Analysis of complications in patients treated with abdomino-pelvic radiation therapy for ovarian carcinoma

Opportunities and challenges of low-dose radiation to enable immunotherapy efficacy

Therapeutic monoclonal antibodies blocking different immune checkpoints, have demonstrated efficacy against a wide variety of solid tumors. The exclusion or absence of lymphocytes within the tumor microenvironment (TME) is one of the main resistance mechanisms to immune checkpoint inhibitor (ICI)-based therapies. Therefore, there is a growing interest in identifying novel approaches to promote T cell infiltration on immune-deserted (cold) and immune-excluded tumors to turn them into inflamed (hot) tumors. Here, we provide a comprehensive overview of the recently published studies showing the potential of low-dose radiation (LDRT) to reprogram the TME to allow and promote T-cell infiltration and thus, improve currently approved ICI-based therapies.

The current understanding of the immune landscape relative to radiotherapy across tumor types

Radiotherapy is part of the standard of care treatment for a great majority of cancer patients. As a result of radiation, both tumor cells and the environment around them are affected directly by radiation, which mainly primes but also might limit the immune response. Multiple immune factors play a role in cancer progression and response to radiotherapy, including the immune tumor microenvironment and systemic immunity referred to as the immune landscape. A heterogeneous tumor microenvironment and the varying patient characteristics complicate the dynamic relationship between radiotherapy and this immune landscape. In this review, we will present the current overview of the immunological landscape in relation to radiotherapy in order to provide insight and encourage research to further improve cancer treatment. An investigation into the impact of radiation therapy on the immune landscape showed in several cancers a common pattern of immunological responses after radiation. Radiation leads to an upsurge in infiltrating T lymphocytes and the expression of programmed death ligand 1 (PD-L1) which can hint at a benefit for the patient when combined with immunotherapy. In spite of this, lymphopenia in the tumor microenvironment of 'cold' tumors or caused by radiation is considered to be an important obstacle to the patient's survival. In several cancers, a rise in the immunosuppressive populations is seen after radiation, mainly pro-tumoral M2 macrophages and myeloid-derived suppressor cells (MDSCs). As a final point, we will highlight how the radiation parameters themselves can influence the immune system and, therefore, be exploited to the advantage of the patient.

Interstitial brachytherapy combined with PARP inhibitors in the treatment of chemoresistant recurrent epithelial ovarian cancer: A case report

Background

Chemoresistance generally develops in patients with advanced epithelial ovarian cancer, and the prognosis is still very poor, with an expected survival time of less than one year. For this population of individuals, there is currently no standard protocol for clinical benefit.

Case presentation

We report a case of an elderly woman diagnosed with stage IIIC high-grade serous ovarian cancer (HGSOC). During a follow-up time of 6 years, the patient initially received multiple sequential courses of chemotherapy with platinum-based regimens and with no maintenance therapy. Similar to most patients with advanced HGSOC, she developed platinum resistance and experienced poor treatment results with a short progression-free survival (PFS). Ultimately, we gave the patient traditional non-platinum-based chemotherapy with bevacizumab and high-dose-rate interstitial brachytherapy followed by olaparib as a maintenance therapy. Up to now, the patient did response well to the treatment, and the PFS had exceeded 12 months.

Conclusion

High-dose-rate interstitial brachytherapy combination with PARP inhibitors may be an option for isolated chemoresistant recurrent epithelial ovarian cancer.

Dosimetric predictors and Lyman normal tissue complication probability model of hematological toxicity in cervical cancer patients with treated with pelvic irradiation

PURPOSE

To identify dosimetric parameters associated with acute hematological toxicity (HT) and identify the corresponding normal tissue complication probability (NTCP) model in cervical cancer patients receiving helical tomotherapy (Tomo) or fixed-field intensity-modulated radiation therapy (ff-IMRT) in combination with chemotherapy, that is, concurrent chemoradiotherapy (CCRT) using the Lyman-Kutcher-Burman normal tissue complication probability (LKB-NTCP) model.

METHODS

Data were collected from 232 cervical cancer patients who received Tomo or ff-IMRT from 2015 to 2018. The pelvic bone marrow (PBM) (including the ilium, pubes, ischia, acetabula, proximal femora, and lumbosacral spine) was contoured from the superior boundary (usually the lumbar 5 vertebra) of the planning target volume (PTV) to the proximal end of the femoral head (the lower edge of the ischial tubercle). The parameters of the LKB model predicting ≥grade 2 hematological toxicity (Radiation Therapy Oncology Group [RTOG] grading criteria) (TD50 (1), m, and n) were determined using maximum likelihood analyses. Univariate and multivariate logistic regression analyses were used to identify correlations between dose-volume parameters and the clinical factors of HT.

RESULTS

In total, 212 (91.37%) patients experienced ≥grade 2 hematological toxicity. The fitted normal tissue complication probability model parameters were TD50 (1) = 38.90 Gy (95%CI, [36.94, 40.96]), m = 0.13 (95%CI [0.12, 0.16]), and n = 0.04 (95%CI [0.02, 0.05]). Per the univariate analysis, the NTCP (the use of LKB-NTCP with the set of model parameters found, p = 0.023), maximal PBM dose (p = 0.01), mean PBM dose (p = 0.021), radiation dose (p = 0.001), and V16-53 (p < 0. 05) were associated with ≥grade 2 HT. The NTCP (the use of LKB-NTCP with the set of model parameters found, p = 0.023; AUC = 0.87), V16, V17, and V18 ≥ 79.65%, 75.68%, and 72.65%, respectively (p < 0.01, AUC = 0.66∼0.68), V35 and V36 ≥ 30.35% and 28.56%, respectively (p < 0.05; AUC = 0.71), and V47 ≥ 13.43% (p = 0.045; AUC = 0.80) were significant predictors of ≥grade 2 hematological toxicity from the multivariate logistic regression analysis.

CONCLUSIONS

The volume of the PBM of patients treated with concurrent chemoradiotherapy and subjected to both low-dose (V16-18 ) and high-dose (V35,36 and V47 ) irradiation was associated with hematological toxicity, depending on the fractional volumes receiving the variable degree of dosage. The NTCP were stronger predictors of toxicity than V16-18 , V35, 36 , and V47 . Hence, avoiding radiation hot spots on the PBM could reduce the incidence of severe HT.

Low-Dose Radiotherapy Reverses Tumor Immune Desertification and Resistance to Immunotherapy

Developing strategies to inflame tumors is critical for increasing response to immunotherapy. Here, we report that low-dose radiotherapy (LDRT) of murine tumors promotes T-cell infiltration and enables responsiveness to combinatorial immunotherapy in an IFN-dependent manner. Treatment efficacy relied upon mobilizing both adaptive and innate immunity and depended on both cytotoxic CD4⁺ and CD8⁺ T cells. LDRT elicited predominantly CD4⁺ cells with features of exhausted effector cytotoxic cells, with a subset expressing NKG2D and exhibiting proliferative capacity, as well as a unique subset of activated dendritic cells expressing the NKG2D ligand RAE1. We translated these findings to a phase I clinical trial administering LDRT, low-dose cyclophosphamide, and immune checkpoint blockade to patients with immune-desert tumors. In responsive patients, the combinatorial treatment triggered T-cell infiltration, predominantly of CD4⁺ cells with Th1 signatures. Our data support the rational combination of LDRT with immunotherapy for effectively treating low T cell-infiltrated tumors. SIGNIFICANCE: Low-dose radiation reprogrammed the tumor microenvironment of tumors with scarce immune infiltration and together with immunotherapy induced simultaneous mobilization of innate and adaptive immunity, predominantly CD4⁺ effector T cells, to achieve tumor control dependent on NKG2D. The combination induced important responses in patients with metastatic immune-cold tumors.This article is highlighted in the In This Issue feature, p. 1.

Survival Analysis of Radiation Therapy in Ovarian Cancer: A SEER Database Analysis

Results

A total of 20031 ovarian cancer patients were included, with 291 (1.45%) patients who received radiotherapy. The median overall survival (OS) in patients who received radiotherapy was shorter than which in patients without radiotherapy (23 vs. 75 months, P < 0.001). The Elderly, nonepithelial pathology, advanced American Joint Committee on Cancer (AJCC) stage, elevated level of CA125, and receiving radiotherapy were risk predictors to survival in both multivariable analyses before and after PSM. Among 11872 patients with III/IV stage, the radiotherapy group also showed a significantly worse prognosis (median OS: 19 vs. 44 months in patients without radiotherapy, P < 0.001). Consistent results were observed in stratification analyses on pathology and stage among patients with III/IV stage.

Conclusions

For patients with ovarian cancer, radiotherapy was associated with a poor prognosis regardless of pathology or stage. Considering this is a retrospective study, future studies concerning radiotherapy combination with other new agents in ovarian cancer are needed.

Adjuvant intensity modulated whole-abdominal radiation therapy for high-risk patients with ovarian cancer FIGO stage III: final results of a prospective phase 2 study

Background

To assess late toxicity, quality of life and oncological outcome after consolidative whole abdominal radiotherapy (WART) following cytoreductive surgery and carboplatin/paclitaxel chemotherapy in high risk patients with advanced ovarian cancer FIGO stage III using IMRT (Intensity modulated radiation therapy).

Methods

The OVAR-IMRT-02 study is a multi-center single-arm phase-II-trial. Twenty patients with optimally debulked ovarian cancer stage FIGO III with complete remission after chemotherapy were treated with intensity modulated WART. A total dose of 30 Gy in 20 fractions was applied to the entire peritoneal cavity. Primary endpoint was treatment tolerability; secondary objectives were acute and chronic toxicities, quality of life, rates of therapy disruption/abortion, progression-free survival (PFS) and overall survival (OS).

Results

All patients completed treatment and 10/20 patients (50%) reached the final study follow-up of 36 months. Late side effects consisted of °1-°2 lower limb edema (44.5%), with one patient (5.6%) showing °3 edema. Three patients (16.7%) showed elevated gamma-Glutamyltransferase. There were no severe late side effects regarding renal or hepatic function or any gastrointestinal toxicity greater than °2. During WART, mean global health status decreased by 18.1 points (95%-CI: 7.1–29.0), but completely normalized after 6 months. The same trend was observed for the function scale scores. Kaplan-Meier-estimated 1-, 2- and 3-year PFS was 74, 51 and 40%, respectively. 1-, 2- and 3-year OS was 89, 83 and 83%, respectively.

Conclusions

Intensity modulated WART after aggressive surgery and carboplatin/paclitaxel chemotherapy is associated with an acceptable risk of acute and late toxicity and minor impact on long-term quality of life. Together with the promising results for PFS and OS, intensity modulated WART could offer a new therapeutic option for consolidation treatment of patients with advanced ovarian cancer.

Trial registration

The study is registered with ClinicalTrials.gov (NCT01180504). Registered 12 August 2010 – retrospectively registered.

The role of radiotherapy in epithelial ovarian cancer: a literature overview

Ovarian cancer (OC) accounts for 3% of all cancer in women and for 5% of all cancer-related deaths. Epithelial Ovarian Cancer (EOC) is a radiosensitive malignancy with a poor prognosis. In the pre-chemotherapy era, radiation therapy (RT) delivered to the abdominopelvic region (whole abdominal irradiation, WAI) has historically played a role in the adjuvant and consolidation setting. Specific cluster of patients with early-stage disease and definite histologies may take advantage of RT. Platinum-based chemotherapy (CT) has replaced RT and plays a major role in most of the clinical settings. Radiation Therapy for palliation is recommended in patients with localized symptoms. Nevertheless, modern RT represents a reliable treatment option, with a mild toxicity profile, particularly effective for oligo-recurrent or progressive disease. The present literature review aims to highlight the historical role of RT in EOC, the actual lines of evidence, and the future perspectives.

Effect of alpha-lipoic acid on radiation-induced small intestine injury in mice

Purpose

Radiation therapy is a highly effective treatment for patients with solid tumors. However, it can cause damage and inflammation in normal tissues. Here, we investigated the effects of alpha-lipoic acid (ALA) as radioprotection agent for the small intestine in a mouse model.

Materials and Methods

Whole abdomen was evenly irradiated with total a dose of 15 Gy. Mice were treated with either ALA (100 mg/kg, intraperitoneal injection [i.p.]) or saline (equal volume, i.p.) the prior to radiation as 100 mg/kg/day for 3 days. Body weight, food intake, histopathology, and biochemical parameters were evaluated.

Results

Significant differences in body weight and food intake were observed between the radiation (RT) and ALA + RT groups. Moreover, the number of crypt cells was higher in the ALA + RT group. Inflammation was decreased and recovery time was shortened in the ALA + RT group compared with the RT group. The levels of inflammation-related factors (i.e., phosphorylated nuclear factor kappa B and matrix metalloproteinase-9) and mitogen-activated protein kinases were significantly decreased in the ALA + RT group compared with those in the RT group.

Conclusions

ALA treatment prior to radiation decreases the severity and duration of radiation-induced enteritis by reducing inflammation, oxidative stress, and cell death.

Adjuvant Intensity Modulated Whole-Abdominal Radiation Therapy for High-Risk Patients With Ovarian Cancer (International Federation of Gynecology and Obstetrics Stage III): First Results of a Prospective Phase 2 Study

PURPOSE

To assess treatment tolerance and toxicity rates of consolidative whole-abdominal radiation therapy (WART) following cytoreductive surgery and carboplatin/paclitaxel chemotherapy in high-risk patients with advanced ovarian cancer (International Federation of Gynecology and Obstetrics stage III) using intensity modulated radiation therapy.

METHODS AND MATERIALS

The OVAR-IMRT-02 study is a multicenter, single-arm, phase 2 trial. Twenty patients with optimally debulked ovarian cancer (International Federation of Gynecology and Obstetrics stage III) with complete remission after chemotherapy were treated with intensity modulated WART as a consolidation therapy. A total dose of 30 Gy in 20 fractions of 1.5 Gy was applied to the entire peritoneal cavity. The primary endpoint was treatment tolerability, defined as lack of any Common Terminology Criteria for Adverse Events grade 4 toxicity within 10 weeks after start of treatment; secondary objectives were acute and chronic toxicity, quality of life, rates of therapy disruption and abortion, and progression-free and overall survival.

RESULTS

Intensity modulated WART resulted in excellent coverage of the whole peritoneal cavity, with effective sparing of all organs at risk. The primary analysis included all 20 enrolled patients, of whom 19 did not experience Common Terminology Criteria for Adverse Events grade 4 toxicity. Only 1 patient experienced acute grade 4 hematologic toxicity. Thus, the tolerability rate of intensity modulated WART was significantly higher than 70%. No gastrointestinal acute toxicities higher than grade 2 have been observed. During WART, mean global health status decreased by 18.1 points (95% confidence interval 7.1, 29.0). Six weeks after WART, global health status had already increased, with a mean score difference of 4.6 (95% confidence interval -11.1, 20.4) compared with baseline. Similar characteristics were observed for all function scale scores.

CONCLUSION

Intensity modulated WART after aggressive surgery and carboplatin/paclitaxel chemotherapy is associated with an acceptable risk of acute toxicity and a treatment tolerability rate significantly higher than 70%. Together with our knowledge about clinical feasibility, meaning excellent coverage of the planning target volume and effective sparing of organs at risk, intensity modulated WART could offer a new therapeutic option for consolidation treatment of patients with advanced ovarian cancer.

Rebamipide ameliorates radiation-induced intestinal injury in a mouse model

Radiation-induced enteritis is a major side effect in cancer patients undergoing abdominopelvic radiotherapy. Radiation exposure produces an uncontrolled inflammatory cascade and epithelial cell loss leading to impaired epithelial barrier function. The goal of this study was to determine the effect of rebamipide on regeneration of the intestinal epithelia after radiation injury. The abdomens of C57BL/6 mice were exposed to 13Gy of irradiation (IR) and then the mice were treated with rebamipide. Upon IR, intestinal epithelia were destroyed structurally at the microscopic level and bacterial translocation was increased. The intestinal damage reached a maximum level on day 6 post-IR and intestinal regeneration occurred thereafter. We found that rebamipide significantly ameliorated radiation-induced intestinal injury. In mice treated with rebamipide after IR, intestinal barrier function recovered and expression of the tight junction components of the intestinal barrier were upregulated. Rebamipide administration reduced radiation-induced intestinal mucosal injury. The levels of proinflammatory cytokines and matrix metallopeptidase 9 (MMP9) were significantly reduced upon rebamipide administration. Intestinal cell proliferation and β-catenin expression also increased upon rebamipide administration. These data demonstrate that rebamipide reverses impairment of the intestinal barrier by increasing intestinal cell proliferation and attenuating the inflammatory response by inhibiting MMP9 and proinflammatory cytokine expression in a murine model of radiation-induced enteritis.

Fractionated Palliative Pelvic Radiotherapy as an Effective Modality in the Management of Recurrent/Refractory Epithelial Ovarian Cancers: An Institutional Experience

BACKGROUND

The advent of effective chemotherapeutic agents for ovarian carcinoma has made radical abdomino-pelvic radiation redundant. Nevertheless, palliative pelvic radiotherapy still has a role in palliating local symptoms. However, its effect on progression-free survival (PFS) may be debated.

AIMS

To study the outcome of fractionated palliative pelvic radiotherapy in relapsed ovarian cancers in terms of symptom control and PFS.

METHODS

Twenty-three patients of ovarian cancers, heavily pretreated with chemotherapy and with recurrent or residual pelvic masses, were planned for palliative pelvic radiotherapy to the dose of 46-50 Gy in 23-25 fractions in 4.5-5 weeks. Symptom control and outcomes have been analyzed.

RESULTS

Post-radiotherapy, abdominal pain was controlled in 15 out of 17 patients (88.2 %), bleeding per vaginum in all 5 patients and vaginal discharge stopped in 4 out of 5 patients (80 %). On follow-up, of 23 patients, 17 (74 %) had progressive disease post-radiation, and median time to disease progression was 10 months (range 1-49). On univariate analysis, increased PFS was observed in patients who received radiation late in their course of disease, those with serous histology, and with lesser disease bulk in pelvis (≤2 cm) prior to radiation initiation.

CONCLUSION

Fractionated palliative pelvic radiotherapy is an efficient method for symptom palliation in relapsed ovarian cancers. Patients who are heavily pretreated with chemotherapy and have a small-volume pelvic disease may show a prolonged PFS with addition of pelvic radiotherapy. Indications of radiotherapy, however, need to be defined.

Intensity-modulated whole abdomen irradiation following adjuvant carboplatin/taxane chemotherapy for FIGO stage III ovarian cancer : four-year outcomes

INTRODUCTION

A prospective study to assess toxicity and survival outcomes after intensity-modulated whole-abdominal irradiation (IM-WAI) following surgery and adjuvant intravenous carboplatin/taxane chemotherapy in advanced FIGO stage III ovarian cancer.

PATIENTS AND METHODS

Between 2006 and 2009, 16 patients with optimally resected FIGO stage III ovarian cancer, who had received six cycles of adjuvant carboplatin/taxane chemotherapy were treated with consolidation IM-WAI. Radiotherapy was delivered to a total dose of 30 Gy in 1.5-Gy fractions, using step-and-shoot (n = 3) or helical tomotherapy (n = 13). The first 10 patients were treated within a phase I trial; the following patients received the same treatment modality. The target volume included the entire peritoneal cavity, the diaphragm, the liver capsule, and the pelvic and para-aortic node regions. Organs at risk were kidneys, liver, heart, and bone marrow.

RESULTS

Median follow-up was 44 months (range 19.2-67.2 months). No grade 4 toxicities occurred during IM-WAI. Common Toxicity Criteria for Adverse Events (CTCAE) grade 3 toxicities were: diarrhea (25 %), leucopenia (19 %), nausea/vomiting (6 %), and thrombocytopenia (6 %). No toxicity-related treatment break was necessary. Small bowel obstruction occurred in a total of 6 patients: in 3 cases (19 %) due to postsurgical adhesions and in 3 cases due to local tumor recurrence (19 %). Median recurrence-free survival (RFS) was 27.6 months (95 % confidence interval, CI = 24-44 months) and median overall survival (OS) was 42.1 months (95 %CI = 17-68 months). The peritoneal cavity was the most frequent site of initial failure.

CONCLUSION

Consolidation IM-WAI following surgery and adjuvant chemotherapy is feasible and can be performed with manageable acute and late toxicity. The favorable RFS outcome is promising and justifies further clinical trials.

Effects of oral glutamine during abdominal radiotherapy on chronic radiation enteritis: a randomized controlled trial

OBJECTIVE

Glutamine has been proposed as a preventive treatment for toxicity related to cancer therapies. The aim of this study was to test the efficacy of glutamine in the prevention of radiation enteritis.

METHODS

A randomized, double-blind, controlled trial was performed including 69 patients who were assigned to receive either glutamine (Gln, 30 g/d) or placebo while they were receiving abdominal radiotherapy. Patients were re-evaluated 1 y after completion of treatment. The presence of chronic enteritis was assessed using the Radiation Therapy Oncology Group scale. Nutritional status was evaluated using subjective global assessment, weight, and bioimpedance. Relative risk (RR) and its confidence interval (CI) were also calculated.

RESULTS

The trial initially included 69 patients (34 Gln, 35 placebo), but 11 patients were lost during follow-up (4 Gln, 7 placebo; P = 0.296). Chronic enteritis was developed by 14 % of patients: Gln 16.7 % versus placebo 11.1% (RR = 1.33; 95% CI, 0.35-5.03; P = 0.540). Most cases of enteritis were grade I (75%), with no differences between groups. The stool frequency increased after radiotherapy in patients who received Gln (from 1 ± 1 to 2 ± 2 stools per day, P = 0.012), but remained unchanged with placebo (1 ± 1 stools per day, P = 0.858; difference between groups P = 0.004). There were no differences between the two groups in terms of weight, fat mass, or fat-free mass index, or between patients with enteritis and those without intestinal toxicity.

CONCLUSIONS

Chronic enteritis is a relatively infrequent phenomenon, and Gln administration during radiotherapy does not exert a protective effect.

Consolidation whole abdomen irradiation following adjuvant carboplatin-paclitaxel based chemotherapy for advanced uterine epithelial cancer: feasibility, toxicity and outcomes

BACKGROUND

To evaluate feasibility and preliminary outcomes associated with sequential whole abdomen irradiation (WAI) as consolidative treatment following comprehensive surgery and systemic chemotherapy for advanced endometrial cancer.

METHODS

We conducted a retrospective analysis of patients treated at our institution from 2000 to 2011. Inclusion criteria were stage III-IV endometrial cancer patients with histological proof of one or more sites of extra-uterine abdomen-confined disease, treated with WAI as part of multimodal therapy. Endpoints were feasibility, acute toxicity, late effects, recurrence-free survival (RFS) and overall survival (OS). Twenty patients were identified. Chemotherapy consisted of 3 to 6 cycles of a platinum-paclitaxel regimen in 18 patients. WAI was delivered using conventional technique to a median total dose of 27.5 Gy.

RESULTS

No grade 4 toxicities occurred during chemotherapy or radiotherapy. No radiation dose reduction was necessary. Three patients developed small bowel obstruction, all in the context of recurrent intraperitoneal disease. Kaplan-Meier estimates and 95% confidence intervals for RFS and OS at one year were 63% (38-80%) and 83% (56-94%) and at 3 years 57% (33-76%) and 62% (34-81%), respectively. On univariate Cox analysis, stage IVB and serous papillary (SP) histology were found to be statistically significantly (at the p = 0.05 level) associated with worse RFS and OS. The peritoneal cavity was the most frequent site of initial failure.

CONCLUSIONS

Consolidative WAI following chemotherapy is feasible and can be performed without interruption with manageable acute and late toxicity. Patients with endometrioid adenocarcinoma, especially stage FIGO III, had favorable outcomes possibly meriting prospective evaluation of the addition of WAI following chemotherapy in selected patients. Patients with SP do poorly and do not routinely benefit from this approach.

Revisiting the role of radiation treatment for non-serous subtypes of epithelial ovarian cancer

Except for its palliative use, radiation has been largely abandoned in the management of ovarian cancers because of the recognized efficacy of chemotherapy agents. Whole abdominal irradiation (WAR), however, has been shown to be of adjuvant and curative value in ovarian cancer with microscopic or minimal residual disease in the pelvis, the so-called "intermediate risk group." Recent hypothesis generating data from the use of adjuvant radiation following adjuvant chemotherapy in ovarian cancer has shown an incremental survival benefit for the rarer non-serous ovarian subtypes including clear cell, endometrioid, and mucinous. No incremental benefit was observed for the more common serous subtype. A retrospective examination of early trials using WAR as the sole postoperative treatment in ovarian cancer has determined that the majority of patients in these studies and cured by radiation actually had the non-serous subtypes. The recognition that the non-serous subtypes differ from the serous cancers in their stage of presentation, their molecular characteristics, their response to classic chemotherapy, and their outcomes suggest the non-serous subtypes should be treated as rare and different cancers. In addition to specific targeting therapies that may be developed, radiation should be reconsidered as part of the treatment armamentarium for these diseases.

Chemotherapy followed by abdominal cavity irradiation for feline lymphoblastic lymphoma

Combination chemotherapy is standard care for feline lymphoma, although clinically relevant improvements in remission duration are unlikely to result from manipulations of chemotherapy agents alone. Lymphopoietic tissues generally are sensitive to radiation, and support for chemoradiotherapy as a treatment for lymphoma is found in both humans and dogs. The goal of this prospective pilot study was to determine the normal tissue tolerance to 15 Gy total abdomen fractionated radiation therapy following induction chemotherapy in cats with lymphoblastic lymphoma. Eight cats with lymphoblastic gastrointestinal or multicentric lymphoma confined to the abdominal cavity were treated with a 6-week combination chemotherapy protocol followed 2 weeks later by whole-abdomen radiation therapy consisting of 10 daily fractions of 1.5 Gy. Treatment was well tolerated; renal insufficiency documented in one cat at the start of radiation therapy progressed to stable chronic renal failure. One cat not in complete remission at the time of radiation therapy relapsed 2 weeks later, one cat with multicentric lymphoma relapsed with hepatic large granular lymphoma, and one cat was euthanatized 3 weeks following completion of radiation therapy for other reasons; no evidence of lymphoma or radiation toxicoses was identified on post mortem evaluation. The remaining five cats remain in remission at least 266 days after starting therapy; median remission duration has not been reached (range, > 266 to > 1332 days). Results of this study suggest that 15 Gy total abdomen fractionated radiation therapy after induction chemotherapy is tolerated satisfactorily. This protocol is suitable for further testing to quantify efficacy.

Phase II study evaluating consolidation whole abdominal intensity-modulated radiotherapy (IMRT) in patients with advanced ovarian cancer stage FIGO III--the OVAR-IMRT-02 Study

BACKGROUND

The prognosis for patients with advanced FIGO stage III epithelial ovarian cancer remains poor despite the aggressive standard treatment, consisting of maximal cytoreductive surgery and platinum-based chemotherapy. The median time to recurrence is less than 2 years, with a 5-years survival rate of -20-25%. Recurrences of the disease occur mostly intraperitoneally.Ovarian cancer is a radiosensitive tumor, so that the use of whole abdominal radiotherapy (WAR) as a consolidation therapy would appear to be a logical strategy. WAR used to be the standard treatment after surgery before the chemotherapy era; however, it has been almost totally excluded from the treatment of ovarian cancer during the past decade because of its high toxicity. Modern intensity-modulated radiation therapy (IMRT) has the potential of sparing organs at risk like kidneys, liver, and bone marrow while still adequately covering the peritoneal cavity with a homogenous dose.Our previous phase I study showed for the first time the clinical feasibility of intensity-modulated WAR and pointed out promising results concerning treatment tolerance. The current phase-II study succeeds to the phase-I study to further evaluate the toxicity of this new treatment.

METHODS/DESIGN

The OVAR-IMRT-02 study is a single-center one arm phase-II trial. Thirty seven patients with optimally debulked ovarian cancer stage FIGO III having a complete remission after chemotherapy will be treated with intensity-modulated WAR as a consolidation therapy.A total dose of 30 Gy in 20 fractions of 1.5 Gy will be applied to the entire peritoneal cavity including the liver surface and the pelvic and para-aortic node regions. Organ at risk are kidneys, liver (except the 1 cm-outer border), heart, vertebral bodies and pelvic bones.Primary endpoint is tolerability; secondary objectives are toxicity, quality of life, progression-free and overall survival.

DISCUSSION

Intensity-modulated WAR provides a new promising option in the consolidation treatment of ovarian carcinoma in patients with a complete pathologic remission after adjuvant chemotherapy. Further consequent studies will be needed to enable firm conclusions regarding the value of consolidation radiotherapy within the multimodal treatment of advanced ovarian cancer.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01180504.

Whole-abdominal IMRT for advanced ovarian carcinoma: planning issues and feasibility

INTRODUCTION

Despite enormous efforts to improve therapeutic strategies for patients with advanced ovarian carcinoma, outcome remains poor even with the advent cisplatinum-based chemotherapy regimen or taxanes with over 70% of patients developing local failure. Several trials were able to establish the potential benefit of adjuvant whole abdominal RT (WAI) though at the cost of sometimes marked side-effects. New technologies like IMRT have the potential of sparing normal tissues thus also potentially limiting treatment-related toxicity, hence a phase I trial was initiated to evaluate potential clinical benefit of WAI with IMRT. We intended to demonstrate that whole-abdominal IMRT is feasible and can be used in a routine clinical setting.

METHODS

A water-equivalent phantom containing OARs was created simulating organ shape of the upper abdomen to investigate the necessary number of beams for the upper abdominal target irrespective of the number of segments and hence treatment times. We prescribed a total dose of 30 Gy in 1.5 Gy fractions to the median of the target. IMRT treatment plans for three patients with advanced ovarian cancer were created using 2 isocentres and between 12 and 14 beams while restricting the number of segments so as to restrict treatment times to less than 45 min. Dose to OARs such as kidneys and liver was strictly limited even below established maxima.

RESULTS

In the phantom plans, no clear indication as to the optimum number of beams could be shown though there seems to be a slight trend toward a higher number of beams yielding better results. Examples demonstrating clinically inacceptable dose distributions for plans using only 9 beams. Acceptable treatment plans for real patients could be achieved using 12-14 beams and 2 isocentres. Treatment plans consisted of 264-286 segments resulting in an overall treatment time of approximately 37-45 min. Mean doses to the kidneys could be limited to 29.3% [23.1-33.2%] (right), and 26.8% [21-30.4%] (left). 50% of the liver received less than 72.4% [61-83%].

CONCLUSION

IMRT for whole abdominal irradiation in patients with advanced ovarian carcinoma is applicable and feasible though treatment planning is complex and time-consuming. There is a significant reduction of dose to critical organs by using IMRT while maintaining target volume coverage.

Whole abdomen radiation therapy in ovarian cancers: a comparison between fixed beam and volumetric arc based intensity modulation

Purpose

A study was performed to assess dosimetric characteristics of volumetric modulated arcs (RapidArc, RA) and fixed field intensity modulated therapy (IMRT) for Whole Abdomen Radiotherapy (WAR) after ovarian cancer.

Methods and Materials

Plans for IMRT and RA were optimised for 5 patients prescribing 25 Gy to the whole abdomen (PTV_WAR) and 45 Gy to the pelvis and pelvic nodes (PTV_Pelvis) with Simultaneous Integrated Boost (SIB) technique. Plans were investigated for 6 MV (RA6, IMRT6) and 15 MV (RA15, IMRT15) photons. Objectives were: for both PTVs V_90% > 95%, for PTV_Pelvis: D_max < 105%; for organs at risk, maximal sparing was required. The MU and delivery time measured treatment efficiency. Pre-treatment Quality assurance was scored with Gamma Agreement Index (GAI) with 3% and 3 mm thresholds.

Results

IMRT and RapidArc resulted comparable for target coverage. For PTV_WAR, V_90% was 99.8 ± 0.2% and 93.4 ± 7.3% for IMRT6 and IMRT15, and 98.4 ± 1.7 and 98.6 ± 0.9% for RA6 and RA15. Target coverage resulted improved for PTV_Pelvis. Dose homogeneity resulted slightly improved by RA (Uniformity was defined as U_5-95% = D_5%-D_95%/D_mean). U₅-_95% for PTV_WAR was 0.34 ± 0.05 and 0.32 ± 0.06 (IMRT6 and IMRT15), 0.30 ± 0.03 and 0.26 ± 0.04 (RA6 and RA15); for PTV_Pelvis, it resulted equal to 0.1 for all techniques. For organs at risk, small differences were observed between the techniques. MU resulted 3130 ± 221 (IMRT6), 2841 ± 318 (IMRT15), 538 ± 29 (RA6), 635 ± 139 (RA15); the average measured treatment time was 18.0 ± 0.8 and 17.4 ± 2.2 minutes (IMRT6 and IMRT15) and 4.8 ± 0.2 (RA6 and RA15). GAI_IMRT6 = 97.3 ± 2.6%, GAI_IMRT15 = 94.4 ± 2.1%, GAI_RA6 = 98.7 ± 1.0% and GAI_RA15 = 95.7 ± 3.7%.

Conclusion

RapidArc showed to be a solution to WAR treatments offering good dosimetric features with significant logistic improvements compared to IMRT.

Whole abdominal radiotherapy in ovarian cancer

OBJECTIVES

The aim of the study was to evaluate the clinical outcome and toxicity after adjuvant whole abdominal radiotherapy (WART) in patients with ovarian cancer.

MATERIAL AND METHODS

Ten patients with optimal cytoreduced ovarian cancer, with a mean age of 58 years (40-70) and stage Ic: 4, stage II: 2, stage III: 4, were treated with WART and adjuvant chemotherapy (9/10). The total radiation dose was 22.5 Gy in the whole abdomen and 42-45 Gy in the pelvis.

RESULTS

The mean follow-up was 8 years. The 5-year actuarial disease-free survival (DFS) was 60%, and the overall survival (OS) was 70%. Four patients had disease recurrence. The sites of recurrence were the abdomen in 2 patients and distant metastases in the other 2 patients (liver and brain metastasis). Gastrointestinal toxicity was as follows: acute 3/10 grades I and II, and late toxicity: 2/10 grades I and II, and only 1 patient developed small bowel obstruction (SBO) that required surgery.

CONCLUSIONS

Whole abdominal radiotherapy after surgery and platinum-based chemotherapy achieves high locoregional disease control with an acceptable risk of acute toxicity.

Non-viral Smad7 gene delivery and attenuation of postoperative peritoneal adhesion in an experimental model

BACKGROUND

Postoperative intra-abdominal adhesion is associated with high morbidity and mortality. Smad7, a protein that occupies a strategic position in fibrogenesis, inhibits the transforming growth factor (TGF) beta/Smad signalling pathway. In this study the therapeutic potential of exogenous Smad7 in preventing fibrogenesis in postoperative intra-abdominal adhesion was investigated.

METHODS

Intra-abdominal adhesion was induced in a rodent model by peritoneal abrasion. Smad7 was delivered into the peritoneal cavity by a non-viral ultrasound-microbubble-mediated naked gene transfection system. The effect of Smad7 transgene on adhesion formation was studied by measuring changes in TGF-beta, fibrogenic factors, alpha-SMA and Smad2/3 activation in the anterior abdominal wall.

RESULTS

Four weeks after surgical abrasion, all rats developed significant peritoneal adhesion with enhanced TGF-beta expression, increased levels of extracellular matrix components and activated myofibroblasts, accompanied by decreased Smad7 expression and increased Smad2/3 activation. In rats treated with the Smad7 transgene, the incidence and severity of peritoneal adhesion were significantly reduced, with biochemical downregulation of fibrogenic factors and inhibition of Smad2/3 activation. Serial quantitation using magnetic resonance imaging revealed a significant reduction in adhesion areas from day 14 onwards.

CONCLUSION

Ultrasound-microbubble-mediated gene transfection provides timely targeted gene delivery for the treatment of postoperative peritoneal adhesions.

Treatment planning of epithelial ovarian cancers using helical tomotherapy

Whole abdomen radiotherapy (WAR) for epithelial ovarian cancer, though effective, has been used sparingly due to inadequate target coverage and poor sparing of organs at risk (OAR) leading to significantly higher toxicities. Newer radiation techniques have shown potential for significant improvement in the therapeutic ratio. The purpose of this study was to evaluate helical tomotherapy (HT) for WAR. The objective parameters were to obtain uniform and adequate target coverage with maximum OAR sparing. HT plans were generated for five patients with field width of 5.0/2.5 cm, modulation factor of 3.5/3.0, and a pitch of 0.3. A dose of 25 Gy in 25 fractions was prescribed to the abdomen with a simultaneous boost of 45 Gy in 25 fractions to the pelvis. Dose‐volume parameters and various indices were analyzed and compared. Mean volume (standard deviation) of abdominal and pelvic PTV (planning target volume) was 6630 ± 450 cm3 and 1235 ± 98 cm3, respectively. Mean length of PTV in cranio‐caudal direction was 41 ± 4 cm. Volume receiving 95% and 107% of the prescription dose (V95% and V107%) was 95.6 ± 2.7% and 2.6 ± 0.5% for abdominal‐PTV, and 95.7±2.4% and 0% for pelvic‐PTV, respectively. Homogeneity and conformity indices were 17.5±1.7,1.2±0.03 for abdominal PTV, and 5.2±0.7,1.1±0.02 for pelvic‐PTV, respectively. Median dose received by the kidneys, liver and bone marrow was 9.6±1.2Gy,17±2.7Gy and 22±1.4Gy, respectively. HT achieves an excellent coverage of WAR target with simultaneous pelvic boost and better organ (kidneys and liver) sparing. HT for WAR has the potential as consolidative therapy; this is being evaluated further in a phase II cohort study in epithelial ovarian cancers.

PACS number: 87.53 Kn, 87.55. D‐, 87.55.dk.

Intensity-modulated whole abdominal radiotherapy after surgery and carboplatin/taxane chemotherapy for advanced ovarian cancer: phase I study

PURPOSE

To assess the feasibility and toxicity of consolidative intensity-modulated whole abdominal radiotherapy (WAR) after surgery and chemotherapy in high-risk patients with advanced ovarian cancer.

METHODS AND MATERIALS

Ten patients with optimally debulked ovarian cancer International Federation of Gynecology and Obstetrics Stage IIIc were treated in a Phase I study with intensity-modulated WAR up to a total dose of 30 Gy in 1.5-Gy fractions as consolidation therapy after adjuvant carboplatin/taxane chemotherapy. Treatment was delivered using intensity-modulated radiotherapy in a step-and-shoot technique (n = 3) or a helical tomotherapy technique (n = 7). The planning target volume included the entire peritoneal cavity and the pelvic and para-aortal node regions. Organs at risk were kidneys, liver, heart, vertebral bodies, and pelvic bones.

RESULTS

Intensity-modulated WAR resulted in an excellent coverage of the planning target volume and an effective sparing of the organs at risk. The treatment was well tolerated, and no severe Grade 4 acute side effects occurred. Common Toxicity Criteria Grade III toxicities were as follows: diarrhea (n = 1), thrombocytopenia (n = 1), and leukopenia (n = 3). Radiotherapy could be completed by all the patients without any toxicity-related interruption. Median follow-up was 23 months, and 4 patients had tumor recurrence (intraperitoneal progression, n = 3; hepatic metastasis, n = 1). Small bowel obstruction caused by adhesions occurred in 3 patients.

CONCLUSIONS

The results of this Phase I study showed for the first time, to our knowledge, the clinical feasibility of intensity-modulated whole abdominal radiotherapy, which could offer a new therapeutic option for consolidation treatment of advanced ovarian carcinoma after adjuvant chemotherapy in selected subgroups of patients. We initiated a Phase II study to further evaluate the toxicity of this intensive multimodal treatment.

Adjuvant whole abdominal intensity modulated radiotherapy (IMRT) for high risk stage FIGO III patients with ovarian cancer (OVAR-IMRT-01) - Pilot trial of a phase I/II study: study protocol

Background

The prognosis for patients with advanced epithelial ovarian cancer remains poor despite aggressive surgical resection and platinum-based chemotherapy. More than 60% of patients will develop recurrent disease, principally intraperitoneal, and die within 5 years. The use of whole abdominal irradiation (WAI) as consolidation therapy would appear to be a logical strategy given its ability to sterilize small tumour volumes. Despite the clinically proven efficacy of whole abdominal irradiation, the use of radiotherapy in ovarian cancer has profoundly decreased mainly due to high treatment-related toxicity. Modern intensity-modulated radiation therapy (IMRT) could allow to spare kidneys, liver, and bone marrow while still adequately covering the peritoneal cavity with a homogenous dose.

Methods/Design

The OVAR-IMRT-01 study is a single center pilot trial of a phase I/II study. Patients with advanced ovarian cancer stage FIGO III (R1 or R2< 1 cm) after surgical resection and platinum-based chemotherapy will be treated with whole abdomen irradiation as consolidation therapy using intensity modulated radiation therapy (IMRT) to a total dose of 30 Gy in 1.5 Gy fractions. A total of 8 patients will be included in this trial. For treatment planning bone marrow, kidneys, liver, spinal cord, vertebral bodies and pelvic bones are defined as organs at risk. The planning target volume includes the entire peritoneal cavity plus pelvic and para-aortic node regions.

Discussion

The primary endpoint of the study is the evaluation of the feasibility of intensity-modulated WAI and the evaluation of the study protocol. Secondary endpoint is evaluation of the toxicity of intensity modulated WAI before continuing with the phase I/II study. The aim is to explore the potential of IMRT as a new method for WAI to decrease the dose to kidneys, liver, bone marrow while covering the peritoneal cavity with a homogenous dose, and to implement whole abdominal intensity-modulated radiotherapy into the adjuvant multimodal treatment concept of advanced ovarian cancer FIGO stage III.

Postoperative whole abdominal radiotherapy in clear cell adenocarcinoma of the ovary

OBJECTIVES

The aim of this study was to clarify the efficacy of postoperative whole abdominal radiotherapy (WAR) for ovarian clear cell adenocarcinoma (OCCA).

METHODS

Between 1996 and 2004, 16 patients with OCCA underwent initial debulking surgery and received postoperative WAR. Indications for WAR were as follows: OCCA, International Federation of Gynaecology and Obstetrics (FIGO) stage Ic-III, no macroscopic residual disease in the upper abdomen and residual disease in the pelvic cavity < or = 2 cm. The planned WAR comprised external beam radiotherapy (EBRT) to the entire abdominal cavity with 22.0-24.0 Gy/22-24 fractions followed by EBRT to the pelvis with 23.4-21.6 Gy/12-13 fractions. Overall survival (OS) and disease-free survival (DFS) were compared with 12 historical control (HC) patients treated with initial debulking surgery followed by platinum-based chemotherapy.

RESULTS

The FIGO stage in the WAR group was stage Ic in 11 patients, stage II in 3, and stage III in 2. Fifteen of the 16 patients (94%) completed the planned WAR. Two patients developed radiation enterocolitis and required bowel surgery. Five-year OS and DFS in the WAR/HC group were 81.8%/33.3% and 81.2%/25.0% (p=0.031 and p=0.006), respectively.

CONCLUSIONS

This study suggests that postoperative WAR may be effective in selected patients with OCCA. Prospective randomized trials should be considered to assess postoperative WAR for OCCA.

Whole-abdomen radiotherapy for non-Hodgkin's lymphoma using twice-daily fractionation

PURPOSE

To report the tolerability and efficacy of twice-daily whole-abdomen irradiation (WAI) for non-Hodgkin's lymphoma (NHL).

METHODS AND MATERIALS

Of 123 patients treated for NHL with WAI, 37% received previous chemotherapy, 28% received WAI as part of comprehensive lymphatic irradiation (CLI), and 32% received WAI for palliation. The median dose to the whole abdomen was 25.0 Gy, followed by a median tumor boost of 9.8 Gy in 58 patients. Fractionation was 1.0 Gy once daily (54%) or 0.8 Gy twice daily (46%). Blood counts were measured weekly.

RESULTS

At a median follow-up of 4.3 years, local control was 72% and overall survival was 55% at 5 years. Median time of WAI was 42 days for once-daily treatment and 32 days for twice-daily treatment. Patients receiving twice-daily WAI did not have a significantly higher rate of acute side effects (e.g., nausea, diarrhea, platelet or red blood cell toxicity). Overall, acute thrombocytopenia was the most frequent side effect of treatment; 24 of 96 patients (25%) with available hematologic data had Grade 3+ toxicity. There was no acute Grade 3 gastrointestinal toxicity and no late small bowel obstruction. Multiple regression indicated that patients with four or less involved sites and disease size < or =6 cm had improved local control and overall survival.

CONCLUSIONS

Twice-daily WAI using 0.8 Gy/fraction does not appear to have any greater toxicity compared with once-daily treatment using 1 Gy/fraction. Small doses per fraction (0.8-1 Gy/fx) are effective, tolerated well in the acute setting, and associated with a low rate of late toxicity.

Consolidative abdominopelvic radiotherapy after surgery and carboplatin/paclitaxel chemotherapy for epithelial ovarian cancer

PURPOSE

To assess the feasibility and morbidity of sequential cytoreductive surgery, carboplatin/paclitaxel chemotherapy, and consolidative abdominopelvic radiotherapy (APRT) in ovarian cancer.

METHODS AND MATERIALS

Between 1998 and 2000, 29 patients with optimally cytoreduced epithelial ovarian cancer were treated with carboplatin (135 mg/m2) and paclitaxel (area under the curve [AUC] of 6) followed by APRT in a prospective protocol. All patients were clinically, radiographically, and biochemically (CA-125) free of disease at the completion of chemotherapy. Abdominopelvic radiotherapy was delivered using 6 MV anterior-posterior photon fields to encompass the peritoneal cavity. Median follow-up was 4 years.

RESULTS

Two patients experienced Radiation Therapy Oncology Group Grade 3 gastrointestinal toxicity during APRT; 6 patients, Grade 3 or 4 neutropenia; and 3 patients, Grade 3 or 4 thrombocytopenia. Overall, 10 patients had Grade 3 or 4 acute toxicity. All of the acute side effects resolved after treatment was completed, and there were no serious consequences such as sepsis or hemorrhage. Abdominopelvic radiotherapy was abandoned prematurely in 3 patients. Late side effects were seen in 5 patients, including 1 small bowel obstruction, 2 symptomatic sacral insufficiency fractures, 1 case of severe dyspareunia, and 1 case of prolonged fatigue. All resolved with supportive management. The 4-year actuarial disease-free survival was 57%, and the overall survival was 92%. Eleven of 12 patients who relapsed received salvage chemotherapy, which was well tolerated.

CONCLUSIONS

Abdominopelvic radiotherapy after optimal surgery and carboplatin/paclitaxel chemotherapy is associated with an acceptable risk of acute and late side effects and does not limit subsequent salvage chemotherapy. Consolidative APRT warrants further investigation as a means of improving the outcome of patients with ovarian cancer.

A comparison of forward and inverse planned conformal, multi segment and intensity modulated radiotherapy for the treatment of prostate and pelvic nodes

BACKGROUND AND PURPOSE

Full inverse planned intensity modulated radiotherapy (IMRT) may be indicated to treat concave targets like prostate and pelvic nodes, because concave dose distributions cannot be generated with conformal radiotherapy (CRT). We investigated whether this concave dose distribution can be produced using simplified forward planned multi segment radiotherapy (MSRT).

PATIENTS AND METHODS

CRT, MSRT and IMRT dose distributions were calculated and compared for five patients treated in our current IMRT prostate and pelvic node dose escalation trial. The same beam arrangement was used for CRT, MSRT and IMRT, increasing the number of segments. The MSRT concave dose distribution was realised regarding left and right pelvic nodes as two separate targets. The IMRT dose distribution had been used to treat the patients using a step and shoot delivery.

RESULTS

Contrary to CRT, forward planned MSRT concave dose distributions had improved target coverage at lower or equivalent bowel doses than inverse planned IMRT. The five MSRT beams had a maximum of three segments per beam. Both lateral beams had two segments to deliver the two dose levels to prostate and nodes. The posterior field needed a third segment to avoid using a central block. The two anterior oblique beams needed a third segment to account for the different beam weighting because the nodes were irradiated partially using four and partially using five beams. Inverse planned IMRT used up to 15 segments in any one beam, with an average of 11.4 per beam.

CONCLUSIONS

Concave dose distributions for prostate and pelvic node treatment were generated using forward planned multi segment techniques. The plans met clinical constraints used in our IMRT protocol. MSRT presented a significant advantage over both CRT and IMRT.

IMRT dose escalation for positive para-aortic lymph nodes in patients with locally advanced cervical cancer while reducing dose to bone marrow and other organs at risk

PURPOSE

To evaluate the feasibility of dose-escalated para-aortic lymph node (PALN) intensity modulated radiation therapy (IMRT) in reducing the dose to bone marrow, bowel, spinal cord, and kidneys, compared with conventional radiation techniques of PALNs in patients with locally advanced cervical cancer and PALN metastases.

METHODS AND MATERIALS

Computed tomography scans and MRI studies of 5 cervical cancer patients with PALN involvement were transferred to an IMRT treatment planning workstation (Eclipse/Helios) for image fusion and definition of target volumes and critical structures. The positive PALNs identified on fused computed tomography-magnetic resonance images were defined as the gross target volume (GTV), and the PALN region was defined as the planning target volume. There were 2 distinct treatment regions: the PALN region superior to the isocenter and the whole-pelvis region inferior to the isocenter. Three treatment planning techniques were compared: AP/PA (both regions), 4-field box (both regions), and PALN-IMRT with 4-field box to the whole-pelvis field. With IMRT, the radiation dose to the GTV was escalated from the conventional 45 Gy to 60 Gy (2.4 Gy/fraction), whereas the planning target volume and whole-pelvis region received 45 Gy. The treatment planning isocenter was placed at the L4-L5 vertebral body interspace, and this allowed the two treatment regions to be abutted using independent jaws.

RESULTS

This study has demonstrated the feasibility of escalating the dose delivered to grossly positive PALNs to 60 Gy (2.4 Gy/fraction) with a 95.6% median GTV coverage, concomitantly with conventional treatment of the whole-pelvis region. PALN-IMRT significantly reduced V(40) bone marrow compared to the AP/PA and 4-field box techniques with a median of 21.3%, 98%, and 49.7%, respectively. The PALN-IMRT and 4-field box techniques showed a reduction in V(45) bowel over the AP/PA technique, but a level of statistical significance was not reached. The spinal cord received a significantly higher maximum dose when PALNs were treated with AP/PA fields. Alternatively, the use of the 4-field box technique yielded a significant increase in V(22) kidney on both sides. The placement of the treatment planning isocenter at the L4-L5 interspace allowed the PALN-IMRT and whole-pelvis regions to be treated with a relatively uniform dose at the abutment region.

CONCLUSION

In this dosimetric analysis, we demonstrated that dose-escalated PALN-IMRT with conventional whole-pelvis radiotherapy is feasible with significant sparing of critical normal structures compared to PALN conventional radiation techniques.

High-dose whole abdominal and pelvic irradiation for treatment of ovarian carcinoma: long-term toxicity and outcomes

PURPOSE

To evaluate the role of high-dose whole abdominal and pelvic irradiation (WART) in the treatment of epithelial ovarian carcinoma.

METHODS AND MATERIALS

A retrospective review was performed on 71 patients with Stage I-III ovarian carcinoma who were treated with WART using an open field technique after total abdominal hysterectomy and bilateral oophorectomy with or without omentectomy. Whole abdominal doses greater than typically recommended were used in a series of patients to enhance local control and to decrease abdominal recurrence. None of the patients had received chemotherapy before RT. Thirty-one patients received Alkeran or cyclophosphamide and two received cisplatin-based chemotherapy after WART. The median whole abdominal dose was 36 Gy (range 9-45.5), delivered in a median of 30 fractions (range 8-46). A pelvic boost was delivered using AP-PA fields during whole abdominal RT to a total midline pelvic dose of 200 cGy/d. The median pelvic dose was 51 Gy (range 16-59). The right lobe and a portion of the left lobe of the liver were shielded with custom blocks at a median dose of 25 Gy (range 9-41). The kidneys were shielded either AP-PA or PA from the first day of RT. The median dose to the kidneys was 19 Gy (range 4-30).

RESULTS

The 5-year overall survival rate was 93%, 48%, and 29% for Stage I, II, and III patients, respectively. On multivariate analysis, stage and the extent of residual disease were independent prognostic factors. The 5- and 10-year overall survival rate for the 46 patients in the intermediate-risk group was 61% and 54%, respectively. For this group, a total abdominal dose of > or /=36 Gy was associated with a longer overall survival independent of stage, grade, and the amount of residual disease. This was most likely due to a significant reduction in the incidence of abdominal recurrence in patients receiving >36 Gy to the whole abdomen (18% vs. 49%, p = 0.006). Multivariate analysis revealed that grade (p = 0.023) and abdominal dose (p = 0.018) were independent factors influencing the rate of abdominal recurrence. Pelvic recurrence was rare as a first site of failure (6%). Twenty-one percent (n = 15) of the patients developed Grade 3 or 4 (Radiation Therapy Oncology Group [RTOG] criteria) chronic small or large bowel toxicity. Eleven percent of all patients had a small bowel obstruction requiring surgery. A whole abdominal dose >30 Gy and a pelvic dose >50 Gy were associated with a significant increase in small bowel obstruction (p = 0.01) independent of other factors. Chronic Grade 3 or 4 (Common Toxicity Criteria) anemia, thrombocytopenia, and leukopenia were seen in 7%, 1%, and 4% of the patients, respectively. Transient liver enzyme elevation was common (62%). Two patients had Grade 3 (RTOG) hepatic toxicity. Grade 3 or 4 renal toxicity (RTOG) was observed in 4%, and 2 patients (3%) were diagnosed with pelvic insufficiency fractures that were managed conservatively.

CONCLUSION

Survival after RT for ovarian carcinoma rivals that achieved with systemic chemotherapy. The results of this study suggest a possible dose-control relationship between the whole abdominal dose and the risk of abdominal recurrence; however, a higher rate of small bowel obstruction was observed when greater abdominal doses and greater pelvic doses were combined. Careful attention to balancing toxicity and efficacy is imperative if RT is to have a future role in the treatment of this disease.

The relationship between belly board position and patient anatomy and its influence on dose-volume histogram of small bowel for postoperative radiotherapy of rectal cancer

The influence of three different belly board (BB) positions in radiotherapy of rectal cancer on the dose-volume histogram of the small bowel (SB) were analysed for 20 patients. Placing the lower border of the BB opening near the lumbosacral junction, both the volume of SB within the pelvis and the volume of SB within all tested dose levels were lower compared to its position near the symphysis or the lumbosacral junction.

IMRT of large fields: whole-abdomen irradiation

PURPOSE

To assess the feasibility of inverse planning for whole-abdomen intensity-modulated radiation therapy (IMRT) with bone marrow and kidney sparing and to develop approaches to circumventing field size restrictions in the application of whole-abdomen IMRT using dynamic multileaf collimators (DMLC).

METHODS AND MATERIALS

The entire peritoneal cavity as derived from serial computerized tomography scans was defined as the gross target volume, whereas the planning target volume (PTV) was defined as the gross target volume plus a 5-mm margin extending 1 cm superiorly and inferiorly. In 10 randomly selected patients, the PTV ranged from 5629 to 12578 cc (median 7935 cc), and the superior-inferior, lateral, and anterior-posterior dimensions of the PTV ranged from 37 to 46 cm (median 42.5 cm), 27 to 33 cm (median 29 cm), and 18 to 23 cm (median 20 cm), respectively. A single isocenter was defined for patients with field length <40 cm. For patients with fields >40 cm, two isocenters were defined: one in the abdominal region, and the other in the pelvis. For IMRT planning, five 15-MV intensity-modulated beams at gantry angles of 180 degrees, 105 degrees, 35 degrees, 325 degrees, and 255 degrees were used. Optimization was designed to spare kidneys and bones. To fully account for the significant scattered dose contributions, an iterative process for dose calculations was implemented in the optimization. To overcome the 15-cm field width limit of our DMLC delivery system, fields with a width >15 cm were split into two or more subfields. To minimize field match errors, adjacent subfields overlapped by at least 2 cm, with intensity "feathering" in the overlap region. For patients with two isocenters, fields were overlapped and feathered in the cephalad-caudad direction by at least 3 cm. For comparison, conventional anterior-posterior/posterior-anterior 6-MV photon beams with posterior kidney blocks at extended distance were also generated for each patient.

RESULTS

Treatment plan optimization calculations required 20-80 min on a 500-MHz DEC alpha workstation. Including beam splitting, an average of 16 DMLC beams was used per patient. Delivery of 150 cGy required, on average, 1442 monitor units. For the same dose constraints on the kidneys, whole-abdomen IMRT resulted in significant dose reduction to the bones and improved PTV coverage as compared to conventional treatment. For a prescription dose of 30 Gy, the volume of the pelvic bones receiving more than 21 Gy was reduced on average by almost 60% with IMRT, and the mean dose to all bones was reduced from 24.0 +/- 1.5 Gy to 18.5 +/- 1.0 Gy (p = 0.002). PTV coverage, as measured by V95 (the volume receiving 95% of the prescription dose), improved from 71.7 +/- 4.8% with conventional treatment to 83.5 +/- 3.9% with IMRT (p = 0.002), although small regions of underdose in areas near the kidneys could not be avoided completely. The high-dose regions within the PTV, as measured by D05 (the dose covering 5% of PTV volume), increased slightly from 31.2 +/- 0.6 Gy with conventional treatment to 32.8 +/- 0.2 Gy with IMRT.

CONCLUSION

We have developed a process to plan and deliver whole-abdomen IMRT using standard linear accelerators and DMLC. IMRT can achieve better PTV coverage with the same level of kidney sparing and improved sparing of the bone marrow. These methods may be applicable also to other sites requiring large-field irradiation.

IMRT clinical implementation: prostate and pelvic node irradiation using Helios and a 120-leaf multileaf collimator

Dynamic intensity modulated radiation therapy (IMRT) to treat prostate and pelvic nodes using the Varian 120-leaf Millennium multileaf collimator (MLC) has been implemented in our clinic. This paper describes the procedures that have been undertaken to achieve this, including some of the commissioning aspects of Helios, verification of the dynamic dose delivery, and quality assurance (QA) of the dose delivered to the patient. Commissioning of Helios included measurements of transmission through the 120-leaf MLC, which were found to be 1.7% for 6 mV and 1.8% for 10 MV. The rounded leaf edge effect, known as the dosimetric separation, was also determined using two independent methods. Values of 1.05 and 1.65 mm were obtained for 6 and 10 MV beams. Five test patients were planned for prostate and pelvic node irradiation to 70 and 50 Gy, respectively. Dose and fluence verification were carried out on specially designed phantoms and dose points in the prostate were measured to be within 2.0% (mean 0.9%, s.d. 0.6%) of the calculated dose and in the nodes within 3.0% (mean 1.6%, s.d. 1.1%). Following the results of this commissioning and implementation study, we have started to treat men with a target Volume including the prostate and pelvic nodes using Helios optimized dynamic IMRT delivery in a dose escalation protocol.

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.

[Results of a randomized prospective trial comparing postoperative abdominopelvic radiotherapy with postoperative chemotherapy in early ovarian cancer]

PURPOSE

In a prospective randomized trial, our aim was to evaluate and compare the tolerance and efficacy of postoperative radiotherapy and chemotherapy in the treatment of early ovarian cancer.

MATERIAL AND METHODS

Between 1990 and 1996, 150 patients with ovarian cancer stage IA, IB grades G2-3, and all patients classified IC and IIA, who did not have evidence of residual disease after surgery, were randomized to two treatment branches: radiotherapy or chemotherapy (CH). In the radiotherapy branch (76 patients), a whole abdomen irradiation of 30 Gy in 24 fractions over 5 weeks, with a pelvic boost to 50 Gy, was delivered. In the chemotherapy branch (74 patients), there were six series of polychemotherapy separated with 3-weeks interval. In each series patients received association of cisplatin (50 mg/m2, d1), adriamycin (50 mg/m2, d1) and cyclophosphamide (500 mg/m2, d1).

RESULTS

The tolerance of the treatment was good and comparable in both groups. In the radiotherapy branch, three late grade G3 intestinal complications were observed (three bowel obstructions, which required surgery in two cases). The actuarial survival rate without evidence of disease was 81% at 5 years for both groups. In our series we found that histological grade had the strongest influence on survival prognosis; it was the only significant factor in a multivariate analysis. Patients with grade G3 tumors had the worst survival.

CONCLUSION

These data suggest that efficacy of postoperative radiotherapy and chemotherapy administered to our patients with early ovarian cancer gave approximately identical results.

Dexamethasone for the prophylaxis of radiation-induced emesis: a National Cancer Institute of Canada Clinical Trials Group phase III study

PURPOSE

To investigate the efficacy of dexamethasone as a prophylactic antiemetic for patients receiving fractionated radiotherapy to the upper abdomen in a randomized controlled trial.

PATIENTS AND METHODS

One hundred fifty-four patients planned to receive fractionated radiotherapy to fields involving the upper abdomen (minimum total dose, 20 Gy; minimum number of fractions, five) were randomized to receive prophylactic dexamethasone (2 mg orally three times a day [tid], starting in the morning of first treatment and continuing until after their fifth treatment) or placebo. The primary end point of the study was the proportion of patients free from emesis during the study period. Secondary end points included a quality-of-life assessment using the core questionnaire of the European Organization for Research and Treatment of Cancer and side effects of dexamethasone therapy in this population of patients.

RESULTS

Fifty-four (70%) out of 75 patients receiving dexamethasone had complete protection versus 37 (49%) out of 75 patients on placebo (P = .025). Most emetic episodes occurred during the initial phase of treatment. Although there was no difference in global quality of life between the two sets of patients, patients receiving dexamethasone had less nausea and vomiting and less loss of appetite but more insomnia.

CONCLUSION

Dexamethasone 2 mg tid seems to be an effective prophylactic antiemetic in this situation. Side effects were acceptable, but there seemed to be no overall effect on global quality of life.

Integrating radiation therapy in the curative management of ovarian cancer: current issues and future directions

Although important advances in surgery, chemotherapy (CT), and radiation therapy (RT) have been made, overall survival for patients with ovarian cancer (OC) has not changed significantly. Despite its long history in the treatment of OC and its proven curative role in patients with microscopic or minimal residual disease, the proper role of RT in the management of OC is not clearly established. Although the use of primary adjuvant RT (whole abdominal irradiation) has declined in the last 15 years, there has been a resurgence of interest in RT as part of a combined modality approach and as salvage therapy for patients with small-volume persistent disease after primary cytoreductive surgery and platinum-based CT. This article reviews the evidence supporting the use of RT alone or combined with chemotherapy as primary adjuvant therapy or in the salvage setting. Current issues in the radiotherapeutic management are discussed along with ideas for future clinical research directions.

Whole abdominal radiotherapy following second-look laparotomy for ovarian carcinoma

AIM

The safety and efficacy of whole abdominal radiotherapy was evaluated as salvage or consolidation treatment for ovarian cancer patients treated with primary surgery and chemotherapy, followed by second-look laparotomy (SLL). Overall survival and acute and late toxicity of treated patients were assessed.

METHODS

Patients were recruited between April 1981 and June 1994. All patients had SLL performed at Royal Prince Alfred Hospital after completion of primary chemotherapy. Data collected included demographic details, diagnosis, tumor stage, histology, grade, adjuvant chemotherapy, and radiotherapy. Radiation dose and fractionation, field size, boost volume and dose, failure to complete treatment and treatment interruptions, renal dose, and acute and late toxicity were recorded.

RESULTS

Fifty-one patients were evaluated; the median age was 51 years. Median follow-up for patients still alive was 62 months. Prior to 1988, chemotherapy comprised oral chlorambucil, with or without cisplatin (n = 25), while after this date all patients (n = 26) received primary cisplatin-based therapy. A radiation dose of 22. 5 Gy over 22 fractions was planned to the whole abdomen followed by a pelvic boost of 22 Gy in 11 fractions. Radiotherapy was completed in 37 (73%) patients. Treatment interruptions were necessary in 12 (24%) patients. Thrombocytopenia, neutropenia, nausea, vomiting, and diarrhea were the main causes of incomplete or interrupted treatment. Late bowel toxicity was seen in 6 (12%) patients, 2 of whom required laparotomy to relieve obstruction. There were no treatment-related deaths. Seven of the 51 patients are alive and free of disease, 2 died from other causes, and 2 are alive with evidence of recurrent or progressive disease. Mean follow-up time for surviving patients is 78.5 months. Overall survival at 2, 5, and 10 years was 65, 27, and 10%, respectively. Residual disease after primary surgery, smaller preirradiation tumor residuum, and completion of radiotherapy were independently associated with improved overall survival.

CONCLUSION

In this poor-prognosis group of patients, a combined approach of surgery, chemotherapy, and radiotherapy, while associated with acceptable toxicity, may not afford a prolongation of survival.

Treatment of early epithelial ovarian cancer with chemotherapy and abdominopelvic radiotherapy: results of a prospective treatment protocol

PURPOSE

To test the hypothesis that the combination of adjuvant chemotherapy and abdominopelvic radiation (APRT) improves the outcome of patients with early ovarian cancer compared to treatment with APRT alone.

METHODS AND MATERIALS

Between 1991 and 1994, 93 patients with Stage I to III, optimally cytoreduced, invasive, epithelial ovarian cancer were treated with sequential chemotherapy and APRT. Treatment was assigned using a prognostic classification that was derived from previous cohorts of patients. Low-risk patients (n = 9) received APRT alone, intermediate-risk patients (n = 66) received two courses of cisplatin followed by APRT, and high-risk patients (n = 18) received 6 courses of cisplatin and cyclophosphamide followed by APRT.

RESULTS

Disease recurred in 22 patients, and was confined to the pelvis or abdomen in 15. Nine patients died and the remainder were alive with disease after receiving salvage chemotherapy. The 3-year disease-free and overall survivals were 78% and 91%, respectively. The prognostic classification used to assign treatment was the only factor that predicted disease-free survival (83% and 59% at 3 years for low/intermediate- and high-risk patients, respectively; p = 0.03). There was no detectable difference in outcome between the present series and an historical control group treated with APRT alone. Treatment was well tolerated and only 2 patients (2.5%) developed serious complications.

CONCLUSION

APRT is an effective adjuvant treatment for carefully selected patients with early ovarian cancer. The addition of chemotherapy as used in this study to APRT does not significantly improve outcome compared to APRT alone.

[D-xylose test of resorption as a method to determine radiation side effects in the small intestine]

BACKGROUND

The D-xylose test is the most important method to determine a disorder of carbohydrates resorption in proximal small intestine. The application is based on an impaired resorption due to pathological change of small intestine surface, leading to a decreased blood level or decreased excretion in urine.

PATIENTS AND METHOD

D-xylose test was applied in 91 patients before, shortly after, 1/2 and 1 year after radiotherapy. All patients received an abdominal radiotherapy. We determined the blood level of D-xylose by a capillary blood sample 1 hour after oral D-xylose administration.

RESULTS

A significant decrease of the mean blood level of D-xylose to 1.88 mmol/l was determined after radiotherapy in comparison with 2.17 mmol/l before radiotherapy. Half a year after radiotherapy the mean blood level of D-xylose returned to normal. Regarding a threshold value of D-xylose blood level of 1.70 mmol/l 29 patients (32%) showed a pathologically decreased D-xylose resorption after radiotherapy. Twenty out of the 29 patients already showed a normal resorption half a year after the determination of the resorption disorder, 5 patients after 1 year and 4 patients after 1 1/2 years. There was no correlation between the detection of a disorder of D-xylose resorption and of a loss of body weight. The acute clinical side effects seemed to be more marked in connection with a disorder of D-xylose resorption, but this correlation is not significant. Eleven or 14 of the 29 patients, respectively, with pathologically decreased D-xylose resorption only had complaints of lower or upper gastrointestinal tract, respectively, and 10 patients did not have abdominal complaints at all.

CONCLUSIONS

The D-xylose test is an important and simple method for determination of radiogen induced carbohydrate malabsorption in proximal small intestine. By means of it radiation side effects on small intestine can also be determined in patients who are otherwise free of complaints.

Effect of filgrastim (G-CSF) during chemotherapy and abdomino-pelvic radiation therapy in patients with ovarian carcinoma

PURPOSE

To evaluate the safety and effectiveness of filgrastim (granulocyte colony-stimulating factor, G-CSF) in reducing neutropenia and treatment interruptions during whole abdominal radiotherapy for ovarian cancer.

METHODS AND MATERIALS

Sixteen patients with ovarian cancer treated with 2 to 6 courses of cisplatin-containing chemotherapy and abdomino-pelvic radiation therapy received filgrastim for neutrophil counts <2 x 10(9)/L. Endpoints for analysis included the ability to maintain the neutrophil count in the target range, number of treatment interruptions due to neutropenia, and toxicity attributed to filgrastim.

RESULTS

Fourteen patients received a mean of 2.9 courses of filgrastim (each with a mean duration of 4.1 days), with no treatment interruptions due to neutropenia. The majority of neutrophil counts were maintained above the target range of 2 x 10(9)/L during treatment. Thrombocytopenia requiring treatment interruption was seen in six patients and necessitated platelet transfusions in one. Thrombocytopenia occurred at a mean abdominal radiation dose of 2207 cGy and in all but one patient was preceded by one or more episodes of neutropenia. In comparison with a control group of 31 patients treated without filgrastim there was no reduction in treatment interruptions. Four patients did not complete treatment because of persistent thrombocytopenia yet received a mean of 94% of the planned abdominal radiation dose and 69% of the planned pelvic dose. Filgrastim toxicity was limited to mild skeletal pains in six patients and a Grade 1 skin rash in two patients.

CONCLUSIONS

Filgrastim is safe and effective in preventing neutropenia and reducing neutropenic treatment interruptions during abdominal radiotherapy in patients with ovarian cancer. However, there was no clear benefit to the use of filgrastim as thrombocytopenia became the dose-limiting toxicity resulting in a risk of treatment interruptions and early termination of radiotherapy.

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.

WART revisited: the treatment of epithelial ovarian cancer by whole abdominal radiotherapy

The present study investigated outcomes for 78 women with epithelial ovarian carcinoma treated by whole abdominal radiotherapy (WART) after cyto-reductive surgery at Westmead Hospital between 1980 and 1993. These patients had 5-year relapse-free and overall survival rates of 52 and 55%, respectively. The median follow-up was 7.5 years. Fifty-eight of the 78 women fulfilled the criteria as defined by the Princess Margaret Hospital's intermediate risk' category. These patients had both a relapse-free and overall survival rate of 62% at 5 years (P = 0.001 as compared with the remaining 20 women). Mild gastrointestinal upset was common during radiotherapy. Five women did not complete treatment. Late toxicity (grade 3 or more, using the Radiotherapy Oncology Group (RTOG) system) occurred in eight women, and five women required surgery for intestinal complications (6.4%). There were no deaths due to late side effects. In conclusion the results are consistent with those of other series in the treatment of epithelial ovarian cancer by adjuvant WART. When compared to a similar-stage disease treated with cisplatin-based chemotherapy, there is no evidence to support the exclusive use of chemotherapy.

Late renal function following whole abdominal irradiation

Sixty patients treated with whole abdominal radiotherapy who had remained disease-free since completion of treatment participated in a study to assess the late clinical and biochemical effects of bilateral renal irradiation. Minimum follow-up was 5 years with a maximum of 20 years and a median of 9 years. Fifty-two patients in the study group were treated for primary ovarian cancer. Seven had non-Hodgkins lymphoma arising in the gastrointestinal tract and one patient had a carcinoid tumour arising in small bowel. None of the patients received chemotherapy. Abdominal radiation was given using an open beam technique to a mean dose of 22.92 Gy (range 6.68-27.54 Gy) in 1.02 to 1.25 Gy fractions treated once daily. Posterior kidney shields were used in order to limit the renal dose to < 20 Gy. Mean radiation dose to both kidneys (retrospectively calculated) was 19.28 Gy (range 6.68-22.99 Gy). Patients ranged in age from 32-81 years with a median of 61 years. No patient had clinical evidence of renal impairment. Nine patients were hypertensive prior to radiotherapy and a further five patients became hypertensive after treatment. Serum creatinine values ranged from 44-123 mumol/l, with a mean of 87 mumol/l. Creatinine clearance ranged from 0.61-2.38 ml/s (mean 1.28 ml/s). Tubular function tests revealed one borderline high 24-h protein excretion and normal 24-h phosphorous and uric acid. Using a multiple linear regression analysis with creatinine clearance as the endpoint, age was the only significant variable (P < 0.00001) and renal dose and interval from treatment were not independently significant. There was no evidence of late renal toxicity more than 5 years after whole abdominal radiotherapy delivered with this technique and dose/fractionation schedule, and using the clinical and biochemical endpoints assessed in this study.

Ovarian cancer

This synthesis of the literature on radiotherapy for cancer originating in the ovaries is based on 74 scientific articles, including 12 randomized studies, 18 prospective studies, and 36 retrospective studies. These studies involve 6,140 patients. Treatment for patients at early stages of ovarian cancer (stages I and II) is surgery. The value of adjuvant treatment, ie, chemotherapy or radiotherapy, is not demonstrated. Tumor volume is decisive to the success of radiotherapy. Microscopic or small macroscopic cancer residuals, remaining after surgery, may respond to radiotherapy, thereby promoting survival. The importance of radiotherapy for advanced ovarian cancer is controversial, and studies frequently show contradictory results. Two studies have shown the favorable role played by radiotherapy in consolidation treatment of patients if they become cancer-free at advanced stages. The role of radiotherapy in treating larger volumes of residual cancer has not been demonstrated, except for strictly palliative treatment.

Abdomino pelvic irradiation after second-look laparotomy for stage III ovarian carcinoma

OBJECTIVE

The purpose of this retrospective analysis of 34 patients with stage III ovarian carcinoma was to review results and morbidity of whole abdominal irradiation after surgery and chemotherapy.

METHODS AND MATERIALS

All of the 34 patients had reached a complete clinical remission after first cytoreductive surgery and chemotherapy. After second-look laparotomy each patient underwent whole abdominal irradiation. Except for two patients with chronic myelosuppression, the dose administered was of 22.5 Gy to the abdominal cavity with a boost of 22.5 Gy added to the pelvis.

RESULTS

Three and 5-year overall survival rates were 62% and 43%, respectively. Three and 5-year disease-free survival rates were 53% and 38%. Twenty-three patients (68%) developed local relapse or local disease progression. Metastasis occurred in five cases and were always associated with an abdominal cavity recurrence. Residual disease after first cytoreductive surgery appeared as a prognostic factor in univariate analysis. Patients with unresected residuum had a 5-year survival probability of 35% versus 83% for patients without residual disease. We observed 12% grade-3 intestinal toxicities and one fatal case of radiation enteritis.

CONCLUSION

Despite its curative potential, the long term benefit of whole abdominal irradiation in the multimodality treatment of advanced ovarian carcinoma must be evaluated in well designed controlled trials.