[The locoregional recurrence of rectal carcinoma. A computed tomographic analysis and a target volume concept for adjuvant radiotherapy]

Evidence and research in rectal cancer

The main evidences of epidemiology, diagnostic imaging, pathology, surgery, radiotherapy, chemotherapy and follow-up are reviewed to optimize the routine treatment of rectal cancer according to a multidisciplinary approach. This paper reports on the knowledge shared between different specialists involved in the design and management of the multidisciplinary ESTRO Teaching Course on Rectal Cancer. The scenario of ongoing research is also addressed. In this time of changing treatments, it clearly appears that a common standard for large heterogeneous patient groups have to be substituted by more individualised therapies based on clinical-pathological features and very soon on molecular and genetic markers. Only trained multidisciplinary teams can face this new challenge and tailor the treatments according to the best scientific evidence for each patient.

Patterns of failure and local control after intraoperative electron boost radiotherapy to the presacral space in combination with total mesorectal excision in patients with locally advanced rectal cancer

PURPOSE

To evaluate local control and patterns of failure in patients treated with intraoperative electron beam radiotherapy (IOERT) after total mesorectal excision (TME), to appraise the effectiveness of intraoperative target definition.

METHODS AND MATERIALS

We analyzed the outcome of 243 patients with rectal cancer treated with IOERT (median dose, 10 Gy) after TME. Eighty-eight patients received neoadjuvant and 122 patients adjuvant external beam radiotherapy (EBRT) (median dose, 41.4 Gy), and in 88% simultaneous chemotherapy was applied. Median follow-up was 59 months.

RESULTS

Local failure was observed in 17 patients (7%), resulting in a 5-year local control rate of 92%. Only complete resection and absence of nodal involvement correlated positively with local control. Considering IOERT fields, seven infield recurrences were seen in the presacral space, resulting in a 5-year local control rate of 97%. The remaining local relapses were located as follows: retrovesical/retroprostatic (5), anastomotic site (2), promontorium (1), ileocecal (1), and perineal (1).

CONCLUSION

Intraoperative electron beam radiotherapy as part of a multimodal treatment approach including TME is a highly effective regimen to prevent local failure. The presacral space remains the site of highest risk for local failure, but IOERT can decrease the percentage of relapses in this area.

Definition and delineation of the clinical target volume for rectal cancer

PURPOSE

Optimization of radiation techniques to maximize local tumor control and to minimize small bowel toxicity in locally advanced rectal cancer requires proper definition and delineation guidelines for the clinical target volume (CTV). The purpose of this investigation was to analyze reported data on the predominant locations and frequency of local recurrences and lymph node involvement in rectal cancer, to propose a definition of the CTV for rectal cancer and guidelines for its delineation.

METHODS AND MATERIALS

Seven reports were analyzed to assess the incidence and predominant location of local recurrences in rectal cancer. The distribution of lymphatic spread was analyzed in another 10 reports to record the relative frequency and location of metastatic lymph nodes in rectal cancer, according to the stage and level of the primary tumor.

RESULTS

The mesorectal, posterior, and inferior pelvic subsites are most at risk for local recurrences, whereas lymphatic tumor spread occurs mainly in three directions: upward into the inferior mesenteric nodes; lateral into the internal iliac lymph nodes; and, in a few cases, downward into the external iliac and inguinal lymph nodes. The risk for recurrence or lymph node involvement is related to the stage and the level of the primary lesion.

CONCLUSION

Based on a review of articles reporting on the incidence and predominant location of local recurrences and the distribution of lymphatic spread in rectal cancer, we defined guidelines for CTV delineation including the pelvic subsites and lymph node groups at risk for microscopic involvement. We propose to include the primary tumor, the mesorectal subsite, and the posterior pelvic subsite in the CTV in all patients. Moreover, the lateral lymph nodes are at high risk for microscopic involvement and should also be added in the CTV.

Preoperative hyperfractionated chemoradiation for locally recurrent rectal cancer in patients previously irradiated to the pelvis: A multicentric phase II study

PURPOSE

The combination of irradiation and total mesorectal excision for rectal carcinoma has significantly lowered the incidence of local recurrence. However, a new problem is represented by the patient with locally recurrent cancer who has received previous irradiation to the pelvis. In these patients, local recurrence is very often not easily resectable and reirradiation is expected to be associated with a high risk of late toxicity. The aim of this multicenter phase II study is to evaluate the response rate, resectability rate, local control, and treatment-related toxicity of preoperative hyperfractionated chemoradiation for locally recurrent rectal cancer in patients previously irradiated to the pelvis.

METHODS AND MATERIALS

Patients with histologically proven pelvic recurrence of rectal carcinoma, with the absence of extrapelvic disease or bony involvement and previous pelvic irradiation with doses < or =55 Gy; age > or =18 years; performance status (PS) (Karnofsky) > or =60, and who gave institutional review board-approved written informed consent were treated by preoperative chemoradiation. Radiotherapy was delivered to a planning target volume (PTV2) including the gross tumor volume (GTV) plus a 4-cm margin, with a dose of 30 Gy (1.2 Gy twice daily with a minimum 6-h interval). A boost was delivered, with the same fractionation schedule, to a PTV1 including the GTV plus a 2-cm margin (10.8 Gy). During the radiation treatment, concurrent chemotherapy was delivered (5-fluorouracil, protracted intravenous infusion, 225 mg/m(2)/day, 7 days per week). Four to 6 weeks after the end of chemoradiation, patients were evaluated for tumor resectability, and, when feasible, surgical resection of recurrence was performed between 6-8 weeks from the end of chemoradiation. Adjuvant chemotherapy was prescribed to all patients, using Raltitrexed, 3 mg/square meter (sm), every 3 weeks, for a total of 5 cycles. Patients were staged using the computed tomography (CT)-based F-classification (F0: no side-wall involvement; F1, F2, F3: 1, 2, and 3-4 side-walls involved, respectively). Toxicity was evaluated on the basis of the Radiation Therapy Oncology Group (RTOG) criteria.

RESULTS

Fifty-nine patients (38 male, 21 female; median age, 62 years; range, 43-77 years) were enrolled in the study, by 12 different Italian radiotherapy departments. Previous surgery was anterior resection in 45 patients (76.3%) and abdominal-perineal resection in 14 patients (23.7%); previous radiotherapy dosage ranged between 30 and 55 Gy (median, 50.4 Gy); the median interval between prior radiation therapy to the onset of reirradiation was 27 months (range, 9-106 months); 44 patients (74.6%) had received some form of previous chemotherapy (concurrent and/or adjuvant). Fifty-one of 59 patients (86.4%) completed chemoradiation without treatment interruptions: 6 patients (10.2%) had temporary treatment interruption due to toxicity or patient compliance, and 2 patients (3.4%) had definitive treatment interruption. The incidence of Grade 3 lower gastrointestinal acute toxicity was only 5.1%. No patient developed Grade 4 acute toxicity. After chemoradiation, 5 patients (8.5%) had complete response (CR), 21 patients (35.6%) had partial response (PR), 31 patients (52.6%) had no change (NC) and 2 patients (3.4%) showed progressive disease (PD). Overall, the response rate (PR + CR) was 44.1% (95% confidence interval, 29.0-58.9%). Twenty of 24 patients (83.3%) with pelvic pain before treatment had symptomatic response. Tumor resection was performed in 30 of 59 patients (50.8%) including 2 local excisions, 4 anterior resections, 18 abdominoperineal resections, and 6 other. Surgical resection resulted as R0 and R1 in 21 patients (35.6%) and 3 patients (5.1%), respectively. The possibility of radical resection was influenced by tumor response to chemoradiation (PD/NC: 7/33; PR/CR: 14/26; p = 0.009). Thirty-three patients received adjuvant chemotherapy, which was completed in 30 (50.8%). At a median follow-up of 36 months (range, 9-69 months), 28 patients (47.5%) developed local recurrence or tumor progression in the unresected pelvic disease and 18 patients (30.5%) developed distant metastasis. Seven patients showed late toxicity, including 2 skin fibrosis, 2 impotence, 2 urinary complications requiring nephrostomy, and 1 small bowel fistula requiring surgical diversion. Overall median survival was 42 months. Five-year actuarial survival was 39.3%; 66.8% in R0 resected patients and 22.3% in patients treated without surgery or undergoing subtotal tumor removal. Local control and disease-free survival were significantly correlated with the interval between surgical treatment for primary tumor and local recurrence (p = 0.028 and p = 0.003, respectively). Radical resection significantly influenced local control, disease-free survival, and overall survival (p = 0.010, p = 0.010, and p = 0.050 respectively). The multivariate analysis confirmed the impact of surgery-relapse interval on local control (p = 0.016) and disease-free survival (p = 0.002), and confirmed the correlation between R0 surgery with local control and disease-free survival (p = 0.016).

CONCLUSIONS

Use of hyperfractionated chemoradiation was associated with a low rate of acute toxicity and an acceptable incidence of late complications. Pain control was excellent. The overall 5-year survival was 39%. Despite 87.4% of patients having F1-3 stage disease, approximately one-third (35%) achieved R0 resection, and two-thirds of patients in this cohort of patients were alive at the 5-year mark. However, further studies using innovative treatment algorithms are warranted to, hopefully, improve the local tumor response and control.

Urinary tract involvement by colorectal cancer

PURPOSE

Involvement of the urinary tract by colorectal cancer is sufficiently rare to be encountered by an individual surgeon on an infrequent basis. The aim of this review is to highlight technical and oncologic issues that should be considered when dealing with complex colorectal cancer that involves the urinary tract.

METHODS

The relevant literature from 1975 to 2001 was identified using the MEDLINE database of the U.S. National Library of Medicine and reviewed. Because of the diversity of forms of presentation of urologic involvement, few randomized, controlled trials are available, with most evidence derived from retrospective studies.

RESULTS

Three distinct clinical situations in which the urinary tract may be affected by colorectal cancer were identified: involvement by primary colorectal cancer, involvement by recurrent cancer, and unexpected intraoperative findings of urinary tract involvement. Management strategies to identify and treat locally advanced primary or recurrent colorectal cancer involving the urinary tract improve survival with acceptable morbidity and mortality. Careful preoperative assessment of all patients with colorectal cancer will reduce unexpected identification of urinary tract invasion at the time of surgery. In patients in whom cure is not possible, endourologic techniques combined with judicious surgical resection can provide high-quality palliation. Optimal care of many of these conditions is facilitated by specialist urologic advice.

CONCLUSIONS

The wide spectrum of possible urinary tract involvement by colorectal cancer requires individual patient-specific and disease-specific consideration. The literature offers important guidelines that aid decision making and improve management of these challenging problems.

Quality assurance in the EORTC 22921 trial on preoperative radiotherapy with or without chemotherapy for resectable rectal cancer: evaluation of the individual case review procedure

The aim of this study was to assess any inconsistency with the protocol guidelines for preoperative radiotherapy for rectal cancer among radiotherapy institutions participating in the framework of a multicentre phase-III European Organization for Research and Treatment of Cancer (EORTC) clinical trial. Twelve radiotherapy departments with more than 10% of the evaluable patients recruited in the trial, were invited to participate in this individual case review. Participating institutions were asked to send five full patient records with the chemotherapy charts, surgical and pathology reports, radiation treatment charts, treatment planning calculations, computed tomography (CT) scans, portal images and follow-up charts. The sample of the 5 patients per institution was randomly selected at the EORTC Data Center. All 12 departments participated. In 21 (35%) of the cases, a three-field technique with two lateral opposed wedge fields and a posterior field was used, while in 39 (65%) of the cases a four-field pelvic box technique was used. All participants used linear accelerators with a minimum of 6 MeV photon-beam energy. In general, the patients were eligible, documentation of clinical data was fair to good and there were no systematic major protocol deviations. The actual total dose was 44.7+/-a standard deviation (S.D.) of 4.6 Gy. Some variation was found in the fraction size. All institutions complied with the protocol in specifying the reference dose at the ICRU point. The clinical target volume (CTV) drawn on the CT scan was narrow in 7 (12%) cases, but eventually the actually treated volumes in terms of planned treatment volume (PTV) were correct. In two institutions, although the CTV was drawn correctly, the fields appeared to be narrow especially in cranio-caudal direction. Variations in treated volumes and total radiation dose were encountered in the individual case review. By providing recommendations early during the course of the trial, we expect to improve the inter-institutional consistency and to promote a high quality treatment in all of the participating institutions.

Quality assurance in preoperative radiotherapy of rectal cancer: evaluation of a pre-trial dummy-run

PURPOSE

To assess inter-institution variability of treated volumes in preoperative radiotherapy for rectal cancer among Austrian radiotherapy institutions in the framework of a multi-centre phase-III clinical trial.

MATERIALS AND METHODS

All eleven Austrian radiotherapy departments were invited to participate in this pre-study dummy-run. They received a short history of two 'dummy patients' (case A and case B); three computer assisted tomography (CT) slices; simulation films; and the protocol describing the radiation technique to be used. Participants were asked to prepare a treatment plan for either case on the basis of the materials provided and to use their computerized planning systems. Additionally and independently of the CT-based treatment plans, they were asked to delineate the fields to be treated on the simulation films.

RESULTS

Nine of eleven departments participated. All participants used a three or four field technique as requested. The variation of beam widths and planning target volumes (PTVs) in the central plane was 6-11% and 11-16%, respectively. The standard deviations (SD) were 21 and 24% for the two cases for mean treated volumes of 2.1 and 2.9 l, respectively. The variation of beam widths in the central plane was less pronounced in the simulation based treatment plans as compared with the CT-based treatment plans for the dorsal fields, the opposite was true for the laterals.

CONCLUSION

Considerable variation of treated volumes is inevitable in multi-institution trials despite detailed treatment guidelines. Simulator based treatment fields seem to result in less pronounced inter-institution variations compared with CT-based treatment planning, if bony landmarks can be used as is the case in rectal cancer. Continuous quality control is thus warranted in multi-centre trials to increase homogeneity of volumes treated.