Reirradiation of locally recurrent rectal cancer: A systematic review

Re-irradiation for recurrent rectal cancer - a single-center experience

Background: There is no clear consensus on the use of re-irradiation (reRT) in the management of locally recurrent rectal cancer (LRRC). The aim of the present study was to investigate all reRT administered for rectal cancer at a large referral institution and to evaluate patient outcomes and toxicity.Material and methods: All patients with rectal cancer were identified who had received previous pelvic radiotherapy (RT) and underwent reRT during 2006-2016. Medical records and RT details of the primary tumor treatments and rectal cancer recurrence treatments were registered, including details on reRT, chemotherapy, surgery, adverse events, and long-term outcomes.Results: Of 77 patients who received ReRT, 67 had previously received pelvic RT for rectal cancer and were administered reRT for LRRC. Re-irradiation doses were 30.0-45.0 Gy, most often given as hyperfractionated RT in 1.2-1.5 Gy fractions twice daily with concomitant capecitabine. The median time since initial RT was 29 months (range, 13-174 months). Of 36 patients considered as potentially resectable, 20 underwent surgery for LRRC within 3 months after reRT. Operated patients had better 3-year overall survival (OS) (62%) compared to those who were not operated (16%; HR 0.32, p = .001). The median gross tumor volume (GTV) was 107 cm³, and 3-year OS was significantly better in patients with GTV <107 cm³ (44%) compared to patients with GTV ≥107 cm³ (21%; HR 0.52, p = .03).Conclusion: Three-year survival was significantly better for patients who underwent surgery after reRT or who had small tumor volume. Prospective clinical trials are recommended for further improvements in patient selection, outcomes, and toxicity assessment.

Long-term outcomes following salvage surgery for locally recurrent rectal cancer: A 15-year follow-up study

BACKGROUND

Locally recurrent rectal cancer (LRRC) is a complex problem requiring multidisciplinary consultation and specialized surgical care. Given the paucity of published longer-term survival data, skepticism persists regarding the benefit of major extirpative surgery. We investigated ultra-long-term (~15 years) outcomes following radical resection of LRRC and sought relevant clinicopathologic prognostic variables.

METHODS

A cohort of 52 consecutive patients who underwent resection of LRRC at our institution between 1997 and 2005 were followed with serial exams and imaging up to the point of death, or 30/06/2019.

RESULTS

Median follow-up time was 16.5 years (9.9-18.3) for patients who were alive at last follow-up; only one patient was lost to follow-up, at 9.9 years. For the entire cohort of 52 patients, disease-specific survival (DSS) at 5, 10, and 15 years following salvage surgery was 41%, 33%, and 31%, respectively. All patients who had distant metastatic disease at the time of LRRC resection (n = 6) subsequently died of cancer, at a median of 21 months (4-46). In those without distant metastases at time of salvage surgery (n = 46), DSS at 5, 10, and 15 years was 47%, 38%, and 35%, respectively, median 60 months. Negative resection margin (R0) was independently predictive of superior outcomes. In patients with M0 disease who had R0 resection (n = 37), DSS at 5, 10 and 15 years was 58%, 47%, and 44%, respectively, median 73 months. No patient developed re-recurrence after 5.5 years.

CONCLUSIONS

This study demonstrates exceptionally durable long-term cancer-free survival following salvage surgery for LRRC, indicating that cure is possible.

Increased risk for second primary rectal cancer after pelvic radiation therapy

BACKGROUND

The aim of this study was to analyse the association between pelvic radiation therapy (RT) and the development of rectal cancer as a second primary cancer.

METHODS

Data on patients treated for a primary pelvic cancer between 1989 and 2007 were retrieved from the population-based Netherlands Cancer Registry. Patients treated for more than one pelvic cancer were excluded. To estimate the cumulative incidence of rectal cancer, Fine and Gray's competing risk model was used with death as a competing event. Survival was calculated using multivariable Cox regression.

RESULTS

A total of 192,658 patients were included, of which 62,630 patients were treated with RT for their pelvic cancer. Primary tumours were located in the prostate (50.1%), bladder (19.2%), endometrium (13.9%), ovaries (10.0%), cervix (6.4%) and vagina (0.4%). At a median interval of 6 years (range 0-24), 1369 patients developed a rectal cancer. Overall, the risk for rectal cancer was increased in patients who underwent RT for the previous pelvic cancer (subhazard ratio [SHR]: 1.72, 95% confidence interval [CI]: 1.55-1.91). Analysis for each tumour location specifically showed an increased risk in patients who received RT for prostate (SHR: 1.89, 95% CI: 1.66-2.16) or endometrial cancer (SHR: 1.50, 95% CI: 1.13-2.00). A protective effect of RT was observed for patients with bladder cancer (SHR 0.67, 95% CI: 0.47-0.94). There was no survival difference between patients with rectal cancer with or without previous RT (hazard ratio: 0.94, 95% CI: 0.79-1.11).

CONCLUSIONS

Patients who received RT for a previous pelvic cancer were at increased risk for rectal cancer. The risk was modest and pronounced in patients receiving RT for prostate and endometrial cancer.

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.

Salvage Curative-Intent Reirradiation Stereotactic Body Radiation Therapy for Isolated Pelvic and/or Paraortic Recurrences of Gynecologic Malignancies

PURPOSE

To determine the feasibility of stereotactic body radiation therapy (SBRT) for isolated nodal recurrences of gynecologic malignancies within a previously irradiated area.

METHODS AND MATERIALS

A retrospective review was performed on 20 patients who underwent 21 curative-intent reirradiation SBRT treatments for locoregional recurrences of gynecologic malignancies. Disease control and survival outcomes were analyzed with the Kaplan-Meier method and log-rank test. Treatment toxicities were graded according to Common Terminology Criteria for Adverse Events version 4.03.

RESULTS

All patients had an isolated pelvic, paraortic, or intra-abdominal nodal recurrence, with the exception of 1 patient who had a concurrent paraortic and right acetabulum metastasis, both of which were irradiated with SBRT. Primary sites included cervix (30.0%), uterus (55.0%), vulva (5.0%), vagina (5.0%), and ovary (5.0%). Median prior external beam radiation therapy dose was 45 Gy. Recurrences were in field in 14 (66.7%) and marginal in 7 (33.3%). SBRT was directed to the pelvis in 13 cases (61.9%) and to paraortic or celiac nodes in 8 (38.1%). The most common SBRT regimen was 40 to 45 Gy in 5 fractions (n = 12). At a median follow-up of 31.2 months, 3-year actuarial in-field local control, distant progression-free survival, and overall survival were 61.4%, 44.0%, and 51.9%, respectively. At the time of last follow-up, 9 (45.0%) patients remained alive without evidence of disease. Actuarial 3-year risk of grade ≥2 and grade ≥3 late toxicities was 38.1% and 14.3%, respectively.

CONCLUSIONS

SBRT for isolated pelvic or intra-abdominal recurrences of gynecologic malignancies within a previously irradiated field is feasible with an acceptable toxicity rate. With this approach, about half of patients achieved durable disease-free survival.

Clinical safety and efficacy of salvage reirradiation for upper abdominal malignancies

PURPOSE

Reirradiation has the potential to provide effective local control of upper abdominal malignancies. This study aimed to evaluate the safety and efficacy of reirradiation for upper abdominal malignancies.

METHODS

A total of 42 patients with a history of prior radiotherapy (RT) received reirradiation for abdominal malignancies between 2005 and 2017. Each patient's medical records, contours, and dose distribution for both RT courses were reviewed. The median dose of the prior RT was 50.0 Gy (range, 30.0-60.0 Gy) and the median dose of reirradiation was 45.0 Gy (range, 15.0-75.0 Gy).

RESULTS

With a median follow-up of 10.9 months, the median infield-failure-free survival (IFFS) rate was 9.2 months. Gross tumor volume (GTV) significantly related to IFFS in both the univariate (p = 0.009) and multivariate analyses (p = 0.024), and patients with a GTV of <60.0 mL had an improved IFFS (p = 0.001). Four patients experienced ≥grade 3 late toxicities. In the retrospective dose reconstruction analysis in these patients, the cumulative dose to the most exposed 2 cc (D2cc) of the duodenum was >60.0 Gy (range, 60.1-73.7 Gy). In the univariate analysis, the D2cc of the duodenum and a preexisting duodenal ulcer identified using endoscopy prior to reirradiation significantly correlated with late severe toxicity (p = 0.021 and 0.017, respectively).

CONCLUSIONS

Reirradiation for upper abdominal malignancies could be safely performed for patients without preexisting gastrointestinal morbidity unless the duodenum received excessive radiation doses. Reirradiation could also provide substantial IFFS, especially for patients with a GTV of <60.0 mL.

A Practical Radiotherapy Treatment Planning Technique for Second-Incidence Cancers That Incorporates Complete Organ-At-Risk Dose History

INTRODUCTION

Patients requiring treatment for second cancer incidences present unique radiotherapy plan development challenges. Historical dose delivered to organs at risk must be accounted for to properly estimate lifetime toxicity risks, but historical dose delivered to the region now occupied by tumours does not contribute to the prescription dose. Treatment planning systems permit inclusion of a base plan but do not provide the ability to manipulate it. We present a technique, dose cropping, which incorporates organ-at-risk dose history into the base plan while selectively excising dose history to diseased tissues now occupied by tumours. A retrospective plan comparison is performed to assess the effectiveness of dose cropping.

METHODS AND MATERIALS

Nine patients who received a second course of radiotherapy for cancers of the head-and-neck were replanned using the proposed technique. Clinical second courses and replans were compared on the basis of conformity index, heterogeneity index, maximum point dose, tissue control probability (TCP), normal tissue complication probability (NTCP), and whether the planning guidelines could be met by the treatment planning system. Replan constraints and guidelines followed the clinical treatment. In addition, a tissue recovery model was incorporated, applied to both clinical and replan courses, and compared to estimate the relevance of the dose cropping technique in such regimes.

RESULTS AND DISCUSSION

Replans had reduced organ-at-risk maximum point doses (5 Gy for spinal cord, 4 Gy for brainstem), NTCP (2.9% median reduction), and were able to more consistently achieve the V_95% > 98% coverage target regardless of the tissue recovery model. At the same time, replans using the dose cropping technique were statistically indistinguishable from clinical second courses on the basis of plan conformity, heterogeneity, or TCP (P > .31 in all cases).

CONCLUSIONS

Dosimetric history cropping is a valuable and widely applicable technique for second cancer radiotherapy planning. It also provides a natural means to incorporate tissue recovery models, biologically effective dose conversion, and NTCP and TCP model evaluation.

Cancer risk assessment in modern radiotherapy workflow with medical big data

Modern radiotherapy (RT) is being enriched by big digital data and intensive technology. Multimodality image registration, intelligence-guided planning, real-time tracking, image-guided RT (IGRT), and automatic follow-up surveys are the products of the digital era. Enormous digital data are created in the process of treatment, including benefits and risks. Generally, decision making in RT tries to balance these two aspects, which is based on the archival and retrieving of data from various platforms. However, modern risk-based analysis shows that many errors that occur in radiation oncology are due to failures in workflow. These errors can lead to imbalance between benefits and risks. In addition, the exact mechanism and dose-response relationship for radiation-induced malignancy are not well understood. The cancer risk in modern RT workflow continues to be a problem. Therefore, in this review, we develop risk assessments based on our current knowledge of IGRT and provide strategies for cancer risk reduction. Artificial intelligence (AI) such as machine learning is also discussed because big data are transforming RT via AI.

Second Re-irradiation: Clinical Examples of Worthwhile Treatment

INTRODUCTION

 Improved treatment approaches have resulted in longer survival of patients with certain types of incurable cancer, without eliminating the need for symptom palliation and supportive measures. In this context, re-irradiation is an increasingly important option. Little data exists about a second or repeat re-irradiation.

METHODS

From a single institution database, patients who received a second re-irradiation with cumulative equivalent doses (equivalent dose in 2-Gy fractions (EQD2) for late effects, alpha/beta-value 3 Gy) of more than 90 Gy and survived for more than six months were identified. Illustrative clinical examples were provided.

RESULTS

The examples describe the treatment of sacral bone metastases, recurrent rectal cancer, and pelvic lymph node metastases. The maximum cumulative EQD2 was 142 Gy. Symptomatic responses were obtained without clinically relevant side effects.

CONCLUSION

 These three cases illustrate that a second re-irradiation has the potential to provide worthwhile palliative effects without causing overt late toxicity during the remaining life time. In patients who tolerated previous radiotherapy well, further re-irradiation may contribute to the ever-increasing armamentarium of options that increase the survival of patients with incurable cancer and try to prolong the time period where independent living is possible.

Outcomes and prognostic factors of multimodality treatment for locally recurrent rectal cancer with curative intent

PURPOSE

Radical management of locally recurrent rectal cancer (LRRC) can lead to prolonged survival. This study aims to assess outcomes and identify prognostic factors for patients with LRRC treated using a multimodality treatment protocol.

METHODS

An analysis of a prospectively maintained institutional database of consecutive patients who underwent radical surgical resection for LRRC was performed. Potential prognostic factors were investigated using a Cox proportional hazards model.

RESULTS

Ninety-eight patients were included in this study. A multimodality approach was taken in the majority, including preoperative chemoradiation (78%), intraoperative radiation therapy (47%) and adjuvant chemotherapy (41%). Extended resection was performed where required: bone resection (34%) and lateral pelvic sidewall dissection (31%). The rate of R0 resection was 66%. Estimated rates of 5-year overall survival (OS) and progression-free survival (PFS) were 41.8% (95% CI 32.5-53.7) and 22.5% (95% CI 15.3-33.1). On multivariate analysis, stage III disease at initial primary surgery, a positive margin at initial primary surgery, synchronous or previously resected oligometastases, a lateral or sacral invasive-type pelvic recurrence and the requirement for IORT all predicted for inferior PFS (p < 0.05). Eleven percent of patients subsequently underwent further pelvic surgery for pelvic re-recurrence and had an estimated 5-year OS rate of 54.5% (95% CI 29.0-100.0) from repeat surgery.

CONCLUSIONS

Radical multimodality management of LRRC leads to prolonged survival in approximately 40% of patients. Those with sacral or lateral invasive-type recurrence or oligometastatic disease have inferior outcomes and further research is needed to optimise treatment for these groups.

Second re-irradiation: a narrative review of the available clinical data

BACKGROUND

Considerable controversy exists about the safety and efficacy of second re-irradiations (three courses of radiotherapy to overlapping volumes). Therefore, all published clinical studies were reviewed.

MATERIAL AND METHODS

Contemporary and historical articles were identified. Outcomes such as survival, local control, symptom improvement and side effects were extracted. Contemporary results were grouped by anatomical location of the re-irradiated region in the body.

RESULTS

Most data were derived from central nervous system tumors, pelvic tumors and bone metastases. We could include nine contemporary, retrospective studies with 2-25 patients each. Nearly, all patients were treated with palliative intent. Most of the prescribed re-irradiation regimens were highly individualized and thus difficult to compare. Symptomatic responses were recorded in most patients. In palliatively treated patients with pelvic and bony target volumes, high-grade toxicity was uncommon.

CONCLUSIONS

Despite of issues related to study size, length of follow-up and calculation of lifetime cumulative equivalent dose, the available data provide an initial framework for future studies and discussion of dose constraints. Selected dose-fractionation regimens may result in a satisfactory therapeutic ratio even after two previous courses of radiotherapy, if these were well tolerated.

Response of Fibroblasts MRC-5 to Flufenamic Acid-Grafted MCM-41 Nanoparticles

Recently, flufenamic acid (FFA) was discovered among fenamates as a free radical scavenger and gap junction blocker; however, its effects have only been studied in cancer cells. Normal cells in the surroundings of a tumor also respond to radiation, although they are not hit by it directly. This phenomenon is known as the bystander effect, where response molecules pass from tumor cells to normal ones, through communication channels called gap junctions. The use of the enhanced permeability and retention effect, through which drug-loaded nanoparticles smaller than 200 nm may accumulate around a tumor, can prevent the local side effect upon controlled release of the drug. The present work, aimed at functionalizing MCM-41 (Mobil Composition of Matter No. 41) silica nanoparticles with FFA and determining its biocompatibility with human fibroblasts MRC-5 (Medical Research Council cell strain 5). MCM-41, was synthesized and characterized structurally and chemically, with multiple techniques. The biocompatibility assay was performed by Live/Dead technique, with calcein and propidium–iodide. MRC-5 cells were treated with FFA-grafted MCM-41 for 48 h, and 98% of cells remained viable, without signs of necrosis or morphological changes. The results show the feasibility of MCM-41 functionalization with FFA, and its potential protection of normal cells, in comparison to the role of FFA in cancerous ones.

Pelvic re-irradiation using stereotactic ablative radiotherapy (SABR): A systematic review

BACKGROUND AND PURPOSE

To perform a systematic review regarding the use of stereotactic ablative radiotherapy (SABR) for the re-irradiation of recurrent malignant disease within the pelvis, to guide the clinical implementation of this technique.

MATERIAL AND METHODS

A systematic search strategy was adopted using the MEDLINE, EMBASE and Cochrane Library databases.

RESULTS

195 articles were identified, of which 17 were appropriate for inclusion. Studies were small and data largely retrospective. In total, 205 patients are reported to have received pelvic SABR re-irradiation. Dose and fractionation schedules and re-irradiated volumes are highly variable. Little information is provided regarding organ at risk constraints adopted in the re-irradiation setting. Treatment appears well-tolerated overall, with nine grade 3 and six grade 4 toxicities amongst thirteen re-irradiated patients. Local control at one year ranged from 51% to 100%. Symptomatic improvements were also noted.

CONCLUSIONS

For previously irradiated patients with recurrent pelvic disease, SABR re-irradiation could be a feasible intervention for those who otherwise have limited options. Evidence to support this technique is limited but shows initial promise. Based on the available literature, suggestions for a more formal SABR re-irradiation pathway are proposed. Prospective studies and a multidisciplinary approach are required to optimise future treatment.

CT-guided 125I brachytherapy for recurrent ovarian cancer

This retrospective study was to evaluate the local control and survival of ¹²⁵I brachytherapy for recurrent ovarian cancer. 52 ¹²⁵I brachytherapy procedures were performed in 47 patients with 51 recurrent ovarian cancer lesions. The follow-up period was 1-55 months (median 12 months). The local control rate (LC) of 3, 6, 12, 24 and 36 months was 93.3%, 77.7%, 58.9%, 38.7% and 19.3%, respectively. Patients with tumor size ≤ 4cm (85.7% vs 40.0%, P = 0.037) and actual D90 between 110 to 130Gy (47.4% vs 66.7% vs 62.5%, P = 0.029) had better LC. The 1, 2 and 3 years of overall survival (OS) was 79.3%, 63.0% and 52.5%, respectively. The poor performance status (HR 3.821, 95% CI 1.383-10.555; P = 0.010), concurrent distant metastasis (HR 9.222, 95% CI 1.710-49.737; P = 0.010) and large postoperative residual tumor size (HR 6.157, 95% CI 1.438-26.367; P = 0.014) were closely correlated with a poor OS. Our data indicate thatCT-guided ¹²⁵I brachytherapy is an effective and safe modality for the local treatment of recurrent ovarian cancer.

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.

Preserving the legacy of reirradiation: A narrative review of historical publications

PURPOSE

The purpose of this study is to illustrate the historical development of reirradiation during several decades of the 20th century, in particular between 1920 and 1960.

METHODS AND MATERIALS

We chose the format of a narrative review because the historical articles are heterogeneous. No systematic extraction of baseline data, treatment details, or follow-up care was possible in many cases.

RESULTS

Both hematological malignancies and solid tumors were treated with a second course of radiation therapy, and indications included local relapse, regional nodal recurrence, and second primary tumors developing in a previously treated region. The literature consists of retrospective single-institution analyses describing treatment approaches that included external beam radiation therapy, brachytherapy, or combinations thereof. Data on toxicities and survival were often provided. Breast cancer and gynecological, head and neck, brain, and skin tumors are among the entities included in this review.

CONCLUSIONS

The leading pioneers in the field are fully aware of many of the challenges we continue to debate today. These include the process of late tissue changes and development of personalized treatment approaches and better ways to select patients who are likely to benefit from a second course of radiation therapy.

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.

Radiotherapy for Colorectal Cancer: Current Standards and Future Perspectives

BACKGROUND

Multimodal treatment approaches are indispensable for patients with advanced-stage colorectal cancer. Radiotherapy has been established as essential part of perioperative concepts and was introduced as an option to face challenges such as local relapse or oligometastases.

METHODS

A literature review was performed to summarize evidence and current standards of radiotherapeutic concepts in the treatment of colorectal cancer.

RESULTS

For stage II/III rectal cancer, neoadjuvant radiotherapy is superior to adjuvant treatment. Two preoperative regimens have been established and are commonly used with different objectives: short-course radiotherapy (SC-RT) and long-course chemoradiotherapy (LC-CRT). Both reduce the risk of local relapse. Additionally, LC-CRT aims at downsizing the tumor to potentially reduce radicalness of surgery. There is increasing evidence that not all stage II/III rectal cancer patients need neoadjuvant irradiation but also that in some cases surgery might be omitted. Stereotactic body radiotherapy (SBRT) of the liver shows high rates of local control in oligometastatic patients. Intraoperative and particle radiotherapy extend the spectrum of treatment options for locally recurrent patients.

CONCLUSION

Radiotherapeutic concepts are crucial for the primary management of locally advanced colorectal cancer and can essentially contribute to treatment approaches in locally recurrent, oligometastatic or palliative patients.

Surgery for Locally Recurrent Rectal Cancer: Tips, Tricks, and Pitfalls

Rectal cancer can recur locally in up to 10% of the patients who undergo definitive resection for their primary cancer. Surgical salvage is considered appropriate in the curative setting as well as select cases with palliative intent. Disease-free survival following salvage resection is dependent upon achieving an R0 resection margin. A clear understanding of applied surgical anatomy, appropriate preoperative planning, and a multidisciplinary approach to aggressive soft tissue, bony, and vascular resection with appropriate reconstruction is necessary. Technical tips, tricks, and pitfalls that may assist in managing these cancers are discussed and the roles of additional boost radiation and intraoperative radiation therapy in the management of such cancers are also discussed.

HMGB1 knockdown effectively inhibits the progression of rectal cancer by suppressing HMGB1 expression and promoting apoptosis of rectal cancer cells

Rectal cancer is a malignant gastrointestinal tumor, which is associated with high morbidity and mortality. High‑mobility group protein 1 (HMGB1) is widely present in the nucleus of eukaryotic cells, and is highly conserved between humans and rodents. Recently, HMGB1 has been reported to be involved in the progression and metastasis of human cancer; however, its role in the development and metastasis of human rectal cancer remains unclear. The present study detected the expression levels of HMGB1 in pathological specimens from patients with clinically identified rectal cancer using immunohistochemistry and western blotting. The results demonstrated that HMGB1 was highly expressed in samples from patients with rectal cancer. The positive rate of HMGB1 in rectal cancer tissues was 96.08% (49/51), which was significantly higher compared with 3.92% (2/51) in normal tissues. In addition, western blotting indicated that HMGB1 was distributed and located not only in the nucleus, but also in the cytoplasm of colorectal cancer cells. HMGB1‑specific short hairpin (sh)RNA was used to silence the endogenous expression of HMGB1 in colorectal cancer cells. A functional assay demonstrated that knockdown of endogenous HMGB1 expression significantly inhibited the proliferation of SW620 and Colo320 cells. Furthermore, western blotting revealed that knockdown of endogenous HMGB1 expression contributed to activation of caspase‑3 and the substrate poly (ADP‑ribose) polymerase. The expression levels of B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein (Bax) were also detected by western blotting. As expected, decreased levels of Bcl‑2 and increased levels of Bax were detected in the HMGB1 shRNA‑transfected colorectal cancer cells, and the Bax/Bcl‑2 ratio was increased in HMGB1 shRNA‑transfected cells. These data indicated that HMGB1 may act as an oncogene in rectal cancer, and knockdown of endogenous HMGB1 expression may significantly inhibit the proliferation of colorectal cancer cells and promote apoptosis of tumor cells. Further research regarding the mechanisms underlying the effects of HMGB1 on the progression of rectal cancer may provide novel targets for the treatment of rectal cancer, and provide a theoretical reference for clinical treatment.

Efficacy and toxicity of rectal cancer reirradiation using IMRT for patients who have received prior pelvic radiation therapy

Purpose

Locally recurrent rectal cancer may cause significant morbidity. Prior reports of rectal cancer reirradiation following local recurrence suggest treatment efficacy, with variable rates of late toxicity. Modern techniques including intensity modulated radiation therapy (IMRT) may improve the therapeutic index. We report outcomes for pelvic reirradiation as treatment for rectal cancer using IMRT.

Methods and materials

The records of 31 patients undergoing reirradiation for rectal cancer between 2004 and 2013 were reviewed. All patients underwent IMRT using an accelerated hyperfractionation (39 Gy in 1.5-Gy fractions delivered twice daily, n=15) or once-daily fractionation technique (median dose, 30.4 Gy; range, 27-40 Gy in 15-22 fractions; n = 16). The median cumulative dose was 77 Gy (range, 59-113), and the median interval from prior pelvic radiation therapy was 39.8 months (range, 10.1-307.6). Treatment intent was palliative in 20 patients and neoadjuvant or adjuvant in 11 patients. Surgery was generally reserved for patients with an isolated local recurrence. Concurrent chemotherapy was administered for 25/31 patients, most frequently capecitabine (n=11) or continuous infusion 5-fluorouracil (n=10).

Results

Median follow-up was 11.3 months. The prescribed treatment was completed in 29/31 patients (93.5%). Among 18 patients with symptoms attributable to recurrent disease, successful palliation was achieved in 10/18 (55.6%). The rate of grade 2 and grade 3 acute toxicities was 32.3% and 3.2%, respectively. Local control rates at 1 and 2 years were 61.3% and 47.3%, respectively. Median overall survival was 21.9 months, and 1-year survival was 66.7% for patients who had surgical resection versus 58.7% for those who did not (P = .0802).

Conclusions

Rectal cancer reirradiation using IMRT is well-tolerated in the setting of prior pelvic radiation therapy. Given significant risk of local progression, further dose escalation may be warranted for patients with life expectancy exceeding 1 year.

Feasibility and response of helical tomotherapy in patients with metastatic colorectal cancer

Purpose

To investigate the treatment outcome and the toxicity of helical tomotherapy (HT) in patients with metastatic colorectal cancer (mCRC).

Materials and Methods

We retrospectively reviewed 18 patients with 31 lesions from mCRC treated with HT between 2009 and 2013. The liver (9 lesions) and lymph nodes (9 lesions) were the most frequent sites. The planning target volume (PTV) ranged from 12 to 1,110 mL (median, 114 mL). The total doses ranged from 30 to 70 Gy in 10-30 fractions. When the α/β value for the tumor was assumed to be 10 Gy for the biologically equivalent dose (BED), the total doses ranged from 39 to 119 Gy₁₀ (median, 55 Gy₁₀). Nineteen lesions were treated with concurrent chemotherapy (CCRT).

Results

With a median follow-up time of 16 months, the median overall survival for 18 patients was 33 months. Eight lesions (26%) achieved complete response. The 1- and 3-year local progression free survival (LPFS) rates for 31 lesions were 45% and 34%, respectively. On univariate analysis, significant parameters influencing LPFS rates were chemotherapy response before HT, aim of HT, CCRT, PTV, BED, and adjuvant chemotherapy. On multivariate analysis, PTV ≤113 mL and BED >48 Gy₁₀ were associated with a statistically significant improvement in LFPS. During HT, four patients experienced grade 3 hematologic toxicities, each of whom had also received CCRT.

Conclusion

The current study demonstrates the efficacy and tolerability of HT for mCRC. To define optimal RT dose according to tumor size of mCRC, further study should be needed.

Rectal Radiotherapy--Intensity-modulated Radiotherapy Delivery, Delineation and Doses

The use of intensity-modulated radiotherapy in rectal cancer is attractive in that it may reduce acute and late toxicities and potentially facilitate dose escalation. Intensity-modulated radiotherapy probably has a role in selected patients, but further investigation is required to identify the parameters for selection. Delineation of specific nodal groups allows maximal sparing of bladder and small bowel. In locally advanced tumours a simultaneous integrated boost allows dose escalation incorporating hypofractionation and a shorter overall treatment time. However, due to a sparsity of data on late toxicity in doses ≥ 60 Gy, doses at this level should be used with caution, ideally within prospective trials. Future studies investigating dose escalation must ascertain late toxicity as well as local control, as both can significantly affect quality of life and without both, the risk-benefit ratio cannot be calculated.

Phase II study of computed tomography-guided (125)I-seed implantation plus chemotherapy for locally recurrent rectal cancer

BACKGROUND AND PURPOSE

This trial evaluated the efficacy and safety of CT guided (125)I-seed implantation (CTII) plus chemotherapy with fluorouracil, leucovorin, and irinotecan (FOLFIRI) compared with FOLFIRI alone as second-line treatment for locally recurrent rectal cancer (LRRC).

MATERIAL AND METHODS

Patients with LRRC who received one prior chemotherapy regimen were enrolled and divided randomly assigned to FOLFORI alone (Arm A) and FOLFORI plus CTII (Arm B). The primary endpoint was local control time (LCT). Overall survival (OS) and treatment related adverse events (TRAEs) were also observed.

RESULTS

Fifty-seven patients were enrolled from October 2008 and December 2014. Twenty-seven were assigned into Arm A and 30 into Arm B. The overall response rate of locally recurrent tumor was improved to 100% in Arm B versus 29.6% in Arm A (P<0.001). A significant longer LCT was observed in Arm A (P<0.001); median LCT was 12 months in Arm B versus 4 months in Arm A. A borderline significant improvement in OS was also observed in Arm B (P=0.0464); median OS was 25 months in Arm B versus 19 months in Arm A. For patients without distant metastases, median OS was 37 months in Arm B versus 21 months in Arm A (P=0.0101). For patients with (neo)adjuvant radiotherapy (ART), a longer LCT and OS were also found in Arm B (P<0.001 and P=0.0217, respectively). TRAEs were not serious generally. There was no statistically significant difference in treatment related toxicity between Arm A and B both for all patients and patients receiving ART.

CONCLUSIONS

CTII plus FOLFIRI improves the LCT with tolerable toxicities as a second-line treatment in patients with local recurrent rectal cancer, and is helpful to prolong the OS, particularly in patients without distant metastases or with a history of radiotherapy.

Intraoperative radiation therapy (IORT) for gynecologic malignancies

Every year almost 95,000 women are diagnosed with a gynecologic malignancy and over 28,000 women will succumb to their disease. For patients with an isolated locoregional recurrence after primary therapy, surgical resection may sometimes provide a chance of cure. To optimize the chance of local control intraoperative radiation therapy (IORT) has been used. The combination of salvage surgery and IORT has resulted in reasonable control in the IORT field. The addition of external beam radiation to limited volumes seems to result in improved disease control over surgery and IORT alone. Side effects are closely related to radical surgery, although neuropathy is seen more frequently after IORT; especially if doses of >20Gy are prescribed. Margin status remains critical, even with IORT.