Interstitial brachytherapy as a boost to patients with anal carcinoma and poor response to chemoradiation: Single-institution long-term results

Brachytherapy for rectal and anal cancer: Where are we and current perspectives?

Anal and rectal cancers were some of the first disease sites treated with brachytherapy due to the anatomic ease of implantation. As external beam radiotherapy grew in popularity the use of ano-rectal brachytherapy declined. However, the past few years have seen a steady resurgence in the use of brachytherapy in the ano-rectum supported by the use of large clinical series and randomized trials. The increasing acceptance by the surgical community of organ preservation as a valid treatment strategy for rectal cancer has encouraged the use of nonsurgical approaches and brachytherapy has shown itself to be a valuable tool for this. The current role of anal and rectal brachytherapy is presented with perspectives on its future use.

The impact of brachytherapy boost for anal canal cancers in the era of de-escalation treatments

PURPOSE

To analyze clinical outcomes of high-dose-rate (HDR) interstitial brachytherapy boost (ISBT) after external beam radiation therapy (EBRT) or chemoradiotherapy (CRT) for the treatment of anal canal cancers (ACC).

METHODS AND MATERIALS

A total of 78 patients with ACC were treated at our institution by ISBT. Local Control (LC), disease-free survival (DFS), overall survival (OS), colostomy-free survival (CFS) and toxicity rates were analyzed.

RESULTS

With a median followup (FU) of 59.8 months (95% CI [55.8-64.2]), six (7.7%) local recurrences with 2 patients (2.6%) having persistent disease at 3 months were observed. The 5-year rate of LC for the entire population was 92% [83-96%]. The 5-year DFS rate was 86% [76-93%]. The 5-year OS was 96% [88-99%]. In the univariate analysis, chemotherapy was significantly associated with morbidity grade ≥2. Late digestive toxicity grade ≥3 was reported in 8.9% patients, 1 patient underwent colostomy due to toxicity. The 5-year CFS rate was 88% [79-94%].

CONCLUSIONS

HDR interstitial brachytherapy boost provide excellent rates of tumor control and colostomy-free survival with a favorable profile of GI toxicity. Continence in anal cancer survivors is a challenge and the boost technique must be discussed in a multidisciplinary approach as part of de-escalation treatments.

Brachytherapy boost in anal canal cancer - A GEC ESTRO PDR task force meta-analysis

Purpose

A meta-analysis is presented comparing clinical outcomes and toxicities between high dose rate (HDR) and pulsed dose rate (PDR) brachytherapy (BT) for anal cancer.

Methods and material

Retrospective or prospective clinical trials were identified on electronical databases. Data were collected per Preferred Reporting Items for Systematic Reviews and meta-Analyses guidelines. Pooled effect size for HDR and PDR BT were compared using subgroup analyses.

Results

Nine retrospective studies with a total of 481 patients treated were included of which 219 with HDR and 262 with PDR. Significant differences were observed between the two groups for baseline characteristics and treatment. The cumulative proportion of stage T3-T4 was lower in the HDR group, 0.15 [95 % confidence interval (CI) 0.07-0.29] vs 0.27 [95 %CI 0.09-0.57] in the LDR group, p < 0.001. Lower BT doses (in equivalent 2-Gy fraction dose) were given for patients in the HDR group, 11.9 Gy [95 %CI 8.2-15.5] vs 19.5 Gy [95 %CI 15.0-24.0] in the PDR group, p < 0.001. No significant differences were found for clinical outcomes or toxicities. The pooled effect size of the overall survival at 5 years for HDR and PDR was respectively 0.82 [95 %CI 0.70-0.94] and 0.82 [95 %CI 0.73-0.91], p > 0.99. The 5 years local control was 0.86 [95 % confidence interval (CI) 0.81-0.91] and 0.83 [95 %CI 0.77-0.89], p = 0.62. Cumulative toxicity-related colostomy proportion was 0.04 [95 %CI 0.02-0.09] and 0.03 [95 %CI 0.02-0.07], p = 0.85.

Conclusion

Both modalities provided a good profile of tolerance and are effective organ conservative strategies for patients with anal canal cancer. In parallel with ongoing developments to better determine the optimal fractionation and dose for HDR-BT treatments, especially in large tumors, PDR BT still has a crucial role for dose escalation strategy in advanced cases.

Gastrointestinal Brachytherapy

Brachytherapy is a sophisticated and proven treatment technique of different GI localizations. Here the development of GI- brachytherapy of last 20 years, current position and the perspectives for next years are discussed. In summary: The GI-brachytherapy of different localizations is very effective, in experienced hands a safe technique and should be part of armamentarium of every radiation oncologist.

Current treatment and future directions in the management of anal cancer

Although rare, the rate of squamous cell carcinoma of the anus (SCCA) is rising globally. Most patients present with nonmetastatic disease and are curable with appropriate treatment, which has evolved significantly over the last several decades. Before the 1970s, SCCA was managed with radical surgery, resulting in a permanent colostomy. Researchers found that preoperative treatment with chemotherapy and concurrent radiation could achieve a pathologic complete response. After this observation, definitive therapy shifted from radical surgery to sphincter-preserving chemoradiation. Investigations into the necessity of chemotherapy and the optimal regimen found that chemotherapy with mitomycin-C and 5-fluorouracil is required for cure. Further studies evaluating the addition of induction or maintenance chemotherapy, monoclonal antibody therapy, or higher radiation doses have demonstrated no significant benefit to disease control. Advanced radiation delivery with intensity-modulated radiotherapy techniques is now considered the standard of care because of its prospectively determined, favorable acute toxicity profile compared with 3-dimensional conformal radiation. It is important to note that chemoradiation treatment response may be slow (up to 26 weeks) and should be assessed through serial clinical examinations. Today, surgical management of SCCA is reserved only for the lowest risk, early stage tumors or for recurrent/persistent disease. Current studies are evaluating radiation dose de-escalation in early stage disease and radiation dose escalation and the addition of immune checkpoint inhibitors in locally advanced cancers. In reviewing how and why modern-day treatment of SCCA was established, the objective of this report is to reenforce adherence to current treatment paradigms to assure the best possible outcomes for patients.

Pulse-dose-rate interstitial brachytherapy in anal squamous cell carcinoma: clinical outcomes and patients' health quality perception

Purpose

To examine clinical outcomes and quality of life of patients with anal squamous cell carcinoma treated with interstitial pulsed-dose-rate brachytherapy (PDR-BT) with a boost to residual tumor after external radiotherapy.

Material and methods

Medical records of patients receiving a brachytherapy boost after radiotherapy for anal squamous cell carcinoma in our Institute between 2008 and 2019 were retrospectively reviewed. After receiving pelvic irradiation ± concurrent chemotherapy, patients received PDR-BT boost to residual tumor, in order to deliver a minimal total dose of 60 Gy. Patients’ outcomes were analyzed, with primary focus on local control, sphincter preservation, morbidity, and quality of life.

Results

A total of 42 patients were identified, included 24, 13, and 5 patients with I, II, and III tumor stages, respectively. Median brachytherapy (BT) dose was 20 Gy (range, 10-30 Gy). Median dose per pulse was 42 cGy (range, 37.5-50 cGy). With median follow-up of 60.4 months (range, 5.4-127.4 months), estimated local control and colostomy-free survival rates at 5 years were both 88.7% (95% CI: 67.4-96.4%). The largest axis of residual lesion after external beam radiation therapy (EBRT) and poor tumor shrinkage were associated with more frequent relapses (p = 0.02 and p = 0.007, respectively). Out of 40 patients with more than 6 months follow-up, only one experienced severe delayed toxicity (fecal incontinence). Health quality perception was very good or good in 20 of 22 (91%) patients, according to their replies of quality-of-life surveys. A total dose ≥ 63 Gy was associated with higher number of anorectal grade 1+ toxicities (n = 1.5 vs. n = 0.61, p = 0.02).

Conclusions

In this cohort of 42 patients with mainly I and II tumor stages, PDR-BT boost allowed for local control in 88.7% of patients, with only one grade 3 anorectal toxicity.

Management of anal cancer patients - a pattern of care analysis in German-speaking countries

Background

Radiotherapy dose and target volume prescriptions for anal squamous cell carcinoma (ASCC) vary considerably in daily practice and guidelines, including those from NCCN, UK, Australasian, and ESMO. We conducted a pattern-of-care survey to assess the patient management in German speaking countries.

Methods

We developed an anonymous questionnaire comprising 18 questions on diagnosis and treatment of ASCC. The survey was sent to 361 DEGRO-associated institutions, including 41 university hospitals, 118 non-university institutions, and 202 private practices.

Results

We received a total of 101 (28%) surveys, including 20 (19.8%) from university, 36 (35.6%) from non-university clinics, and 45 (44.6%) from private practices. A total of 28 (27.8%) institutions reported to treat more than 5 patients with early-stage ASCC and 42 (41.6%) institutions treat more than 5 patients with locoregionally-advanced ASCC per year.

Biopsy of suspicious inguinal nodes was advocated in only 12 (11.8%) centers. Screening for human immunodeficiency virus (HIV) is done in 28 (27.7%). Intensity modulated radiotherapy or similar techniques are used in 97%. The elective lymph node dose ranged from 30.6 Gy to 52.8 Gy, whereas 87% prescribed 50.4–55. 8 Gy (range: 30.6 to 59.4 Gy) to the involved lymph nodes. The dose to gross disease of cT1 or cT2 ASCC ranged from 50 to ≥60 Gy. For cT3 or cT4 tumors the target dose ranged from 54 Gy to more than 60 Gy, with 76 (75.2%) institutions prescribing 59.4 Gy. The preferred concurrent chemotherapy regimen was 5-FU/Mitomycin C, whereas 6 (6%) prescribed Capecitabine/Mitomycin C. HIV-positive patients are treated with full-dose CRT in 87 (86.1%) institutions. First assessment for clinical response is reported to be performed at 4–6 weeks after completion of CRT in 2 (2%) institutions, at 6–8 weeks in 20 (19.8%), and 79 (78%) institutions wait up to 5 months.

Conclusions

We observed marked differences in radiotherapy doses and treatment technique in patients with ASCC, and also variable approaches for patients with HIV. These data underline the need for an consensus treatment guideline for ASCC.

Efficacy and tolerance of high-dose-rate brachytherapy boost after external radiotherapy in the treatment of squamous cell carcinoma of the anal canal

Purpose

The aim of this study was to evaluate the efficacy and toxicity of high-dose-rate brachytherapy (HDR-BT) boost in anal squamous cell carcinoma (ASCC).

Material and methods

This was a monocentric retrospective study involving patients treated by external irradiation (± chemotherapy), with HDR-BT boost, for a localized ASCC. Clinical evaluation was performed every six months. Oncological results were analyzed with: local relapse-free survival (LRFS), colostomy-free survival (CFS), metastatic-free survival (MFS), disease-free survival (DFS), and overall survival (OS). Acute and late toxicities were collected (CTCV4.0) and LENT/SOMA score was performed.

Results

From May 2005 to January 2018, 46 patients (pts) were analyzed. The median follow-up was 61 months (10-145 months), the median age was 65 years (34-84 years), with a sex ratio M/F = 0.24. The TNM classification was as follows: T1 - 13 pts (21.7%), T2 - 34 pts (73.9%), T3 - 2 pts (4.3%), N+ - 6 pts (13.1%). External beam radiotherapy (EBRT) delivered a median dose of 45 Gy (36-50.4 Gy) in 25 fractions, and HDR-BT 12 Gy (10-18 Gy) in 3 fractions. The median overall treatment time (OTT) was 58 days (41-101 days), with a median EBRT/brachytherapy interval of 17 days (4-60 days). Oncological findings showed 5-year rates of LRFS 81.2%, MFS 88.7%, DFS 70%, and OS 90%. All abdominoperineal amputations were performed in case of local relapse (4 pts, 8.7%), leading to a 5-year CFS of 79.5%. Acute urinary toxicities were frequent (G1 41.3%, G2 4.3%). The acute digestive toxicities were: G1 71.7%, G2 6.5%, and G3 2.2%. The late urinary toxicities were: G1 4.3%, G2 2.2%, and G3 2.2%. Late digestive toxicities were: G1 56.5%, G2 8.7%, G3 2.2%, and G4 2.2%.

Conclusions

In ASCC management, HDR-BT boost appears to be a treatment with a long-term acceptable toxicity profile, shorter than EBRT boost, with a reduction of side effects.

Brachytherapy boost after chemoradiation in anal cancer: a systematic review

Radio-chemotherapy (RCT) is the primary treatment of anal cancer (AC). However, the role and the optimal total dose of a radiation boost is still unclear. No randomized controlled trials nor systematic reviews have been performed to analyze the efficacy of brachytherapy (BRT) as boost in AC. Therefore, we performed this systematic review based on PRISMA methodology to establish the role of BRT boost in AC.

A systematic search of the bibliographic databases: PubMed, Scopus, and Cochrane library from the earliest possible date through January 31, 2018 was performed. At least one of the following outcomes: local control (LC), loco-regional control (LRC), overall survival (OS), disease-free survival (DFS), or colostomy-free survival (CFS) had to be present for inclusion in this systematic review in patients receiving a BRT boost. Data about toxicity and sphincter function were also included.

Ten articles fulfilled the inclusion criteria. All the studies had retrospective study design. All studies were classified to provide a level of evidence graded as 3 according to SIGN classification. Median 5-year LC/LRC, CFS, DFS, and OS were: 78.6% (range, 70.7-92.0%), 76.1% (range, 61.4-86.4%), 75.8% (range, 65.9-85.7%), and 69.4% (63.4-82.0%), respectively. The reported toxicities were acceptable.

RCT is the treatment cornerstone in AC. High-level evidences from studies on BRT boost in AC are lacking. Further studies should investigate: efficacy of BRT boost in comparison to no boost and to external beam boost, patients who can benefit from this treatment intensification, and optimal radiation dose.