Radiation injury of the rectum

Synbiotics protected radiation-induced tissue damage in rectal cancer patients: A controlled trial

BACKGROUND & AIMS

Colorectal cancer (CRC), particularly rectal cancer, often requires neoadjuvant radiotherapy (RT) as part of its treatment plan. Although effective, RT can cause significant gastrointestinal side effects. Because the onset of RT-induced tissue injury can be anticipated, there is an opportunity to apply preventive measures before the damage occurs. This study aimed to assess whether prebiotic and synbiotic interventions could mitigate RT-induced gut injury by modulating the mucosa-associated microbiota, reducing inflammation, and enhancing gut barrier function in patients undergoing RT for rectal cancer.

METHODS

Thirty patients with rectal adenocarcinoma scheduled for preoperative short-term RT (5 × 5 Gy) were divided into three groups: a control group (Ctrl), a prebiotic group (Fiber) receiving oat bran, and a synbiotic group (Synbiotics) receiving oat bran with L. plantarum HEAL19 and blueberry husks. The study products were administered daily for two weeks, starting one week before RT. Blood, faecal, and biopsy samples were collected before and after RT to evaluate inflammatory markers, intestinal permeability, histopathological changes, and mucosa-associated microbiota.

RESULTS

The Fiber and Synbiotics groups exhibited a significant reduction in white blood cell counts following RT (p = 0.01 for both), whereas the Ctrl group did not demonstrate a significant change. However, there was no significant difference in the magnitude of change in white blood cell counts among the three groups (p = 0.12). Histopathological analysis revealed that the Synbiotics group had reduced inflammation and fibrosis compared to the Fiber and Ctrl groups. Although RT reduced bacterial diversity overall, the Synbiotics group preserved a greater proportion of bacterial species, experiencing only a 25.1 % reduction compared to a 55.4 % reduction in the Fiber group.

CONCLUSION

Synbiotic interventions may protect rectal mucosa by reducing inflammation and modulating mucosa-associated microbiota. The effects were primarily localized to the tissue, reflecting the short-term duration of treatment. While immediate benefits were observed, longer-term interventions should be explored to reduce systemic inflammation.

Gluteal Fasciocutaneous Flap Reconstruction After Salvage Surgery for Pelvic Sepsis

BACKGROUND

Chronic pelvic sepsis mostly originates from complicated pelvic surgery and failed interventions. This is a challenging condition that often requires extensive salvage surgery consisting of complete debridement with source control and filling of the dead space with well-vascularized tissue.

OBJECTIVE

This study aimed to describe the outcomes of gluteal fasciocutaneous flaps for the treatment of secondary pelvic sepsis.

DESIGN

Retrospective single-center cohort study.

SETTINGS

Tertiary referral center.

PATIENTS

Patients who underwent salvage surgery for secondary pelvic sepsis between 2012 and 2020 using a gluteal flap were included in this study.

MAIN OUTCOME MEASURES

Percentage of complete wound healing.

RESULTS

In total, 27 patients were included, of whom 22 underwent index rectal resection for cancer and 21 had undergone (chemo)radiotherapy. A median of 3 (interquartile range, 1-5) surgical and 1 (interquartile range, 1-4) radiological interventions preceded salvage surgery during a median period of 62 (interquartile range, 20-124) months. Salvage surgery included partial sacrectomy in 20 patients. The gluteal flap consisted of a V-Y flap in 16 patients, superior gluteal artery perforator flap in 8 patients, and a gluteal turnover flap in 3 patients. Median hospital stay was 9 (interquartile range, 6-18) days. During a median follow-up of 18 (interquartile range, 6-34) months, wound complications occurred in 41%, with a reintervention rate of 30%. The median time to wound healing was 69 (interquartile range, 33-154) days, with a complete healing rate of 89% at the end of follow-up.

LIMITATIONS

Retrospective design and heterogeneous patient population.

CONCLUSIONS

In patients undergoing major salvage surgery for chronic pelvic sepsis, the use of gluteal fasciocutaneous flaps is a promising solution because of the high success rate, limited risks, and relatively simple technique. See Video Abstract at http://links.lww.com/DCR/C160 .

RECONSTRUCCIN CON COLGAJO FASCIOCUTNEO GLTEO DESPUS DE UNA CIRUGA DE RESCATE POR SEPSIS PLVICA

ANTECEDENTES:La sepsis pélvica crónica esta causada principalmente por cirugías pélvicas complicadas e intervenciones fallidas. Esta es una condición desafiante que a menudo requiere una cirugía de rescate extensa que consiste en un desbridamiento completo controlando el orígen infeccioso y rellenando el espacio muerto con tejido bien vascularizado, como por ejemplo un colgajo de tejido autólogo. La pared abdominal (colgajo de recto abdominal) o la pierna (colgajo de gracilis) se utilizan principalmente como sitios donantes para esta indicación, mientras que los colgajos glúteos pueden ser alternativas atractivas.OBJETIVO:Describir los resultados de los colgajos fasciocutáneos glúteos en el tratamiento de la sepsis pélvica secundaria.DISEÑO:Estudio de cohortes retrospectivo en un solo centro.AJUSTES:Centro de referencia terciario.PACIENTES:Todos aquellos que se sometieron a cirugía de rescate por sepsis pélvica secundaria entre 2012 y 2020 utilizando un colgajo fasciocutáneo glúteo.PRINCIPALES MEDIDAS DE RESULTADO:El porcentaje de cicatrización completa de la herida.RESULTADOS:En total, se incluyeron 27 pacientes, de los cuales 22 fueron sometidos a resección rectal por cáncer indicada y 21 pacientes que habían recibido (quimio)radioterapia. Una mediana de tres (RIC 1-5) intervenciones quirúrgicas y una (RIC 1-4) intervenciones radiológicas precedieron a la cirugía de rescate durante una mediana de 62 (RIC 20-124) meses.La cirugía de rescate incluyó una resección parcial del sacro en 20 pacientes. El colgajo fasciocutáneo glúteo consistió en la confección de un colgajo en V-Y en 16 pacientes, un colgajo incluyendo la perforante de la arteria glútea superior en 8 y un colgajo de rotación de músculo glúteo en 3 pacientes.La mediana de estancia hospitalaria fue de nueve (RIC 6-18) días. Durante una mediana de seguimiento de 18 (IQR 6-34) meses, se produjeron complicaciones de la herida en el 41%, con una tasa de reintervención del 30%.La mediana de tiempo hasta la cicatrización de la herida fue de 69 (IQR 33-154) días con una tasa de cicatrización completa del 89 % al final del seguimiento cicatricial.LIMITACIONES:Diseño retrospectivo y población heterogénea de pacientes.CONCLUSIONES:En pacientes sometidos a cirugía mayor de rescate por sepsis pélvica crónica, el uso de colgajos fasciocutáneos glúteos es una solución prometedora debido a la alta tasa de éxito, los riesgos limitados y la técnica relativamente simple. Video Resumen en http://links.lww.com/DCR/C160 . (Traducción-Dr. Xavier Delgadillo ).

Psychosocial needs of post-radiotherapy cancer survivors and their direct caregivers - a systematic review

Radiotherapy is an important modality for cancer treatment. About 50% of cancer patients receive radiotherapy, and one-third of radiotherapy recipients were identified as having unmet psychosocial needs. The unmet psychosocial needs worsen the patient's quality of life and treatment effectiveness. This review aims to identify the psychosocial needs of post-radiotherapy cancer survivors and their direct caregivers. Systematic research of Embase, Scopus and PubMed was done and 17 studies were selected for analysis. The results show that patients encounter distress and fear due to treatment immobilization and unfamiliarity with procedures respectively. Information provision is a common need raised by patients and caregivers. Patients and caregivers report relationship problems due to affected sexual functions. To facilitate future studies, solutions to each identified psychosocial need are proposed in the discussion based on the 17 selected papers and other supporting literature. This review proposes art therapy to alleviate psychological distress, and pre-treatment information sessions to reinforce information delivery. Creative interventions such as a sexual rehabilitation program are recommended. Future studies are warranted to examine the interventions and thus improve the patients' and caregivers' well-being.

Therapeutic approach of adipose-derived mesenchymal stem cells in refractory peptic ulcer

Peptic ulcer is one of the most common gastrointestinal tract disorders worldwide, associated with challenges such as refractory morbidity, bleeding, interference with use of anticoagulants, and potential side effects associated with long-term use of proton pump inhibitors. A peptic ulcer is a defect in gastric or duodenal mucosa extending from muscularis mucosa to deeper layers of the stomach wall. In most cases, ulcers respond to standard treatments. However, in some people, peptic ulcer becomes resistant to conventional treatment or recurs after initially successful therapy. Therefore, new and safe treatments, including the use of stem cells, are highly favored for these patients. Adipose-derived mesenchymal stem cells are readily available in large quantities with minimal invasive intervention, and isolation of adipose-derived mesenchymal stromal stem cells (ASC) produces large amounts of stem cells, which are essential for cell-based and restorative therapies. These cells have high flexibility and can differentiate into several types of cells in vitro. This article will investigate the effects and possible mechanisms and signaling pathways of adipose tissue-derived mesenchymal stem cells in patients with refractory peptic ulcers.

Rectal wall dose-volume effect of pre- or post KUSHEN Ningjiaos relationship with 3D brachytherapy in cervical cancer patients

BACKGROUND

The present prospective study evaluated the safety and efficacy of the rectum following KUSHEN Ningjiaos in cervical cancer. We compared rectal wall changes during brachytherapy with or without KUSHEN Ningjiaos in cervical cancer patients and analyzed the difference in spatial dose distribution, including whole rectum-wall (R-w), anterior rectum-wall (R-a) and posterior rectum-wall (R-p).

METHODS AND MATERIALS

One hundred cervical cancer patients with and without KUSHEN Ningjiaos were treated with brachytherapy (600 cGy). The whole R-w was divided into two areas of R-a and R-p, and R-w dose surface map were constructed. The volume of each R-w was compared in patients pre- and post-KUSHEN Ningjiaos.

RESULTS

When the pre- vs. post-KUSHEN groups were compared the volume of R-w increased. In the post-KUSHEN group, a significantly higher proportion of the D2cc of V_R-w and V_R-a compared with the pre-KUSHEN group showed that the D2cc_mean increased from 532.45 cGy to 564.7 cGy and 533.51 cGy to 565.26 cGy, respectively; however, results demonstrated a decrease in the D2cc_mean of R-p from 260.5 cGy to 240.0868 cGy (P < 0.05). The insertion of KUSHEN Ningjiaos resulted in a reduction of the relative volume of R-p exposed to high doses, and regressive analysis showed that the D_R-p-max correlated most strongly with V_R-w and D2cc_R-p (P < 0.01 and P < 0.05, respectively).

CONCLUSION

The insertion of KUSHEN Ningjiaos can protect the rectum. KUSHEN Ningjiaos appears to be safe and well tolerated; therefore, we believe that there will be fewer adverse events after brachytherapy for patients.

TRIAL REGISTRATION

A multi-center, prospective clinical trial for KUSHEN Ningjiaos was inserted into rectum to reduce the rate of radiation proctitis in three-dimensional brachytherapy of cervical cancer. ChiCTR1900021631 . 2 Mar 2019-Retrospectively registered.

Expression of vascular endothelial growth factor and its correlation with clinical symptoms and endoscopic findings in patients with chronic radiation proctitis

AIM

The aim of this study was to assess the expression of vascular endothelial growth factor (VEGF) as a key proangiogenic factor and determine whether there is any correlation between its expression and clinical symptoms or endoscopic changes in patients with chronic radiation proctitis (ChRP).

METHOD

Fifty patients who had all undergone radiotherapy for prostate, cervical or uterine cancer were included in the study (37 women, 13 men). There was a control group of 20 patients (9 women, 11 men). The Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) scoring system was used for grading the severity of the proctitis. Endoscopic scoring of late rectal mucosal damage was performed using Gilinsky's classification. Serum levels of VEGF were analysed by the enzyme-linked immunosorbent assay method.

RESULTS

Most patients presented with Grade 1 symptoms. Endoscopic assessment showed that most patients had Grade 1 late rectal mucosal damage. The predominant endoscopic finding was the presence of telangiectasia. Assessment of VEGF correlation between the control group and the degrees of endoscopic changes showed statistically significant differences for all three degrees (P < 0.0001, P = 0.0251 and P = 0.0005, respectively). Due to the small numbers of patients with Grades 2 and 3 symptoms using the RTOG/EORTC scoring system, they were grouped with Grades 1 and 4 respectively forming two groups for statistical purposes. VEGF expression differed significantly between controls and group I and between controls and group II (P = 0.0001, P = 0.0009, respectively).

CONCLUSION

A significant increase in VEGF expression was found to correlate with clinical symptoms and endoscopic rectal mucosa changes in patients with ChRP, suggesting that it may play an important role in pathological angiogenesis.

Defecation into clothing without forewarning and mean radiation dose to bowel and anal-sphincter among gynecological cancer survivors

BACKGROUND

To analyze the relationship between mean radiation dose to the bowels and the anal-sphincter and occurrence of 'defecation into clothing without forewarning', a specific and serious fecal incontinence symptom after gynecological radiotherapy. Additional potential risk factors associated with the symptom are explored.

MATERIAL AND METHODS

Data were collected for 519 eligible gynecological cancer survivors, treated with pelvic radiotherapy, with a median follow-up of 5.8 years, using a study-specific questionnaire and medical records. Correlations between defecation into clothing without forewarning and mean dose to organs at risk; the anal-sphincter region, the rectum, the sigmoid and the small intestines were investigated, also taking other risk factors into account.

RESULTS

Twelve percent reported having had the symptom at least once in the preceding six months. Mean doses >50 Gy to the anal-sphincter region, the rectum, the sigmoid and the small intestines were related to the occurrence of the symptom. Significantly associated risk factors were deliveries with high birth weight, heart failure and lactose and/or gluten intolerance. After adjusting for these factors, mean doses >50 Gy to the anal-sphincter region, the sigmoid and the small intestines remained related to the occurrence of the symptom.

CONCLUSION

Mean doses to the bowels and anal-sphincter region are related to the risk of defecation into clothing without forewarning in long-term gynecological cancer survivors treated with pelvic radiotherapy. Further radiobiological modeling may distinguish which organ(s) contribute most to development of the symptom.

Efficacy and safety of Yunxiangjing derived from Chinese herbal medicine administered as an enema in the management of acute radiation-induced proctitis in patients with pelvic malignancy

OBJECTIVE

To assess the efficacy and safety of Yunxiangjing (YXJ), derived from Chinese herbal medicine, in the management of acute radiation-induced proctitis (ARIP) in patients with pelvic malignancy.

METHODS

Forty-eight patients with grade 2 ARIP were administered YXJ as an enema (1 : 30 dilution) for 2 weeks and followed up for 2 years. All were assessed for response and ARIP grade. Quality of life (QOL) was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30.

RESULTS

Of the 48 patients, six (12.5%) achieved complete remission of ARIP and 28 (58.3%) showed a decrease from grade 2 to grade 1 ARIP. No patient experienced a grade ≥3 toxicity. At the end of radiotherapy, patients showed significant improvements in QOL (P < 0.05). Two years after treatment, 46 patients showed no late toxicity, with only two experiencing grade 1 late toxicity.

CONCLUSION

YXJ can be used as an enema to manage acute radiation-induced proctitis in cancer patients undergoing radiotherapy. These findings suggest that YXJ enema may be an alternative treatment of ARIP.

Intersphincteric completion proctectomy with omentoplasty for chronic presacral sinus after low anterior resection for rectal cancer

AIM

This study aimed to determine the clinical outcome of salvage surgery without restoring continuity for symptomatic chronic presacral sinus after low anterior resection (LAR) for rectal cancer.

METHOD

Out of a prospective cohort of 46 patients with chronic presacral sinus (> 1 year after LAR), 27 underwent completion proctectomy with omentoplasty between January 2005 and July 2014.

RESULTS

The initial treatment for rectal cancer included neoadjuvant radiotherapy in 26 (96%) patients. Besides a chronic presacral sinus, a secondary fistula was present in 15 (56%) patients. Definitive salvage surgery was performed after a median of 40 (12-350) months from the primary resection. The median hospital stay after single- and multiple-stage salvage surgery was 11 and 17 days. Postoperative complications occurred in 44% of patients. The re-intervention rate was 33% with a range of 1-10 interventions per patient. During a median follow-up of 20 (4-45) months from salvage surgery, healing of the chronic presacral sinus occurred in 78% of patients, with a healing rate after single- and multiple-stage procedures of 88% and 64% respectively (P = 0.19).

CONCLUSION

Patients with a symptomatic chronic presacral sinus after LAR for rectal cancer, in whom restoration of continuity is not intended, can be effectively managed by completion proctectomy with complete debridement of the sinus and fistula tracts followed by an omentoplasty to fill the presacral cavity, preferably as a single-stage procedure.

Radiation therapy in patients with inflammatory bowel disease and colorectal cancer: risks and benefits

PURPOSE

The effects of radiotherapy are debated in inflammatory bowel disease (IBD). We examined IBD patients with colorectal cancer (CRC) and compared those who underwent external beam radiation therapy (EBRT) to those who did not. We then compared those same patients treated with EBRT to similarly treated non-IBD patients to ascertain differences in toxicity and perioperative outcomes.

METHODS

Fifty-seven IBD patients with CRC received EBRT, of which 23 had perioperative follow-up and 15 had complete records. The 23 patients were compared to 229 IBD patients with CRC who did not receive EBRT. The 15 patients were matched, 1:2, to similarly treated non-IBD patients with CRC based on age (±5 years), treatment year (±1 year), BMI (±10 kg/m2), and clinical stage.

RESULTS

There was significantly more postoperative bleeding (5.3 % vs. 0 %, p < 0.01), wound dehiscence (3.5 % vs. 0 %, p < 0.01), and perineal infection (8.8 % vs. 1.3 %, p < 0.01) in IBD patients with EBRT compared to those without EBRT. IBD patients were significantly more likely to have grade 3 or higher lower GI toxicity (40 % vs. 7 %, p = 0.02) and wound dehiscence (36 % vs. 7 %, p = 0.02) than non-IBD patients, however without significant difference in bleeding, infection, ileus, or survival.

CONCLUSION

IBD patients with CRC who received EBRT were more likely than similar patients without EBRT to experience perioperative complications. These patients also experienced more lower GI toxicity than similarly treated non-IBD patients with CRC. The expected decrease in survival in IBD-associated CRC was not observed. Thus, EBRT may contribute to a survival benefit in this group.

Perineal wound healing after abdominoperineal resection for rectal cancer: a two-centre experience in the era of intensified oncological treatment

PURPOSE

Intensified treatment for distal rectal cancer has improved oncological outcome, but at the expense of more perineal wound complications in patients undergoing an abdominoperineal resection (APR). The aim of this study was to analyse perineal wound healing after APR with primary perineal wound closure over time.

METHOD

All patients undergoing APR for primary rectal cancer with primary wound closure between 2000 and 2013 were included and analysed in three consecutive time periods. Both early (<30 days postoperatively) and late perineal wound complications were determined. Independent risk factors of early perineal wound complications were identified using multivariable analysis.

RESULTS

A total of 136 patients were identified, of whom 129 patients underwent primary perineal wound closure. The use of neo-adjuvant (chemo)radiotherapy increased from 72 to 91%, and the use of an extralevator approach increased from 9 to 19%. The rate of early perineal wound complications increased from 18 to 31% and was independently associated with an extralevator approach [odds ratio (OR) 3.17; 95% confidence interval (CI) 1.16-8.66] and intra-operative perforation (OR 3.35; 95% CI 1.06-10.57). Perineal wound complications had no impact on local recurrence or 3-year overall survival rate. During a median follow-up of 28 months [interquartile range (IQR) 14-56], a persistent presacral sinus was diagnosed in 10%, and a perineal hernia occurred in 8% of the patients.

CONCLUSION

The increased use of an extralevator APR for rectal cancer significantly increased the risk of perineal wound complications over time. Intra-operative perforation was also independently associated with impaired perineal wound healing.

Flagellin and LPS each restores rat lymphocyte populations after colorectal irradiation

Radiation-induced gastrointestinal toxicity, including its shift of the immune balance, remains a major limitation to delivering tumoricidal doses of abdominal radiation therapy. This study evaluates the effect on the colon's innate and adaptive immune responses to moderate irradiation doses and the therapeutic possibilities of maintaining immune homeostasis. We investigated whether administration of the TLR4 agonist LPS or of the TLR5 agonist flagellin, 3 days after a single 20-Gy colorectal irradiation, modified recruitment of neutrophils, NK cells, or CD4⁺ or CD8⁺ T cells, 7 days postirradiation. Flow cytometric analysis showed that LPS and flagellin reduced irradiation-induced neutrophil infiltration and normalized NK frequency. LPS normalized the CD4⁺ population and enhanced the CD8⁺ population, whereas flagellin maintained the radiation-induced elevation in the frequencies of both. Irradiation also modified TLR4 and TLR5 expression on the surface of both populations, but LPS and flagellin each subsequently normalized them. LPS and flagellin were strong inducers of Th1 cytokines (IL-12p35, IL-12p40, and IFN-γ) and thus, contributed to a shift from the Th2 polarization induced by irradiation toward a Th1 polarization, confirmed by an increase of the T-bet:GATA3 ratio, which assesses the Th1 or Th2 status in mixed cell populations. LPS and flagellin treatment resulted in overexpression of FoxP3, IL-2Rα (CD25), IL-2, and OX40, all expressed specifically and involved in high levels of Treg cell expansion. We observed no variation in Treg function-related expression of IL-10 or CTLA-4. These data suggest that the use of TLR ligands limits the effects of irradiation on innate and adaptive immunity.

Repeated autologous bone marrow-derived mesenchymal stem cell injections improve radiation-induced proctitis in pigs

The management of proctitis in patients who have undergone very-high-dose conformal radiotherapy is extremely challenging. The fibrosis-necrosis, fistulae, and hemorrhage induced by pelvic overirradiation have an impact on morbidity. Augmenting tissue repair by the use of mesenchymal stem cells (MSCs) may be an important advance in treating radiation-induced toxicity. Using a preclinical pig model, we investigated the effect of autologous bone marrow-derived MSCs on high-dose radiation-induced proctitis. Irradiated pigs received repeated intravenous administrations of autologous bone marrow-derived MSCs. Immunostaining and real-time polymerase chain reaction analysis were used to assess the MSCs' effect on inflammation, extracellular matrix remodeling, and angiogenesis, in radiation-induced anorectal and colon damages. In humans, as in pigs, rectal overexposure induces mucosal damage (crypt depletion, macrophage infiltration, and fibrosis). In a pig model, repeated administrations of MSCs controlled systemic inflammation, reduced in situ both expression of inflammatory cytokines and macrophage recruitment, and augmented interleukin-10 expression in rectal mucosa. MSC injections limited radiation-induced fibrosis by reducing collagen deposition and expression of col1a2/col3a1 and transforming growth factor-β/connective tissue growth factor, and by modifying the matrix metalloproteinase/TIMP balance. In a pig model of proctitis, repeated injections of MSCs effectively reduced inflammation and fibrosis. This treatment represents a promising therapy for radiation-induced severe rectal damage.

Flagellin or lipopolysaccharide treatment modified macrophage populations after colorectal radiation of rats

Radiation-induced acute intestinal toxicity remains a major limitation to the delivery of tumoricidal doses of colorectal irradiation. Recent reports indicate that Toll-like receptor (TLR) agonists TLR4 and TLR5 protect against toxicity due to intestinal irradiation. The phenotype (M1 or M2) of macrophages expressing TLRs may play a role in tissue repair. The aim was to investigate whether administration of TLR4 agonist lipopolysaccharide (LPS) or TLR5 agonist flagellin after irradiation modified the recruitment and phenotype of colonic macrophages and improved tissue damage. Rats were exposed to single 20- or 27-Gy doses of colorectal irradiation. TLR4 agonist LPS or TLR5 agonist flagellin (at 50 or 200 µg/rat) was administered i.p. 3 days after irradiation. Flow cytometric analysis, immunostaining, and real-time polymerase chain reaction analysis were used to assess the M1/M2 phenotype and crypt cell proliferation 7 days after irradiation. Irradiation (20 and 27 Gy) increased TLR4⁺ and TLR5⁺ macrophage frequency in the mucosa. LPS or flagellin administration maintained this elevated frequency after the 27-Gy irradiation. LPS and flagellin drove macrophages toward the anti-inflammatory M2 phenotype by increasing Arg1 and CD163 expression and microenvironmental effector molecules (C-C motif chemokine 22, transforming growth factor-β1, and interleukin-10). Proliferating cell nuclear antigen immunostaining, Ki67 expression, and antimicrobial factor Reg3γ showed that the M2 shift correlated with epithelial regeneration. In conclusion, administration of either LPS or flagellin after colorectal irradiation may provide effective protection against epithelial remodeling. This tissue repair was associated with an M2 macrophage shift. Using TLR agonists to moderately activate innate immunity should be considered as a strategy for protecting healthy tissue from irradiation.

Late rectal and bladder toxicity following radiation therapy for prostate cancer: Predictive factors and treatment results

AIM

This study aimed at investigating factors associated to late rectal and bladder toxicity following radiation therapy and the effectiveness of Hyperbaric Oxygen Therapy (HBOT) when toxicity is grade ≥2.

BACKGROUND

Radiation is frequently used for prostate cancer, but a 5-20% incidence of late radiation proctitis and cystitis exists. Some clinical and dosimetric factors have been defined without a full agreement. For patients diagnosed of late chronic proctitis and/or cystitis grade ≥2 treatment is not well defined. Hyperbaric Oxygen Therapy (HBOT) has been used, but its effectiveness is not well known.

MATERIALS AND METHODS

257 patients were treated with radiation therapy for prostate cancer. Clinical, pharmacological and dosimetric parameters were collected. Patients having a grade ≥2 toxicity were treated with HBOT. Results of the intervention were measured by monitoring toxicity by Common Toxicity Criteria v3 (CTCv3).

RESULTS

Late rectal toxicity was related to the volume irradiated, i.e. V50 > 53.64 (p = 0.013); V60 > 38.59% (p = 0.005); V65 > 31.09% (p = 0.002) and V70 > 22.81% (p = 0.012). We could not correlate the volume for bladder. A total of 24 (9.3%) patients experienced a grade ≥2. Only the use of dicumarinic treatment was significant for late rectal toxicity (p = 0.014). A total of 14 patients needed HBOT. Final percentage of patients with a persistent toxicity grade ≥2 was 4.5%.

CONCLUSION

Rectal volume irradiated and dicumarinic treatment were associated to late rectal/bladder toxicity. When toxicity grade ≥2 is diagnosed, HBOT significantly ameliorate symptoms.

Impact of late anorectal dysfunction on quality of life after pelvic radiotherapy

PURPOSE

Anorectal dysfunction is common after pelvic radiotherapy. This study aims to explore the relationship of subjective and objective anorectal function with quality of life (QoL) and their relative impact in patients irradiated for prostate cancer.

METHODS

Patients underwent anal manometry, rectal barostat measurement, and completed validated questionnaires, at least 1 year after prostate radiotherapy (range 1-7 years). QoL was measured by the Fecal Incontinence Quality of Life scale (FIQL) and the Expanded Prostate Cancer Index Composite Bowel domain (EPICB)-bother subscale. Severity of symptoms was rated by the EPICB function subscale.

RESULTS

Anorectal function was evaluated in 85 men. Sixty-three percent suffered from one or more anorectal symptoms. Correlations of individual symptoms ranged from r = 0.23 to r = 0.53 with FIQL domains and from r = 0.36 to r = 0.73 with EPICB bother scores. They were strongest for fecal incontinence and urgency. Correlations of anal sphincter pressures, rectal capacity, and sensory thresholds ranged from r = 0.00 to r = 0.42 with FIQL domains and from r = 0.15 to r = 0.31 with EPICB bother scores. Anal resting pressure correlated most strongly. Standardized regression coefficients for QoL outcomes were largest for incontinence, urgency, and anal resting pressure. Regression models with subjective parameters explained a larger amount (range 26-92 %) of variation in QoL outcome than objective parameters (range 10-22 %).

CONCLUSIONS

Fecal incontinence and rectal urgency are the symptoms with the largest influence on QoL. Impaired anal resting pressure is the objective function parameter with the largest influence. Therefore, sparing the structures responsible for an adequate fecal continence is important in radiotherapy planning.

Gastrointestinal radiation injury: Symptoms, risk factors and mechanisms

Ionising radiation therapy is a common treatment modality for different types of cancer and its use is expected to increase with advances in screening and early detection of cancer. Radiation injury to the gastrointestinal tract is important factor working against better utility of this important therapeutic modality. Cancer survivors can suffer a wide variety of acute and chronic symptoms following radiotherapy, which significantly reduces their quality of life as well as adding an extra burden to the cost of health care. The accurate diagnosis and treatment of intestinal radiation injury often represents a clinical challenge to practicing physicians in both gastroenterology and oncology. Despite the growing recognition of the problem and some advances in understanding the cellular and molecular mechanisms of radiation injury, relatively little is known about the pathophysiology of gastrointestinal radiation injury or any possible susceptibility factors that could aggravate its severity. The aims of this review are to examine the various clinical manifestations of post-radiation gastrointestinal symptoms, to discuss possible patient and treatment factors implicated in normal gastrointestinal tissue radiosensitivity and to outline different mechanisms of intestinal tissue injury.

Increased rectal wall stiffness after prostate radiotherapy: relation with fecal urgency

BACKGROUND

  Late anorectal toxicity is a frequent adverse event of external beam radiotherapy (EBRT) for prostate cancer. The pathophysiology of anorectal toxicity remains unknown, but we speculate that rectal distensibility is impaired due to fibrosis. Our goal was to determine whether EBRT induces changes of rectal distensibility as measured by an electronic barostat and to explore whether anorectal complaints are related to specific changes of anorectal function.

METHODS

  Thirty-two men, irradiated for localized prostate carcinoma, underwent barostat measurements, anorectal manometry, and completed a questionnaire prior to and 1 year after radiotherapy. The primary outcome measure was rectal distensibility in response to stepwise isobaric distensions. In addition, we assessed sensory thresholds, anal pressures, and anorectal complaints.

KEY RESULTS

  External beam radiotherapy reduced maximal rectal capacity (227 ± 14 mL vs 277 ± 15 mL; P < 0.001), area under the pressure-volume curve (3212 ± 352 mL mmHg vs 3969 ± 413 mL mmHg; P < 0.005), and rectal compliance (15.7 ± 1.2 mL mmHg(-1) vs 17.6 ± 0.9 mL mmHg(-1) ; P = 0.12). Sensory pressure thresholds did not significantly change. Sixteen of the 32 patients (50%) had one or more anorectal complaints. Patients with urgency (n = 10) had a more reduced anal squeeze and maximum pressure (decrease 29 ± 11 mmHg vs 1 ± 7 mmHg; P < 0.05 and 31 ± 12 mmHg vs 2 ± 8 mmHg; P < 0.05 respectively) compared with patients without complaints, indicating a deteriorated external anal sphincter function.

CONCLUSIONS & INFERENCES

  Irradiation for prostate cancer leads to reduced rectal distensibility. In patients with urgency symptoms, anal sphincter function was also impaired.

Side-effects of post-treatment biopsies in prostate cancer patients treated with endocrine therapy alone or combined with radical radiotherapy in the Scandinavian Prostate Cancer Group-7 randomized trial

OBJECTIVE

Post-treatment prostate biopsy side-effects were evaluated in patients with locally advanced prostate cancer on endocrine therapy alone or combined with radiotherapy in the Scandinavian Prostate Cancer Group-7 randomized trial.

MATERIAL AND METHODS

One-hundred and twenty patients underwent transrectalultrasound-guided biopsy, and were requested to complete a questionnaire on side-effects occurring within 7 days' follow-up.

RESULTS

The questionnaire was returned by 109 patients (91%) (endocrine therapy only 52%, combined endocrine therapy and radiotherapy 48%). Previous therapy had no significant influence on pain, urinary flow, haematuria or haematospermia. Pain at biopsy was reported in 63% (mild, 57%; moderate, 5.6%; severe, one patient) and pain at follow-up in 31% (mild, 27%; moderate, four patients). Haematuria (mean duration 2.2 days) was reported in 41%, and reduced urinary flow in 20% (mild, 18%; severe: four patients; no patient had urinary retention). Haematospermia was scarce. No patient reported urinary tract infection. Rectal bleeding occurred in 18% in the endocrine and 35% in the combined therapy group (p = 0.047), with a mean duration of 1.6 and 2.2 days, respectively (p = 0.031). In logistic regression analysis, a trend towards increased rectal bleeding was found in patients on combined endocrine therapy and radiotherapy (odds ratio 2.4, p = 0.050).

CONCLUSION

Patient-reported post-treatment prostate biopsy side-effects were mild and self-limiting.

A murine model for the study of molecular pathogenesis of radiation proctitis

PURPOSE

To establish a novel mouse brachytherapy model with which to study the role of inflammation in the pathogenesis of radiation proctitis.

METHODS AND MATERIALS

The distal rectums of BALB/c and C57BL/6 mice were irradiated with three to five fractions of 5.5 to 8 Gy. Tissues were harvested and evaluated for histopathology, using the radiation injury score (RIS). Cytokine mRNA expression was assessed using real-time PCR.

RESULTS

Fifty percent of the mice treated with 22 Gy delivered in four fractions of 5.5 Gy died as a result of anorectal stenosis and distal bowel obstruction prior to the time of scheduled sacrifice, with a latency period of 4 to 10 weeks for the BALB/c and 3 to 4 weeks for the C57BL/6 mice. The RISs were 7, 12, and 8 at 2, 6, and 11 weeks, respectively, in the BALB/c mice and was 8.7 in the C57BL/6 mice on week 6. A 100- to 300-fold increase in interleukin-1beta (IL-1beta) (p = 0.04) and IL-6 mRNA (p = 0.07) and a 5- to 6-fold increase in transforming growth factor (TGF) and tumor necrosis factor-alpha mRNA expression levels (p < 0.001 and p = 0.01) were observed at 2 to 6 weeks after radiation. Cytokine mRNA tissue expression correlated positively with radiation dose (p < 0.0001). The RIS correlated well with IL-1beta and IL-6 mRNA levels in the BALB/c mice and with IL-1beta, IL-6, and TGF mRNA levels in C57BL/6 mice. Analysis of receiver operating characteristic curve showed that IL-1beta and IL-6 have the largest area under the curve and therefore are good markers of radiation proctitis (p < 0.001).

CONCLUSIONS

Radiation-induced proctitis was associated with a dose-dependent, characteristic proinflammatory cytokine response pattern in a novel mouse model suitable for interventional studies.

PPARs in Irradiation-Induced Gastrointestinal Toxicity

The use of radiation therapy to treat cancer inevitably involves exposure of normal tissues. Although the benefits of this treatment are well established, many patients experience distressing complications due to injury to normal tissue. These side effects are related to inflammatory processes, and they decrease therapeutic benefit by increasing the overall treatment time. Emerging evidence indicates that PPARs and their ligands are important in the modulation of immune and inflammatory reactions. This paper discusses the effects of abdominal irradiation on PPARs, their role and functions in irradiation toxicity, and the possibility of using their ligands for radioprotection.

Preoperative irradiation with 5 x 5 Gy in a murine isolated colon loop model does not cause anastomotic weakening after colon resection

INTRODUCTION

There are conflicting studies on the influence of fractionated preoperative 5 days of 5 Gy irradiation on tissue oxygenation and subsequent colonic anastomotic strength. To elucidate the effect of preoperative irradiation on anastomotic strength, an isolated colon loop model was developed.

METHODS

Male Wistar rats (n = 164) were randomly divided into three groups. One group remained untreated (control). In the other two groups, a loop of descending colon was exteriorized to create a hernia of the abdominal wall. After 4 weeks' recovery, this loop was locally irradiated with 5 x 5 Gy of gamma-rays or sham irradiated. One week after (sham-) irradiation, an anastomosis was performed in all groups. Tissue oxygenation (StO2) was determined with visible light spectroscopy. The animals were sacrificed 3 or 7 days after the operation and the anastomosis was tested for bursting pressure and breaking strength.

RESULTS

Irradiated rats showed significantly more weight loss (90% SD 4.3 of initial body weight vs. 96% SD 2.8, p < or = 0.05) and enteritis (18% vs. 5%, p = 0.013) compared to sham and control animals. StO2 was not influenced by irradiation and was not predictive for anastomotic strength. The control group showed significantly lower bursting pressure and breaking strength compared to (sham-) irradiated animals.

CONCLUSION

We developed a new isolated loop model for intermittent irradiation of the colon. Preoperative irradiation of the distal part of a colon anastomosis was successfully administered with acceptable side effects and did not cause reduced tissue oxygenation nor clinical signs of anastomotic weakening, nor objective reduction in bursting pressure and breaking strength.

A genetically determined dose-volume histogram predicts for rectal bleeding among patients treated with prostate brachytherapy

PURPOSE

To examine whether possession of genetic alterations in the ATM (ataxia telangiectasia) gene is associated with rectal bleeding in a dose-dependent and volume-dependent manner.

METHODS AND MATERIALS

One hundred eight prostate cancer patients who underwent brachytherapy using either an (125)I implant, a (103)Pd implant, or the combination of external beam radiotherapy with a (103)Pd implant and had a minimum of 1 year follow-up were screened for DNA sequence variations in the 62 coding exons of the ATM gene using denaturing high-performance liquid chromatography. Rectal dose was reported as the volume (in cubic centimeters) of rectum receiving the brachytherapy prescription dose. The two-sided Fisher exact test was used to compare differences in proportions.

RESULTS

A significant correlation between the presence of any ATM sequence alteration and Grade 1 to 2 proctitis was obtained when the radiation dose to rectal tissue was quantified. Rectal bleeding occurred in 4 of 13 patients (31%) with a variant versus 1 of 23 (4%) without a genetic alteration for patients who had <0.7 cm(3) of rectal tissue receiving the implant prescription dose (p = 0.05). Of patients in whom 0.7-1.4 cm(3) of the rectum received the implant prescription, 4 of 11 (36%) with an ATM alteration exhibited Grade 1 to 2 proctitis, whereas 1 of 21 (5%) without a variant (p = 0.04) developed this radiation-induced late effect.

CONCLUSIONS

The possession of genetic variants in the ATM gene is associated with the development of radiation-induced proctitis after prostate cancer radiotherapy for patients who receive the full prescription dose to either a low or a moderate volume of rectal tissue.

The effects of carbon ion irradiation revealed by excised perforated intestines as a late morbidity for uterine cancer treatment

PURPOSE

Clinical trials of carbon ion therapy have been performed due to the advantages of high-dose energy delivery with precise localization control to targeted organs and strong cell-killing activities to cancers. Perforated intestines as a late morbidity after carbon ion radiotherapy for uterine cancers were examined to reveal the biological characteristics of carbon ion for future applications for the treatment of gastrointestinal cancers.

METHODS

Between June 1995 and December 2004, 94 patients with carcinoma of the uterine cervix or corpus were treated with carbon ion therapy. Among them, 9 patients (9.6%) developed major late gastrointestinal (GI) complications. Four out of 9 patients had intestinal perforations excised operatively at our institute. The postoperative clinical courses and histopathological findings of the excised intestine were investigated.

RESULTS

Carbon ion irradiation severely damaged smooth muscle layers by coagulation necrosis as well as atrophy of the intestinal epithelium and middle-sized arterial thromboses of the intestines. After evaluating late complications, the dose constraints on the GI tracts were set under 60 GyE to prevent major complications. Thereafter, the incidence of major GI complications markedly decreased.

CONCLUSION

Our findings demonstrated the characteristic histopathological effects of carbon ion radiotherapy and thus are expected to facilitate future additional applications of carbon ion radiotherapy for the treatment of gastrointestinal cancers.

Reduced late rectal mucosal changes after prostate three-dimensional conformal radiotherapy with endorectal balloon as observed in repeated endoscopy

PURPOSE

The aim of this study was to investigate prospectively the rectal wall (Rwall) spatial dose distribution, toxicity, and mucosal changes after prostate cancer radiotherapy with or without an endorectal balloon (ERB).

METHODS AND MATERIALS

A total of 24 patients with ERB and 24 without ERB (No-ERB) were treated with three-dimensional conformal radiotherapy (3D-CRT) to a dose of 67.5 Gy. The Rwall was divided into 16 mucosal areas and Rwall dose surface maps were constructed. After 3 months, 6 months, 1 year, and 2 years a rectosigmoidoscopy was performed, and each mucosal area was scored on telangiectasia, congestion, ulceration, stricture, and necrosis. Late rectal toxicity was correlated with the endoscopic findings.

RESULTS

The ERB significantly reduced the Rwall volume exposed to doses >40 Gy. Late rectal toxicity (grade >or=1, including excess of bowel movements and slight rectal discharge) was reduced significantly in the ERB group. A total of 146 endoscopies and 2,336 mucosal areas were analyzed. Telangiectases were most frequently seen and appeared after 6 months. At 1 and 2 years, significantly less high-grade telangiectasia (T 2-3) was observed in the ERB group at the lateral and posterior part of the Rwall. In mucosal areas exposed to doses >40 Gy, less high-grade telangiectases (T 2-3) were seen in the ERB group compared with the No-ERB group.

CONCLUSIONS

An ERB reduced the Rwall volume exposed to doses >40 Gy, resulting in reduction of late rectal mucosal changes and reduced late rectal toxicity. Although further analysis is needed, these data suggest an ERB-induced increased tolerance for late Rwall damage.

Low-dose rate prostate brachytherapy is well tolerated in patients with a history of inflammatory bowel disease

PURPOSE

We report on the follow-up of 24 patients with a prior history of inflammatory bowel disease (IBD) treated with brachytherapy for early-stage prostate cancer.

METHODS AND MATERIALS

Twenty-four patients with a history of inflammatory bowel disease (17 with ulcerative colitis (UC), 7 with Crohn's disease [CD]) underwent prostate brachytherapy between 1992 and 2004. Fifteen patients were treated with I-125 implantation and 6 patients were treated with Pd-103 alone or in combination with 45 Gy external beam radiation. Charts were reviewed for all patients, and all living patients were contacted by phone. National Cancer Institute common toxicity scores for proctitis were assigned to all patients. Actuarial risk of late toxicity was calculated by the Kaplan-Meier method. Statistical analysis was performed using SPSS software. Follow-up ranged from 3 to 126 months (median, 48.5 months; mean, 56.8 months).

RESULTS

None of the patients experienced Grade 3 or 4 rectal toxicity. Four patients experienced Grade 2 late rectal toxicity. The 5-year actuarial freedom from developing late Grade 2 rectal toxicity was 81%. At a median follow-up of 48.5 months, 23 patients were alive and had no evidence of disease with a median prostate-specific antigen for the sample of 0.1 ng/mL (range, <0.05-0.88 ng/mL). One patient died of other causes unrelated to his prostate cancer.

CONCLUSIONS

Prostate brachytherapy is well tolerated in patients with a history of controlled IBD. Therefore, brachytherapy should be considered a viable therapeutic option in this patient population.

Rectosigmoid cancer after radiotherapy for prostate cancer can be detected early and successfully treated

The clinical features and outcomes of rectosigmoid cancers (RSCs) occurring after radiotherapy (RT) for prostate cancer were reviewed to determine whether they are significantly different to RSC occurring without those precedents, whether the subsequent RSC could be either predicted or detected early, and whether they can be effectively treated. Eight patients who had been treated by RT for prostate cancer subsequently developed lower gastrointestinal tract symptoms consistent with proctopathy, however, investigation by endoscopy indicated RSC. These cases were reviewed in detail. The most common presenting symptom was mild bleeding. All eight RSCs were detected before the development of metastatic disease and successfully treated. Only one required an anteroposterior resection. Otherwise, there were no unusual features about any of the cases that would have predicted the occurrence of RSC or enabled earlier detection. No complications occurred that could be attributed to prior RT. Six recommendations for clinicians are offered on the basis of these cases and the relevant published work. In particular, when symptoms of proctopathy occur after RT for prostate cancer the conclusion that radiation proctopathy is the cause should not be drawn until confirmed by endoscopy. Prior RT did not increase the risks involved in colorectal surgery in this setting.

Argon plasma coagulation for radiation proctitis

BACKGROUND

Rectal blood loss is a common late sequel of radiation proctitis. Teleangiectasias appear in the mucosa in 2-5% of patients after radiotherapy of the pelvis. Since pharmacotherapy is usually not beneficial, local treatment modalities with formalin irrigation, Nd:YAG laser and argon plasma coagulation (APC) have been advocated, but experience is still limited.

METHODS

Between January 1997 and August 2001, 50 consecutive patients with rectal bleeding due to radiation proctitis were included for treatment with APC. Thirteen patients suffered from anaemia, six of whom required blood transfusion. Nine patients were receiving anticoagulant therapy and 10 patients used low-dose aspirin. APC was performed, applying the no-touch spotting technique at an electrical power of 50 Watt and an argon gas flow of 2.0 l/min. Pulse duration was less than 0.5 s. Treatment sessions were carried out at intervals of 3 weeks.

RESULTS

In 47 out of 48 patients (98%) in whom the effect could be assessed, APC led to persistent clinical and endoscopic remission of rectal bleeding after a median of three sessions. One patient developed recurrent blood loss after resuming anticoagulant therapy for his aortic valve prosthesis. No adverse effects were encountered after initial treatment. One serious complication occurred in a patient with recurrent blood loss when he was prescribed aspirin for a transient ischaemic attack 2 years after the initial APC. Re-treatment resulted in a major rectal bleeding from a small ulcer with a visible vessel.

CONCLUSIONS

APC is a safe, effective and well-tolerated treatment for blood loss due to radiation proctitis. The use of anticoagulants and aspirin seems to be a co-factors that induces bleeding.

Prevention of acute radiation-induced proctosigmoiditis by balsalazide: a randomized, double-blind, placebo controlled trial in prostate cancer patients

PURPOSE

A common complication of pelvic radiotherapy (RT) is acute radiation-induced proctosigmoiditis (RIPS), for which a multitude of therapies have been tried. The 5-aminosalicylates (5-ASA), which are traditionally used to treat inflammatory bowel disease, have been tested; however, all but one prior randomized attempt to limit or prevent RIPS with 5-ASA-type agents have failed. We sought to evaluate balsalazide, a new 5-ASA drug, for its potential to prevent or limit RIPS in patients undergoing RT for carcinoma of the prostate, as a representative sample of pelvic RT patients. Balsalazide has a unique delivery system in that 99% of ingested drug is delivered to and activated in the colon, a higher yield than all other oral agents currently available in this class. Furthermore, it lacks the antigenic sulfa moiety present in sulfasalazine, the only other 5-ASA with demonstrated benefit in this setting. Thus, it was deemed an ideal candidate for preventing or limiting RIPS.

METHODS AND MATERIALS

Eligible patients included prostate cancer patients, American Joint Committee on Cancer Stage T1-3, M0 being treated with external beam radiotherapy in the University of Kentucky Department of Radiation Medicine. Between January 1, 2003 and July 1, 2004, 27 eligible patients were enrolled in the study. Patients were administered 2250 mg of balsalazide or an identical-appearing placebo twice daily beginning 5 days before RT and continuing for 2 weeks after completion. Toxicities were graded weekly according to National Cancer Institute Common Toxicity Criteria v. 2.0 for each of the following: proctitis, diarrhea, dysuria, weight loss, fatigue, nausea, and vomiting. A symptom index was formulated for each toxicity consisting of the toxicity's numeric grade multiplied by the number of days it was experienced, and summed for each grade experienced throughout the course of RT.

RESULTS

With the exception of nausea or vomiting, seen in 3 patients on balsalazide and 2 on placebo, all toxicities were appreciably lower in patients taking balsalazide. Proctitis was prevented most significantly with a mean proctitis index of 35.3 in balsalazide patients and 74.1 in placebo patients (p = 0.04). Placebo patients lost an average of 2.7 pounds, whereas balsalazide patients on average gained weight. Unexpectedly, dysuria was also lower in balsalazide-treated patients.

CONCLUSIONS

Balsalazide is a new-generation 5-ASA drug that yields a high concentration of active drug to the distal colon. Results of this pilot study suggest that it is able to prevent or reduce symptoms of RIPS in patients undergoing RT for prostate cancer. We feel that these results justify the formation of a cooperative group trial to assess its efficacy in a multi-institutional setting.

Fitting late rectal bleeding data using different NTCP models: results from an Italian multi-centric study (AIROPROS0101)

BACKGROUND AND PURPOSE

Recent investigations demonstrated a significant correlation between rectal dose-volume patterns and late rectal toxicity. The reduction of the DVH to a value expressing the probability of complication would be suitable. To fit different normal tissue complication probability (NTCP) models to clinical outcome on late rectal bleeding after external beam radiotherapy (RT) for prostate cancer.

PATIENTS AND METHODS

Rectal dose-volume histograms of the rectum (DVH) and clinical records of 547 prostate cancer patients (pts) pooled from five institutions previously collected and analyzed were considered. All patients were treated in supine position with 3 or 4-field techniques: 123 patients received an ICRU dose between 64 and 70 Gy, 255 patients between 70 and 74 Gy and 169 patients between 74 and 79.2 Gy; 457/547 patients were treated with conformal RT and 203/547 underwent radical prostatectomy before RT. Minimum follow-up was 18 months. Patients were considered as bleeders if showing grade 2/3 late bleeding (slightly modified RTOG/EORTC scoring system) within 18 months after the end of RT. Four NTCP models were considered: (a) the Lyman model with DVH reduced to the equivalent uniform dose (LEUD, coincident with the classical Lyman-Kutcher-Burman, LKB, model), (b) logistic with DVH reduced to EUD (LOGEUD), (c) Poisson coupled to EUD reduction scheme and (d) relative seriality (RS). The parameters for the different models were fit to the patient data using a maximum likelihood analysis. The 68% confidence intervals (CI) of each parameter were also derived.

RESULTS

Forty six out of five hundred and forty seven patients experienced grade 2/3 late bleeding: 38/46 developed rectal bleeding within 18 months and were then considered as bleeders The risk of rectal bleeding can be well calculated with a 'smooth' function of EUD (with a seriality parameter n equal to 0.23 (CI 0.05), best fit result). Using LEUD the relationship between EUD and NTCP can be described with a TD50 of 81.9 Gy (CI 1.8 Gy) and a steepness parameter m of 0.19 (CI 0.01); when using LOGEUD, TD50 is 82.2 Gy and k is 7.85. Best fit parameters for RS are s=0.49, gamma=1.69, TD50=83.1 Gy. Qualitative as well as quantitative comparisons (chi-squared statistics, P=0.005) show that the models fit the observed complication rates very well. The results found in the overall population were substantially confirmed in the subgroup of radically treated patients (LEUD: n=0.24 m=0.14 TD50=75.8 Gy). If considering just the grade 3 bleeders (n=9) the best fit is found in correspondence of a n-value around 0.06, suggesting that for severe bleeding the rectum is more serial.

CONCLUSIONS

Different NTCP models fit quite accurately the considered clinical data. The results are consistent with a rectum 'less serial' than previously reported investigations when considering grade 2 bleeding while a more serial behaviour was found for severe bleeding. EUD may be considered as a robust and simple parameter correlated with the risk of late rectal bleeding.

Clinical effects in a cohort of cancer patients overexposed during external beam pelvic radiotherapy

PURPOSE

To evaluate the clinical outcome of 28 overexposed cancer patients in a cohort of 153 treated with pelvic irradiation and to correlate the outcome with the doses received.

METHODS AND MATERIALS

Between August 2000 and March 2001, 153 patients were treated at the Instituto Oncológico Nacional of Panama with radiotherapy for cancers of the cervix, uterus, endometrium, prostate, and rectum using conventional techniques. In 56 patients, irradiated with partially blocked teletherapy fields, the treatment times were determined using a treatment planning system that generated isodose distributions. The absorbed doses received by the patients were calculated and the biologically effective doses (BEDs) and 2-Gy equivalent doses derived. The clinical outcome was evaluated using the Radiation Therapy Oncology Group (RTOG) and late effects on normal tissues-subjective, objective, management, analytic scales (LENT/SOMA). The relationships between clinical outcome and dose were investigated and compared with published data.

RESULTS

Of the 56 patients for whom treatment times were generated with the treatment planning system, 28 received some doses per fraction approximately double those prescribed. Using an alpha/beta = 10 Gy, the tumor BED(10) values ranged from 77 to 225 Gy. The rest of the patients received doses within 10% of the prescribed values. Seventeen of the 28 overexposed patients died 35 days to 21 months after treatment; 13 of the fatalities were caused by rectal complications. Survival was longer in those patients who had undergone colostomy. Bladder complications were less enhanced. The nonoverexposed patients with cervical cancer exhibited a greater incidence of treatment failures than generally reported in other centers.

CONCLUSION

This study provides the clinical outcome after high doses of pelvic radiotherapy in a range not previously well documented. For cervical cancer patients receiving both tele- and brachytherapy, some deaths in this overexposure cohort occurred from assumed consequential rectal injury within 2 years, when the BED(10) values exceeded 70-80 Gy. The incidence was asymptotic to 100% fatalities at >150 Gy. This confirmed and extended other data in the literature.

Spontaneous improvement in late rectal mucosal changes after radiotherapy for prostate cancer

PURPOSE

To describe the natural history of mucosal changes, in particular the development of telangiectases in the rectum, after radiotherapy (RT) for prostate cancer.

METHODS AND MATERIALS

Twenty patients undergoing local-field, nonconformal RT for prostate cancer underwent flexible sigmoidoscopy every 6 months for up to 3 years after RT completion. Telangiectasis was scored as absent, single, multiple, or multiple confluent. The site and circumferential extent were also documented. The patients filled in a diary to document the symptoms they were experiencing, including rectal bleeding.

RESULTS

Of the 20 patients, 12 developed multiple telangiectases, and 10 of these had rectal bleeding, which in all cases was mild. Telangiectasis was most commonly seen between 4 (anorectal junction) and 8 cm from the anal verge. In 5 patients, 4 of whom had multiple telangiectases, spontaneous resolution occurred.

CONCLUSION

Late radiation effects in the rectum do not appear to be permanent in all cases. This first prospective prolonged evaluation may provide an explanation for the observation that rectal bleeding resolves in a large proportion of patients with mild symptoms after RT. The reasons for improvement in the late radiation changes in the rectum compared with the permanent changes seen in organs such as the skin are unknown.

Rectal dose-volume constraints in high-dose radiotherapy of localized prostate cancer

PURPOSE

To investigate the relationship between rectal bleeding and dosimetric-clinical parameters in patients receiving three-dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer.

METHODS

In a retrospective national study (AIROPROS01-01, AIRO: Associazione Italiana Radioterapia Oncologica), planning/clinical data for 245 consecutive patients with stage T1-4N0-x prostate carcinoma who underwent 3D-CRT to 70-78 Gy (ICRU point) were pooled from four Italian institutions. The correlation between late rectal bleeding and rectal dose-volume data (the percentage of rectum receiving more than 50, 55, 60, 65, 70, and 75 Gy [V(50-70)]) and other dosimetric and clinical parameters were investigated in univariate (log-rank) and multivariate (Cox regression model) analyses. Median follow-up was 2 years.

RESULTS

Twenty-three patients were scored as late bleeders according to a modified RTOG definition (Grade 2: 16; Grade 3: 7); the actuarial 2-year rate was 9.2%. Excepting V75, all median and third quartile V(50-70) values were found to be significantly correlated with late bleeding at univariate analysis. The smallest p value was seen for V(50) below/above the third quartile value (66%). The V70 (cut-off value: 30%) was found to be also predictive for late bleeding. In the high-dose subgroup (74-78 Gy), Grade 3 bleeding was highly correlated with this constraint. The predictive value of both V(50) and V(70) was confirmed by multivariate analyses.

CONCLUSIONS

The present article provides evidence for correlation between rectal DVH parameters and late rectal bleeding in patients treated with curative intent with 3D-CRT. To keep the rate of moderate/severe rectal bleeding below 5-10%, it seems advisable to limit V(50) to 60-65%, V(60) to 45-50%, and V70 to 25-30%.

Finding dose–volume constraints to reduce late rectal toxicity following 3D-conformal radiotherapy (3D-CRT) of prostate cancer

BACKGROUND AND PURPOSE

The rectum is known to display a dose-volume effect following high-dose 3D-conformal radiotherapy (3D-CRT). The aim of the study is to search for significant dose-volume combinations with the specific treatment technique and patient set-up currently used in our institution.

PATIENTS AND METHODS

We retrospectively analyzed the dose-volume histograms (DVH) of 135 patients with stage T1b-T3b prostate cancer treated consecutively with 3D-CRT between 1996 and 2000 to a total dose of 76 Gy. The median follow-up was 28 months (range 12-62). All late rectal complications were scored using RTOG criteria. Time to late toxicity was assessed using the Kaplan-Meyer method. The association between variables at baseline and > or=2 rectal toxicity was tested using chi(2) test or Fisher's exact test. A multivariate analysis using logistic regression was performed.

RESULTS

Late rectal toxicity grade > or=2 was observed in 24 of the 135 patients (17.8%). A 'grey area' of increased risk has been identified. Average DVHs of the bleeding and non-bleeding patients were generated. The area under the percent volume DVH for the rectum of the bleeding patients was significantly higher than that of patients without late rectal toxicity. On multivariate analysis the correlation between the high risk DVHs and late rectal bleeding was confirmed.

CONCLUSIONS

The present analysis confirms the role of the rectal DVH as a tool to discriminate patients undergoing high-dose 3D-CRT into a low and a high risk of developing late rectal bleeding. Based on our own results and taking into account the data published in the literature, we have been able to establish new dose-volume constraints for treatment planning: if possible, the percentage of rectal volume exposed to 40, 50, 60, 72 and 76 Gy should be limited to 60, 50, 25, 15 and 5%, respectively.

Effects of radiation on normal tissue: consequences and mechanisms

The use of radiation therapy to treat cancer inevitably involves exposure of normal tissues. As a result, patients may experience symptoms associated with damage to normal tissue during the course of therapy for a few weeks after therapy or months or years later. Symptoms may be due to cell death or wound healing initiated within irradiated tissue, and may be precipitated by exposure to further injury or trauma. Many factors contribute to risk and severity of normal tissue reactions; these factors are site specific and vary with time after treatment. Treatments that reduce the risk or severity of damage to normal tissue or that facilitate the healing of radiation injury are being developed. These could greatly improve the quality of life of patients treated for cancer.

Radiation-induced rectal complications are not influenced by age: a dose fractionation study in the rat

Radiation-induced complications of the rectum are an important dose-limiting factor in radiotherapy of pelvic malignancies. In general, animal studies demonstrated no differences in acute and late normal tissue toxicity with age, but little is known about rectal complications in relation to age. For this purpose, an extensive histological and dose fractionation study was carried out on the rectum of young (12 weeks) and older (77-80 weeks) rats. In this paper, the results of dose fractionation are presented in relation to age at the time of irradiation. Young and older animals were irradiated with single and fractionated doses. After irradiation, rectal complications could lead to occlusion and stenosis, eventually resulting in the clinical symptoms of a megacolon and a possible fistula. For each dose group, cumulative survival rates were obtained with Kaplan-Meier analysis, from which dose-effect curves and the associated LD(50) values for a megacolon/fistula were calculated. The majority of responders died between 8 and 24 weeks after irradiation, irrespective of age. For both age groups, only the fractionation data showed a reduction in the mean latency with increasing dose. In the older age group, 39% of the responders developed a fistula compared to 26% for the younger animals. The LD(50) values increased from around 30 Gy after single doses to nearly 65 Gy after 10 fractions. The increases in LD(50) values with the number of fractions were independent of the age of the rats. For each of the dose fractionation schedules, log-rank testing indicated no significant differences in cumulative survival rates between younger and older animals (P > 0.10). The high alpha/beta ratios obtained for both the young and older animals strongly suggested that the late rectal complications were a consequence of early epithelial injury. Associated histological findings indicated that blood vessel damage, which was already evident at a high incidence at 4 weeks after irradiation, could also play a significant role in the occurrence of consequential late injuries. In conclusion, data obtained for the latent period of rectal occlusion, for the dose-effect curves, for the log-rank testing of cumulative survival rates, and for the alpha/beta ratios strongly support the hypothesis that the incidence of radiation-induced rectal complications is independent of age. Late rectal complications could be a consequence of radiation-induced acute injury.

Quality of life during radiotherapy for rectal cancer

The aim of this study was to assess symptoms and health-related quality of life (HRQL) during (neo)adjuvant radiotherapy for rectal cancer. Patients receiving pelvic radiotherapy 50 Gy for rectal cancer, were studied prospectively (n=42). The European Organization for Research and Treatment of Cancer (EORTC) questionnaires quality of life-core 30 QLQ-C30 and QLQ-CR38 and a 5-day symptom diary were completed at the start and end of radiotherapy and 4-6 weeks later. At the end of radiotherapy, mean scores of diarrhoea, fatigue and appetite loss had significantly increased (P<0.01) compared with pretreatment scores, but this was not observed for scores for nausea or pain. At the end of radiotherapy, diarrhoea, fatigue, appetite loss, physical function, social function and global quality of life (QL) were significantly worse than the population-based norms. 64% of the patients reported an increase in fatigue and 52% an increase in diarrhoea during radiotherapy. HRQL scores had returned to pre-treatment levels 4-6 weeks after radiotherapy. Thus, diarrhoea, fatigue and appetite loss increased transiently during pelvic radiotherapy.