Long-term results of reirradiation for patients with recurrent rectal carcinoma

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.

Radiotherapy for Canine Apocrine Gland Anal Sac Adenocarcinoma: Survival Outcomes and Side Effects of a Palliative Treatment Protocol of 20 Gy in Five Consecutive Fractions

This research aims to evaluate the outcomes of a radiotherapy protocol, consisting of five fractions of 4 Gy each, resulting in a total dose of 20 Gy for apocrine gland anal sac tumors and local lymph nodes in canines. This protocol was assessed as a palliative treatment for macroscopic tumors alone, or in combination with additional therapies under different scenarios. Medical records from fifty canine patients met the inclusion criteria and were divided into different treatment groups: radiotherapy alone (n = 22, 44%), radiotherapy with chemotherapy or targeted therapy with toceranib (n = 18, 36%), surgery with radiotherapy (n = 5, 10%), and surgery with radiotherapy and chemotherapy or targeted therapy with toceranib (n = 5, 10%). Patients who received radiotherapy alone had a median survival time of 384 days (95% CI 198-569) and 628 days (95% CI 579-676) for RT + additional therapies. The median time to progression for patients with radiotherapy alone was 337 days (95% CI 282-391 days), and 402 days (95% CI 286-517 days) for radiotherapy plus additional treatments. Acute side effects were mild, with the majority having diarrhea (61%), and only one patient developed grade III late effects VRTOG v2 classification; however, this happened 22 months after the first radiotherapy protocol after re-irradiation. The results demonstrate that radiotherapy alone under this protocol provided a comparable median time to progression vs. radiotherapy plus additional treatments while maintaining acceptable side effects. The combination of this protocol with other treatment modalities offers attractive results for local disease control and survival while maintaining acceptable toxicities. Overall, these findings contribute to the growing evidence supporting the role of radiotherapy in managing apocrine gland anal sac adenocarcinoma in dogs.

Novel and Innovative Surgical Strategies for Recurrent Rectal Cancer: Uncommon Resections, Local Interventions for Pelvic Reoccurrence, and Intraoperative Radiation Therapy

The frequency of recurrent rectal cancer has dropped significantly with improved surgical approaches and adjunctive therapies. These recurrences have proven challenging to obtain R0 resection with salvage operations. Meticulous planning, clear understanding of anatomy with imaging, and multispecialty support have become essential in local control and long-term survival with pelvic recurrence of rectal cancer. Technical considerations and prognosis indicators along with role of intraoperative radiation or boost radiation are discussed within.

Adenocarcinoma involving the urinary bladder

A man in his 70s previously diagnosed with an adenocarcinoma of the prostate, received external beam radiation therapy (EBRT) and brachytherapy 11 years ago. Ten years later, he developed urinary symptoms and a cystoscopy identified a bladder neck tumour. A transurethral resection of a bladder tumour was performed, and pathology revealed a high-grade adenocarcinoma consistent with a colorectal primary. A colonoscopy was unremarkable, and imaging studies showed tumour involving the bladder and prostate. Tumour markers and a CARIS genomic prevalence score also favoured a colorectal cancer primary.The patient refused surgery and underwent chemoradiation with a combination of EBRT and brachytherapy with concurrent capecitabine. Imaging studies obtained 6 months after reirradiation revealed an enlarged left-sided mesorectal lymph node concerning for disease recurrence. The lymph node was treated with Stereotactic Body Radiation Therapy and his post-treatment imaging revealed a response to treatment with no other evidence of disease.

Comparing Oncologic Outcomes and Toxicity for Combined Modality Therapy vs. Carbon-Ion Radiotherapy for Previously Irradiated Locally Recurrent Rectal Cancer

No standard treatment paradigm exists for previously irradiated locally recurrent rectal cancer (PILRRC). Carbon-ion radiotherapy (CIRT) may improve oncologic outcomes and reduce toxicity compared with combined modality therapy (CMT). Eighty-five patients treated at Institution A with CIRT alone (70.4 Gy/16 fx) and eighty-six at Institution B with CMT (30 Gy/15 fx chemoradiation, resection, intraoperative electron radiotherapy (IOERT)) between 2006 and 2019 were retrospectively compared. Overall survival (OS), pelvic re-recurrence (PR), distant metastasis (DM), or any disease progression (DP) were analyzed with the Kaplan-Meier model, with outcomes compared using the Cox proportional hazards model. Acute and late toxicities were compared, as was the 2-year cost. The median time to follow-up or death was 6.5 years. Median OS in the CIRT and CMT cohorts were 4.5 and 2.6 years, respectively (p ≤ 0.01). No difference was seen in the cumulative incidence of PR (p = 0.17), DM (p = 0.39), or DP (p = 0.19). Lower acute grade ≥ 2 skin and GI/GU toxicity and lower late grade ≥ 2 GU toxicities were associated with CIRT. Higher 2-year cumulative costs were associated with CMT. Oncologic outcomes were similar for patients treated with CIRT or CMT, although patient morbidity and cost were lower with CIRT, and CIRT was associated with longer OS. Prospective comparative studies are needed.

Rectal Cancer after Prostate Radiation: A Complex and Controversial Disease

A small proportion of rectal adenocarcinomas develop in patients many years after the treatment of a previous cancer using pelvic radiation, and the incidence of these rectal cancers depends on the length of follow-up from the end of radiotherapy. The risk of radiation-associated rectal cancer (RARC) is higher in patients treated with prostate external beam radiotherapy than it is in patients treated with brachytherapy. The molecular features of RARC have not been fully investigated, and survival is lower compared to non-irradiated rectal cancer patients. Ultimately, it is unclear whether the worse outcomes are related to differences in patient characteristics, treatment-related factors, or tumor biology. Radiation is widely used in the management of rectal adenocarcinoma; however, pelvic re-irradiation of RARC is challenging and carries a higher risk of treatment complications. Although RARC can develop in patients treated for a variety of malignancies, it is most common in patients treated for prostate cancer. This study will review the incidence, molecular characteristics, clinical course, and treatment outcomes of rectal adenocarcinoma in patients previously treated with radiation for prostate cancer. For clarity, we will distinguish between rectal cancer not associated with prostate cancer (RCNAPC), rectal cancer in non-irradiated prostate cancer patients (RCNRPC), and rectal cancer in irradiated prostate cancer patients (RCRPC). RARC represents a unique but understudied subset of rectal cancer, and thus requires a more comprehensive investigation in order to improve its treatment and prognosis.

Pelvic exenteration: a review of current issues/controversies

Management of advanced or recurrent pelvic cancer has evolved dramatically over the past few decades. Patients who were previously considered inoperable are now candidates for potentially curative surgery and avoid suffering with intractable symptoms. Up to 10% of primary rectal cancers present with isolated advanced local disease and between 10% and 15% of patients develop localized recurrence following proctectomy. Advances in surgical technique, reconstruction and multidisciplinary involvement have led to a reduction in mortality and morbidity and culminated in higher R0 resection rates with superior longer-term survival outcomes. Recent studies boast over 50% 5-year survival for rectal with an R0 resection. Exenteration has cemented itself as an important treatment option for advanced primary/recurrent pelvic tumours, however, there are still a few controversies. This review will discuss some of these issues, including: limitations of resection and the approach to high/wide tumours; the role of acute exenteration; re-exenteration; exenteration in the setting of metastatic disease and palliation; the role of radiotherapy (including intra-operative and re-irradiation); management of the empty pelvis; and the impact on quality of life and function.

Quality of internet information to aid patient decision making in locally advanced and recurrent rectal cancer

BACKGROUND

To review whether online decision aids are available for patients contemplating pelvic exenteration (PE) for locally advanced and recurrent rectal cancer (LARC and LRRC).

METHODS

A grey literature review was carried out using the Google Search™ engine undertaken using a predefined search strategy (PROSPERO database CRD42019122933). Written health information was assessed using the DISCERN criteria and International Patient Decision Aids Standards (IPDAS) with readability content assessed using the Flesch-Kincaid reading ease test and Flesch-Kincaid grade level score.

RESULTS

Google search yielded 27, 782, 200 results for the predefined search criteria. 131 sources were screened resulting in the analysis of 6 sources. No sources were identified as a decision aid according to the IPDAS criteria. All sources provided an acceptable quality of written health information, scoring a global score of 3 for the DISCERN written assessment. The median Flesch-Kincaid reading ease was 50.85 (32.5-80.8) equating to a reading age of 15-18 years and the median Flesch-Kincaid grade level score was 7.65 (range 3-9.7), which equates to a reading age of 13-14.

CONCLUSIONS

This study has found that there is a paucity of online information for patients contemplating PE. Sources that are available are aimed at a high health literate patient. Given the considerable morbidity associated with PE surgery there is a need for high quality relevant information in this area. A PDA should be developed to improve decision making and ultimately improve patient experience.

Carbon Ion Radiotherapy for Locally Recurrent Rectal Cancer of Patients with Prior Pelvic Irradiation

BACKGROUND

This study aimed to assess the safety and efficacy of carbon-ion radiotherapy (CIRT) for salvage of previously X-ray-irradiated (XRT) locally recurrent rectal cancer (LRRC).

METHODS

Between September 2005 and December 2017, 77 patients with LRRC were treated with CIRT re-irradiation. All the patients had received prior XRT with a median dose of 50.0 Gy (range 20-74 Gy), principally for neoadjuvant or adjuvant recurrence prophylaxis in 34 patients and for recurrence in 43 patients. The total CIRT dose of 70.4 Gy (RBE) (gray relative biologic effectiveness) was administered in 16 fixed fractions during 4 weeks (4.4 Gy [RBE] per fraction).

RESULTS

All the patients completed the scheduled treatment course. None of the patients received resection after CIRT. Acute grade 3 toxicities occurred for eight patients (10 %), including five grade 3 pelvic infections (2 involving pain and 1 involving neuropathy). Late grade 3 toxicities occurred for 16 patients (21 %): 13 with late grade 3 pelvic infections, 9 with gastrointestinal toxicity, 1 with skin toxicity, 2 with pain, and 4 with neuropathy. No grade 4+ toxicity was noted. The overall local control rates (infield + out-of-field recurrence) were 69 % at 3 years and 62 % at 5 years. In the planning target volume (PTV), the infield recurrence rates were 90 % and 87 % respectively. The control rates for regional recurrence were 85 % at 3 years and 81 % at 5 years. The median overall survival time was 47 months. The survival rates were 61 % at 3 years and 38 % at 5 years.

CONCLUSION

Carbon-ion re-irradiation of previously X-ray-irradiated locally recurrent rectal cancer appears to be safe and effective, providing good local control and survival advantage without unacceptable morbidity.

A multicentre retrospective review of SABR reirradiation in rectal cancer recurrence

BACKGROUND AND PURPOSE

Locally recurrent rectal cancer (LRRC) is associated with considerable morbidity, poor quality of life and an overall survival of 9 months. The non-operative treatment of LRRC is an understudied area, there is no consensus on management in this setting. We aim to perform a retrospective, multicentre analysis of patients treated with SABR reirradiation.

MATERIALS AND METHODS

All patients were identified who received SABR re-irradiation for LRRC, at 3 UK centres, between August 2015 and September 2020. Eligible patients had pelvic recurrence and were either not suitable/opted not for surgery, or margin positive after exenturative surgery. Patients were treated with 30 Gy in 5 fractions and followed up with clinical review and CT scan at 3, 6, 12, 18 and 24 months.

RESULTS

69 patients with 81 lesions were identified and median follow up was 28 months. Median progression free survival (PFS) and overall survival (OS) were 12.1 months (10.4, 17.7) and 38.7 months (28.9,-) respectively. 2-year OS was 0.77 (0.66, 0.89). 58.3% of deaths were as a result of consequences of local relapse. 42.6% of patients had local relapse at death or last follow up.

CONCLUSION

Our outcomes are encouraging for a population who had R1 resections, refused or were refused surgery; as they are similar to those in surgical series. Prospective data including details of survival, local relapse and QOL; with an optimised SABR technique, is required to establish SABR as an alternative to surgery.

Re-Irradiation in Patients with Recurrent Rectal Cancer is Safe and Feasible

BACKGROUND

There is no consensus yet for the best treatment regimen in patients with recurrent rectal cancer (RRC). This study aims to evaluate toxicity and oncological outcomes after re-irradiation in patients with RRC in our center. Clinical (cCR) and pathological complete response (pCR) rates and radicality were also studied.

METHODS

Between January 2010 and December 2018, 61 locally advanced RRC patients were treated and analyzed retrospectively. Patients received radiotherapy at a dose of 30.0-30.6 Gy (reCRT) or 50.0-50.4 Gy chemoradiotherapy (CRT) in cases of no prior irradiation because of low-risk primary rectal cancer. In both groups, patients received capecitabine concomitantly.

RESULTS

In total, 60 patients received the prescribed neoadjuvant (chemo)radiotherapy followed by surgery, 35 patients (58.3%) in the reRCT group and 25 patients (41.7%) in the long-course CRT group. There were no significant differences in overall survival (p = 0.82), disease-free survival (p = 0.63), and local recurrence-free survival (p = 0.17) between the groups. Patients in the long-course CRT group reported more skin toxicity after radiotherapy (p = 0.040). No differences were observed in late toxicity. In the long-course CRT group, a significantly higher cCR rate was observed (p = 0.029); however, there was no difference in the pCR rate (p = 0.66).

CONCLUSIONS

The treatment of RRC patients with re-irradiation is comparable to treatment with long-course CRT regarding toxicity and oncological outcomes. In the reCRT group, less cCR was observed, although there was no difference in pCR. The findings in this study suggest that it is safe and feasible to re-irradiate RRC patients.

Cost-Effectiveness and Quality-Adjusted Survival of Watch and Wait After Complete Response to Chemoradiotherapy for Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision (TME) is the standard treatment for locally advanced rectal cancer. There is interest in deescalating local therapy after a clinical complete response to CRT. We hypothesized that a watch-and-wait (WW) strategy offers comparable cancer-specific survival, superior quality-adjusted survival, and reduced cost compared with upfront TME.

METHODS

We developed a decision-analytic model to compare WW, low anterior resection, and abdominoperineal resection for patients achieving a clinical complete response to CRT. Rates of local regrowth, pelvic recurrence, and distant metastasis were derived from series comparing WW with TME after pathologic complete response. Lifetime incremental costs and quality-adjusted life-years (QALY) were calculated between strategies, and sensitivity analyses were performed to study model uncertainty.

RESULTS

The base case 5-year cancer-specific survival was 93.5% (95% confidence interval [CI] = 91.5% to 94.9%) on a WW program compared with 95.9% (95% CI = 93.6% to 97.4%) after upfront TME. WW was dominant relative to low anterior resection, with cost savings of $28 500 (95% CI = $22 200 to $39 000) and incremental QALY of 0.527 (95% CI = 0.138 to 1.125). WW was also dominant relative to abdominoperineal resection, with a cost savings of $32 100 (95% CI = $21 800 to $49 200) and incremental QALY of 0.601 (95% CI = 0.213 to 1.208). WW remained dominant in sensitivity analysis unless the rate of surgical salvage fell to 73.0%.

CONCLUSIONS

Using current multi-institutional recurrence estimates, we observed comparable cancer-specific survival, superior quality-adjusted survival, and decreased costs with WW compared with upfront TME. Upfront TME was preferred when surgical salvage rates were low.

Carbon-ion Radiotherapy for Colorectal Cancer

Heavy-ion radiotherapy (RT) is a kind of particle RT, and carbon-ion beam constitutes the primary delivery method of heavy-ion RT. Unlike the conventional photon modalities, particle RT, in particular carbon-ion radiotherapy (CIRT), offers unique physical and biological advantages. Particle therapy allows for substantial dose delivery to tumors with minimal surrounding tissue damage. In addition, CIRT in particular possesses biological advantages such as inducing increased double-strand breaks in DNA structures, causing irreversible cell damage independently of cell cycle or oxygenation, more so than proton or photon. It can be expected that CIRT is effective on radioresistant cancers such as colorectal cancers (CRCs). We introduced the results of CIRT for local recurrent rectal cancer, lung metastasis, liver metastasis, and lymph node metastasis.

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.

Complex Clinical Decision-Making Process of Re-Irradiation

As patients live longer with their cancer as a result of more effective treatment, recurrences and second malignancies in a previously irradiated field are an increasing challenge. The technical advances that enable high-dose radiation to limited volumes, excluding critical normal tissues, have increased the use of re-irradiation for many tumour sites. Minimising the volume, selecting patients with good performance status, negative metastatic screening and longer disease-free intervals are important principles. Despite this there is a narrow therapeutic window, and careful consideration with open discussion, including the patient, of the probable benefit and the implications of potential toxicities will always be essential. In this overview we evaluate the various radiobiological factors that need to be considered for re-irradiation, tissue recovery and dose tolerances in the setting of re-irradiation and summarise the available literature to guide clinicians in their decision-making for re-irradiation to primary and metastatic site/s of disease.

A national surveillance study of the current status of reirradiation using brachytherapy in Japan

PURPOSE

This study aimed to explore the current status and pattern of practice for reirradiation using brachytherapy (ReRT-BT) through a survey in Japan.

MATERIALS AND METHODS

We distributed an e-mail-based questionnaire to 153 institutions equipped with high-dose-rate brachytherapy facilities.

RESULTS

We received responses from 76 institutions (49.7%). Forty-three of these institutions performed ReRT-BT and 42 institutions (55%) performed ReRT-BT during 2009-2018. However, 29 of the 42 institutions (69%) reported difficulty in obtaining ReRT-BT case information from their respective databases. Almost all the institutions encountered insufficient database system to extract details about the ReRT-BT cases. Responses from 33 institutions included the number of ReRT-BT cases; this increased from 90 in the period 2009-2013 (institution median = 0.5; 0-16) to 172 in the period 2014-2018 (institution median = 2; 0-26). Nine institutions had to perform ReRT-BT for more than one case per year. The major location for cancer treatment was the pelvis (94%), followed by the head and neck (5%) and others (1%). In six site-specific scenarios, barring uterine corpus cancer recurrence, more than 90% of radiation oncologists agreed to perform ReRT-BT, whereas other areas (head and neck, prostate, and rectal cancer) gained 16-37% agreement.

CONCLUSIONS

This decade saw an increase in the number of ReRT-BT cases in Japan and radiation oncologists' interest in ReRT-BT as a viable therapeutic option. However, scarce availability, immature education system, and insufficient database system are barriers to further consensus building.

Pelvic Reirradiation Utilizing Pulsed Low-dose Rate Radiation Therapy

Pulsed low-dose rate radiation therapy has been shown to reduce normal tissue damage while decreasing DNA damage repair in tumor cells. In a cohort of patients treated with palliative or definitive pelvic reirradiation using pulsed low-dose rate radiation therapy, we observed substantial local control and low rates of toxicity.

Stereotactic Body Radiation Therapy Reirradiation for Locally Recurrent Rectal Cancer: Outcomes and Toxicity

Purpose

Stereotactic body radiation therapy (SBRT) has emerged as a potential therapeutic option for locally recurrent rectal cancer (LRRC) but contemporaneous clinical data are limited. We aimed to evaluate the local control, toxicity, and survival outcomes in a cohort of patients previously treated with neoadjuvant pelvic radiation therapy for nonmetastatic locally recurrent rectal cancer, now treated with SBRT.

Methods and Materials

Inoperable rectal cancer patients with ≤3 sites of pelvic recurrence and >6 months since prior pelvic radiation therapy were identified from a prospective registry over 4 years. SBRT dose was 30 Gy in 5 fractions, daily or alternate days, using cumulative organ at risk dose constraints. Primary outcome was local control (LC). Secondary outcomes were progression free survival, overall survival, toxicity, and patient reported quality of life scores using the EQ visual analog scale (EQ-VAS) tool.

Results

Thirty patients (35 targets) were included. Median gross tumor volume size was 14.3 cm³. In addition, 27 of 30 (90%) previously received 45 to 50.4 Gy in 25 of 28 fractions, with 10% receiving an alternative prescription. All patients received the planned reirradiation SBRT dose. The median follow-up was 24.5 months (interquartile range, 17.8-28.8). The 1-year LC was 84.9% (95% confidence interval [CI], 70.6-99) and a 2-year LC was 69% (95% CI, 51.8-91.9). The median progression free survival was 12.1 months (95% CI, 8.6-17.66), and median overall survival was 28.3 months (95% CI, 17.88-39.5 months). No patient experienced >G2 acute toxicity and only 1 patient experienced late G3 toxicity. Patient-reported QoL outcomes were improved at 3 months after SBRT (Δ EQ-VAS, +10 points, Wilcoxon signed-rank, P = .009).

Conclusions

Our study demonstrates that, for small volume pelvic disease relapses from rectal cancer, reirradiation with 30 Gy in 5 fractions is well tolerated and achieves an excellent balance between high local control rates with limited toxicity.

An In Vivo Mouse Model of Pelvic Recurrence of Human Colorectal Cancer

Pelvic recurrence of colorectal cancer is a crucial problem because radical surgery can lead to excessive invasion. Novel therapeutic strategies are required instead of surgery. However, there are few suitable models because of the difficulty in transplanting and observing tumors in the pelvis. We have established an appropriate injection site suitable for the establishment of colorectal cancer pelvic recurrence that allows for the observation of tumor growth. DLD-1 cells stably expressing luciferase (DLD-1 clone#1-Luc) were inoculated into various points of female BALB/c nude mice and the engrafted cells were analyzed with an imaging system employing bioluminescent signals and computed tomography. Weekly analysis with the imaging system showed that a triangular area defined by the vagina, the anus, and the ischial spine was suitable for the engraftment of pelvic tumors. The imaging system was able to detect the engrafted tumor 7 days after the inoculation of cells. Weight loss was observed in our model, and overall survival was 21–42 days. Tumor involvement of adjacent organs was detected histopathologically, as is the case in the clinical situation. These findings suggest that this model is valid for evaluations of the therapeutic effects of novel treatments under development. It is hoped that this model will be used in preclinical research.

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.

A Review on the Special Radiotherapy Techniques of Colorectal Cancer

Colorectal cancer is one of the commonest cancers worldwide. Radiotherapy has been established as an indispensable component of treatment. Although conventional radiotherapy provides good local control, radiotherapy treatment side-effects, local recurrence and distant metastasis remain to be the concerns. With the recent technological advancements, various special radiotherapy treatment options have been offered. This review article discusses the recently-developed special radiotherapy treatment modalities for various conditions of colorectal cancer ranging from early stage, locally advanced stage, recurrent, and metastatic diseases. The discussion focuses on the areas of feasibility, local control, and survival benefits of the treatment modalities. This review also provides accounts of the future direction in radiotherapy of colorectal cancer with emphasis on the coming era of personalized radiotherapy.

Results of re-irradiation for pelvic recurrence in anorectal cancer patients

OBJECTIVE

To evaluate outcomes and toxicity profiles after re-irradiation in patients with pelvic recurrence of anorectal cancer.

METHODS

25 anorectal cancer patients who received re-irradiation for pelvic recurrence between 2005 and 2015 were included. For initial treatment, all patients underwent surgical resection and preoperative or postoperative radiotherapy.

RESULTS

The median follow-up duration was 21.5 months (range, 2.9-84.4). After a median of 43.3 months (range, 11.7-218.5), patients received re-irradiation with a median dose of 45 Gy (range, 36-60). The equivalent dose in 2 Gy fractions (EQD2) of re-irradiation-calculated using α/β = 10 Gy-ranged from 34.5 to 84.0 Gy (median, 46.4). Surgical resection was performed for 11 patients, and 14 patients received concurrent chemotherapy with re-irradiation. The 3-year local progression-free survival was 29.7%. The 3-year overall survival was 49.7%. Concurrent chemotherapy with re-irradiation and re-irradiation doses >50 Gy EQD2_α/β=10 were significant prognostic factors for local progression free survival and overall survival according to multivariate analysis. 90% (9 of 10) of patients with symptoms had improvement after re-irradiation. Among 23 patients available for evaluation of late toxicity, 12 developed late toxicities. There were no Grade 4 late toxicities, and 6 patients had Grade 3 late toxicities (small bowel obstruction, bowel perforation and fistula).

CONCLUSION

Re-irradiation for pelvic recurrence of anorectal cancer improved symptoms of patients but the rate of late toxicity was high. Further investigation for patient selection is required.

ADVANCES IN KNOWLEDGE

Re-irradiation could be considered as a possible option for pelvic recurrence of anorectal cancer in selected patients.

Carbon-ion radiotherapy for locally recurrent rectal cancer: Japan Carbon-ion Radiation Oncology Study Group (J-CROS) Study 1404 Rectum

PURPOSE

We investigated the efficacy and safety of carbon-ion radiotherapy (C-ion RT) for locally recurrent rectal cancer (LRRC).

PATIENTS AND METHODS

Data from patients with LRRC treated with C-ion RT from November 2003 to December 2014 at three institutions were retrospectively analyzed. The endpoints of this clinical trial were overall survival (OS), local control (LC), and acute/late toxicity.

RESULTS

A total of 224 patients' data were collected. The prescribed dose was 70.4 Gy (relative biological effectiveness [RBE]-weighted absorbed dose) or 73.6 Gy (RBE) in 16 fractions. The median follow-up period from the initiation of C-ion RT was 62 months (range 6-169 months). The OS rates were 73% (95% confidence interval [CI], 67%-79%) at 3 years and 51% (95%CI 44%-58%) at 5 years. The LC rates were 93% (95%CI 88%-96%) at 3 years, and 88% (95%CI 82%-93%) at 5 years. Grade 3 acute toxicity was observed in three patients: gastrointestinal toxicity (n = 1) and pelvic infection (n = 2). Grade 3 late toxicity was observed in 12 patients: skin reaction (n = 2), gastrointestinal toxicity (n = 2), neuropathy (n = 1), and pelvic infection (n = 7). There was no grade 4 or 5 acute or late toxicity.

CONCLUSIONS

This first multi-institutional analysis of C-ion RT for LRRC indicated relatively favorable outcomes with limited toxicities.

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.

Magnetic Resonance-guided Inter-fraction Monitoring Opens Doors to Delivering Safer Reirradiation: An Illustrative Case Report and Discussion

Locoregional recurrence in the pelvis after definitive treatment for rectal cancer can lead to significant morbidity. Furthermore, the toxicity associated with reirradiation may also negatively impact the quality of life and even survival. Here we present the case of a 39-year-old male with locoregionally recurrent rectal cancer in a left pelvic sidewall lymph node, treated with stereotactic magnetic resonance (MR)-guided ablative radiotherapy after previously receiving long-course chemoradiation that had already exceeded ideal bowel dose constraints. We discuss the distinct advantages of MR-guidance in the setting of pelvic reirradiation, particularly with regard to inter- and intra-fraction visualization of the target and neighboring bowel anatomy. In this context, MR-guidance may allow radiation oncologists to increase target precision and accuracy, while simultaneously decreasing toxicity to neighboring tissues.

Local Control and Toxicity of External Beam Reirradiation With a Pulsed Low-dose-rate Technique

PURPOSE

To evaluate the efficacy and toxicity of external beam reirradiation using a pulsed low-dose-rate (PLDR) technique.

METHODS AND MATERIALS

We evaluated patients treated with PLDR reirradiation from 2009 to 2016 at a single institution. Toxicity was graded using the Common Terminology Criteria for Adverse Events, version 4.0, and local control was assessed using the Response Evaluation Criteria In Solid Tumors, version 1.1. On univariate analysis (UVA), the χ2 and Fisher exact tests were used to assess the toxicity outcomes. Competing risk analysis using cumulative incidence function estimates were used to assess local progression.

RESULTS

A total of 39 patients were treated to 41 disease sites with PLDR reirradiation. These patients had a median follow-up time of 8.8 months (range 0.5-64.7). The targets were the thorax, abdomen, and pelvis, including 36 symptomatic sites. The median interval from the first radiation course and reirradiation was 26.2 months; the median dose of the first and second course of radiation was 50.4 Gy and 50 Gy, respectively. Five patients (13%) received concurrent systemic therapy. Of the 39 patients, 9 (23%) developed grade ≥2 acute toxicity, most commonly radiation dermatitis (5 of 9). None developed grade ≥4 acute or subacute toxicity. The only grade ≥2 late toxicity was late skin toxicity in 1 patient. On UVA, toxicity was not significantly associated with the dose of the first course of radiation or reirradiation, the interval to reirradiation, or the reirradiation site. Of the 41 disease sites treated with PLDR reirradiation, 32 had pre- and post-PLDR scans to evaluate for local control. The local progression rate was 16.5% at 6 months and 23.8% at 12 months and was not associated with the dose of reirradiation, the reirradiation site, or concurrent systemic therapy on UVA. Of the 36 symptomatic disease sites, 25 sites (69%) achieved a symptomatic response after PLDR, including 6 (17%) with complete symptomatic relief.

CONCLUSION

Reirradiation with PLDR is effective and well-tolerated. The risk of late toxicity and the durability of local control were limited by the relatively short follow-up duration in the present cohort.

Feasibility and Outcome of Concurrent Chemoradiotherapy for Recurrent Cervical Carcinoma after Initial Surgery

Aims and background

The prognosis for recurrent cervical carcinoma following initial surgery is dismal even when aggressive radiotherapy or salvage surgery is used. We retrospectively reviewed hospital records to evaluate the efficacy and feasibility of concurrent chemoradiotherapy as a salvage treatment.

Methods

From 1999 to 2007, 47 patients received salvage chemoradiotherapy. Involved-field irradiation was delivered at a median dose of 64.8 Gy (range, 36–100.2), including brachytherapy boost in 10 patients. Pelvic re-irradiation was performed in 4 of the 12 women who had a previous history of pelvic radiotherapy. All but one patient received cisplatin-based concomitant chemotherapy during radiotherapy.

Results

The median overall follow-up period was 27 months and for surviving patients was 57 months. The interval between initial surgery and recurrence was 22 months (range, 4–203), and the median recurrent mass size was 4 cm (range, 0.5–11). In 34 patients, recurrent tumors were confined to the pelvis (21 central and 13 peripheral). Grade 3–4 acute hematologic toxicity was the most frequent toxicity and was observed in 29 (62%) women. Five-year actuarial cumulative incidence of severe gastrointestinal and genitourinary toxicity was 13% and 7%, respectively. Thirty-three patients (70%) showed a complete response and 9 (19%) a partial response following salvage chemoradiation. Five-year overall and disease-free survival rates were 44% and 41%, respectively.

Conclusions

Salvage chemoradiotherapy appears to be a feasible treatment option for women with recurrent cervical carcinoma following surgery. The treatment had a high salvage rate and acceptable late complication rate, despite being associated with substantial acute toxicity.

Feasibility of helical tomotherapy for radical dose retreatment in pelvic area: A report of 4 cases

Aims and background

To retrospectively determine acute toxicity and local control in patients with recurrence after definitive radiotherapy for prostate, bladder and rectal carcinoma.

Methods

Between September 2009 and March 2010, 4 patients with a prior history of pelvic radiotherapy were treated with helical tomotherapy. The prior course of radiotherapy was given for prostate cancer in 2 patients, bladder carcinoma in 1 patient and rectal carcinoma in 1 patient. The median prescribed dose of the prior course of radiotherapy was 6320 cGy (range, 5000–7600), and the median elapsed time between the first and second course was 17 months (range, 4–73). The total prescribed dose for tomotherapy retreatment was 60 Gy in 3 patients and 50 Gy in 1 patient. Hormone therapy was administered to 2 patients before and during radiation. No patient underwent surgical resection.

Results

The cumulative mean dose to the rectum ranged from 3813 to 6058 cGy; cumulative rectal maximum dose to 1 cc ranged from 6475 to 8780 cGy. Regarding the bladder, the cumulative mean dose was between 4384 and 7612 cGy; cumulative maximum dose to 1 cc ranged from 7560 to 9790 cGy. All patients completed the re-irradiation course. Acute genitourinary toxicity (RTOG scale) was grade 0 in 3 patients and grade 1 in 1 patient; acute gastrointestinal toxicity was grade 0 in 3 patients and grade 1 in 1 patient. With a median follow-up of 9 months (range, 7–12), late toxicity was G0 in all patients. Three patients showed partial response with computed tomography or magnetic resonance imaging, and 1 had a PSA decrease.

Conclusions

Re-irradiation with helical tomotherapy was well tolerated, with low rates of acute and late toxicity. It can be therefore considered a useful tool to improve local control in patients previously treated with radiotherapy. However, a larger number of patients and a longer follow-up are required to assess retreatment safety.

Preliminary results of a cohort study of induction chemotherapy-based treatment for locally recurrent rectal cancer

BACKGROUND

A significant number of patients treated for locally recurrent rectal cancer have local or systemic failure, especially after incomplete surgical resection. Neoadjuvant treatment regimens in patients who have already undergone preoperative (chemo)radiotherapy for the primary tumour are limited. The objective of the present study was to evaluate the influence of a neoadjuvant regimen incorporating induction chemotherapy (ICT) in patients with locally recurrent rectal cancer who had preoperative (chemo)radiotherapy for the primary cancer or an earlier local recurrence.

METHODS

Patients were treated with a sequential neoadjuvant regimen including three or four cycles of 5-fluorouracil and oxaliplatin-containing chemotherapy. When no progressive disease was found at evaluation, neoadjuvant treatment was continued with chemoradiation therapy (CRRT) using 30 Gy with concomitant capecitabine. If there was a response to ICT, the patient was advised to continue with systemic chemotherapy after CRRT as consolidation chemotherapy while waiting for resection. These patients were compared with patients who received CRRT alone in the same time interval.

RESULTS

Of 58 patients who had ICT, 32 (55 per cent) had surgery with clear resection margins, of whom ten (17 per cent) exhibited a pathological complete response (pCR). The remaining 26 patients had 23 R1 and three R2 resections. In 71 patients who received CRRT, a similar rate of R0 (35 patients) and R1 (36) resection was found (P = 0·506), but only three patients (4 per cent) had a pCR (P = 0·015).

CONCLUSION

The incorporation of ICT in neoadjuvant regimens for locally recurrent rectal cancer is a promising strategy.

[Reconstruction of abdo-perineal resection by Taylor flap: About 68 patients]

PURPOSES

Healing after abdomino-perineal resection is often difficult, especially in patients who have undergone radiation therapy. Vaginal reconstruction is also an important issue for the women who undergo this surgery. We describe and analyze here our series of perineal reconstructions with modified Taylor flaps. Between 2010 and 2016, 68 patients (52 women, 16 men) with cancer of the anal canal (53), adenocarcinoma of the lower rectum (9), or other malignant neoplasms of the perineum underwent reconstruction with a rectus abdominis myocutaneous (RAM) flap with an inferior pedicle and an oblique skin paddle.

RESULTS

This review of records showed that all patients healed, with a median of 30 days. The reoperation rate was 11.7% including 1 for eventration. The principal causes for delayed healing were scar dehiscence, abscess, and partial necrosis. No flap required removal, however. The mean duration of hospitalization was 23.7 days.

CONCLUSION

Modified Taylor flaps substantially improved the reconstruction of defects resulting from abdomino-perineal resection. They enabled complete and rapid healing with low comorbidity.

Re-irradiation of locoregional esophageal cancer recurrence following definitive chemoradiotherapy: A report of 6 cases

There is currently no consensus on salvage therapy for recurrent esophageal cancer. Salvage surgery is a well-established option for attaining long-term survival; however, it is associated with a high risk of perioperative morbidity and mortality. A total of 6 patients who underwent re-irradiation for recurrence of locoregional esophageal cancer following definitive chemoradiotherapy were investigated. The median interval between initial radiotherapy and re-irradiation was 17.4 months (range, 6.4-59.2 months). Re-irradiation salvage therapy was mostly administered with concurrent chemotherapy, which consisted of several cycles of nedaplatin on day 1 and oral S-1 administration on days 1-14. The median survival after re-irradiation was 13.6 months (range, 1.9-33.3 months). A total of 3 patients who completed hyperfractionated radiation therapy survived for >1 year. One patient has had no signs of recurrence or late radiation toxicity for >2 years. Severe acute hematological adverse events (AEs) occurred in 3 patients, including 1 case of grade 4 leukopenia. One severe late AE occurred in 1 patient, who developed grade 3 dysphagia and became permanently dependent on percutaneous endoscopic gastrostomy tube feeding. Salvage radiotherapy is considered to be a good treatment option for inoperable locoregional recurrent esophageal cancer. The results of the present study demonstrated that re-irradiation, with or without chemotherapy, for recurrent esophageal carcinoma after definitive chemoradiotherapy was tolerable and yielded reasonably satisfactory results.

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.

A Systematic Review to Assess Resection Margin Status After Abdominoperineal Excision and Pelvic Exenteration for Rectal Cancer

OBJECTIVE

The aim of this study was to assess resection margin status and its impact on survival after abdominoperineal excision and pelvic exenteration for primary or recurrent rectal cancer.

SUMMARY OF BACKGROUND DATA

Resection margin is important to guide therapy and to evaluate patient prognosis.

METHODS

A meta-analysis was performed to assess the impact of resection margin status on survival, and a regression analysis to analyze positive resection margin rates reported in the literature.

RESULTS

The analysis included 111 studies reporting on 19,607 participants after abdominoperineal excision, and 30 studies reporting on 1326 participants after pelvic exenteration. The positive resection margin rates for abdominoperineal excision were 14.7% and 24.0% for pelvic exenteration. The overall survival and disease-free survival rates were significantly worse for patients with positive compared with negative resection margins after abdominoperineal excision [hazard ratio (HR) 2.64, P < 0.01; HR 3.70, P < 0.01, respectively] and after pelvic exenteration (HR 2.23, P < 0.01; HR 2.93, P < 0.01, respectively). For patients undergoing abdominoperineal excision with positive resection margins, the reported tumor sites were 57% anterior, 15% posterior, 10% left or right lateral, 8% circumferential, 10% unspecified. A significant decrease in positive resection margin rates was identified over time for abdominoperineal excision. Although positive resection margin rates did not significantly change with the size of the study, some small size studies reported higher than expected positive resection margin rates.

CONCLUSIONS

Resection margin status influences survival and a multidisciplinary approach in experienced centers may result in reduced positive resection margins. For advanced anterior rectal cancer, posterior pelvic exenteration instead of abdominoperineal excision may improve resection margins.

Irreversible Electroporation to Treat Malignant Tumor Recurrences Within the Pelvic Cavity: A Case Series

OBJECTIVE

To describe the initial experience with irreversible electroporation (IRE) to treat pelvic tumor recurrences.

METHODS

A retrospective single-center analysis was performed. Adverse events were recorded using Common Terminology Criteria of Adverse Events (CTCAE) 4.0. Clinical outcome was determined using pain- and general- symptom assessment, including Seddon's peripheral nerve injury (PNI) types. Radiological outcome was evaluated by comparing baseline with three-month 18F-FDG PET-CT follow-up.

RESULTS

Eight patients (nine tumors [recurrences of primary rectal (n = 4), anal (n = 1), sigmoid (n = 1), cervical (n = 1), and renal cell carcinoma (n = 1)]) underwent percutaneous IRE as salvage therapy. Median longest tumor diameter was 3.7 cm (range 1.2-7.0). One CTCAE grade III adverse event (hemorrhage) and eight CTCAE grade II complications occurred in 6/8 patients: vagino-tumoral fistula (n = 1), lower limb motor loss (n = 3; PNI type II) with partial recovery in one patient, hypotonic bladder (n = 2; PNI types I and II) with complete recovery in one patient, and upper limb motor loss (n = 2; PNI type II) with partial recovery in both patients. No residual tumor tissue was observed at 3-month follow-up. After a median follow-up of 12 months, local progression was observed in 5/9 lesions (4/5 were >3 cm pre-IRE); one lesion was successfully retreated. Debilitating preprocedural pain (n = 3) remained unchanged (n = 1) or improved (n = 2).

CONCLUSION

IRE may represent a suitable technique to treat pelvic tumor recurrences, although permanent neural function loss can occur. Complete ablation seems realistic for smaller lesions; for larger lesions symptom control should be the focus.

Characterization of efficacy and toxicity after high-dose pelvic reirradiation with palliative intent for genitourinary second malignant neoplasms or local recurrences after full-dose radiation therapy in the pelvis: A high-volume cancer center experience

Purpose

The use of large-field external beam reirradiation (re-RT) after pelvic radiation therapy (RT) for genitourinary (GU) cancers has not been reported. We report the results of such treatment in patients with either symptomatic GU second malignant neoplasms or locally recurrent pelvic tumors after initial RT for whom surgery or further systemic therapy was not an option.

Methods and materials

The records of 28 consecutive patients with advanced, bulky GU malignancies treated with high-dose, large-field re-RT with palliative intent between 2008 and 2014 were retrospectively reviewed. Descriptive outcome analyses focused on toxicities and symptom control, and responses were evaluated by 2 independent observers.

Results

Twenty-seven male patients (96%) were included. Median initial external beam RT dose was 64 Gy (range, 30-75.6 Gy). The median time between initial RT and re-RT was 9.5 years (range, 0.2-32 years). At the time of re-RT, there were 16 local recurrences and 12 second malignant neoplasms together comprising 16 bladder, 10 prostate, 1 ureteral, and 1 penile cancer. Indications for re-RT were pain and bleeding/hemorrhage. The median equivalent sphere diameter planning target volume for re-RT was 8.6 cm (range, 4.7-16.3 cm). Given the severity of the symptoms and the bulk of the disease at the time of re-RT, a higher dose of RT was administered. The median re-RT dose was 50 Gy (range, 27.5-66 Gy). For patients who received <60 Gy, hypofractionation of 250 cGy was used. The median cumulative dose was 113.9 Gy (range, 81.5-132.8 Gy). Re-RT was well tolerated with no Radiation Therapy Oncology Group grade 3-4 toxicities. Twenty-four patients (92%) had complete resolution of symptoms, and relief was durable in 67% of patients. The median overall survival was 5.8 months (range, 0.3-38.9 months). Of those patients who are still alive, 100% remain free of initial symptoms.

Conclusion

This small series suggests that aggressive re-RT of inoperable and symptomatic GU malignancies that is undertaken with meticulous treatment planning is well tolerated and provides excellent, durable relief without undue short-term toxicity. Validation in a larger prospective cohort is required.

Intraoperative radiation therapy for colon and rectal cancers: a clinical review

Although there have been significant advances in the adjuvant therapy of colorectal cancer, results for patients have historically been poor when complete resection is unlikely or not possible. Similarly, locally recurrent colorectal cancer patients often experience significant tumor related morbidity and disease control and long term survival have historically been poor with standard therapies. Intraoperative radiation therapy (IORT) has been proposed as a possible tool for dose escalation in patients with locally advanced colorectal cancer.

For patients with locally advanced primary or recurrent colon cancer, the absence of prospective controlled trials limits the ability to draw definitive conclusions in completely resected patients. In subtotally resected patients, the available evidence is consistent with marked improvements in disease control and survival compared to historical controls. For patients with locally advanced primary or recurrent rectal cancer, a relatively large body of evidence suggests improved disease control and survival, especially in subtotally resected patients, with the addition of IORT to moderate dose external beam radiation (EBRT) and chemotherapy. The most important prognostic factor in nearly all series is the completeness of surgical resection. Many previously irradiated patients may be carefully re-treated with radiation and IORT in addition to chemotherapy resulting in long term survival in more than 25% of patients. Peripheral nerve is dose limiting for IORT and patients receiving 15 Gy or more are at higher risk.

IORT is a useful tool when dose escalation beyond EBRT tolerance limits is required for acceptable local control in patients with locally advanced primary or recurrent colorectal cancer. Previously irradiated patients should not be excluded from treatment consideration.