Radiation therapy for epidermoid carcinoma of the anal canal, clinical and treatment factors associated with outcome

Radiomics; Contemporary Applications in the Management of Anal Cancer; A Systematic Review

INTRODUCTION

The management of anal cancer relies on clinical and histopathological features for treatment decisions. In recent years, the field of radiomics, which involves the extraction and analysis of quantitative imaging features, has shown promise in improving management of pelvic cancers. The aim of this study was to evaluate the current application of radiomics in the management of anal cancer.

METHODS

A systematic search was conducted in Medline, EMBASE, and Web of Science databases. Inclusion criteria encompassed randomized and non-randomized trials investigating the use of radiomics to predict post-operative recurrence in anal cancer. Study quality was assessed using the QUADAS-2 and Radiomics Quality Score tools.

RESULTS

The systematic review identified a total of nine studies, with 589 patients examined. There were three main outcomes assessed in included studies: recurrence (6 studies), progression-free survival (2 studies), and prediction of human papillomavirus (HPV) status (1 study). Radiomics-based risk stratification models were found to provide valuable insights into treatment response and patient outcomes, with all developed signatures demonstrating at least modest accuracy (range: .68-1.0) in predicting their primary outcome.

CONCLUSION

Radiomics has emerged as a promising tool in the management of anal cancer. It offers the potential for improved risk stratification, treatment planning, and response assessment, thereby guiding personalized therapeutic approaches.

Prognostic impact of post-treatment FDG PET/CT in anal canal cancer: A prospective study

BACKGROUND AND PURPOSE

The aim of our prospective study was to assess the prognostic value of 18F-FDG PET/CT performed two months post treatment for anal canal neoplasm.

POPULATION AND METHODS

Consecutive patients with histologically proved anal cancer, with 18F-FDG PET/CT pre and two months post treatment were included. Patients were not previously treated for this neoplasm and then received radiotherapy ± chemotherapy. Clinical and pathologic data were collected and for 18F-FDG PET/CT visual and quantitative analysis (standardized uptake value, metabolic volume) were performed; response was classified according to EORTC and PERCIST criteria. The results were assessed for disease free survival and local recurrence free survival using the log-Rank test RESULTS: From December 2014 to September 2019, 94 consecutive patients were screened and 78 were included in this study. Median follow-up was 51 months. Two months post treatment, 37 patients (47.4%) had a complete radiological response according to both EORTC and PERCIST criteria, 66 patients (84.6%) had a clinical complete response. For disease free survival, the prognostic value of complete response was statistically significant (p=0.02) with 18F-FDG PET/CT and with clinical examination (p<0.001). For local recurrence free survival, the prognostic value with 18F-FDG PET/CT was lower (p=0.04) than clinical examination (p < 0.007).

CONCLUSION

While clinical examination remains the gold standard for post treatment evaluation in anal cancer, 18F-FDG PET/CT has a statistically significant prognostic value. These two assessments could be combined to improve early evaluation.

Follow-up imaging of anal cancer after treatment

Anal cancer treatment response assessment can be challenging with both magnetic resonance imaging (MRI) and clinical evaluation considered essential. MRI, in particular, has shown to be useful for the assessment of treatment response, the detection of recurrent disease in follow up and surveillance, and the evaluation of possible post-treatment complications as well as complications from the tumor itself. In this review, we focus on the role of imaging, mainly MRI, in anal cancer treatment response assessment. We also describe the treatment complications that can occur, and the imaging findings associated with those complications.

Construction and validation of a prognostic nomogram for anal squamous cell carcinoma

Background

Anal squamous cell carcinoma (ASCC) is the main subtype of anal cancer and has great heterogeneity in prognosis. We aimed to construct a nomogram for predicting their 1‐, 3‐, and 5‐year overall survival (OS) rates.

Methods

Patients with ASCC, enrolled between January 1, 2010 and December 31, 2017, were identified from the SEER database. They were divided into a training group and a validation group in a ratio of 7:3. Univariate and multivariate Cox analyses were used to identify the prognostic factors for OS. Then a prognostic nomogram was established and validated by Harrell consistency index (C‐index), area under the curve (AUC) of the receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA).

Results

We identified 761 patients in training group and 326 patients in validation group. Four prognostic factors including age, sex, AJCC stage, and radiotherapy were identified and integrated to construct a prognostic nomogram. The C‐index and AUC values proved the model's effectiveness and calibration plots manifested its excellent discrimination. Furthermore, in comparison to the AJCC stage, the C‐index, AUC, and DCA proved the nomogram to be of good predictive value. Finally, we constructed a risk stratification model for dividing patients into low‐risk, medium‐risk, and high‐risk groups, and there were obvious differences in OS.

Conclusions

A prognostic nomogram was firstly established for predicting the survival probability of ASCC patients and helping clinicians improve their risk management.

What is the optimal treatment for T1N0 anal squamous cell carcinoma? Analysis of current practices in the prospective French FFCD ANABASE cohort

INTRODUCTION

for localized T1N0 squamous cell carcinoma of the anus (SCCA) standard radiotherapy (RT) may result in overtreatment and alternative strategies are debated.

METHODS

T1N0M0 SCCA treated between 2015 and 2020 by local excision (LE) or RT were analyzed from the French prospective FFCD ANABASE cohort. Treatment strategies, recurrence-free and colostomy-free survivals (RFS, CFS) and prognostic factors were reported.

RESULTS

among 1135 SCCA patients, 99 T1N0M0 were treated by LE(n = 17,17.2%), or RT (n = 82,82.8%) including RT alone (n = 65,79.2%) or chemo-RT (n = 17, 20.7%). Median follow-up was 27.2 months [0.03-54.44]. Median tumor size were 11.4 mm [0.9-20] and 15.3 mm [2-20] in the LE and RT groups respectively. Mean RT tumor dose was 59.4 Gy [18-69.4 Gy]. One patient in LE group and 9 in RT group had a pelvic recurrence, either local (60%), nodal (10%) or both (30%). RFS and CFS at 24 months were 92.2%[95%CI,83.4-96.4] and 94.6%[95%CI,86.1-98.0], at 36 months 88.1%[95%CI,77.1-94.2] and 88.5%[95%CI,77.0-94.5], in LE and RT group respectively, without any significative difference (HR = 0.57;[95%CI,0.07-4.45];p = 0.60). By univariate analysis, male gender was the only prognostic factor(HR = 5.57;95%CI, 1.76-17.63; p = 0.004).

CONCLUSION

this cohort confirms the heterogeneity of T1N0M0 SCCA management, questioning the place of RT alone, reduced dose or RT volume, and the safety of LE.

A population-based analysis of chemoradiation versus radiation alone in the definitive treatment of patients with stage I-II squamous cell carcinoma of the anus

Background

The optimal management of patients with stage I-II squamous cell carcinoma (SCC) of the anus is controversial. The current study evaluates the efficacy of combined chemotherapy and radiation therapy (CRT) versus radiation therapy (RT) alone in the treatment of these patients using the Surveillance, Epidemiology, and End Results (SEER) registries.

Methods

SEER 18 Custom Data registries were queried for patients with stage I-II SCC of the anus. Univariate analysis (UVA) and multivariable analysis (MVA) using Kaplan-Meier and Cox proportional hazards regression modeling were performed. Propensity-score matched analysis with inverse probability of treatment weighting (IPTW) was used to account for indication bias.

Results

A total of 4,288 patients with stage I-II disease were identified, of whom 3,982 (93%) underwent CRT and 306 (7%) underwent RT. Median follow-up was 42 months. Approximately 30.8% had T1 disease and 69.2% had T2-T3 disease. The IPTW-adjusted 5-year overall survival (OS) was 76.7%, with no significant differences between the CRT and RT groups (77% vs. 73.5%, P=0.33). On multivariate IPTW-adjusted analysis, the lack of association between CRT use and OS was upheld (HR, 0.84, 95% CI, 0.65-1.08, P=0.2). On subgroup analyses, 5-year OS was 86% with CRT (n=1,216) and 84.2% with RT (n=103) (P=0.74) in stage I (T1N0) patients, while 5-year OS was 72.8% with CRT (n=2,766) and 66.4% with RT (n=203) (P=0.13) in stage II (T2-3N0) patients. CRT was associated with improved median OS in stage II patients (119 months vs. not reached, P=0.04).

Conclusions

The current study suggests that omission of concurrent chemotherapy is not associated with inferior OS in patients with stage I SCC of the anus. However, combined chemoradiation was superior to radiation alone in patients with stage II disease. Prospective evidence is needed to optimize clinical decision-making in this patient population.

MRI-Based Radiomics Input for Prediction of 2-Year Disease Recurrence in Anal Squamous Cell Carcinoma

Simple Summary

Exclusive chemo-radiotherapy (CRT) is the standard treatment for non-metastatic anal squamous cell carcinomas. Identifying novel prognostic factors could help to improve CRT outcomes, notably for locally advanced diseases where relapses still occur in around 35% of patients. In this study, we aim to assess the potential value of a pre-therapeutic MRI radiomic analysis added to standard clinical variables in order to build a logistic regression model predicting 2-year recurrence after CRT. In a population of 82 patients randomly divided in training (n = 54) and testing (n = 28) sets, after selection of optimal variables, a model using two radiomic (FirstOrder_Entropy and GLCM_JointEnergy) and two clinical (tumor size and CRT length) features was able to predict the 2-year recurrence with good performances in the testing set. Radiomic biomarkers provided valuable additional and independent information added to clinical data, and could help contribute to identify high risk patients amenable to treatment intensification with view of personalized medicine.

Abstract

Purpose: Chemo-radiotherapy (CRT) is the standard treatment for non-metastatic anal squamous cell carcinomas (ASCC). Despite excellent results for T1-2 stages, relapses still occur in around 35% of locally advanced tumors. Recent strategies focus on treatment intensification, but could benefit from a better patient selection. Our goal was to assess the prognostic value of pre-therapeutic MRI radiomics on 2-year disease control (DC). Methods: We retrospectively selected patients with non-metastatic ASCC treated at the CHU Bordeaux and in the French FFCD0904 multicentric trial. Radiomic features were extracted from T2-weighted pre-therapeutic MRI delineated sequences. After random division between training and testing sets on a 2:1 ratio, univariate and multivariate analysis were performed on the training cohort to select optimal features. The correlation with 2-year DC was assessed using logistic regression models, with AUC and accuracy as performance gauges, and the prediction of disease-free survival using Cox regression and Kaplan-Meier analysis. Results: A total of 82 patients were randomized in the training (n = 54) and testing sets (n = 28). At 2 years, 24 patients (29%) presented relapse. In the training set, two clinical (tumor size and CRT length) and two radiomic features (FirstOrder_Entropy and GLCM_JointEnergy) were associated with disease control in univariate analysis and included in the model. The clinical model was outperformed by the mixed (clinical and radiomic) model in both the training (AUC 0.758 versus 0.825, accuracy of 75.9% versus 87%) and testing (AUC 0.714 versus 0.898, accuracy of 78.6% versus 85.7%) sets, which led to distinctive high and low risk of disease relapse groups (HR 8.60, p = 0.005). Conclusion: A mixed model with two clinical and two radiomic features was predictive of 2-year disease control after CRT and could contribute to identify high risk patients amenable to treatment intensification with view of personalized medicine.

Post-operative radiation therapy with or without chemotherapy for anal squamous cell carcinoma incidentally discovered after local excision: a propensity score matched analysis of retrospective multicenter study

OBJECTIVE

To evaluate the results of post-operative radiation therapy (RT) for anal squamous cell carcinoma (ASCC) incidentally detected after excision, and compare these outcomes with those of definitive RT without excision for exploring the possibility of treatment de-intensification.

METHODS AND MATERIALS

A total of 25 patients with T1-2N0-1 ASCC who underwent RT following incidental tumor resection were selected from multicenter retrospective database. And, we selected one-to-one matched 25 patients receiving definitive RT from the same database using propensity score matching method, and the outcomes were compared.

RESULTS

Median age was 60 years (range, 30-76), and 18 patients (72%) were female. 19 patients (76%) had T0/1 tumors and four patients (16%) had regional lymph node metastases. Hemorrhoidectomy was performed in eight patients (32%) and the others underwent local excision. 12 patients (48%) had microscopic or gross residual diseases. Median RT dose to the primary lesion was 50.4 Gy (range, 40-60). Concurrent chemotherapy was delivered to 23 patients (92%). Median follow-up period was 71 months (range, 4.5-203.1 months). None of the patients showed recurrence during follow-up. However, one patient died after 6 months due to the chemotherapy-related hematologic toxicity. When compared with those patients receiving definitive RT, clinicopathological variables were well-balanced between the two groups. While matched paired patients treated with definitive RT received a higher median RT dose of 54 Gy (range, 45-61.2) and concurrent chemotherapy was given to 22 patients (88%), overall survival was not significantly different (p = 0.262).

CONCLUSION

Patients treated with RT for early stage ASCC after local excision showed favorable treatment outcomes. Further study is warranted to justify the de-intensification of the treatment for these patients.

ADVANCES IN KNOWLEDGE

Post-operative RT can achieve favorable treatment outcomes in incidental ASCC with residual diseases after local excision.

Temporal improvements in loco-regional failure and survival in patients with anal cancer treated with chemo-radiotherapy: treatment cohort study (1990-2014)

Background

We evaluated oncological changes in patients with squamous cell carcinoma of the anus (SCCA) treated by chemoradiotherapy (CRT) from a large UK institute, to derive estimates of contemporary outcomes.

Methods

We performed a treatment-cohort analysis in 560 patients with non-metastatic SCCA treated with CRT over 25 years. The primary outcomes were 3-year loco-regional failure (LRF), 5-year overall survival (OS), and 5-year cancer-specific survival (CSS). We developed prediction models; and overlaid estimates on published results from historic trials.

Results

Age distributions, proportions by gender and cT stage remained stable over time. The median follow-up was 61 (IQR: 36–79) months. Comparing the first period (1990–1994) with the last period (2010–2014), 3-year LRF declined from 33 to 16% (P_trends < 0.001); 5-year OS increased from 60% to 76% (P_trends = 0.001); and 5-year CCS increased from 62% in to 80% (P_trends = 0.001). For 2020, the models predicted a 3-year LRF of 14.7% (95% CIs: 0–31.3); 5-year OS of 74.7% (95% CIs: 54.6–94.9); and 5-year CSS of 85.7% (95% CIs: 75.3–96.0). Reported oncological outcomes from historic trials generally underestimated contemporary outcomes.

Conclusions

Current and predicted rates for 3-year LRF and 5-year survivals are considerably improved compared with those in historic trials.

Prognostic value of fluorodeoxyglucose positron emission tomography/computed tomography and inguinal sentinel lymph node biopsy in patients with anal cancer

AIM

The aim of this study was to assess the value of positron emission tomography (PET)/CT and sentinel lymph node (SLN) biopsy in staging inguinal lymph nodes in anal cancer patients and to determine if the results of the two methods could be of prognostic value.

METHOD

Sixty-three patients with anal cancer and clinically negative inguinal lymph nodes underwent lymphoscintigraphy and inguinal SLN biopsy and/or fluorodeoxyglucose (FDG) PET/CT scan. All patients were treated with radiotherapy combined with 5-fluorouracil and mitomycin-C.

RESULTS

Overall (OS) and disease-free survival (DFS) were 43 months (range 5-211) and 43 months (range 4-142) respectively. PET/CT examination showed high FDG uptake in the inguinal lymph nodes in 25% of patients. Thirty-five patients with inguinal uptake at lymphoscintigraphy underwent inguinal SLN biopsy and metastatic nodes were found in 31.4%. There was no statistical difference in OS (55 vs 41 months; P = 0.652) and DFS (48 vs 38 months; P = 0.992) between the group which showed inguinal uptake on PET/CT and the group which did not, while a positive inguinal SLN was associated with a worse OS (28 vs 59 months; P = 0.028) and DFS (56 vs 21 months; P = 0.046). When the two examinations were compared PET/CT showed a sensitivity, specificity, positive predictive value and negative predictive value of 22%, 82%, 33% and 73% respectively.

CONCLUSION

The technique of SLN biopsy had a better diagnostic accuracy than total body FDG-PET/CT for the staging of inguinal lymph nodes in anal cancer patients; moreover it was a stronger predictor of OS and DFS than PET/CT.

FDG-PET parameters predict for recurrence in anal cancer - results from a prospective, multicentre clinical trial

Background

To investigate the prognostic significance of positron emission tomography (PET) parameters from F-18 fluorodeoxyglucose (FDG) PET scans performed pre- and post- chemo-radiotherapy (CRT) for squamous cell carcinoma of the anal canal (AC).

Methods

From January 2013 to January 2017, 19 patients with non-metastatic AC enrolled on a prospective trial underwent FDG-PET/CT imaging before and 12 weeks following CRT. A computer-generated volume of interest (VOI) was snapped around the primary tumour using six different standard uptake value (SUV) thresholds and the following parameters were extracted: SUV max, mean, median, standard deviation and peak as well as metabolic tumour volume (MTV) and total lesion glycolysis. Exact logistic regression and ROC AUC analyses were performed for each metric at each timepoint.

Results

With a median follow up of 15.8 months, 3/19 patients had a local recurrence and 5/19 had any recurrence. On post-CRT PET, the median SUV within a VOI bounded by an SUV of 3 correlated with local recurrence (p < 0.01) and demonstrated excellent discrimination (ROC AUC 1.00, perfect separation was achieved at a median SUV of 3.38). The mean SUV at this threshold did not quite reach significance for prediction of local recurrence (p = 0.06) but demonstrated excellent discrimination (ROC AUC 0.91). The MTV bounded by a threshold of 41% SUVmax on the pre-CRT PET predicted for any recurrence (p = 0.03) and showed excellent discrimination (ROC AUC 0.89).

Conclusions

FDG-PET parameters are predictive of recurrence in AC. FDG-PET may represent a valuable tool for prognostication and response assessment in AC.

Trial registration

ANZCTR, ACTRN12614001219673. Registered 19 November 2014 - Retrospectively registered.

Survival benefits and predictors of use of chemoradiation compared with radiation alone for early stage (T1-T2N0) anal squamous cell carcinoma

Background

Standard of care treatment for anal squamous cell carcinoma (SCC) is concurrent chemoradiation (CRT). However, the necessity of CRT over radiation alone for T1-2N0 disease is less certain.

Methods

The National Cancer Database (NCDB) was queried to identify patients who received CRT, defined as initiation of chemo and RT within 14 days of each other, or RT alone (without any chemo during initial treatment phase) for cT1-2N0M0 SCC of the anus. The cohort was limited to patients less than 70 years old with Charlson-Deyo Comorbidity Index of 0, receiving a radiation dose range of 4,500-5,940 cGy. Univariable and multivariable logistic regression were performed to assess for predictors of CRT usage. Five-year overall survival (OS) was analyzed using the Kaplan-Meier method with the log rank test both for the full cohort and then on the subsets of T1 and T2 patients.

Results

We identified 4,564 patients, of whom 4,371 (95.8%) received CRT and 193 (4.2%) received RT alone. Median follow up was 49.8 months. About 33.5% of patients had cT1N0 disease, while 66.5% of patients had cT2N0 disease. On multivariable logistic regression, patients were more likely to receive CRT if they had T2 disease [OR 2.318 (1.732-3.102), P<0.0001]. Five-year OS was 86.6% for CRT and 79.1% for RT (P=0.001). For T1 patients, 5-year OS was 90.3% with CRT and 84.7% with RT (P=0.114). For T2 patients, 5-year OS was 84.7% with CRT and 72.8% with RT (P<0.0001). Multivariable Cox regression analysis confirmed association between OS and CRT use [HR 0.588 (95% CI: 0.430-0.804), P=0.001].

Conclusions

The vast majority of patients under age 70 without significant comorbidities are treated with CRT over radiation alone for early stage anal SCC, with better survival associated with CRT.

Anal sphincter dysfunction in patients treated with primary radiotherapy for anal cancer: a study with the functional lumen imaging probe

BACKGROUND

Sphincter-sparing radiotherapy or chemoradiation are standard treatments for patients with anal cancer. The ultimate treatment goal is full recovery from anal cancer with preserved anorectal function. Unfortunately, long-term survivors often suffer from severe anorectal symptoms. The aim of the present study was to characterize changes in anorectal physiology after radiotherapy for anal cancer.

METHOD

We included 13 patients (10 women, age 63.4 ± 1.9) treated with radiotherapy or chemoradiation for anal cancer and 14 healthy volunteers (9 women, age 61.4 ± 1.5). Symptoms were assessed with scores for fecal incontinence and low anterior resection syndrome. Anorectal physiology was examined with anorectal manometry and the Functional Lumen Imaging Probe.

RESULTS

Patients had a median Wexner fecal incontinence score of 5 (0-13) and a median LARS score of 29 (0-39). Compared to healthy volunteers, patients had lower mean (±SE) anal -resting (38 ± 5 vs. 71 ± 6, p < .001) and -squeeze pressures (76 ± 11 vs. 165 ± 15, p < .001). Patients also had lower anal yield pressure (15.5 ± 1.3 mmHg vs. 28.0 ± 2.0 mmHg, p < .001), higher distensibility, and lower resistance to flow (reduced resistance ratio of the anal canal during distension, q = 5.09, p < .001). No differences were found in median (range) rectal volumes at first sensation (70.5 (15-131) vs. 57 (18-132) ml, p > .4), urge (103 (54-176) vs. 90 (32-212), p > .6) or maximum tolerable volume (173 (86-413) vs. 119.5 (54-269) ml, p > .10).

CONCLUSION

Patients treated with radiotherapy or chemoradiation for anal cancer have low anal resting and squeeze pressures as well as reduced resistance to distension and flow.

Posttreatment FDG-PET-CT response is predictive of tumor progression and survival in anal carcinoma

PURPOSE

We hypothesize that posttreatment F-18 fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) metabolic response predicts clinical outcomes in patients with anal cancer treated with chemoradiation.

METHODS AND MATERIALS

This was a single-institution retrospective review of 148 patients treated definitively for anal squamous cell carcinoma between 2005 and 2012. All patients were followed with posttreatment PET-CT scans and clinical examinations. Progression-free survival (PFS), cause-specific survival, and overall survival (OS) estimates were calculated using the Kaplan-Meier method.

RESULTS

The median follow-up was 34 months (range, 5-89 months). Pretreatment PET was successful in detecting the primary tumor in 140 cases (95%). Computed tomography (CT) alone was able to detect primary tumors in 78 of 122 patients who had pretreatment CT scans (64%). Inguinal or pelvic lymph nodes were FDG avid in 68 patients, with only 41 of these patients having enlarged lymph nodes by CT criteria (60.3%). Initial posttreatment PET-CT was obtained on average 12.7 ± 4.3 weeks after the last day of radiation (range, 5-25 weeks). Overall complete metabolic response (CR) on initial PET-CT was found in 82 patients (58%). Partial metabolic response was noted in 52 (36.9%) and progression in 7 patients (5%). Only 12/82 patients (14.6%) with a FDG-PET CR eventually recurred. The negative predictive value of a PET-CT scan performed between 13 and 25 weeks posttreatment was 92.9%. The 2-year PFS for patients with CR versus non-CR was 89.8% and 69.2%, respectively (P = .004). The 2-year OS for CR versus non-CR patients was 94.8% and 79.3% (P = .036).

CONCLUSIONS

Complete metabolic response on posttreatment FDG PET-CT is highly predictive of increased PFS and OS in patients treated with chemoradiation for anal carcinoma. In addition to close clinical surveillance, we recommend obtaining posttreatment PET-CT scans >12 weeks following definitive treatment for anal cancer.

The Surgical Anatomy of the Inguinal Lymphatics

Knowledge of the lymphatic system plays critical importance in surgical oncology. The study of the lymphatic system and its role in tumor metastasis continues to advance with new anatomical and surgical studies, and with a new study, we can gain a better understanding on how aggressive surgeons need to be with nodal dissection while balancing the complications with overly aggressive approaches. The lymphatics of the inguinal region represent a network of lymph nodes and vessels, which act as the bridge among the lower extremities, pelvis, perineum, and rest of the body. These lymph nodes are of particular importance in the metastatic spread of genitourinary and lower gastrointestinal epithelial cancer to the inguinal nodes. The aim of this article is to reveal the literature with regard to the inguinal lymph nodes and their relation in various carcinomas.

The role of MRI in the assessment of the local status of anal carcinomas and in their management

This study aims to define the role of Magnetic Resonance (MR) examinations in the assessment and therapy of anal cancer (AC), and to present the main features of the MR examinations and the typical tumor spread pattern. The MR examinations of 67 anal cancer patients with histologically confirmed planocellular cancer were analyzed retrospectively. The tumor size and the signal intensity, the nodal status were examined before and after the treatment, and in recidive tumors (N = 13). At the time of the diagnosis the primary tumor was in early stage (Tis, T1, T2) in 71.5 % of the cases, and it was localized in 97 %. In 97.4 % of the cases the tumor had relatively increased signal intensities compared to the adjacent muscles. Patients received chemo-radiotherapy (CRT). After CRT in 26 out of 39 patients (66.7 %) the size of the tumor decreased (in 75 %), and the signal intensity decreased on the T2 weighted (T2w) images. In the residual tumor cases (19/39) verified 6 patients out of 19 had further decrease in size, and signal intensity a year after the end of the therapy. The MR examination plays a key role in the therapy of AC, by assessing the precise local status, the possible recidive tumors, and monitoring the therapy.

External beam radiotherapy ± chemotherapy in the treatment of anal canal cancer: a single-institute long-term experience on 100 patients

One-hundred patients treated with curative radiotherapy (RT) ± chemotherapy (CT) for an anal canal carcinoma (T1-4N0-3M0) were retrospectively analyzed. Five- and 10-year local control (LC) rates were 73% and 67%, respectively. Acute and late G3-G4 toxicity rates were 32% and 12%, respectively. Two patients underwent a colostomy for a G4 anal toxicity. This study confirms the outcomes of RT ± CT in the treatment of anal canal cancer. Concomitant CT and LC statistically influenced Overall Survival and Colostomy-Free Survival. CT also statistically reduced the risk of nodal relapse. High rates of acute skin toxicity impose tailored volumes and techniques of irradiation.

A novel biomarker-based analysis reliably predicts nodal metastases in anal carcinoma: preliminary evidence of therapeutic impact

AIM

Routine prophylactic inguinal irradiation in anal cancer may cause significant toxicity associated with overtreatment bias. The aim of this study was to determine the risk of regional node metastases in anal carcinoma by identifying predictive molecular biomarkers.

METHOD

Clinicohistopathological data from 50 pretreatment anal carcinoma biopsies were collected. Immunohistochemical analyses with antibodies against Ki67, p53, epidermal growth factor receptor (EGFR) and YKL-40 were performed. Statistical correlations between biomarkers and clinicopathological features and outcomes were studied. Sentinel lymph node biopsy was performed in a subset of 36 patients.

RESULTS

All patients had undergone synchronous radiochemotherapy; tumour recurrence had developed in 26%, and 16% had died. YKL-40 tumour expression correlated with lymph node metastasis, whereas no inguinal node metastases were found in any of the (14%) patients presenting with a YKL-40/EGFR-negative tumour. YKL-40 expression and node metastasis were both significantly associated with shorter overall and disease-free survival. Tumour grade significantly correlated with disease-free survival only. HIV, tumour histological type, Ki67, p53 and EGFR were not associated with outcome.

CONCLUSION

YKL-40 expression in anal carcinoma is correlated with a poor outcome and can predict lymph node metastases. The combined absence of YKL-40 and EGFR expression in a first biopsy of anal carcinoma reliably selects a subset of patients without inguinal metastases. Such patients could be spared sentinel lymph node biopsy and/or inguinal radiotherapy.

[Positron emission tomography for volume delineation of pelvic nodal involvement]

Radiotherapy planification has recently known important developments, with the rise of new technologies, such as conformational radiation therapy, intensity-modulated radiation therapy (IMRT) or stereotaxic radiation therapy. Delineation of target volumes has become primordial. Hybrid imaging by positron emission tomography associated to computed tomography scanner (PET-CT) gives an access to functional and morphological information. Radiotherapist and nuclear physicians working closely have the potential to allow a more optimal delineation, and a better preservation of organs at risk. During the past few years, this has been explored by many articles, and we propose a literature review organized by localization, about the use of PET-CT for pelvic nodes delineation.

Prognostic factors for recurrence and survival in anal cancer: generating hypotheses from the mature outcomes of the first United Kingdom Coordinating Committee on Cancer Research Anal Cancer Trial (ACT I)

BACKGROUND

Only 2 prospective studies have previously reported prognostic factors for anal cancer, European Organization for Research and Treatment of Cancer trial 22861 (EORTC 22861) and Radiation Therapy Oncology Group trial 98-11 (RTOG 98-11). Both of those trials reported that clinically positive lymph nodes and male sex predicted poorer overall survival (OS). The EORTC 22861 trial indicated that the same factors were prognostic for locoregional control. In the current report, the authors investigated potential prognostic factors from the first United Kingdom Coordinating Committee on Cancer Research Anal Cancer Trial (ACT I), in which patients were randomized to receive either radiotherapy alone or chemoradiation (CRT) with concurrent 5-fluorouracil/mitomycin C.

METHODS

In the ACT I trial, associations between several baseline characteristics and 3 endpoints were investigated: locoregional failure (LRF), anal cancer death (ACD), and OS. The analyses were restricted to 292 patients who received CRT, which subsequently became standard treatment. A score was derived using multivariable Cox regression to identify the set of factors that, together, had the best prognostic performance. This score was then validated with a large, independent prospective trial (the ACT II trial).

RESULTS

Palpable, clinically positive lymph nodes were associated with LRF (P = .012), a greater risk of ACD (P = .031), and decreased OS (P = .006) in multivariable analyses. Men had worse outcomes than women for LRF (P = .036), ACD (P = .039), and OS (P = .008). On average, a lower hemoglobin level had an adverse effect on ACD (P = .008), and a higher white blood cell count had an adverse effect on OS (P = .001). However, external validation of the score was poor for LRF (area under the curve [AUC] = 54%) but was better for ACD (AUC = 67%) and OS (AUC = 63%).

CONCLUSIONS

The results from this analysis of the ACT I trial supported evidence for palpable lymph nodes and male sex as prognostic factors for LRF and OS, and lower hemoglobin levels and a higher white blood cell count were identified as prognostic factors for ACD and OS, respectively.

Value of staging squamous cell carcinoma of the anal margin and canal using the sentinel lymph node procedure: an update of the series and a review of the literature

Background:

Inguinal metastases in patients affected by anal cancer are an independent prognostic factor for local failure and overall mortality. Since 2001, sentinel lymph node biopsy was applied in these patients. This original study reports an update of personal and previous published series, which were compared with Literature to value the incidence of inguinal metastases T-stage related and the overall incidence of false negative inguinal metastases at sentinel node.

Methods:

In all, 63 patients diagnosed with anal cancer submitted to inguinal sentinel node. Furthermore a research in the Pub Med database was performed to find papers regarding this technique.

Results:

In our series, detection rate was 98.4%. Inguinal metastases were evidentiated in 13 patients (20.6%). Our median follow-up was 35 months. In our series, no false negative nodes were observed.

Conclusion:

Sentinel node technique in the detection of inguinal metastases in patients affected by anal cancer should be considered as a standard of care. It is indicated for all T stages in order to select patients to be submitted to inguinal radiotherapy, avoiding related morbidity in negative ones. An overall 3.7% rate of false negative must be considered acceptable.

[Curative radiotherapy in patients with anal cancer: clinical outcomes and prognostic factors in a single-institution experience]

PURPOSE

Our aim was to retrospectively analyse a series of patients with anal cancer treated with curative intent at a single institute in terms of survival and local disease control.

MATERIALS AND METHODS

Forty-two patients with anal cancer were treated with primary radiotherapy with or without concurrent chemotherapy. The influence of the prognostic factors on overall (OS), disease-free (DFS), disease-specific (DSS), colostomy-free (CFS) and metastasis-free (MFS) survival was evaluated.

RESULTS

Nine patients had stage I, 15 stage II, four stage IIIA and 14 stage IIIB disease. Tumour progression/ persistence occurred in five patients (12%). The 5-year OS, DSS, DFS, CFS and MFS were 72.7%, 84.2%, 85.7%, 81.1% and 87.1%, respectively. On univariate analysis, T stage emerged as highly significant for OS, DSS, CFS and DFS, whereas N status was a significant prognostic factor for DSS. On multivariate analysis, T stage was a significant prognostic factor for OS and CFS.

CONCLUSIONS

Our data support the view that combined chemoradiation treatment of anal cancer is feasible and may provide survival benefits with an acceptable rate of adverse effects. We should consider T and N stages as important prognostic factors for survival.

New approach to anal cancer: Individualized therapy based on sentinel lymph node biopsy

Oncological treatment is currently directed toward a tailored therapy concept. Squamous cell carcinoma of the anal canal could be considered a suitable platform to test new therapeutic strategies to minimize treatment morbidity. Standard of care for patients with anal canal cancer consists of a combination of radiotherapy and chemotherapy. This treatment has led to a high rate of local control and a 60% cure rate with preservation of the anal sphincter, thus replacing surgical abdominoperineal resection. Lymph node metastases represent a critical independent prognostic factor for local recurrence and survival. Mesorectal and iliac lymph nodes are usually included in the radiation field, whereas the inclusion of inguinal regions still remains controversial because of the subsequent adverse side effects. Sentinel lymph node biopsies could clearly identify inguinal node-positive patients eligible for therapeutic groin irradiation. A sentinel lymph node navigation procedure is reported here to be a feasible and effective method for establishing the true inguinal node status in patients suffering from anal canal cancer. Based on the results of sentinel node biopsies, a selective approach could be proposed where node-positive patients could be selected for inguinal node irradiation while node-negative patients could take advantage of inguinal sparing irradiation, thus avoiding toxic side effects.

Imaging of anal carcinoma

OBJECTIVE

The purpose of this article is to review the role of imaging in the management of patients with anal cancer. The relevant anatomy, imaging techniques, and interpretation of images of patients before and after therapy will be discussed.

CONCLUSION

Anal carcinomas are uncommon but increasing in frequency. Radiologists must recognize typical patterns of disease at initial evaluation, posttherapy appearances, and when to suspect residual or recurrent disease to guide clinicians and achieve optimal patient outcome.

Twenty-year experience in the management of squamous cell anal canal carcinoma with interstitial brachytherapy

OBJECTIVES

The aim of this study was to retrospectively evaluate clinical characteristics, local control, acute and late toxicity, and prognostic factors of patients with anal canal carcinoma treated with brachytherapy.

METHODS

From 1989 to 2009, 38 patients were treated with iridium 192 low-dose-rate (N = 26) or pulsed-dose-rate (N = 12) interstitial brachytherapy at a single institution. The median age was 62 years (range, 38-86 years). The TNM classification was as follows: 10 T1, 22 T2, 5 T3 and 1 T4; 32 N0, 3 N1 and 3 N2. Most patients (32/38) received either a first course of radiochemotherapy (N = 22) or radiotherapy alone (N=10) consisting of a total delivered dose of 45 Gy to the pelvis (range, 32-50) followed by a boost a median of 18 days later of 15-35 Gy (median 20 Gy) to the anal canal. The remaining 6 cases were treated with brachytherapy alone (dose range, 60-65 Gy).

RESULTS

With a median follow-up of 30 months (range, 4-200), 2- and 5-year local control rates were 91% and 87%, respectively. Preservation of the anal sphincter was achieved in 32 patients (84%). Three patients experienced incontinence after brachytherapy. Only 2 patients showed chronic mucositis grade 3/4. Age proved to be a statistically significant prognostic factor for overall survival in the univariate (p = 0.033) and multivariate analyses (p = 0.018). Concurrent chemotherapy with external beam radiotherapy was a statistically significant prognostic factor for disease-free survival in the univariate and multivariate analyses (p = 0.007 and p = 0.044, respectively).

CONCLUSIONS

Interstitial brachytherapy appears to be an effective and well tolerated treatment for anal carcinoma offering both high local tumour control and anal sphincter preservation.

The role of ¹⁸fluoro-deoxy glucose combined position emission and computed tomography in the clinical management of anal squamous cell carcinoma

AIM

Anal squamous cell carcinoma (SCC) is uncommon in the western world but continues to increase in incidence. Optimal treatment and outcome are dependent upon pretreatment staging strategies. We evaluate the role of ¹⁸fluoro-deoxyglucose (¹⁸FDG) combined position emission and computed tomography (PETCT) in the management of anal SCC.

METHOD

Patients with a histologically confirmed anal SCC underwent standard staging investigations, including computed tomography, Magnetic resonance imaging and examination under anaesthetic. A tumour, node, metastasis (TNM) system was used. All patients subsequently underwent additional whole-body ¹⁸FDG PETCT scanning. Management was planned accordingly, blinded to ¹⁸FDG PETCT findings, at a multidisciplinary meeting, and reviewed again following disclosure of PETCT results.

RESULTS

Forty patients (24 men), with a median age of 57 years (range 38-87 years), were prospectively recruited. All primary tumours were ¹⁸FDG avid. PETCT did not alter the T stage but did result in disease upstaging (N and M stages). Management was altered in five (12.5%) patients: one patient was identified to have an isolated distant metastasis, and four patients had ¹⁸FDG-avid lymph nodes not otherwise detected, all of which were tumour-positive on fine needle aspiration cytology/biopsy.

CONCLUSION

PETCT upstages anal SCC and influences subsequent management. PETCT should be considered in the staging of anal SCC, although the definitive benefit of such a strategy requires further evaluation.

Concurrent cisplatin, continuous infusion fluorouracil and radiotherapy followed by tailored consolidation treatment in non metastatic anal squamous cell carcinoma

Background

To evaluate efficacy and feasibility of chemo-radiotherapy in patients with non-metastatic anal squamous-cell-cancer.

Methods

TNM staged anal squamous-cell cancer patients were treated with pelvic radiotherapy concomitant to continuous infusion fluorouracil plus cisplatin for at least 2 cycles. In T3-T4 or any T - N+ tumours or in "slow-responder" cases, 1-2 chemotherapy courses were subsequently administered. Tumour assessment was performed at baseline and 6-8 weeks after radiotherapy to evaluate response.

Results

29 patients were enrolled: 4 males, 25 females; median age 57 years; baseline T1/T2/T3/T4 2/12/7/8; N involvement 17. Median dose pelvic radiotherapy was 59.4 Gy (range: 54-74). In 5 patients 2 chemotherapy courses, in 12 patients three and in 12 patients four courses were performed. At first evaluation, 27 CR (93.1%; 95% CI: 78% - 98%) and 2 SD were observed. Main grade (G) 3 toxic events were neutropenia (8%), diarrhoea (8%) and dermatitis (62%). Most frequent late events G3-G4 occurred in 14 patients: proctitis (5), dermatitis (4), bladder dysfunctions (2), sexual dysfunctions (9), lower extremity venous thromboses (2), dysuria (1), stenosis (1) and tenesmus (1). Five patients reported G1 leucopoenia. The rate of colostomy was 14%. After a median follow up of 42 months (range: 4-81), 20 patients are still alive without relapse and 3 died due to PD. The estimated 7-year DFS was 83.4% (C.I.: 68.3%-98.5%) and the estimated 7-year OS was 85.7% (C.I.: 70% - 100%). The 1-year and the estimated 7-year colostomy-free survivals were 85.9% (C.I.: 73.1% - 98.7%).

Conclusions

Concurrent cisplatin plus fluorouracil and radiotherapy is associated with favourable local control rates and acute toxicity. Future investigations will be directed towards research into molecular biomarkers related to disease progression and resistance to chemo-radiotherapy and to the evaluation of new cytotoxic agents or targeted drugs, such as anti-epidermal growth factor receptor, concomitant to RT and to determining the role of intensity-modulated radiotherapy.

Limited value of staging squamous cell carcinoma of the anal margin and canal using the sentinel lymph node procedure: a prospective study with long-term follow-up

Background

Selection of patients with anal cancer for groin irradiation is based on tumor size, palpation, ultrasound, and fine needle cytology. Current staging of anal cancer may result in undertreatment in small tumors and overtreatment of large tumors. This study reports the feasibility of the sentinel lymph node biopsy (SLNB) in patients with anal cancer and whether this improves the selection for inguinal radiotherapy.

Methods

A total of 50 patients with squamous anal cancer were evaluated prospectively. Patients without a SLNB (n = 29) received irradiation of the inguinal lymph nodes based on lymph node status, tumor size, and location of the primary tumor. Inguinal irradiation treatment in patients with a SLNB was based on the presence of metastases in the SLN.

Results

SLNs were found in all 21 patients who underwent a SLNB. There were 5 patients (24%) who had complications after SLNB and 7 patients (33%) who had a positive SLN and received inguinal irradiation. However, 2 patients with a tumor-free SLN and no inguinal irradiation developed lymph node metastases after 12 and 24 months, respectively.

Conclusions

We conclude that SLNB in anal cancer is technically feasible. SLNB can identify those patients who would benefit from refrain of inguinal irradiation treatment and thereby reducing the incidence of unnecessary inguinal radiotherapy. However, because of the occurrence of inguinal lymph node metastases after a tumor-negative SLNB, introduction of this procedure as standard of care in all patients with anal carcinoma should be done with caution to avoid undertreatment of patient who otherwise would benefit from inguinal radiotherapy.

Sentinel lymph node in patients with rectal cancer invading the anal canal

BACKGROUND

To assess the feasibility of the sentinel lymph node procedure in patients with rectal cancer extending to the anal canal.

METHODS

Between January 2005 and April 2008, 15 patients with adenocarcinoma of the rectum with direct invasion of the anal canal and no clinical evidence of inguinal involvement were prospectively enrolled in the study. The sentinel node procedure consisted of a combination of preoperative radiocolloid lymphoscintigraphy and intraoperative detection of the inguinal sentinel node with a gamma probe. Patent blue dye was also used to facilitate direct identification of the blue-stained lymph node. After removal, the sentinel node was studied by hematoxylin-eosin staining and immunohistochemistry.

RESULTS

Detection and removal of inguinal sentinel nodes was possible in all patients. Four patients (26.7%) had sentinel nodes identified as positive for metastatic adenocarcinoma. All positive cases also had metastases detected in perirectal lymph nodes; three of them developed hepatic or pulmonary metastases within 6 months after surgery. Of the 11 patients with negative sentinel nodes, only four (36.4%) also presented metastatic perirectal lymph nodes. Although none of the negative cases developed late inguinal metastases, three developed systemic or pelvic recurrence within 12 months after surgery.

CONCLUSIONS

The standardized procedure was highly effective in sampling inguinal sentinel nodes in very low rectal cancers, allowing the detection of subclinical metastatic disease. Although this technique can be potentially useful for a subgroup of patients with isolated inguinal metastases, it cannot be routinely recommended for patients with rectal tumors invading the anal canal at this moment.

Sentinel node biopsy by indocyanine green retention fluorescence detection for inguinal lymph node staging of anal cancer: preliminary experience

BACKGROUND

There is some evidence that sentinel lymph node (SLN) biopsy guided by dye injection and/or radioisotopes can improve staging of inguinal lymph nodes (LNs) in anal cancer. This study was performed to investigate the feasibility of fluorescence detection of SLN and lymphatic mapping in anal cancer.

METHODS

Twelve patients with anal cancer without evidence for inguinal LN involvement were included in the study. Intraoperatively, all patients received a peritumorous injection of 25 mg indocyanine green (ICG) for fluorescence imaging of the SLN with a near-infrared camera. For comparison, conventional SLN detection by technetium-(99)m-sulfur radiocolloid injection in combination with blue dye was also performed in all patients. The results of both techniques and the effect on the therapeutic regimen were analyzed.

RESULTS

Overall, ICG fluorescence imaging identified at least one SLN in 10 of 12 patients (detection rate, 83%). With the combination of radionuclide and blue dye, SLN were detected in 9 of 12 patients (detection rate, 75%). Metastatic involvement of the SLN was found in 2 of 10 patients versus 2 of 9 patients. Patients with metastatic involvement of the SLN received extended radiation field with inguinal boost.

CONCLUSIONS

ICG fluorescence imaging allows intraoperative lymphatic mapping and transcutaneous SLN detection for selective biopsy of inguinal SLN in anal cancer. This technique should be further evaluated in comparative studies with larger patient numbers.

FDG-PET/CT imaging for staging and target volume delineation in conformal radiotherapy of anal carcinoma

Background

FDG-PET/CT imaging has an emerging role in staging and treatment planning of various tumor locations and a number of literature studies show that also the carcinoma of the anal canal may benefit from this diagnostic approach. We analyzed the potential impact of FDG-PET/CT in stage definition and target volume delineation of patients affected by carcinoma of the anal canal and candidates for curative radiotherapy.

Methods

Twenty seven patients with biopsy proven anal carcinoma were enrolled. Pathology was squamous cell carcinoma in 20 cases, cloacogenic carcinoma in 3, adenocarcinoma in 2, and basal cell carcinoma in 2. Simulation was performed by PET/CT imaging with patient in treatment position. Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) were drawn on CT and on PET/CT fused images. PET-GTV and PET-CTV were respectively compared to CT-GTV and CT-CTV by Wilcoxon rank test for paired data.

Results

PET/CT fused images led to change the stage in 5/27 cases (18.5%): 3 cases from N0 to N2 and 2 from M0 to M1 leading to change the treatment intent from curative to palliative in a case.

Based on PET/CT imaging, GTV and CTV contours changed in 15/27 (55.6%) and in 10/27 cases (37.0%) respectively. PET-GTV and PET-CTV resulted significantly smaller than CT-GTV (p = 1.2 × 10^-4) and CT-CTV (p = 2.9 × 10^-4). PET/CT-GTV and PET/CT-CTV, that were used for clinical purposes, were significantly greater than CT-GTV (p = 6 × 10^-5) and CT-CTV (p = 6 × 10^-5).

Conclusions

FDG-PET/CT has a potential relevant impact in staging and target volume delineation of the carcinoma of the anal canal. Clinical stage variation occurred in 18.5% of cases with change of treatment intent in 3.7%. The GTV and the CTV changed in shape and in size based on PET/CT imaging.

Radiation dose associated with local control in advanced anal cancer: retrospective analysis of 129 patients

BACKGROUND AND PURPOSE

To retrospectively analyse a large consecutive cohort of patients with anal cancer for treatment-related factors influencing local control and survival.

MATERIALS AND METHODS

All patients referred for primary radiotherapy at Medical University of Vienna in 1990-2002 with anal canal carcinoma without distant metastases were analysed. Treatment consisted of external radiotherapy with or without brachytherapy and with or without chemotherapy. Patient-, tumour-, and treatment-factors were tested for influence on survival and local control using Cox multivariate analysis.

RESULTS

Median age was 67 years (n=129), the UICC stage distribution was 15%, 58%, and 27% for stages I, II, and III, respectively. With median follow-up of 8.0 years for surviving patients (3.9 years including deceased patients), five-year overall survival and disease-free-survival were 57% and 51%, respectively. Local control at 5 years was 87%. Stage and age were significant factors for overall and colostomy-free-survival, N-stage for disease-free-survival. Shorter overall treatment time favoured local control in stage T1-2 (p=.015), higher total radiation dose and female gender were associated with improved local control in T3-4 tumours (p=.021).

CONCLUSIONS

These results support potential improvement of anal cancer treatment by studying advanced technology such as IMRT, making it possible to tailor high-dose regions.

Lymphatic mapping and sentinel lymph node biopsy in epidermoid carcinoma of the anal canal

AIM

Although 15-25% of patients with anal cancer present with superficial inguinal lymph node metastases but the routine application of groin irradiation is controversial because of serious side effects. Inguinal sentinel lymph node biopsy (SLNB) can be used to select patients appropriately for inguinal radiation. The study evaluates the efficiency and clinical impact of SLNB.

METHODS

Forty patients with anal cancer underwent 1 ml Tc(99m)-Nanocolloid injection in four sites around the tumour. Patients with inguinal radio colloid enrichment were selected for sentinel lymph node biopsy (SLNB). Lymph node status was examined by haematoxylin and eosin (H&E) as well as immunohistochemistry-staining. All SLN-positive patients were scheduled for inguinal radiation; SLN-negative patients with T1 and early T2 tumours were not scheduled for inguinal radiation.

RESULTS

SLN were detected in 36/40 patients. Three common patterns of lymphatic drainage were observed: mesenterial, iliacal and inguinal. Twenty patients with inguinal SLN underwent SLN-biopsy. 6/20 patients were SLN-positive. In 10/20 patients SLNB altered the therapy plan--four patients with T1-tumours and positive SLN had additional groin irradiation, whereas 6 patients with small T2-tumors and tumour-free inguinal SLN did not undergo inguinal irradiation.

CONCLUSIONS

Inguinal sentinel node biopsy in anal cancer is efficient and could assist in the decision for inguinal radiation. The validity and safety of the proposed therapeutic algorithm has to be proven by a larger, prospective study.

Clinical outcome after treatment with a brachytherapy boost versus external beam boost for anal carcinoma

PURPOSE

To evaluate the outcome after definitive whole pelvis external beam radiotherapy (EBRT) followed by brachytherapy (BT) boost after treatment break vs. external beam boost without break in the treatment of anal carcinoma.

METHODS AND MATERIALS

Eighty-one consecutive patients with invasive anal carcinoma were analyzed retrospectively. Patients treated with an interstitial (192)Ir high-dose-rate (HDR) implant boost of 14Gy/7 fractions/3d given 3 weeks after completion of whole pelvis 45Gy EBRT were compared with those treated with external beam boost of 14.4Gy, started immediately after completion of whole pelvis 45Gy EBRT. Concomitant chemotherapy (CT) with mitomycin C was applied during whole pelvis EBRT depending on tumor stage. Pattern of care, local disease control (LC), cancer-specific survival (CSS), overall survival (OS), toxicity, and quality of life (QOL) were assessed.

RESULTS

Radiotherapy with or without concomitant CT achieved clinical complete response in 93.4% of patients. In early stage tumors, (192)Ir-HDR BT boost with CT resulted in a 5-year LC and CSS of 100%. In all patients, BT boost did not result in improved LC, OS, and CSS compared with EBRT boost, despite stage and treatment bias favoring small tumors to be treated with BT. The 5-year and 10-year OS were 66% and 44% (BT boost) and 66% and 52% (EBRT boost), respectively. Subgroup analysis of Stages I and II disease revealed no significant improvement after BT boost compared with EBRT boost. Acute skin toxicity was less common in the BT boost group (whole cohort: p=0.14; Stages I-IIIa: p=0.05), but long-term morbidity and QOL were similar. No local necrosis was seen after BT boost and the 10-year sphincter preservation rate was 87% in these patients.

CONCLUSIONS

Interstitial (192)Ir-HDR implant boost with break and EBRT boost without break yield similar results. Acute skin toxicity is reduced with BT boost but long-term morbidity and QOL are identical. BT boost is most beneficial in early stage tumors but the advantage of BT seems to be limited due to its invasiveness, doctor dependence, and logistic circumstances.