Reirradiation for rectal cancer and surgical resection after ultra high doses

Proton beam reirradiation for locally recurrent rectal cancer patients with prior pelvic irradiation

The aim of the present study was to report the feasibility of proton beam reirradiation for patients with locally recurrent rectal cancer (LRRC) with prior pelvic irradiation. The study population included patients who were treated with proton beam therapy (PBT) for LRRC between 2008 and December 2019 in our institution. Those who had a history of distant metastases of LRRC, with or without treatment, before reirradiation, were excluded. Overall survival (OS), progression-free survival (PFS) and local control (LC) were estimated using the Kaplan-Meier method. Ten patients were included in the present study. The median follow-up period was 28.7 months, and the median total dose of prior radiotherapy (RT) was 50 Gy (range, 30 Gy-74.8 Gy). The median time from prior RT to reirradiation was 31.5 months (range, 8.1-96.6 months), and the median reirradiation dose was 72 Gy (relative biological effectiveness) (range, 56-77 Gy). The 1-year/2-year OS, PFS and LC rates were 100%/60.0%, 20.0%/10.0% and 70.0%/58.3%, respectively, with a median survival time of 26.0 months. Seven patients developed a Grade 1 acute radiation dermatitis, and no Grade ≥ 2 acute toxicity was recorded. Grade ≥ 3 late toxicity was recorded in only one patient, who had developed a colostomy due to radiation-related intestinal bleeding. Reirradiation using PBT for LRRC patients who had previously undergone pelvic irradiation was feasible. However, the indications for PBT reirradiation for LRRC patients need to be considered carefully due to the risk of severe late GI toxicity.

Reirradiation for Rectal Cancer Using Pencil Beam Scanning Proton Therapy: A Single Institutional Experience

Purpose

Reirradiation for rectal cancer (RC) after prior pelvic radiation therapy (RT) has been shown to be safe and effective. However, limited data exist for proton therapy (PT), including pencil beam scanning proton therapy (PBS-PT). We hypothesize that PT is safe and feasible for re-treatment and may allow for decreased toxicity and treatment escalation.

Methods and materials

A single-institution, retrospective, institutional review board–approved analysis of all patients with RC and prior pelvic RT receiving PBS-PT reirradiation was performed. Data on patient and treatment characteristics and outcomes were collected. Local progression, progression-free survival, overall survival, and late grade >3 toxicity were estimated using the Kaplan-Meier method.

Results

Twenty-eight patients (median follow-up: 28.6 months) received PBS-PT reirradiation between 2016 and 2019, including 18 patients with recurrent RC (median prior dose: 54.0 Gy) and 10 patients with de novo RC and variable prior RT. The median reirradiation dose was 44.4 Gy (range, 16.0-60.0 Gy; 21 of 28 twice daily), and 24 of 28 patients received concurrent chemotherapy. Six underwent surgical resection. Three (10.7%) experienced grade 3 acute toxicities, and 1 did not complete RT owing to toxicity. Four (14.2%) had late grade <3 toxicity, including 1 grade 5 toxicity in a patient with a prior RT-related injury. The 1-year local progression, progression-free survival, and overall survival rates were 33.7% (95% confidence interval [CI], 14.5%-52.9%), 45.0% (95% CI, 26.2%-63.8%), and 81.8% (95% CI, 67.3%-96.3%), respectively.

Conclusions

This is the largest series using PT for reirradiation for RC and the first study using PBS-PT. Low acute toxicity rates and acceptable late toxicity support PBS-PT as an option for this high-risk patient population, with a need for continued follow-up.

Definitive hyperfractionated, accelerated proton reirradiation for patients with pelvic malignancies

Introduction

Pelvic reirradiation (re-RT) presents challenges due to concerns for late toxicity to tissues-at-risk including pelvic bone marrow (PBM). We routinely utilize a hyperfractionated, accelerated re-RT for recurrent rectal or anal cancer in the setting of prior radiation. We hypothesized that proton beam radiation (PBR) is uniquely suited to limit doses to pelvic non-target tissues better than photon-based approaches.

Materials and methods

All patients who received hyperfractionated, accelerated PBR re-RT to the pelvis from 2007 to 2017 were identified. Re-RT was delivered twice daily with a 6 h minimum interfraction interval at 1.5 Gray Relative Biological Effectiveness (Gy(RBE)) per fraction to a total dose of 39-45 Gy(RBE). Concurrent chemotherapy was given to all patients. Comparison photon plans were generated for dosimetric analysis. Dosimetric parameters compared using a matched-pair analysis and the Wilcoxon signed-rank test. Survival analysis was performed Kaplan Meier curves.

Results

Fifteen patients were identified, with a median prior pelvic RT dose of 50.4 Gy (range 25-80 Gy). Median time between the initial RT and PBRT re-RT was 4.7 years (range 1.0-36.1 years). In comparison to corresponding photon re-RT plans, PBR re-RT plans had lower mean PBM dose, and lower volume of PBM getting 5 Gy, 10 Gy, 20 Gy, and 30 Gy (p < 0.001, p < 0.001, p < 0.001, and p = 0.033, respectively).With median 13.9 months follow-up after PBR re-RT, five patients had developed local recurrences, and four patients had developed distant metastases. One-year overall survival following PBR re-RT was 67.5% and one-year progression free survival was 58.7%. No patients developed acute or late Grade 4 toxicity.

Conclusion

PBR re-RT affords improved sparing of PBM compared with photon-based re-RT. Clinically, PBR re-RT is well-tolerated. However, given modest control rates with definitive re-RT without subsequent surgical resection, a multidisciplinary approach should be favored in this setting when feasible.

Treatment Outcomes of Re-irradiation in Locoregionally Recurrent Rectal Cancer and Clinical Significance of Proper Patient Selection

Background and Purpose: Majority of patients with locoregionally recurrent rectal cancer will require re-irradation (reRT). This study aimed to analyze the treatment outcomes, particularly infield progression, and severe late toxicity rates after reRT for recurrent rectal cancer and further identify a subgroup of patients who may optimally benefit from reRT.

Materials and Methods: Patients with rectal cancer who underwent reRT to the pelvis between January 2000 and December 2017 were included for analysis.

Results: The records of 41 patients were retrospectively reviewed. The median follow-up period after reRT was 53.7 months (range 3.5–130.3 months). The 2-year infield progression-free rate (IPFR) was 49.4%. The 2-year overall survival (OS) and progression-free survival (PFS) rates were 55.3 and 28.5%, respectively. Severe late toxicity events occurred in 17 patients, and the median time from reRT to severe late toxicity event was 10.5 months (range 2.3–33.3 months). The 2-year severe late toxicity free-rate (SLTFR) was 55.5%, and the median SLTFR was 33.3 months. Patients who did not experience severe late toxicity events showed a significantly higher number of recurred tumors at the posterior or lateral location compared to axial or anterior location. The selected subgroup with recurrent tumor size <3.3 cm and treated with total reRT dose of >50 Gy_ab10 (n = 13) showed superior IPFR, OS, and PFS to the other patients.

Conclusion: ReRT was a reasonable treatment option for patients with locoregionally recurrent rectal cancer. However, severe late toxicity rates were substantially high. Thus, patients indicated for ReRT with curative dose should be selected properly according to tumor size and location.

Practical effectiveness of re-irradiation with or without surgery for locoregional recurrence of rectal cancer: A meta-analysis and systematic review

BACKGROUND AND PURPOSE

Re-irradiation might yield local control (LC) or palliation for locoregionally recurrent rectal cancer (LRRC), but iatrogenic complications are a possible hindrance. We aimed to evaluate the efficacy of re-irradiation to determine optimal treatment of LRRC.

METHODS

We performed a systematic review of PubMed, MEDLINE, Cochrane Library, and Embase.

RESULTS

A total of 17 studies involving 744 patients with LRRC were included; median OS ranging from 10 to 45 months (median: 24.5 months). Pooled 1-, 2-, and 3-year OS rates for all patients were 76.1%, 49.1%, and 38.3%, respectively. For patients who underwent re-irradiation and surgery (OP group), these pooled rates were 85.9%, 71.8%, and 51.7%, respectively. For patients who underwent re-irradiation but not surgery (non-OP group), pooled 1-, 2-, and 3-year OS rates were 63.5%, 34.2%, and 23.8%, respectively. The OS difference between both groups was significant for all 3 years (P < 0.05). Pooled 1-, 2-, and 3-year LC rates for the OP group were 84.4%, 63.8%, and 46.9%, and for the non-OP group were 72.0%, 54.8%, and 44.6%, respectively, without significant differences. Pooled grade ≥3 acute and late complication rates were 11.7% and 25.5% in the OP and non-OP groups, respectively. Patients who underwent surgery had a higher risk of grade ≥3 late complications (odds ratio: 6.39). Pooled symptomatic palliation rate was 75.2%.

CONCLUSIONS

Re-irradiation with or without surgery for LRRC showed oncologic and palliative efficacy. Salvage treatment including re-irradiation and surgery showed higher survival, but the late complication was significantly increased with concomitant surgery.

Hyperfractionated abdominal reirradiation for gastrointestinal malignancies

Background

We sought to determine the role of abdominal reirradiation for patients presenting with recurrent or new primary gastrointestinal (GI) malignancies. At our institution, we have established a hyperfractionated, accelerated reirradiation regimen consisting of 39 Gray (Gy) in 26 twice-daily fractions. Although this regimen is used frequently in the pelvis, we sought to determine its toxicity and efficacy for abdominal tumors.

Methods

Twenty-four patients who received abdominal reirradiation with a hyperfractionated, accelerated approach from 2000 to 2017 were identified. Overall survival (OS) and local progression-free survival (LPFS) were calculated using the Kaplan-Meier method. Several patient, tumor and treatment characteristics were evaluated on univariate analyses for association with OS and LPFS using a Cox proportional hazards model.

Results

Of the twenty-four patients identified, the majority (n = 11, 46%) had pancreatic adenocarcinoma as their primary disease but also included upper GI adenocarcinoma (n = 4), colon adenocarcinoma (n = 3), hepatobiliary cancers (n = 4) and other malignancies (n = 2). The majority of patients received 45–50.4Gy in 1.8Gy fractions as their initial abdominal radiation course. The median reirradiation dose was 39Gy in 26 twice-daily fractions with a minimum six hour interval. The median [interquartile range (IQR)] interval between the courses of radiotherapy was 28 [18.6–38.9] months. Only palliative reirradiation intent was associated with decreased OS. While colon adenocarcinoma primary was significantly associated with increased LPFS, the sample size was small (n = 3). The 1-yr rate of LPFS was 38%. The median [IQR] duration of freedom from local progression was 8 [3.8–19.2] months. The 1-year OS was 50% and the median (IQR) OS was 14 [6.3–19.6] months. Thirteen patients (54%) had acute side effects with one patient experiencing G3 nausea and one experiencing a G4 bleed; the remaining patients experienced G1-G2 symptoms.

Conclusion

Hyperfractionated, accelerated reirradiation to the abdomen was relatively well-tolerated but provided limited local control to recurrent or second primary abdominal malignancies. Reirradiation could play a role in treating these patients with palliative or curative intent, but alternative strategies for delivering increased biologically effective dose should be further explored.

Treatment of primary rectal adenocarcinoma after prior pelvic radiation: The role of hyperfractionated accelerated reirradiation

Purpose

Previous studies have reported that hyperfractionated accelerated reirradiation can be used as part of multimodality treatment of locally recurrent rectal cancer with acceptable toxicity and promising outcomes. The purpose of this study was to evaluate the outcomes and toxicity of hyperfractionated accelerated reirradiation for patients with primary rectal adenocarcinoma and a history of prior pelvic radiation for other primary malignancies.

Methods and materials

We identified 10 patients with a prior history of pelvic radiation for other primary malignancies who were treated with hyperfractionated accelerated reirradiation for primary rectal adenocarcinoma. Radiation therapy was administered with 1.5 Gy twice daily fractions to a total dose of 39 Gy to 45Gy.

Results

The median follow-up time was 3.2 years (range, 0.6-9.0 years). Seven of 10 patients received surgery after reirradiation. The 3-year freedom-from-local-progression rate was 62% for all patients and 80% for patients who underwent surgery. The 3-year overall survival rate was 100%, with 3 deaths occurring at 4.7, 6.5, and 9.0 years after reirradiation. One patient had an acute Grade 3 toxicity of diarrhea, and 1 patient experienced a late Grade 3 toxicity of sacral insufficiency fracture.

Conclusions

Hyperfractionated accelerated reirradiation was well tolerated with promising rates of freedom from local progression and overall survival in patients with primary rectal cancer with a history of prior pelvic radiation therapy. This approach, along with concurrent chemotherapy and surgery, appears to be a viable treatment strategy for this patient population.

Standard fractionation external beam radiotherapy with and without intraoperative radiotherapy for locally recurrent rectal cancer: the role of local therapy in patients with a high competing risk of death from distant disease

OBJECTIVE

We sought to evaluate the effectiveness and safety of utilizing radiotherapy (RT) with standard fractionation, with or without intraoperative RT (IORT), to treat locally recurrent rectal cancer (LRRC).

METHODS

Retrospective review of 25 patients with LRRC treated with standard fractionation RT from 2005 to 2011. 15 patients (60%) had prior pelvic RT and 10 (40%) had synchronous metastases. The median equivalent dose in 2-Gy fractions was 30 and 49.6 Gy in patients with and without prior RT, respectively. 23 patients (92%) received concurrent chemotherapy and 16 (64%) underwent surgical resection. Eight patients (33.3%, four with and four without prior RT) received IORT. A competing risks model was developed to estimate the cumulative incidence of local failure with death treated as a competing event.

RESULTS

Median follow-up was 36.9 months after the date of local recurrence. 3-year rates of overall survival (OS), local control (LC) and death with LC were 51.6%, 73.3% and 69.2%, respectively. On multivariable analysis, surgical resection was significantly predictive of improved OS (p < 0.05). If surgical resection were removed from the multivariable model, given the collinearity between IORT delivery and surgical resection, then IORT also became a significant predictor of OS (p < 0.05). Systemic disease at the time of local recurrence was not associated with either LC or OS. No patient had grade ≥3 acute or late toxicity.

CONCLUSION

RT with standard fractionation is safe and effective in the treatment of patients with LRRC, even in patients with significant risk of systemic disease and/or history of prior RT. Advances in knowledge: The utility of RT with standard fractionation, generally with chemotherapy, in the treatment of LRRC is demonstrated. In this high-risk cohort of patients with a 40% incidence of synchronous metastatic disease, surgical resection of the recurrence was the major predictor of OS, though a benefit to IORT was also suggested. No patients had grade ≥3 acute or late toxicity, though 40% had undergone prior RT, underscoring the tolerability of standard fractionation RT in this setting.

Hyperfractionated accelerated reirradiation for rectal cancer: An analysis of outcomes and toxicity

BACKGROUND AND PURPOSE

To evaluate outcomes and toxicity in patients treated with hyperfractionated pelvic reirradiation for recurrent rectal cancer.

MATERIALS AND METHODS

102 patients with recurrent rectal adenocarcinoma were treated with pelvic reirradiation with a hyperfractionated accelerated approach, consisting of 1.5Gy twice daily fractions to a total dose of 30-45Gy (median 39Gy), with the most common total dose 39Gy (n=90, 88%). The median dose of prior pelvic radiation therapy (RT) was 50.4Gy (range: 25-63Gy).

RESULTS

The median follow-up was 40months for living patients (range, 3-150months). The 3-year freedom from local progression (FFLP) rate was 40% and the 3-year overall survival (OS) rate was 39%. Treatment with surgery was significantly associated with improved FFLP and OS, with 3-year FFLP rate of 49% vs. 30% (P=0.013), and 3-year OS rate of 62% vs. 20% (P<0.0001), compared to those without surgery. The actuarial 3-year rate of grade 3-4 late toxicity was 34%; patients who underwent surgery had a significantly higher rate of grade 3-4 late toxicity compared to those without surgery (54% vs. 16%, P=0.001).

CONCLUSIONS

This large, retrospective, single-institution study shows that hyperfractionated accelerated reirradiation was well tolerated. The rate of FFLP was promising, given that the study comprised heavily pre-treated patients with recurrences. Rates of FFLP and OS were particularly impressive in patients who underwent both reirradiation and surgery.

Results of a pooled analysis of IOERT containing multimodality treatment for locally recurrent rectal cancer: Results of 565 patients of two major treatment centres

OBJECTIVE

Aim of this study is analysing the pooled results of Intra-Operative Electron beam Radiotherapy (IOERT) containing multimodality treatment of locally recurrent rectal cancer (LRRC) of two major treatment centres.

METHODS AND MATERIALS

Five hundred sixty five patients with LRRC who underwent multimodality-treatment up to 2010 were studied. The preferred treatment was preoperative chemo-radiotherapy, surgery and IOERT. In uni- and multivariate analyses risk factors for local re-recurrence, distant metastasis free survival, relapse free survival, cancer-specific survival and overall survival were studied.

RESULTS

Two hundred fifty one patients (44%) underwent a radical (R0) resection. In patients who had no preoperative treatment the R0 resection rate was 26%, and this was 43% and 50% for patients who respectively received preoperative re-(chemo)-irradiation or full-course radiotherapy (p < 0.0001). After uni- and multivariate analysis it was found that all oncologic parameters were influenced by preoperative treatment and radicality of the resection. Patients who were re-irradiated had a similar outcome compared to patients, who were radiotherapy naive and could undergo full-course treatment, except the chance of local re-recurrence was higher for re-irradiated patients. Waiting-time between preoperative radiotherapy and IOERT was inversely correlated with the chance of local re-recurrence, and positively correlated with the chance of a R0 resection.

CONCLUSIONS

R0 resection is the most important factor influencing oncologic parameters in treatment of LRRC. Preoperative (chemo)-radiotherapy increases the chance of achieving radical resections and improves oncologic outcomes. Short waiting-times between preoperative treatment and IOERT improves the effectiveness of IOERT to reduce the chance of a local re-recurrence.

Intraoperative radiotherapy for locally advanced or locally recurrent rectal cancer: Does it work at all?

BACKGROUND

Intraoperative radiotherapy (IORT) has been given for primary and locally recurrent rectal cancer for 30 years. Still, its effect is not clear.

MATERIAL AND METHODS

PubMed and EMBASE search for papers after 1989 on surgical treatment and external beam radiotherapy (EBRT) for primary advanced and locally recurrent rectal cancer, with and without IORT. From each center the most recent paper was generally selected. Survival and local recurrence at five years was tabulated for the total groups and separate R-stages. Also, the technique for IORT, use of EBRT and chemotherapy as well as surgical approach was registered.

RESULTS

In primary cancer 18 papers from 14 centers were tabulated, including one randomized and five internally comparing studies, as well as seven studies without IORT. In locally recurrent cancer 18 papers from 13 centers were tabulated, including four internally comparing studies and also five without IORT. Overall survival (OS) and local recurrence rate (LRR) were higher for primary cancer compared to recurrent cancer. Patients with R0 resections had better outcome than patients with R1 or R2 resections. For primary cancer OS and LR rate of the total groups and R0 stages was not influenced by IORT. An effect on R1/R2 stages cannot be excluded. The only randomized study (primary cancer) did not show any effect of IORT.

CONCLUSION

IORT does not convincingly improve OS and LR rate for primary and locally recurrent rectal cancer. If there is an effect of IORT, it is small and cannot be shown outside randomized studies analyzing the separate R stages.

Consensus statement on the multidisciplinary management of patients with recurrent and primary rectal cancer beyond total mesorectal excision planes

BACKGROUND

The management of primary rectal cancer beyond total mesorectal excision planes (PRC-bTME) and recurrent rectal cancer (RRC) is challenging. There is global variation in standards and no guidelines exist. To achieve cure most patients require extended, multivisceral, exenterative surgery, beyond conventional total mesorectal excision planes. The aim of the Beyond TME Group was to achieve consensus on the definitions and principles of management, and to identify areas of research priority.

METHODS

Delphi methodology was used to achieve consensus. The Group consisted of invited experts from surgery, radiology, oncology and pathology. The process included two international dedicated discussion conferences, formal feedback, three rounds of editing and two rounds of anonymized web-based voting. Consensus was achieved with more than 80 per cent agreement; less than 80 per cent agreement indicated low consensus. During conferences held in September 2011 and March 2012, open discussion took place on areas in which there is a low level of consensus.

RESULTS

The final consensus document included 51 voted statements, making recommendations on ten key areas of PRC-bTME and RRC. Consensus agreement was achieved on the recommendations of 49 statements, with 34 achieving consensus in over 95 per cent. The lowest level of consensus obtained was 76 per cent. There was clear identification of the need for referral to a specialist multidisciplinary team for diagnosis, assessment and further management.

CONCLUSION

The consensus process has provided guidance for the management of patients with PRC-bTME or RRC, taking into account global variations in surgical techniques and technology. It has further identified areas of research priority.

Reirradiation to the abdomen for gastrointestinal malignancies

Background

Reirradiation to the abdomen could potentially play a role in palliation of symptoms or local control in patients with gastrointestinal malignancies. Our goal was to retrospectively determine rates of toxicity, freedom from local progression and overall survival in gastrointestinal cancer patients treated with reirradiation to the abdomen.

Methods

Between November 2002 and September 2008, 13 patients with a prior history of abdominal radiotherapy (median dose 45 Gy) were treated with reirradiation for recurrent or metastatic gastrointestinal malignancies. The median interval between the two courses of radiotherapy was 26 months. Patients were treated with a hyperfractionated accelerated regimen, using 1.5 Gy fractions twice daily, with a median dose of 30 Gy (range 24-48 Gy). Concurrent chemotherapy was administered to 8 (62%) patients.

Results

The 1-year rate of freedom from local progression was 50%, and the median duration of freedom from local progression was 14 months. The 1-year rate of overall survival was 62%, and the median duration of overall survival was 14 months. One patient developed grade 3 acute toxicity (abdominal pain and gastrointestinal bleeding), requiring hospitalization during radiotherapy; subsequently, that patient experienced a grade 4 late toxicity (gastrointestinal bleeding). No other patients developed grade 3-4 acute or late toxicity or required hospitalization during radiotherapy.

Conclusion

Hyperfractionated accelerated reirradiation to the abdomen was well-tolerated with low rates of acute and late toxicity. Reirradiation could play a role in providing a limited duration of local control in gastrointestinal cancer patients with a history of prior abdominal radiotherapy.

Hyperfractionated accelerated radiotherapy for rectal cancer in patients with prior pelvic irradiation

PURPOSE

To retrospectively determine rates of toxicity, freedom from local progression, and survival in rectal cancer patients treated with reirradiation.

METHODS AND MATERIALS

Between February 2001 and February 2005, 50 patients with a history of pelvic radiotherapy were treated with hyperfractionated accelerated radiotherapy for primary (n = 2 patients) or recurrent (n = 48 patients) rectal adenocarcinoma. Patients were treated with 150-cGy fractions twice daily, with a total dose of 39 Gy (n = 47 patients) if the retreatment interval was >or=1 year or 30 Gy (n = 3) if the retreatment interval was <1 year. Concurrent chemotherapy was administered to 48 (96%) patients. Eighteen (36%) patients underwent surgical resection following radiotherapy.

RESULTS

Two patients had grade 3 acute toxicity and 13 patients had grade 3 to 4 late toxicity. The 3-year rate of grade 3 to 4 late toxicity was 35%. The 3-year rate of freedom from local progression was 33%. The 3-year freedom from local progression rate was 47% in patients undergoing surgery and 21% in those not undergoing surgery (p = 0.057). The 3-year overall survival rate was 39%. The 3-year overall survival rate was 66% in patients undergoing surgery and 27% in those not undergoing surgery (p = 0.003). The 3-year overall survival rate was 53% in patients with a retreatment interval of >2 years and 21% in those with a retreatment interval of <or=2 years (p = 0.001).

CONCLUSIONS

Hyperfractionated, accelerated reirradiation was well tolerated, with low rates of acute toxicity and moderate rates of late toxicity. Reirradiation may help improve pelvic control in rectal cancer patients with a history of pelvic radiotherapy.

Future directions in neoadjuvant therapy of rectal cancer: maximizing pathological complete response rates

Neoadjuvant therapy is widely accepted as the current standard of care for localized rectal cancer. Downstaging of disease has been significantly improved and pathological complete response rates (pCR) which were historically below 10% with preoperative radiation alone, now range from 15% to 30% with preoperative chemo-radiation. While the availability of new chemotherapeutic drugs (Irinotecan, Oxaliplatin, etc.) and molecular targeted agents (Bevacizamab, Cetuximab, etc.) hold a great deal of promise, results of recent studies indicate that the pCR rate with neoadjuvant therapy appears to have plateaued at 20-30%. The use of more intensive multidrug combinations has, however, significantly increased the toxicity of treatment. New paradigms in neoadjuvant therapy are therefore needed to further improve results of treatment. This review presents strategies for neoadjuvant therapy, with the potential to improve pCR rates and also survival of patients.

Reirradiation after radical radiation therapy: a survey of patterns of practice among Canadian radiation oncologists

PURPOSE

The objective of this study was to survey the use of reirradiation (Re-RT) for in-field failures after previous radical radiation treatment (RT) among Canadian radiation oncologists (ROs).

METHODS AND MATERIALS

An electronic survey was sent to 271 ROs in Canada. The completed surveys were received electronically via e-mail and the data were analyzed using SAS 9.1.3 software.

RESULTS

A total of 183 ROs (67.5%) completed and returned the survey. The majority of the respondents were involved in the practice of either breast (48%) or genitourinary (43%) tumor sites. A total of 49% of the participants were interested in using Re-RT for the management of in-field recurrences. The goals of the therapy would be improvement of quality of life (99%), locoregional control (80%), or cure (32%). Most of the physicians believed that patients should have a minimum Karnofsky performance status of 50 or Eastern Cooperative Oncology Group performance status of 3, a minimum life expectancy of 3 months, and a minimum interval from initial treatment of 3 months if Re-RT were to be given with curative intent.

CONCLUSIONS

This survey showed that a wide variation existed among ROs in their approach to Re-RT. Newer technologies in RT planning and delivery would be employed to facilitate normal tissue avoidance. The results of this study suggested that a consensus meeting was needed to establish guidelines for the practice and prospective evaluation of Re-RT.

Treatment Strategy for Locally Recurrent Rectal Cancer

Despite radical surgery, up to 33% of patients with rectal cancer will develop locoregional relapse. The management of these patients is particularly challenging. Surgery is the mainstay of treatment for those with a mobile recurrence. However, the majority of patients develop recurrence involving the pelvic wall. In these patients, multimodality therapy including radical surgery and intraoperative radiotherapy have been reported with 5-year survival of up to 31% and local control rates of 50-71%. The most important factor for obtaining long-term local control and survival is R0 resection. Extended surgery such as abdomino-sacral resection has not been popular because of 5-year survival rates of 16-31%, and significant postoperative morbidity. Re-recurrence following surgery occurs locally and in the lung, and remains a significant problem. In surgical treatment for local recurrence, surgeon-related factors are crucial. A staging system using degree of fixation and other prognostic factors should be developed so that appropriate treatment modalities are applied to each case.

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

Intraoperative radiotherapy in the multimodality approach to colorectal cancer

The addition of intraoperative radiotherapy (IORT) to the multimodality approach for the treatment of locally advanced and locally recurrent colorectal cancer seems to result in improvements in local control and long-term survival. Local control and survival are most likely in patients in whom a gross total resection is accomplished. Peripheral nerve is the dose-limiting structure for patients treated with IORT. Further improvements in local control require the addition of dose modifiers during external beam radiotherapy or IORT. Distant relapse remains problematic, and effective systemic therapy is necessary to significantly improve long-term survival.

Multimodality management of locally recurrent colorectal cancer

The combined management of locally recurrent colorectal cancer shows considerable promise, but the best way to incorporate the different treatment modalities and the potential benefits remain uncertain. The case series mentioned here were derived from highly selected groups from a much larger population of patients with recurrent disease; thus fully combined management may be only appropriate for a minority of people with recurrent disease. There is a need for multicenter randomized trials to better delineate the real benefits from the combined approach. Multimodality management of recurrent colorectal cancer, however, involves more than the combination of surgery, radiation therapy, and chemotherapy for a select minority of resectable patients. It involves the use of each modality to its greatest advantage for all patients, as determined by a multidisciplinary team of specialists. We should also not confine our attention to the treatment aspects of recurrent disease alone, as the greatest promise for improved survival could be with a more general application of total mesorectal excision. Because most people who develop local recurrence of colorectal cancer will die from their disease, the main contribution of a multimodality approach may be towards palliation.

Comparison of intraoperative radiation therapy-containing multimodality treatment with historical treatment modalities for locally recurrent rectal cancer

PURPOSE

Treatment protocols for patients with locally recurrent rectal cancer have changed in the last two decades. Subsequently, treatment goals shifted from palliation to possible cure. In this retrospective study, we explored the treatment variables that may have contributed to the improvement in outcome by comparing three treatment modalities from two collaborating institutions in patients with similar tumor characteristics.

METHODS

Ninety-four patients were treated with electron-beam radiation therapy only (1975-1990), 19 with combined preoperative electron-beam radiation therapy and surgery (1989-1996), and 33 with intraoperative radiation therapy-multimodality treatment (1994-1999). Intraoperative radiation therapy was delivered either as intraoperative electron-beam radiotherapy (10-17.5 Gy) in 20 patients or as intraoperative high-dose-rate brachytherapy (10 Gy) in 13 patients. No patient had received prior electron-beam radiation therapy.

RESULTS

The three-year survival, disease-free survival, and local control rates were 14, 8, and 10 percent, respectively, in the electron-beam radiation therapy-only group and 11, 0, and 14 percent, respectively, in the combined electron-beam radiation therapy-surgery group. The overall intraoperative radiation therapy-multimodality treatment group showed significantly better three-year survival, disease-free survival, and local control rates of 60, 43, and 73 percent, respectively, compared with the historical control groups (P < 0.001).

CONCLUSION

The outcome of patients with locally recurrent rectal cancer was improved after the introduction of intraoperative radiation therapy-multimodality treatment.

Intraoperative irradiation for locally recurrent colorectal cancer in previously irradiated patients

PURPOSE

Information in the literature regarding salvage treatment for patients with locally recurrent colorectal cancer who have previously been treated with high or moderate dose external beam irradiation (EBRT) is scarce. A retrospective review was therefore performed in our institution to determine disease control, survival, and tolerance in patients treated aggressively with surgical resection and intraoperative electron irradiation (IOERT) +/- additional EBRT and chemotherapy.

METHODS AND MATERIALS

From 1981 through 1994, 51 previously irradiated patients with recurrent locally advanced colorectal cancer without evidence of distant metastatic disease were treated at Mayo Clinic Rochester with surgical resection and IOERT +/- additional EBRT. An attempt was made to achieve a gross total resection before IOERT if it could be safely accomplished. The median IOERT dose was 20 Gy (range, 10--30 Gy). Thirty-seven patients received additional EBRT either pre- or postoperatively with doses ranging from 5 to 50.4 Gy (median 25.2 Gy). Twenty patients received 5-fluorouracil +/- leucovorin during EBRT. Three patients received additional cycles of 5-fluorouracil +/- leucovorin as maintenance chemotherapy.

RESULTS

Thirty males and 21 females with a median age of 55 years (range 31--73 years) were treated. Thirty-four patients have died; the median follow-up in surviving patients is 21 months. The median, 2-yr, and 5-yr actuarial overall survivals are 23 months, 48% and 12%, respectively. The 2-yr actuarial central control (within IOERT field) is 72%. Local control at 2 years has been maintained in 60% of patients. There is a trend toward improved local control in patients who received > or =30 Gy EBRT in addition to IOERT as compared to those who received no EBRT or <30 Gy with 2-yr local control rates of 81% vs. 54%. Distant metastatic disease has developed in 25 patients, and the actuarial rate of distant progression at 2 and 4 years is 56% and 76%, respectively. Peripheral neuropathy was the main IOERT-related toxicity; 16 (32%) patients developed neuropathies (7 mild, 5 moderate, 4 severe). Ureteral narrowing or obstruction occurred in seven patients. All but one patient with neuropathy or ureter fibrosis received IOERT doses > or =20 Gy.

CONCLUSION

Long-term local control can be obtained in a substantial proportion of patients with aggressive combined modality therapy, but long-term survival is poor due to the high rate of distant metastasis. Re-irradiation with EBRT in addition to IOERT appears to improve local control. Strategies to improve survival in these poor-risk patients may include the more routine use of conventional systemic chemotherapy or the addition of novel systemic therapies.

Clinical experience with retreatment for palliation

Every radiation oncologist is faced occasionally with the need to consider reirradiation for palliation. Because reirradiation has the potential to exceed normal tissue tolerances, there is a need to have information on the efficacy and toxicity of retreatment. This article reviews the reirradiation literature and provides guidance to clinicians with regard to the risks, benefits, and side effects of retreatment.

Chemoradiation with or without intraoperative radiation therapy in patients with locally recurrent rectal carcinoma: prognostic factors and long term outcome

BACKGROUND

Rectal carcinoma patients with local recurrence are reported to have a dismal prognosis. The purpose of this study was to evaluate the effect of combined modality therapy on clinical outcome and to determine the prognostic impact of a "presurgical" staging system.

METHODS

Between September 1989 and June 1997, 47 patients (with a median follow-up of 80 months) with locally recurrent, nonmetastatic rectal carcinoma were classified according to the extent of pelvic sidewall involvement as determined by pretreatment computed tomography (CT) scan. They received preoperative external beam radiation (45-47 grays [Gy] in 34 patients; 23.4 Gy in 13 preirradiated patients) plus concomitant 5-fluorouracil (1000 mg/m(2)/day as a 96-hour continuous infusion on Days 1-4 + 29-32) and mitomycin C (10 mg/m(2) as a bolus intravenously on Day 1 + 29). After 4-6 weeks, the patients were evaluated for surgical resection and intraoperative radiation therapy (IORT) procedure (10-15 Gy) or, in unresectable patients, a boost dose was planned by chemoradiation (23.4 Gy) or brachytherapy. Thereafter, adjuvant chemotherapy (5-fluorouracil and leucovorin for a total of six to nine courses) was prescribed.

RESULTS

During chemoradiation, 2 patients (4.3%) developed Radiation Therapy Oncology Group Grade 3-4 acute toxicity. Twenty-five patients (53. 2%) had an objective response after chemoradiation. Twenty-one patients (45%) underwent radical surgical resection. The overall 5-year survival and local control rates were 22% and 32%, respectively. The classification system significantly predicted survival (P = 0.008). Radically resected patients had better local control and survival (P < 0.0001); in patients treated with IORT, the 5-year local control and survival rates were 79% and 41%, respectively.

CONCLUSIONS

The data from the current study suggest that combined modality therapy was well tolerated and improved resectability, local control, and survival. The classification system appears to be a reliable tool with which to predict clinical outcome in patients with locally recurrent rectal carcinoma.

High-dose preoperative radiotherapy does not alter the strength of unilaterally irradiated colon anastomoses in rats

PURPOSE

We studied the influence of preoperative radiotherapy on the strength of colon anastomoses in rats. We compared a conventional (2 Gy/fraction; 1 fraction/day; 5 days/week; cumulative doses of 40.0, 60.0, and 80.0 Gy) and a hyperfractionated schedule (1.6 Gy/fraction, 2 fractions/day, 5 days/week, cumulative doses of 41.6, 60.8, and 80.0 Gy). We compared unilaterally with bilaterally irradiated anastomoses for two conventional radiation schedules.

METHODS AND MATERIALS

The rectosigmoid was always irradiated. Depending on the experiment, the cecum was irradiated or not. A side-to-side anastomosis between rectosigmoid and cecum was constructed the day following the last irradiation. The strength of the anastomosis was evaluated by means of a bursting pressure (BP) measurement after 10 days. A control group and a sham-treated group were carried out.

RESULTS

Compared to controls, the strength of unilaterally irradiated anastomoses was not altered and BP values were independent of the radiation schedule and of the cumulative dose. In case of bilaterally irradiated colon anastomoses, anastomotic strength was significantly reduced at 80 Gy, but not at 40 Gy.

CONCLUSIONS

After high doses of preoperative radiotherapy, colon anastomoses in rats can be safely constructed if only one anastomotic segment is irradiated. The strength of bilaterally irradiated colon anastomoses is dose-dependent.

Curative surgical resection following reirradiation for recurrent rectal cancer

PURPOSE

In spite of adjunctive radiation and chemotherapy, 10 to 25% of patients with resected rectal cancer develop local recurrence in the pelvis. This study evaluates the potential for curative surgical resection of residual disease following reirradiation for recurrent rectal cancer.

METHODS AND MATERIALS

Thirty-nine patients with recurrent adenocarcinoma of the rectum following prior adjunctive therapy underwent reirradiation of the pelvis with concurrent intravenous infusion of 5-fluorouracil. Median time to recurrence following initial treatment was 18 months. Prior radiation doses to the pelvis ranged from 40 to 66 Gy with a median of 50.4 Gy. Reirradiation doses ranged from 20 Gy to 49.2 Gy with a median total dose of 36 Gy. Eight to 12 weeks following reirradiation patients underwent surgical resection of disease. Thirty-one patients had gross total resection of tumor.

RESULTS

Patients have been followed for 24 months to 75 months after reirradiation for recurrent rectal cancer with a median follow-up of 3 years. Reirradiation was well tolerated, with seven patients requiring a significant treatment break. Early termination of reirradiation occurred in five patients because of diarrhea, moist desquamation, or mucositis. No surgical mortality was observed. Postoperatively, two patients developed delayed wound healing. Late complications included six patients who developed small bowel obstruction with three patients developing a bowel fistula. The median survival of patients is 45 months, with a 5-year actuarial survival of 24%. Actuarial local control at 5 years was 45%. The rate of distant metastases was 17%.

CONCLUSION

Selected patients with rectal cancer who develop recurrent disease following previous adjuvant therapy can undergo successful curative surgical resection following reirradiation/chemotherapy with significant long-term survival.

Palliative reirradiation for recurrent rectal cancer

PURPOSE

The purpose of this study was to analyze the efficacy and acute and late toxicity of reirradiation for recurrent rectal cancer.

METHODS AND MATERIALS

Fifty-two patients with recurrent rectal adenocarcinoma following previous pelvic RT underwent reirradiation. Median initial RT dose to the pelvis was 50.4 Gy. Median reirradiation dose was 30.6 Gy. Twenty-two patients received 1.2 Gy b.i.d., and 30 patients received 1.8-2.0 Gy daily. Total cumulative doses ranged from 66.6 to 104.9 Gy (median: 84.4 Gy). Forty-seven patients (90%) received concurrent 5-FU chemotherapy. Forty-four patients were followed until death, and the median follow-up time was 16 months.

RESULTS

The RTOG Grade 3 acute toxicity rate was 31%. The RTOG Grade 3 and 4 late toxicity rates were 23 and 10%, respectively. On multivariate analysis, the only factor associated with reduced late toxicity was hyperfractionated delivery of reirradiation. Bleeding, pain, and mass effect were palliated completely in 100, 65, and 24% of instances, respectively, and the majority of responding patients were palliated until death. The overall median survival time from retreatment was 12 months. The 2- and 3-year overall actuarial survival rates were 25 and 14%, respectively.

CONCLUSION

This unique institutional approach to recurrent rectal cancers resulted in excellent palliation of symptoms. Late complications appeared reduced by hyperfractionated treatment delivery.

A three-dimensional approach for re-irradiation of recurrent colorectal adenocarcinoma

A large number of patients with resected rectal cancer will develop a symptomatic pelvic recurrence despite previous adjuvant radiation therapy. Re-irradiation after previous high dose radiation therapy carries an increased risk of complications in the normal tissues of the pelvis. However, other treatment modalities are not likely to provide a palliative benefit. Previous studies have shown that re-irradiation may be feasible and may palliate the patient. As minimal data is available on the toxicity of additional radiation therapy, this approach would be considered only when there is no other alternative for effective therapy and in the face of progressive and severe symptoms. With the use of three dimensional (3-D) treatment planning, portals can be designed to limit dose to previously irradiated critical structures while minimizing the risk of treatment related complications.