRT; odds ratio [OR], 11.67; p=0.011) and tumor location (body of pancreas; OR, 11.06; p=0.009) were risk factors for gastrointestinal toxicities.

Conclusions

IMRT is associated with significantly fewer gastroduodenal injuries among patients treated with CCRT for pancreatic cancer.     

三维适形放疗与调强放疗治疗原发性肝癌伴门静脉癌栓的剂量学比较

目的评估三维适形放疗(3DCRT)与调强放疗(IMRT)2种不同放疗技术在原发性肝癌伴门静脉癌栓放射治疗中的优缺点。方法 20例不能手术的原发性肝癌并门静脉癌栓的患者分别进行3DCRT和IMRT 2种放疗计划设计,处方剂量均为40 Gy/20 f。比较2组计划的靶区与危及器官剂量学参数及加速器跳数(MU)。2组间比较采用t检验。结果 IMRT在计划靶体积(PTV)的剂量覆盖、均一性及适形度均优于3DCRT(P0.05);3DCRT与IMRT的肝V30 Gy及肝V20 Gy分别为33.55±5.67vs 29.41±2.67(P=0.001)和44.24±6.17 vs 41.28±4.59(P=0.021)。2组的正常肝组织低剂量区范围与胃、小肠、脊髓、双肾的受照射剂量并无显著性差异。3DCRT与IMRT的MU分别为303.7±35.8和377.4±33.2(P=0.000)。结论与3DCRT相比,IMRT有较满意的PTV高剂量覆盖及均匀的剂量分布。在危及器官保护方面,IMRT的肝脏高剂量区范围明显低于3DCRT,而不足的是,IMRT的治疗时间显著长于3DCRT。     

Dosimetric comparison between intensity-modulated radiotherapy and volumetric-modulated arc therapy in patients of left-sided breast cancer treated with modified radical mastectomy: CONSORT

Volumetric-modulated arc therapy (VMAT) is a novel treatment strategy that protects normal tissues and enhances target volume coverage during radiotherapy.This study aimed to clarify whether VMAT is superior to intensity-modulated radiotherapy (IMRT) in treatment planning for left-sided breast cancer patients after modified radical mastectomy.Left-sided breast cancer patients treated with modified radical mastectomy were eligible for analysis. The dose distribution of both planning target volume and organs at risk were analyzed by using dose volume histograms.Twenty-four patients were eligible for analysis. Both VMAT and IMRT plans were sufficient in planning target volume coverage. In terms of conformity, VMAT was superior to IMRT (P = .034). D_mean, V₅, and V₁₀ of the heart were significantly decreased in VMAT plans when compared with IMRT plans. VMAT was as effective as IMRT plans in sparing of other normal tissues. In addition, both the mean number of monitor units and treatment time were significantly reduced when VMAT was compared with IMRT.VMAT plans was equivalent or superior to IMRT plans in dose distribution, and was associated with slightly advantage in sparing of the heart and coronary arteries. Our analyses suggested VMAT as a preferred option in left-sided breast cancer patients treated with modified radical mastectomy.     

Lectin staining of neoplastic and normal background colorectal mucosa in nonpolyposis and polyposis patients

A lectin histochemistry approach was adopted for comparative assessment of a colon cancer risk. Binding of Ulex europaeus agglutinin-I (UEA-I), peanut agglutinin (PNA), Griffonia simplicifolia agglutinin-II (GSA-II), and Dolichos biflorus agglutinin (DBA) was investigated in tumor and background tissue from a total of 34 adenoma and 44 cancer patients and compared with reaction patterns in control and familial adenomatous pplyposis (FAP) patients. Adenoma patients with UEA-I positive rectal mucosa were found to have a 33.3 percent familial history of large bowel cancer, which was significantly higher (P <0.05) than the respective 4.0 percent figure for patients with negative rectal mucosa. In the cancer patients, an even stronger correlation was noted, with a 63.2 percent UEA-I positive family history association being recorded, as opposed to 4.0 percent in the negative rectal mucosa patients (P <0.01). Thus, the results suggest that, apparently, normal rectal background mucosa of individuals genetically at high risk for colon and rectal cancer demonstrates a specific lectin binding ability similar to that of FAP patients and that the simple method using UEA-I staining of rectal biopsy specimens can be of practical use in identification of high-risk colorectal cancer.     

Preoperative or postoperative irradiation in adenocarcinoma of the rectum: Final treatment results of a randomized trial and an evaluation of late secondary effects

From 1980 to 1985, 471 patients with resectable rectal and rectosigmoid cancer were randomly allocated to receive either preoperative short-term high-dose irradiation (25.5 Gy in one week) for all patients or prolonged postoperative radiotherapy (60 Gy in seven to eight weeks) only for patients with a Dukes B or C lesion. After a minimum follow-up of five years, the local recurrence rate was statistically significantly lower after preoperative than after postoperative radiotherapy (13 percent vs. 22 percent;P =0.02). No difference in overall survival was noted (P =0.5). To evaluate possible late side effects on the bowel, urinary bladder, or skin after surgery and additional preoperative or postoperative radiotherapy, all patients included in the randomized trial, together with 58 patients from a preceding pilot study with the same preoperative regimen, were studied in a prolonged follow-up program. The hospital files of all patients were re-examined. Of the patients who were carefully examined, 176 had a survival exceeding five years and 19 had a survival exceeding 10 years. Overall, 7 percent (33/ 464) either were operated upon or have had a radiologic diagnosis of small bowel obstruction: 14/255 (5 percent) after preoperative irradiation, 14/127 (11 percent) after postoperative irradiation, and 5/82 (6 percent) after surgery alone. The cumulative risk of developing a bowel obstruction was significantly increased after postoperative radiotherapy. Among the 98 patients alive after preoperative irradiation, significant morbidity from the bowel was noted in 11 patients, from the urinary bladder in two, and from the skin in six. In the postoperatively treated group of 34 patients, the bowel, urinary bladder, and skin morbidity were significant in five, two, and five patients, respectively. Corresponding morbidity in 44 nonirradiated patients was seen in five, one, and two patients, respectively. It is concluded that preoperative, short-term, high-dose radiotherapy decreases the local recurrence rate relative to postoperative radiotherapy, with no indications of increased late morbidity after a follow-up of 5 to 10 years.Supported by grants from the Swedish Cancer Society, Project No. 1783-B91-08XC.     

Nasopharyngeal carcinoma treated with precision-oriented radiation therapy techniques including intensity-modulated radiotherapy: preliminary results

This paper reports preliminary results with intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma (NPC). Between August 2000 and May 2001, we treated 19 patients with NPC using IMRT. Twelve patients had stage I-II disease and seven had stage III-IV disease. Six patients received 9.0-19.8 Gy three-dimensional conformal radiotherapy (3D-CRT) before IMRT and 18 patients received a brachytherapy boost after IMRT. The mean follow-up time was 13.0 months. All patients with stage II-IV disease except one received two cycles of chemoradiotherapy with cisplatin and 5-fluorouracil (5-FU) during radiotherapy, followed by two to four cycles of chemotherapy after radiotherapy. Tumor response was assessed using clinical examination and computerized tomography or magnetic resonance imaging. The mean doses administered to the gross tumor volume and clinical tumor volume were 70.9 Gy and 63.2 Gy, respectively. The mean doses administered to the right and left parotid glands were 38.1 Gy and 38.6 Gy, respectively. All 19 patients had a complete response of primary and lymph node disease. Grade III mucositis developed during chemoradiotherapy in 15 patients (79%). In addition, clinical grade I xerostomia was recorded in nine patients, grade II in nine, and grade III in one. This study demonstrated that 3D-CRT, IMRT, intracavitary brachytherapy, and chemotherapy are effective and safe methods to treat NPC. Although IMRT treatment spared parotid gland function, its efficacy may be significantly influenced by disease stage and location of the neck lymph nodes. More cases and a longer follow-up to assess survival and complications are planned.     

Functional outcome following rectal surgery—predisposing factors for low anterior resection syndrome

Purpose

Developments in surgical techniques and neoadjuvant treatment have enabled an increasing proportion of patients with rectal cancer to undergo sphincter-sparing resections. The avoidance of a permanent stoma can come at the cost of poor bowel function which can significantly impact patients’ quality of life. The objective of this study was to identify the incidence and risk factors for the development of bowel dysfunction following rectal cancer surgery.

Methods

Patients undergoing anterior resection for rectal cancer between January 2009 and January 2015 were identified from a rectal cancer database at a single centre. All patients who had bowel continuity restored and underwent curative resection were sent a validated low anterior resection syndrome (LARS) questionnaire. Pre-, inter- and postoperative factors were compared between patients with major LARS and those with minor or no LARS using conditional logistic regression.

Results

There was an 80% response rate (n = 68). Thirty-eight patients (56%) had major LARS symptoms. Neoadjuvant radiotherapy, predominantly long-course chemoradiotherapy (LCCRT), was an independent risk factor for development of major LARS symptoms, while restoration of bowel continuity within 6 months was protective.

Conclusions

The use of neoadjuvant radiotherapy (LCCRT) and timing of stoma reversal are risk factors for the development of severe bowel dysfunction. The potential for long-term poor functional results after LCCRT should be discussed with patients and form a part of the decision-making in individual treatment plans. The timing of the ileostomy closure, where safe and feasible, should be performed within 6 months to improve outcome.

     

Bladder and male sexual functions after autonomic nerve-sparing TME with or without lateral node dissection for rectal cancer

Background: We evaluated to what extent lateral lymph node dissection (LND) interferes with bladder and male sexual functions after radical rectal excision with adoption of careful total autonomic nerve preservation. Methods: The study comprised 77 patients resected for mid-rectal or lower rectal cancer. Bladder and male sexual functions were studied by means of a questionnaire more than one year after surgery. Outcomes were compared between patients who received lateral LND (group 1, 65 patients) and those who did not (group 2, 12 patients). Results: Only minor disturbances of bladder function were reported in 10 patients (15%) of group 1, and in 3 patients (25%) of group 2. Ten out of 37 preoperatively sexually active patients (27%) in group 1 males and one of 5 patients (20%) in group 2 males had partial or total impotency after surgery and retrograde ejaculation occurred in 3 of 27 patients (11%) and one of 4 patients (25%), respectively. Erectile impotency occurred less frequently when patients were operated during the period 1993–1996 than during 1988-1992 (11% vs. 42%, p<0.05). The age was significantly greater among patients who had loss of ejaculation. Conclusions: If lateral lymph node dissection should be used with the aim of improving radicality in rectal excision for cancer, it should be combined with careful nerve-preserving technique - which may reduce the risk of bladder and male sexual dysfunctions. Received: 29 October 2002 / Accepted: 16 January 2003 Correspondence to K. Maeda     

Comparing Treatment Plan in All Locations of Esophageal Cancer: Volumetric Modulated Arc Therapy versus Intensity-Modulated Radiotherapy

The aim of this study was to compare treatment plans of volumetric modulated arc therapy (VMAT) with intensity-modulated radiotherapy (IMRT) for all esophageal cancer (EC) tumor locations.This retrospective study from July 2009 to June 2014 included 20 patients with EC who received definitive concurrent chemoradiotherapy with radiation doses >50.4 Gy. Version 9.2 of Pinnacle³ with SmartArc was used for treatment planning. Dosimetric quality was evaluated based on doses to several organs at risk, including the spinal cord, heart, and lung, over the same coverage of gross tumor volume.In upper thoracic EC, the IMRT treatment plan had a lower lung mean dose (P = 0.0126) and lung V5 (P = 0.0037) compared with VMAT; both techniques had similar coverage of the planning target volumes (PTVs) (P = 0.3575). In middle thoracic EC, a lower lung mean dose (P = 0.0010) and V5 (P = 0.0145), but higher lung V20 (P = 0.0034), spinal cord Dmax (P = 0.0262), and heart mean dose (P = 0.0054), were observed for IMRT compared with VMAT; IMRT provided better PTV coverage. Patients with lower thoracic ECs had a lower lung mean dose (P = 0.0469) and V5 (P = 0.0039), but higher spinal cord Dmax (P = 0.0301) and heart mean dose (P = 0.0020), with IMRT compared with VMAT. PTV coverage was similar (P = 0.0858) for the 2 techniques.IMRT provided a lower mean dose and lung V5 in upper thoracic EC compared with VMAT, but exhibited different advantages and disadvantages in patients with middle or lower thoracic ECs. Thus, choosing different techniques for different EC locations is warranted.