The avoidance of small intestine injury in gynecologic cancer

Nomogram for predicting adhesive small bowel obstruction following emergency gastrointestinal surgery

BACKGROUND

Postoperative adhesions are frequent and significant complications that typically arise following abdominal surgery. Currently, the existing evidence for predicting the risk of adhesive small bowel obstruction (ASBO) after emergency gastrointestinal surgery (EGS) remains inadequate. A reliable perioperative model that quantifies the risk of ASBO after EGS serves as a practical tool for guiding individually tailored surveillance.

METHODS

A consecutive series of 1296 patients who underwent EGS for radiologically confirmed bowel/visceral inflammation or perforation between 2012 and 2022 at a tertiary academic medical center were included in this study to establish a best-fit nomogram. The nomogram was externally validated by assessing discrimination and calibration using an independent cohort from a separate medical center.

RESULTS

A total of 116 patients (8.9%) developed at least one episode of ASBO after EGS during a median follow-up duration of 26 months. The results of multivariable logistic analysis indicated that male sex (P = 0.043), preoperative albumin level (P = 0.002), history of pelvic radiotherapy (P = 0.038), laparotomy (P = 0.044), and intensive care unit stay ≥ 72 h (P = 0.047) were identified as independent risk factors for developing ASBO. By incorporating these predictors, the developed nomogram exhibited good accuracy in risk estimation, as evidenced by a guide-corrected C-index score of 0.852 (95% CI 0.667-0.920) in the external validation cohort. Decision curve analysis and clinical impact curve demonstrated a clinically effective predictive model.

CONCLUSION

By incorporating the nomogram as a supplemental tool in perioperative management, it becomes possible to accurately assess the individual's likelihood of developing ASBOs. This quantification enables surgeons to implement appropriate preventive measures, ultimately leading to improved outcomes.

New school technology meets old school technique: Intensity modulated proton therapy and laparoscopic pelvic sling facilitate safe and efficacious treatment of pelvic sarcoma

Purpose

Small bowel tolerance may be dose-limiting in the management of some pelvic and abdominal malignancies with curative-intent radiation therapy. Multiple techniques previously have been attempted to exclude the small bowel from the radiation field, including the surgical insertion of an absorbable mesh to serve as a temporary pelvic sling. This case highlights a clinically meaningful application of this technique with modern radiation therapy.

Methods and Materials

A patient with locally invasive, unresectable high-grade sarcoma of the right pelvic vasculature was evaluated for definitive radiation therapy. The tumor immediately abutted the small bowel. The patient underwent laparoscopic placement of a mesh sling to retract the abutting small bowel and subsequently completed intensity modulated proton therapy.

Results

The patient tolerated the mesh insertion procedure and radiation therapy well with no significant toxic effects. The combination approach achieved excellent dose metrics, and the patient has no evidence of progression 14 months out from treatment.

Conclusions

The combination of mesh as a pelvic sling and proton radiation therapy enabled the application of a curative dose of radiation therapy and should be considered for patients in need of curative-intent radiation when the bowel is in close proximity to the target.

The risk factors for benign small bowel obstruction following curative resection in patients with rectal cancer

Background

So far there have been limited studies about the risk factors for benign small bowel obstruction (SBO) after colorectal cancer surgery. This study aimed to determine the factors affecting the development of benign SBO following curative resection in patients with rectal cancer.

Methods

Patients (3472) receiving curative resection of rectal cancer at the Department of Colorectal Cancer, Tianjin Medical University Cancer Institute and Hospital, between January 2003 and December 2012 were retrospectively studied. The incidence of benign SBO and its risk factors were then determined.

Results

The incidence of benign SBO was 7.3% (253/3472) in follow-up studies with an average time of 68 months. Further, 27% (68/253) of the patients received operative treatment because of the signs of strangulation or the lack of clinical improvement with conservative management. Open surgery and radiotherapy were defined as the risk factors for benign SBO after curative resection in patients with rectal cancer (P <  0.001).

Conclusion

Open surgery plus radiotherapy led to an increased risk of benign SBO in rectal cancer patients receiving curative resection.

Adjuvant Radiotherapy of the Pelvis with or without Reduced Glutathione: A Randomized Trial in Patients Operated on for Endometrial Cancer

A randomized pilot trial was performed to evaluate the feasibility of administration of glutathione (GSH, 1200 mg, i.v.) as a protector in preventing diarrhea in patients operated on for endometrial cancer and submitted to adjuvant radiotherapy of the pelvis. Diarrhea occurred In 52% of patients In the untreated control group and only in 28% of patients In the GSH-treated group. Our preliminary data indicate that GSH administered before radiotherapy reduced the occurrence of diarrhea from oxidative damage to the intestinal mucosa. A large-scale phase III study is required to obtain definitive conclusions on the protective potential of GSH.

Novel use of an air-filled breast prosthesis to allow radiotherapy to recurrent colonic cancer

AIM

The authors present the novel and successful use of an air-filled breast prosthesis for extra pelvic exclusion of small bowel to facilitate adjuvant radiotherapy following resection of recurrent adenocarcinoma of the ascending bowel. The therapeutic use of radiotherapy in colon cancer can cause acute or chronic radiation enteropathy. Mobile small bowel can be sequestered in 'dead space' or by adhesions exposing it to adjuvant radiotherapy. A variety of pelvic partitioning methods have been described to exclude bowel from radiation fields using both native and prosthetic materials.

METHOD

In this case a 68 year old presented with ascending colon adenocarcinoma invading the peritoneum and underwent en bloc peritoneal resection. Thirty-seven months later surveillance CT identified a local recurrence. Subsequent resection resulted in a large iliacus muscle defect which would sequester small bowel loops thus exposing the patient to radiation enteropathy. The lateral position of the defect precluded the use of traditional pelvic partitioning methods which would be unlikely to remain in place long enough to allow radiotherapy. A lightweight air-filled breast prosthesis (Allergan 133 FV 750 cms) secured in place with an omentoplasty was used to fill the defect.

RESULTS

Following well tolerated radiotherapy the prosthesis was deflated under ultrasound guidance and removed via a 7-cm transverse incision above the right iliac crest. The patient is disease free 18 months later with no evidence of treatment related morbidity.

CONCLUSION

The use of a malleable air-filled prosthesis for pelvic partitioning allows specific tailoring of the prosthesis size and shape for individual patient defects. It is also lightweight enough to be secured in place using an omentoplasty to prevent movement related prosthesis migration. In the absence of adequate omentum a mesh sling may be considered to allow fixation. In this case the anatomy of the prosthesis position allowed for its removal without the need for repeat laparotomy. Pre-operative deflation of the air-filled prosthesis under ultrasound guidance also reduces the size of the incision required for removal. This technique may be valuable to prevent collateral small bowel irradiation following resection of renal or retroperitoneal malignancy.

Radiation colitis and proctitis

Radiation therapy is commonly utilized as a major component in the treatment of pelvic malignancy. Unfortunately, secondary toxicity to the lower gastrointestinal tract can occur. This most commonly affects the rectum, although injuries to the colon and small intestine are not uncommon. The presentation can be acute or chronic, and different mechanisms are responsible for each. Symptomatology is quite variable but can result in significant compromise for the patient. Numerous preventive and treatment strategies have been applied to this disease process. This article presents a summary of the current knowledge regarding radiation injury to the lower gastrointestinal tract with special emphasis on treatment options for radiation proctitis.

Recent advances in the management of radiation colitis

Radiation colitis, an insidious, progressive disease of increasing frequency, develops 6 mo to 5 years after regional radiotherapy for malignancy, owing to the deleterious effects of the latter on the colon and the small intestine. When dealing with radiation colitis and its complications, the most conservative modality should be employed because the areas of intestinal injury do not tend to heal. Acute radiation colitis is mostly self-limited, and usually, only supportive management is required. Chronic radiation colitis, a poorly predictable progressive disease, is considered as a precancerous lesion; radiation-associated malignancy has a tendency to be diagnosed at an advanced stage and to bear a dismal prognosis. Therefore, management of chronic radiation colitis remains a major challenge owing to the progressive evolution of the disease, including development of fibrosis, endarteritis, edema, fragility, perforation, partial obstruction, and cancer. Patients are commonly managed conservatively. Surgical intervention is difficult to perform because of the extension of fibrosis and alterations in the gut and mesentery, and should be reserved for intestinal obstruction, perforation, fistulas, and severe bleeding. Owing to the difficulty in managing the complications of acute and chronic radiation colitis, particular attention should be focused onto the prevention strategies. Uncovering the fibrosis mechanisms and the molecular events underlying radiation bowel disease could lead to the introduction of new therapeutic and/or preventive approaches. A variety of novel, mostly experimental, agents have been used mainly as a prophylaxis, and improvements have been made in radiotherapy delivery, including techniques to reduce the amount of exposed intestine in the radiation field, as a critical strategy for prevention.

Laparoscopic pelvic sling placement facilitates optimum therapeutic radiotherapy delivery in the management of pelvic malignancy

BACKGROUND

Radiotherapy has a significant role in the management of pelvic malignancies. However, the small intestine represents the main dose limiting organ. Invasive and non-invasive mechanical methods have been described to displace bowel out of the radiation field. We herein report a case series of laparoscopic placement of an absorbable pelvic sling in patients requiring pelvic radiotherapy.

METHODS

Six patients were referred to our minimally invasive unit. Four patients required radical radiotherapy for localised prostate cancer, one was scheduled for salvage localised radiotherapy for post-prostatectomy PSA progression and one patient required adjuvant radiotherapy post-cystoprostatectomy for bladder carcinoma. All patients had excessive small intestine within the radiation fields despite the use of non-invasive displacement methods.

RESULTS

All patients underwent laparoscopic mesh placement, allowing for an elevation of small bowel from the pelvis. The presence of an ileal conduit or previous surgery did not prevent mesh placement. Post-operative planning radiotherapy CT scans confirmed displacement of the small intestine allowing all patients to receive safely the planned radiotherapy in terms of both volume and radiation schedule.

CONCLUSION

Laparoscopic mesh placement represents a safe and efficient procedure in patients requiring high-dose pelvic radiation, presenting with unacceptable small intestine volume in the radiation field. This procedure is also feasible in those that have undergone previous major abdominal surgery.

Postoperative irradiation for rectal cancer increases the risk of small bowel obstruction after surgery

OBJECTIVE

To determine the risk of small bowel obstruction (SBO) after irradiation (RT) for rectal cancer

BACKGROUND

: SBO is a frequent complication after standard resection of rectal cancer. Although the use of RT is increasing, the effect of RT on risk of SBO is unknown.

METHODS

We conducted a retrospective cohort study using Surveillance, Epidemiology, and End Results cancer registry data linked to Medicare claims data to determine the effect of RT on risk of SBO. Patients 65 years of age and older diagnosed with nonmetastatic invasive rectal cancer treated with standard resection from 1986 through 1999 were included. We determined whether patients had undergone RT and evaluated the effect of RT and timing of RT on the incidence of admission to hospital for SBO, adjusting for potential confounders using a proportional hazards model.

RESULTS

We identified a total of 5606 patients who met our selection criteria: 1994 (36%) underwent RT, 74% postoperatively. Patients were followed for a mean of 3.8 years. A total of 614 patients were admitted for SBO over the study period; 15% of patients in the RT group and 9% of patients in the nonirradiated group (P < 0.001). After controlling for age, sex, race, diagnosis year, type of surgery, and stage, we found that patients who underwent postoperative RT were at higher risk of SBO, hazard ratio 1.69 (95% CI, 1.3-2.1). However, the long-term risk associated with preoperative irradiation was not statistically significant (hazard ratio, 0.89; 95% CI, 0.55-1.46).

CONCLUSIONS

Postoperative but not preoperative RT after standard resection of rectal cancer results in an increased risk of SBO over time.

The different volume effects of small-bowel toxicity during pelvic irradiation between gynecologic patients with and without abdominal surgery: a prospective study with computed tomography-based dosimetry

PURPOSE

To evaluate the effect of abdominal surgery on the volume effects of small-bowel toxicity during whole-pelvic irradiation in patients with gynecologic malignancies.

METHODS AND MATERIALS

From May 2003 through November 2006, 80 gynecologic patients without (Group I) or with (Group II) prior abdominal surgery were analyzed. We used a computed tomography (CT) planning system to measure the small-bowel volume and dosimetry. We acquired the range of small-bowel volume in 10% (V10) to 100% (V100) of dose, at 10% intervals. The onset and grade of diarrhea during whole-pelvic irradiation were recorded as small-bowel toxicity up to 39.6 Gy in 22 fractions.

RESULTS

The volume effect of Grade 2-3 diarrhea existed from V10 to V100 in Group I patients and from V60 to V100 in Group II patients on univariate analyses. The V40 of Group I and the V100 of Group II achieved most statistical significance. The mean V40 was 281 +/- 27 cm(3) and 489 +/- 34 cm(3) (p < 0.001) in Group I patients with Grade 0-1 and Grade 2-3 diarrhea, respectively. The corresponding mean V100 of Group II patients was 56 +/- 14 cm(3) and 132 +/- 19 cm(3) (p = 0.003). Multivariate analyses revealed that V40 (p = 0.001) and V100 (p = 0.027) were independent factors for the development of Grade 2-3 diarrhea in Groups I and II, respectively.

CONCLUSIONS

Gynecologic patients without and with abdominal surgery have different volume effects on small-bowel toxicity during whole-pelvic irradiation. Low-dose volume can be used as a predictive index of Grade 2 or greater diarrhea in patients without abdominal surgery. Full-dose volume is more important than low-dose volume for Grade 2 or greater diarrhea in patients with abdominal surgery.

Interfractional variation of uterine position during radical RT: Weekly CT evaluation

PURPOSE

This study was performed to quantitate the positional change of the uterus during the period of radiotherapy (RT).

METHODS

For 13 patients who received RT with the use of small bowel displacement system (SBDS) for uterine cervix cancer, CT scans were taken before the beginning of RT. Three more weekly CT scans were subsequently performed during the RT period. The position of the uterus on each set of CT images was defined and compared to that on the initial CT images. The difference was quantified by measuring the parameters as follows: the change of uterus border in superior (D(S)), right lateral (D(R)), left lateral (D(L)), anterior (D(A)) and posterior (D(P)) direction measured on images taken before and during treatments. The change of uterus volume was also measured, and the correlation between the uterus volume reduction and uterus mobility was tested.

RESULTS

The most prominent interfractional positional changes were in the cranio-caudal direction. Among the three sets of comparisons, the largest mean values for D(S), D(R), D(L), D(A) and D(P) were -0.77+/-1.87, -0.29+/-1.02, -0.3+/-1.25, -0.20+/-1.13 cm, and -0.55+/-1.21 cm, respectively. The average target volume reductions were 6.4% (p=0.1335), 11.7% (p=0.0138) and 27.2% (p=0.0192) in the 1st, 2nd and 3rd week of treatment, respectively. Significant correlation between D(S) and uterus volume reduction (p=0.002) was found.

CONCLUSIONS

The average interfractional positional changes of the uterus with the use of SBDS were relatively small, while the inter-patient deviations were large. The significant target volume reductions and inter-patient deviations of uterus mobility need to be accounted for when conformal radiation therapy for cervical cancer is performed.

Interfractional dose variation during intensity-modulated radiation therapy for cervical cancer assessed by weekly CT evaluation

PURPOSE

To investigate the interfractional dose variation of a small-bowel displacement system (SBDS)-assisted intensity-modulated radiation therapy (IMRT) for the treatment of cervical cancer.

METHODS

Four computed tomography (CT) scans were carried out in 10 patients who received radiotherapy for uterine cervical cancer. The initial CT was taken by use of the SBDS, before the beginning of radiotherapy, and 3 additional CT scans with the SBDS were done in subsequent weeks. IMRT was planned by use of the initial CT, and the subsequent images were fused with the initial CT set. Dose-volume histogram (DVH) changes of the targets (planning target volume [PTV] = clinical target volume [CTV] + 1.5 cm) and of the critical organs were evaluated after obtaining the volumes of each organ on 4 CT sets.

RESULTS

No significant differences were found in PTV volumes. Changes on the DVH of the CTVs were not significant, whereas DVH changes of the PTVs at 40% to 100% of the prescription dose level were significant (V(90%); 2nd week: p = 0.0091, 3rd week: p = 0.0029, 4th week: p = 0.0050). The changes in the small-bowel volume included in the treatment field were significant. These were 119.5 cm3 (range, 26.9-251.0 cm3), 126 cm3 (range, 38.3-336 cm3), 161.9 cm3 (range, 37.7-294.6 cm3), and 149.1 cm3 (range, 38.6-277.8 cm3) at the 1st, 2nd, 3rd, and 4th weeks, respectively, and were significantly correlated with the DVH change in the small bowel, which were significant at the 3rd (V80%; p = 0.0230) and 4th (V80%; p = 0.0263) weeks. The bladder-volume change correlated to the large volume change (>20%) of the small-bowel volume.

CONCLUSIONS

Significant DVH differences for the small bowel can result because of interfractional position variations, whereas the DVH differences of the CTV were not significant. Strict bladder-filling control and an accurate margin for the PTV, as well as image-guided position verification, are important to achieve the goal of IMRT.

Characteristics and predictive factors of early-onset diarrhoea during pelvic irradiation

This study reported characteristics and predictive factors of early-onset diarrhoea in patients receiving pelvic irradiation. We retrospectively reviewed 229 patients undergoing radiotherapy alone for cervical or uterine cancer. Oral barium was taken 90 min before simulation. According to contrast medium within small intestine only or colon in simulation films, we categorised patients as normal and rapid transit groups. Small or large volume of small-bowel was also evaluated according to barium distribution of simulation films. Whole-pelvic irradiation (39.6-45 Gy/22-25 fractions) was delivered to all patients initially. We recorded the onset of diarrhoea during pelvic irradiation. The rates of early-onset diarrhoea (<10 Gy) were compared between these two groups. The incidence of diarrhoea before 10 Gy was 7% and 17% (p = 0.138) in patients with normal and rapid transit, respectively. In multivariate analysis, interaction among rapid transit, prior abdomen operation and large small-bowel volume (p = 0.019) were noted for early-onset diarrhoea. Further subgroup analysis revealed that rapid transit (p = 0.046) was a significant factor in patients with both prior abdominal operation and large small-bowel volume. The incidence of early-onset diarrhoea was as high as 40% in this particular group. Patients experiencing early-onset diarrhoea had a higher incidence of moderate to severe diarrhoea (65%) than those without early-onset diarrhoea (23%) (p<0.001). In multivariate analysis, early-onset diarrhoea was the only factor of moderate to severe diarrhoea (p = 0.001). In conclusion, rapid small-bowel transit may be predisposed to early-onset diarrhoea during pelvic radiotherapy in patients with both prior abdominal operations and large small-bowel volume. Early-onset diarrhoea is considered as a predictive factor of diarrhoea of a higher grade.

Acute diarrhea during pelvic irradiation: is small-bowel volume effect different in gynecologic patients with prior abdomen operation or not?

OBJECTIVE

To evaluate volume effect of small bowel for diarrhea during pelvic irradiation in gynecologic patients with or without prior abdomen operation.

METHODS

From January 1996 through December 2003, 759 patients undergoing 4-field pelvic irradiation for cervical or uterine cancer were analyzed. Whole pelvic (WP), modified whole pelvic (MWP), or lower pelvic (LP) irradiation were delivered initially. According to contrast medium within small bowel in simulation films, we categorized the small-bowel volume of full dose related to WP fields as small-volume and large-volume groups. We recorded the severity of diarrhea until 39.6 Gy/22 fractions of pelvic irradiation. The actuarial rates of overall and moderate to severe diarrhea were compared among different groups.

RESULTS

Significantly more large-volume distribution (85%) was noted in patients >60 years without prior operation (P < 0.001). Large-volume distribution was 53%, 65%, and 82% in post-operative patients with no diarrhea, mild diarrhea, and moderate to severe diarrhea (P = 0.002), respectively. The corresponding rate was 79%, 77%, and 80% in patients without prior abdomen operation (P = 0.869). In multivariate analysis, prior operation with LP fields (P = 0.005) and prior operation with small volume (P = 0.031) were significantly protective factors for overall diarrhea. The latter was also a protective factor for moderate to severe diarrhea (P = 0.026). Prior operation could diminish overall diarrhea in patients without simultaneous large-field (WP or MWP) and large-volume. Large volume was a significant factor of overall (P = 0.014) and moderate to severe (P = 0.004) diarrhea in large-field patients with operation. The volume effect did not exist in those patients without operation.

CONCLUSION

Age and operation can change small-bowel distribution. Prior operation may attenuate diarrhea if irradiated volume of small bowel is small. There is a volume effect in post-operative rather than non-operative patients receiving large-field irradiation. More practical dose-volume evaluation of small bowel may be applied for volume effect in gynecologic patients without prior operation.

Small-bowel displacement system for the sparing of Small bowel in three-dimensional conformal radiotherapy for cervical cancer

AIMS

The efficacy of the small-bowel displacement system (SBDS) in three-dimensional conformal radiotherapy (3-D CRT) planning for sparing the volume of small bowel is presented for cervical cancer.

MATERIALS AND METHODS

Ten consecutive patients, who received pelvic radiation therapy for uterine cervical cancer with the SBDS from January to March 2003, were included in this study. The SBDS consists of a customised Styrofoam compression device, which can displace the small bowel out of the radiation fields, and an individualised immobilisation board. With oral contrast before scanning, computed tomography was taken in the prone position with and without the SBDS. 3-D conformal planning was carried out, and dose distribution was compared in the target volumes and in the organs-at-risk with and without the SBDS.

RESULTS

In all patients, the SBDS significantly reduced the small-bowel volume within radiation fields. The median small-bowel volume with SBDS was reduced by 56.4% compared with the small-bowel volume without SBDS (from 491 to 214 cm3; P = 0.004). Among the 10 patients, the highest small-bowel volume reduction was 70.2% (from 544 to 62 cm3). At the prescription dose, the median volume of small bowel irradiated was reduced significantly with SBDS (9.8% vs 1.2%; P = 0.005). Differences in the dose-volume histogram for the rectum and the bladder between the 3-D CRT plans with and without SBDS were not statistically significant (P > 0.1). All patients completed radiotherapy without a break in treatment.

CONCLUSION

The SBDS is a novel method that can be used to displace the small bowel away from the 3-D CRT fields effectively, and reduce radiation therapy morbidity.

Optimized radiation of pelvic volumes in the clinical setting by using a novel bellyboard with integrated gonadal shielding

The purpose of this study was to determine the feasibility of a custom-made, modified bellyboard to reduce radiotherapy side effects on small bowel, bladder, skin, and male gonads. Two groups of 10 consecutive patients each were treated from January 2003 through April 2003 with neoadjuvant (45 Gy) or adjuvant (54 Gy) radio(chemo)therapy in single fractions of 5 days a week 1.8 Gy for rectal carcinoma, using a photon energy of 15 MV. One group was positioned in a prone position without an immobilization device, the other group was positioned on our bellyboard. Treatment planning was calculated by using a 4- and a 3-field box technique. Differences in the dose of organs of risk were calculated. For 1 male patient, a gonadal shielding was developed and integrated. All patients examined with the bellyboard demonstrated an anterior and cranial dislocation of the small bowel. Using a 4-field box, the mean dose to the small bowel of patients treated on our bellyboard was 56.5% as compared to 63.1% when treated without the bellyboard. When a 3-field box was used, the mean dose to the small bowel was 52.4% when the bellyboard was used, as compared to a mean dose of 63.1% without the bellyboard. Regarding the dose volume effects to the bladder, the mean dose for patients treated with a 4-field box was about 14.5% higher as compared to patients treated with a 3-field box. The mean dose to the hip joints and skin also depended on the radiation technique. The patient who received gonadal shielding received a maximal total gonadal dose of about 75.0 cGy in single fractions of maximal 3.0 cGy (TL-dosimeters). Daily setup variations evaluated by a beam's-eye view were similar in both groups and ranged from 0.5 cm 1.0 cm. For daily use, our bellyboard appears to be an ideal compromise due to effectiveness, its easy handling, and reproductive positioning; moreover, it can also be used in combination with gonadal shielding.

Dose-volume histogram evaluation of prone and supine patient position in external beam radiotherapy for cervical and endometrial cancer

BACKGROUND AND PURPOSE

To evaluate the influence of patient positioning on dose-volume histograms of organs at risk in external beam radiotherapy for cervical and endometrial cancer.

MATERIALS AND METHODS

In 20 patients scheduled for definitive (7) or postoperative (13) external beam radiotherapy of the pelvis treatment planning CT scans were performed in supine and prone (belly board) positions. After volume definition of target and organs at risk treatment plans were calculated applying the four-field box technique. The dose-volume histograms of organs at risk were compared.

RESULTS

Radiotherapy in prone position causes a reduction of the bladder portion (mean 15%, p<0.001) and an increase of the rectum portion (mean 11%, p<0.001) within the 90% isodose. A reduction of the bowel portion could only be observed in postoperatively treated patients (mean 13%, p<0.001). In definitive radiotherapy the target volume increases in supine position (mean 7%, p=0.02) due to an anterior tumour/uterus movement, so that bowel portions within the 90% isodose are similar. The bladder filling correlates with a reduction of bladder and bowel (postoperatively treated patients) dose.

CONCLUSIONS

External beam radiotherapy of the pelvis should be performed in prone position in postoperative patients because of best bowel protection. Considering the additional HDR brachytherapy rectum protection takes the highest priority in definitive treatment-the requirements are best met in supine position. An adequate bladder filling is important to reduce the irradiated bladder and bowel volumes.

The position and volume of the small bowel during adjuvant radiation therapy for rectal cancer

PURPOSE

The rate of small bowel toxicity from adjuvant pelvic radiation therapy (RT) for rectal cancer has been reported to be lower for patients treated preoperatively (Preop). This was probably due to a lesser volume of irradiated small bowel; however, studies of postoperative treatment reported that patients with an abdominoperineal resection (APR), who likely have the largest volume of small bowel in the pelvis, had less acute and chronic toxicity than those with a low anterior resection (LAR). In this study, three-dimensional treatment planning techniques were used to characterize the position and volume of small bowel in the pelvis and compare these to repeat studies obtained during the typical 5-week course of treatment to attempt to explain the above observations.

METHODS AND MATERIALS

Treatment planning CT scans were obtained in 30 patients with rectal cancer (10 Preop, 10 LAR, 10 APR), including 12 patients with weekly CT scans during RT (65 scans). The position of the small bowel was measured by the distance to the nearest small bowel from the bones of the posterior pelvis and by the volume of small bowel within four anatomically defined regions of the pelvis. The motion of the small bowel was expressed as the standard deviation of the small bowel position measured with both the distance and the volume in the 12 patients with repeat studies.

RESULTS

Contrast-containing small bowel was found an average 2.9 cm more anterior than small bowel without contrast below the sacral promontory. The position of the small bowel in Preop patients was significantly more anterior (p < or = 0.01) with less volume (p < or = 0.04) in the pelvis than postoperatively treated patients. The small bowel was also more anterior for patients with an LAR vs. APR (p < or = 0.03) but with similar volume in all pelvic regions. Small bowel motion, expressed as the standard deviation of the distance from the bones of the posterior pelvis to the closest small bowel, was 2.9 cm, 1.4 cm, and 0.2 cm for the Preop, LAR, and APR group, respectively. The LAR group had a considerable degree of motion in the posterior pelvis. Increased bladder volume was associated with reduced small bowel volumes, although this benefit decreased during treatment.

CONCLUSION

Because treatment planning CT scans can detect small bowel that does not contain contrast, they may be more accurate than the traditional small bowel series. The Preop patients had significantly less pelvic small bowel supporting the clinical observation of better tolerance to therapy. The higher small bowel toxicity reported for LAR vs. APR patients may be explained by the greater variability of both the position and volume of the small bowel in the posterior pelvis for LAR patients. This finding suggests that a single planning study may not be accurate for the block design used for boost treatment of LAR patients. Bladder-filling techniques were useful for Preop and LAR but not APR patients, and decreased in benefit over time. This study suggested that treatment planning CT scans were more useful than a small bowel series and that more than one treatment planning CT may be obtained in any patient receiving > 45 Gy for rectal cancer. However, further research will be necessary to determine the optimal timing and total number of repeat studies.

Using a belly board device to reduce the small bowel volume within pelvic radiation fields in women with postoperatively treated cervical carcinoma

OBJECTIVE

The purpose of this study was to attempt to reduce the small bowel volume in cervical cancer patients undergoing radiation therapy using the belly board device and a four-field technique.

METHODS

From 1994 through 1997, twenty-one patients with cervical cancer were referred to the University of Minnesota Medical Center and underwent surgical staging with or without radical hysterectomy followed by postoperative external beam radiotherapy for various indications including positive nodal disease (n = 11), lymph-vascular space invasion (n = 2), poor histology (n = 3), parametrial disease (n = 4), and positive vaginal margin (n = 1).

RESULTS

The median age of the 21 patients was 42 years (25-54 years) and a median external beam pelvic radiation dose of 4775 cGy (range, 4200-5075 cGy) was administered. All patients were evaluated for amount of small bowel in the field in both the supine and prone positions, with and without the belly board device (BBD), using a four-field technique. With a full bladder, abdominal radiographs with contrast were obtained to evaluate the volume of small bowel within the radiation fields. In most patients, the BBD was effective at minimizing the amount of small bowel in the lateral fields, whereas a prone position on the treatment table (without the BBD) spared the most small bowel with the AP/PA fields. Therefore over a 2-day cycle, the most small bowel sparing was obtained with the patients treated prone on the BBD for the lateral fields on Day 1 and prone on the table for the AP/PA fields on Day 2. Patients had FIGO stage IB (n = 18), IA2 (n = 1), and IIA (n = 2). The median follow-up was 37 months (24-65 months). No significant acute gastrointestinal or genitourinary toxicity was experienced and no patients have experienced a bowel obstruction to date.

CONCLUSIONS

The BBD may offer a means for positioning the mobile small intestine out of the radiation field and improving the tolerance of radiotherapy. The BBD provides a noninvasive technique for reduction of acute and chronic gastrointestinal morbidity.

Dislocation of small bowel volume within box pelvic treatment fields, using new "up down table" device

PURPOSE

To present the impact of a novel minimization device, the up down table (UDT), on the volume of small bowel included within a 4-field pelvic irradiation plan.

METHODS

A polystyrene bowel displacement standard mold was created and added to a customized vacuum cushion (Vac Lok) formed around the abdomen and legs of each patient in the prone position. Two hundred seventy-seven consecutive patients with pelvic malignancies treated with the UDT device were compared with 1 historic series (68 cases) treated at our division. Small bowel contrast dyes at the time of simulation were used in all patients.

RESULTS

The average volume of small bowel within the planning target volume (high-dose volume, calculated with Gallagher method) was 100 cm(3) (median 49 +/- 114) in the series treated with standard box technique and 23 cm(3) (median 0 +/- 64) in the series treated with the UDT (p < 0.001). The average volume of small bowel included in any isodose (any-dose volume) was 505 cm(3) (median 447 +/- 338) and 158 cm(3) (median 69 +/- 207), respectively (p < 0.001). The incidence of G1, G2, and G3 acute enteric toxicity (Radiation Therapy Oncology Group criteria) in the UDT series was 16%, 15%, and 1.5%; in the standard box technique, it was 28%, 25%, and 3%, respectively (p < 0.05). The incidence of acute enteric toxicity directly correlated with the irradiated small bowel volume. In the UDT series, the 5-year actuarial incidence of G3 chronic enteric toxicity was 1.8%. The setup procedures, analyzed in 18 cases, revealed no systematic errors and a standard deviation equal to +/-5 mm for random errors.

CONCLUSIONS

The UDT technique is comfortable, inexpensive, highly reproducible, and permits an almost full bowel displacement from standard radiotherapy fields.

Reduction of irradiated small bowel volume and accurate patient positioning by use of a bellyboard device in pelvic radiotherapy of gynecological cancer patients

PURPOSE

To reduce the volume of small bowel within pelvic treatment fields for gynecological cancer using a bellyboard device and to determine the accuracy of the prone treatment position.

MATERIALS AND METHODS

Fifteen consecutive patients with a gynecologic malignancy who were treated with postoperative pelvic radiotherapy were selected for this study. The volume of small bowel within the treatment fields was calculated for both the supine and prone treatment positions. The patients were treated in the prone position in a so-called bellyboard device. During treatment sessions electronic portal images were obtained. An off-line setup verification and correction protocol was used and the setup accuracy of the positioning in the bellyboard was determined.

RESULTS

The average volume of small bowel within the treatment fields was 229 cm(3) and 66 cm(3) in the supine and prone treatment, respectively, which means an average volume reduction in the prone position of 64% (95% CI 56-72%), as compared with the supine position. For the position of the patient in the field, the systematic error defined by the standard deviation (SD) of the mean difference per patient between simulation and treatment images was 1.7 mm in the lateral direction, 2.1 mm in the craniocaudal direction and 1.7 mm in the ventrodorsal direction. On average, only 0.4 setup correction per patient was required to achieve this accuracy. The random day-to-day variations were 1.9 (1SD), 2.6 and 2.3 mm, respectively. Standard deviations of the systematic differences between patient positioning relative to the bellyboard were 6.2 mm in lateral direction and 9.1 mm in craniocaudal direction.

CONCLUSIONS

Treatment of gynecological cancer patients in the prone position using a bellyboard reduces the volume of irradiated small bowel. An off-line verification and correction protocol ensures accurate patient positioning. Daily setup variations using the bellyboard were small (1 SD<3 mm). Therefore for pelvic radiotherapy in patients with a gynecological malignancy, the use of a bellyboard is recommended.

Adjuvant radiotherapy following radical hysterectomy for patients with early-stage cervical carcinoma (1984-1996)

BACKGROUND AND PURPOSE

The aim of this study was to assess the results of treatment (surgery alone or surgery and postoperative radiotherapy) for early-stage cervical carcinoma and to determine the morbidity associated with adjuvant radiotherapy. A subset of these patients (n = 10) was irradiated postoperatively for tumor related negative prognostic factors only and this retrospective analysis was also performed to determine if this decision was right and if the selection for this treatment was based on the right criteria.

MATERIAL AND METHODS

From 1984 to 1996, 233 women underwent radical hysterectomy as primary treatment of stage I or IIA cervical carcinoma. One hundred and fifty-six patients were treated with surgery alone (67%) and 77 patients (33%) received adjuvant radiotherapy for a, tumor related negative prognostic factors: the combination CLS(+), tumor size > or = 40 mm and poor differentiation grade or the combination tumor size > or = 40 mm and depth of invasion > or = 15 mm (n = 10), or b, positive surgical margins (n = 17), and/or c. lymphnode metastases (n = 42) and/ or d. parametrial involvement (n = 6).

RESULTS

For the entire group the most important prognostic factor for survival and disease free survival was node positivity. Additional factors were depth of invasion and positive surgical margins. Thirty-five patients recurred of which 12 after surgery alone. In all these cases the relapse was in the pelvis (100%). Of the 23 recurrences after surgery and adjuvant radiotherapy 13 were seen in the pelvis (56%) (P = 0.003). All patients with negative prognostic factors and N0, received adjuvant radiotherapy (n = 10) and none of these patients recurred. The incidence of severe gastrointestinal radiation related side effects was low (2%). The incidence of lymphedema of the leg was 11% which was similar in the surgery alone group.

CONCLUSIONS

The relatively low percentage of radiation related side effects together with 0% recurrence in a subgroup of node negative patients with high risk of recurrence, and a relatively low percentage of recurrence in the surgery alone group lead us to the conclusion that postoperative radiotherapy in special subsets of node negative patients is justified.

Effect of customized small bowel displacement system in pelvic irradiation

PURPOSE

Authors designed a customized small bowel displacement system (SBDS) to displace the small bowel out of the pelvic radiation fields and to minimize treatment related bowel morbidity.

METHODS AND MATERIALS

From August 1995 to May 1996, 55 consecutive patients who received pelvic radiation therapy with the SBDS were included in this study. The SBDS consists of a customized Styrofoam compression device that can displace the small bowel out of the radiation fields and an individualized immobilization abdominal board for easy daily setup of the patient in prone position. After opacifying the small bowel with barium, the patients were laid prone and posterior-anterior (PA) and lateral (LAT) simulation films were taken with and without the SBDS. The volume of the small bowel included in the radiation fields with and without the SBDS were compared.

RESULTS

Using the SBDS, the mean small bowel volume was reduced by 59% on PA and 51% on LAT films (p = 0.0001). In six patients (6 of 55, 11%), it was possible that no small bowel was included within the treatment fields. The mean upward displacement of the most caudal small bowel was 4.8 cm using the SBDS. Patients treated with the SBDS manifested a significantly lower incidence of diarrhea requiring medication (8 of 55, 15%) vs. those without the SBDS (24 of 39, 62%) (p < 0.05).

CONCLUSION

The SBDS is a novel method that can be used to displace the small bowel away from the treatment portal effectively and to reduce the radiation therapy morbidity. Compliance with setup is excellent.

Efficacy of a belly board device with CT-simulation in reducing small bowel volume within pelvic irradiation fields

PURPOSE/OBJECTIVE

Acute and chronic small bowel toxicity associated with pelvic irradiation limits dose escalation for both chemotherapy and radiotherapy for rectal cancer. Various surgical and technical maneuvers including compression and belly board devices (BBD) have been used to reduce small bowel volume in treatment fields. However, quantitative dose volume advantages of such methods have not been reported. In this study, the efficacy of BBD with CT-simulation is presented with dose-volume histogram (DVH) analyses for rectal cancer.

METHODS AND MATERIALS

Twelve consecutive patients referred to our department with rectal cancer were included in this study. Patients were given oral contrast 1.5 h prior to scanning and instructed not to empty their bladder during the procedure. The initial CT scan without BBD was taken in the prone position with an immobilization cast. A second CT study was performed with a commercially available BBD consisting of an 18-cm thick hard sponge with an adjustable opening (maximum 42 x 42 cm2). All patients were positioned prone over the BBD so that the opening was above the treatment volume and usually extended from the diaphragm to the bottom of the fourth lumbar spine. Image fusion between both sets of CT scans (with and without BBD) was performed using common bony landmarks to maintain the same target volume. The critical structures including small bowel and bladder were delineated on each slice for DVH analysis. On each study, a three-field optimized plan with conformal blocks in beams-eye-view was generated for volumetric analysis. The DVHs with and without BBD were evaluated for each patient.

RESULTS

The median age and body weight of 12 patients (4 females and 8 males) were 57.5 years and 82.7 kg, respectively. The changes in posterior-anterior (PA) and lateral separation with and without BBD at central axis slices were analyzed. The changes in lateral separation were minimal (<0.8 cm); however, the PA separation was reduced by 11.3 +/- 3.3% when BBD was used. The reduction in PA separation was directly related to the reduction in small bowel volume. The small bowel volume was significantly reduced with a median reduction of 70% (range 10-100%) compared to the small bowel volume without BBD. The small bowel volume reduction did not correlate either with body weight, age, gender, or sequence of radiation treatment with surgery (pre-op vs. post-op). The DVH analysis of small bowel with BBD showed significant volume reduction at each dose level. For 50% patients, the DVH analysis demonstrated an increase in bladder volume with BBD. All patients treated with the BBD completed their treatment without any break and without significant acute gastrointestinal or genitourinary toxicity.

CONCLUSIONS

For rectal cancers, small bowel is the dose-limiting structure for acute and chronic toxicity. The use of the BBD should improve the tolerance of aggressive combined modality treatment by reducing the small bowel volume within the pelvis compared to the prone position alone. The BBD provides an easy, economical, comfortable, and noninvasive technique to displace small bowel from pelvic treatment fields. The small bowel volume is dramatically reduced at each dose level. The volume reduction does not correlate with gender, age, weight, pelvic separation, and sequence of radiation treatment vs. surgery.

The lack of impact of pelvic irradiation on small bowel mobility: implications for radiotherapy treatment planning

PURPOSE

Small bowel contrast is frequently used during simulation for patients undergoing pelvic radiotherapy to assist in the design of blocks that exclude small bowel from the radiation field. In many instances, a large field is treated to 45 gray (Gy), followed by a field reduction to exclude the small bowel. This prospective study was designed to assess whether the position and mobility of the small bowel changed after the initial 45 Gy, thereby determining whether a special small bowel series done at initial simulation is applicable at the time of field reduction.

METHODS AND MATERIALS

Twelve patients undergoing pelvic irradiation were given small bowel contrast for their initial simulation. Radiographs were taken with the bladder empty and the bladder full. The location of the small bowel and its displacement with bladder distention was measured. This entire procedure was repeated prior to field reduction (after 39.6-46.0 Gy).

RESULTS

There was no demonstrable alteration in small bowel mobility after 39.6-46.0 Gy. The approximate position of the small bowel relative to bony landmarks was unchanged.

CONCLUSION

The position and mobility of the small bowel appears not to be affected by 39.6-46.0 Gy of pelvic radiotherapy. Therefore, it is reasonable to design reduced pelvic fields to exclude the small bowel based on special small bowel series done at initial treatment simulation.

Intestinal complications of radiotherapy in gynecologic malignancy--clinical presentation and management

Radiation therapy is an effective treatment modality for various gynecologic malignancies. In spite of advances in radiotherapy equipment and techniques over the years, the gastrointestinal and urinary tracts have remained a considerable problem with radiotherapy of the pelvis and abdomen. Clinical presentation of intestinal complications, current concepts of pathophysiology and principles of medical and surgical management are reviewed.

A simple manual method of repositioning small bowel during pelvic irradiation

Small intestine is often unnecessarily irradiated during radiotherapy because it lies near tumor volumes and thus may be dose limiting. Repositioning of normal tissues can sometimes be accomplished by mechanical rather than invasive surgical techniques. At our institution, physical displacement of small bowel tissues was carried out on a population of patients with good result. Patients suffering from prostatic, cervical, and rectal carcinoma were treated using a custom built and padded block composed of rigid Styrofoam. The block, in most cases, successfully displaced significant amounts of healthy tissues from treatment fields. Maximum displacement of bowel was accomplished at the time of simulation using fluoroscopy and manual positioning of the device. The optimum displacement position and location of the Small Bowel Displacement Device (SBDD) were recorded by means of orthogonal radiographs. The device was affixed to a piece of mylar that had been previously scribed with an X and Y coordinate system, which could be used to permanently anchor the SBDD to its position of maximum displacement. Displacements of as much as 4.0 to 5.0 cm were noted on most patients. Patients generally tolerated the device well as long as they were able to lie prone. Patients with recent abdominal surgery were less likely to tolerate the SBDD, and omental slings or meshes generally precluded movement of the small bowel.

Late effects of radiation therapy on the gastrointestinal tract

Late gastrointestinal complications of radiation therapy have been recognized but not extensively studied. In this paper, the late effects of radiation on three gastrointestinal sites, the esophagus, the stomach, and the bowel, are described. Esophageal dysmotility and benign stricture following esophageal irradiation are predominantly a result of damage to the esophageal wall, although mucosal ulcerations also may persist following high-dose radiation. The major late morbidity following gastric irradiation is gastric ulceration caused by mucosal destruction. Late radiation injury to the bowel, which may result in bleeding, frequency, fistula formation, and, particularly in small bowel, obstruction, is caused by damage to the entire thickness of the bowel wall, and predisposing factors have been identified. For each site a description of the pathogenesis, clinical findings, and present management is offered. Simple and reproducible endpoint scales for late toxicity measurement were developed and are presented for each of the three gastrointestinal organs. Factors important in analyzing late complications and future considerations in evaluation and management of radiation-related gastrointestinal injury are discussed.

The volume effect in radiation-related late small bowel complications: results of a clinical study of the EORTC Radiotherapy Cooperative Group in patients treated for rectal carcinoma

PURPOSE

The purpose of this study was to quantify the correlation between irradiated small bowel volume and late occurring small bowel complications.

METHODS

Small bowel volumes in the high-dose region were measured using orthogonal barium films for 203 patients treated for rectal carcinoma with pelvic postoperative radiotherapy to 50 Gy in an EORTC multicentric study.

RESULTS

The 5-year estimate of late pelvic small bowel obstruction requiring surgery was 11%. No correlation between the irradiated small bowel volume and obstruction was detected. The actuarial 5-year estimate of chronic diarrhea varied from 31% in patients with irradiated small bowel volumes below 77 cm3 to 42% in patients with volumes over 328 cm3. This correlation was significant in the univariate and multivariate analysis (p = 0.025). The type of rectal surgery significantly influenced the incidence of chronic diarrhea and malabsorption, the actuarial 5-year estimate being 49% and 26% after low anterior resection and abdominoperineal resection, respectively (p = 0.04).

CONCLUSIONS

This study demonstrated that there is a volume-effect in radiation-induced diarrhea at a dose of 50 Gy in 25 fractions. No volume-effect for small bowel obstruction was detected at this dose-level in pelvic postoperative radiotherapy. A review of the literature data on small bowel obstruction indicates that the volume effect at this dose level can only be demonstrated in patients who were treated with extended field radiotherapy (estimated small bowel volume 800 cm3) after intra-abdominal surgery.

The variation of small bowel volume within the pelvis before and during adjuvant radiation for rectal cancer

Prior to adjuvant postoperative radiation therapy for carcinoma of the rectum, 21 consecutive patients had small bowel barium studies to determine whether there was an optimal interval between ingestion of barium sulphate and imaging, and whether the volume of small bowel within the posterior pelvis was constant throughout the course of treatment. It was found that the optimum interval prior to imaging after ingestion of barium was 1.5-2 h. For seven patients there was no, or minimal, small bowel visualised within the posterior pelvis at any time. For six patients there was an apparently fixed loop of bowel within the posterior pelvis at simulation, both before and during treatment. For a further eight, the small bowel was mobile and the volume of bowel within the posterior pelvis was reduced by bladder distension. Seven of these eight patients had repeat studies during the course of treatment and in five the difference between the appearance of the small bowel with the bladder full and empty was lost. It is concluded that the displacement of small bowel from the posterior pelvis by bladder distension may not be reliably maintained throughout a course of pelvic radiation.

Late complications of postoperative radiation therapy for cancer of the rectum and rectosigmoid

PURPOSE

We retrospectively examined the surgical, medical, radiotherapeutic and technical factors associated with late small bowel and nonsmall bowel morbidity.

METHODS AND MATERIALS

The medical records of 224 patients with cancer of the rectum and rectosigmoid treated mainly with abdominoperineal resection or anterior resection and postoperative radiotherapy at the University of Texas M.D. Anderson Cancer Center from 1973 to 1990 were reviewed. The median dose was 54 Gy (range 34-66 Gy) at 1.8-2 Gy per fraction using various techniques (23 had extended fields to L1 or L2; pelvic fields were treated with anterior-posterior in 85, 83 had a 3-field plan and 33 had a 4-field "box"). A positioning technique that treats patients on an open table-top device was used in 78 patients to move the small intestine out of the pelvis. Bladder distension was used in eight. Forty-seven patients received concomitant 5-fluorouracil. Small bowel series were performed in 122 patients to assess the volume of small bowel inside the pelvis below the conjugate line.

RESULTS

In 29 patients, the median time to the development of small bowel obstruction was 7 months (range 0-69 months); 18 patients required reoperations. The small bowel obstruction rate was 30% in patients treated with daily extended field radiotherapy, 21% in those with a single pelvic field and 9% with multiple pelvic fields. Small bowel obstruction was positively correlated with postsurgical adhesions prior to radiotherapy and absence of reperitonealization at the time of initial surgery (p < 0.05). There was no correlation of small bowel obstruction with a history of hypertension, diabetes, prior surgery, history of abdominal infections, postoperative infections, wound healing, pathologic tumor stage, types of surgical procedures, sites of primary tumor, age, or sex. Patients developing small bowel obstruction had larger amounts of small bowel assessed radiologically below the conjugate line than those without complications. With the open table-top device, the small bowel obstruction rate was 3%. In 47 patients treated with radiation and chemotherapy on the open table-top device, the small bowel obstruction rate was 15%, but these patients had more small bowel inside the pelvis than those without the complication. The median time to the development of nonsmall bowel obstruction in 29 patients was 8 months (range 0-85 months), and the nonsmall bowel obstruction complications were significantly correlated with postoperative infection. Most nonsmall bowel obstruction complications were in the genitourinary tract and occurred in patients who had abdominoperineal resection.

CONCLUSION

The open table-top device, by moving the small bowel out of the treatment field, reduces small bowel obstruction in patients treated with radical surgery and postoperative radiotherapy for cancer of the rectum and rectosigmoid. This technique is facile, reproducible, and does not require patient compliance.

Effect of pelvic irradiation on gastrointestinal function: a prospective longitudinal study

PURPOSE

Although radiation enteritis is a well-recognized sequel of therapeutic irradiation, the effects of abdominal and/or pelvic irradiation on gastrointestinal function are poorly defined and treatment is often unsuccessful. To determine both the short- and long-term effects of therapeutic irradiation on gastrointestinal function, we performed a prospective study.

PATIENTS AND METHODS

Various aspects of gastrointestinal function were evaluated in 27 patients with potentially curable malignant disease (23 female, 4 male) before the commencement of, during, and 6 to 8 weeks, 12 to 16 weeks, and 1 to 2 years following completion of radiation therapy. Seventeen patients received pelvic irradiation alone and 10 patients received both abdominal and pelvic irradiation. Gastrointestinal symptoms, absorption of bile acid, vitamin B12, lactose, and fat, gastric emptying, small-intestinal and whole-gut transit, stool weight, and intestinal permeability were measured. Results were compared with those obtained in 18 normal volunteers.

RESULTS

All 27 patients completed at least 2 series of measurements and 18 patients completed all 5 series of experiments. During radiation treatment, increased stool frequency (p < 0.001) was associated with decreased bile acid and vitamin B12 absorption (p < 0.001 for both), increased fecal fat excretion (p < 0.05), an increased prevalence of lactose malabsorption (p < 0.01), and more rapid small-intestinal (p < 0.01) and whole-gut (p < 0.05) transit. Although there was improvement in most of these changes with time, at 1 to 2 years after the completion of irradiation, the frequency of bowel actions was greater (p < 0.001), bile acid absorption was less (p < 0.05), and small-intestinal transit was more rapid (p < 0.01) when compared with that of baseline and the normal subjects. At this time, at least 1 parameter of gastrointestinal function was abnormal in 16 of the 18 patients. Stool weight was greater (p < 0.05) and whole-gut transit faster (p < 0.01) in patients who received both pelvic and abdominal irradiation, when compared with those who received pelvic irradiation alone. Stool frequency (p < 0.001) and fecal fat excretion (p < 0.05) were greater in those patients who had surgery before radiation therapy.

CONCLUSION

Pelvic irradiation is usually associated with widespread, persistent effects on gastrointestinal function.

Volumetric analysis of small bowel displacement from radiation portals with the use of a pelvic tissue expander

PURPOSE

Many techniques and devices have been used in an attempt to minimize gastrointestinal morbidity of pelvic irradiation. The value of a temporary intrapelvic tissue expander to displace small bowel from pelvic radiotherapy fields was analyzed by comparing volumetric treatment parameters of patients with and without such a device.

METHODS AND MATERIALS

Between 1983 and 1991, 77 patients with a diagnosis of endometrial (n = 35), colorectal (n = 41), or anal carcinoma (n = 1) received adjuvant postoperative radiotherapy after undergoing treatment planning simulation with the use of small bowel oral contrast medium. Fourteen of these patients underwent surgical placement of a temporary intrapelvic tissue expander prior to radiotherapy, and 63 patients did not. Small bowel volume within the treatment portals was measured for both initial pelvic and conedown fields for all cases, and compared between the two patient groups.

RESULTS

The volume of small bowel within the initial pelvic fields receiving full dose irradiation was significantly less among patients with a tissue expander. For patients with a tissue expander, mean volume receiving full dose irradiation was 25 cm3 (median 0 cm3, range 0-297 cm3), whereas the corresponding volume was 239 cm3 (median 181 cm3, range 0-943 cm3) without a tissue expander (p < .0001). A similar reduction of irradiated small bowel volume was noted in the conedown fields with the use of a tissue expander (p = .07). Volumes receiving less than full dose irradiation were also less within the initial pelvic (p = .0001) and conedown (p = .002) fields with a tissue expander. Multivariate analysis of patient and treatment-related parameters showed the use of a tissue expander to be the only factor correlated with decreased small bowel volume within the treatment field (p = .003). Morbidity related to placement and removal of the tissue expander was acceptable. Acute radiation-related morbidity was significantly less in patients irradiated with a tissue expander in place (p < .001).

CONCLUSIONS

Placement of an intrapelvic tissue expander was correlated with decreased small bowel volume within the radiotherapy treatment field. Diminished radiation-induced acute gastrointestinal morbidity was noted with use of a tissue expander.

Pelvic failure rate and radiation toxicity in relation to total dose of radiation alone for the treatment of cancer of the uterine cervix

Seventy-four patients presenting between 1978 and 1989 with carcinoma of the uterine cervix were analysed to compare our results with the published literature, especially with regard to the pelvic failure rate and radiation toxicity. Overall 5-year survival reached 41%. Overall 2-year survival rate for Stage IIB was 85% and Stage IIIB was 32%. For Stage IIB the results agreed with those reported in the literature. Pelvic control was related to total dose and the application of intracavitary irradiation. For Stage IIIB the results were disappointing, partly due to a large number of bulky tumours and also to a relatively low paracentral dose and dose to the pelvic side wall. Percentages of radiation side-effects were low compared with those reported in the literature, probably also due to the relatively low total dose.

Use of peritoneal insufflation to displace the small bowel during pelvic and abdominal radiotherapy in carcinoma of the cervix

Peritoneal insufflation is a technique which reliably displaces small bowel from pelvic and abdominal radiotherapy fields with the aim of reducing bowel reactions which limit the dose of radiation applied to these sites. Use of this technique in five patients undergoing radiotherapy for advanced carcinoma of the cervix, and the degree of bowel displacement resulting, dosimetry, acute reactions and tolerability of the technique are presented, with discussion of the possibility of future escalation in radiotherapy dose.

Radiation therapy for advanced colorectal cancer

Locally advanced, inoperable, and recurrent colorectal cancer requires multitechnique therapy to achieve optimal control and palliation. The role of radiation therapy as an adjuvant in resectable rectal cancer has been studied extensively in clinical trials, but its role in more advanced disease has not been explored to the same extent. The use of radiation in colonic rather than rectal cancer is more problematic because of natural tissue tolerance constraints in the abdomen versus the pelvis. The current and past role of radiation in advanced colorectal cancer will be reviewed, and avenues of ongoing and future investigation will be outlined. The role of radiation for palliation also will be discussed.

Postoperative radiotherapy of carcinoma in bilharzial bladder: improved disease free survival through improving local control

Two hundred thirty-six patients with T3 bladder cancer who survived radical surgery and proved to have P3a, P3b, or P4a tumors were randomized in two phases into three groups: (a) no further treatment (83 patients); (b) postoperative radiotherapy multiple daily fractionation (MDF), using 3 daily fractions of 1.25 Gy each, with 3 hr between fractions, up to a total dose of 37.5 Gy in 12 days (75 patients); and (c) postoperative radiotherapy conventional fractionation (CF), for a total dose of 50 Gy/5 weeks (78 patients). The tolerance of the patients to postoperative radiotherapy was quite acceptable, with equal acute reactions in MDF and CF groups. The 5-year disease-free survival (DFS) rates amounted to 49 and 44% in MDF and CF postoperative radiotherapy groups, respectively, compared to 25% in the cystectomy-alone group. The 5-year local control rates were 87% and 93% for those treated with multiple daily fractionation and conventional fractionation while it was 50% in the surgery-alone group. The therapeutic benefit of postoperative irradiation was consistent for all tumor types, histological grades, and pathological stages for both the disease-free survival and local control. Patients with nodal metastases demonstrated lower recurrence rates in the postoperative radiotherapy groups, but this was not associated with improved disease-free survival. Multivariate analysis using the Cox Model confirmed these results. The independent prognostic factors affecting both disease-free survival and local control were the addition of postoperative radiotherapy, the nodal status, the pathological stage, and the tumor grade. Late complications of radiotherapy in the skin, small intestine, rectum, and the anastomotic site of the urinary division were lower with MDF than with conventional fractionation.

A preliminary report on new efforts to decrease radiotherapy related small bowel toxicity

Ten consecutive patients operated for gynaecological cancer had an absorbable polyglycolic mesh (Dexon) inserted to elevate the small bowel out of the pelvis to prevent radiation toxicity. Four patients developed minimal small bowel toxicity, while no complications of the mesh were seen. The method warrants further investigation.

Analysis of complications in patients with endometrial carcinoma receiving adjuvant irradiation

We analyzed the complications in 310 patients with pathologically documented endometrial carcinoma who received adjuvant radiation therapy (RT) at Fox Chase Cancer Center between 1970 and 1986. Variables included timing of treatment, technique, total dose, age, diabetes, previous abdominal surgery, hypertension, prior bowel pathology, and lymphadenectomy. According to the FIGO (1985) system, 258 patients had Stage I disease, 48 had Stage II, and one had Stage III. One hundred seventy patients received preoperative (preop) RT, 138 received postoperative (postop) RT, and 2 received preop and postop RT. A 4-field technique was used for 212 of 235 patients receiving external-beam (EX) RT, and 75 patients were treated with intracavitary (IC) RT only. Median follow-up was 5.5 years. Actuarial survival of all 310 patients was 78% at 5 years. Thirty-two complications occurred, involving the rectum, small bowel, femur, or lower extremity. Complications were graded according to the ECOG scoring system as grade 2 (mild) and grades 3, 4, or 5 (serious). One of 75 patients treated with IC RT only experienced a grade-2 complication (proctitis). Of 71 patients receiving 4-field EX RT only, 25 preop (16%) and 14 postop (14%) patients had complications. Of 139 patients treated with both EX and IC RT, grade-2 complications were seen in 5% of 87 preop patients and 12% of 52 postop patients (p = 0.17), whereas serious complications were observed in 4% of each group. Univariate analysis of the variables of interest revealed that the incidence of complications was associated with a lymphadenectomy (p = .03), use of external RT (p less than .01), and decreasing age (p = .04). Multivariate analysis confirmed that use of external RT was the most significant predictor for complications. In conclusion, similar complication rates were found in patients treated with either preop or postop 4-field EX RT. While pelvic RT clearly decreases pelvic relapse in patient with endometrial carcinoma, the risk benefit ratio for treatment of these patients should be carefully considered when recommending adjuvant RT for pelvic control.

Decreasing gastrointestinal morbidity with the use of small bowel contrast during treatment planning for pelvic irradiation

Small bowel tolerance is a major dose-limiting factor in treating the pelvis with radiation therapy (RT). The use of small bowel contrast during RT simulation is one technique used to localize the bowel and identify the treatment plan that would exclude the greatest volume. To determine the influence of treatment planning with oral contrast on gastrointestinal injury, acute and chronic small bowel morbidity was analyzed in 115 patients with endometrial and rectal carcinoma who received postoperative radiation therapy at the Fox Chase Cancer Center. Mean and median time of follow-up were 31 and 27 months, respectively. Acute diarrhea was seen in 82% of the patient population. Ten percent of patients experienced major complications requiring hospitalization. Ninety-three percent of patients simulated without contrast experienced side effects compared to 77% of patients simulated with contrast (p = .026). There was an increased incidence of chronic complications in patients who were not simulated with contrast dye (50% vs 23%, p = .014). Median duration of minor side effects was 4 months for patients planned without oral contrast and 1 month for patients who had contrast at the time of simulation (p = .036). The superior aspect of the treatment field was determined to be at a more inferior location in patients simulated with contrast, thereby excluding small bowel from treatment. Seventy-four percent of patients simulated without contrast had the upper border of the field placed at the superior aspect of the sacroiliac joint or above, compared to only 40% of patients planned with oral contrast (p = .002). This study has demonstrated decreased complications (both overall and chronic) as well as a change in the location of the treatment field with the use of small bowel contrast. Multivariate analysis revealed that both the use of oral contrast (p = .026) and a lower superior border of the treatment field (p = .007) were predictive for fewer sequelae to RT, indicating that planning with contrast leads to changes in the technical delivery of RT other than field placement (e.g., block placement). The reduced incidence and duration of small bowel morbidity may be in part caused by alterations of the treatment plan made when the small bowel is visualized at the time of simulation. It is therefore recommended that oral small bowel contrast be used during treatment planning for pelvic irradiation.