Modeling of High-Grade Hematologic Toxicity in Anal Cancer Patients Treated With Intensity Modulated Proton Therapy (IMPT) and Volumetric Modulated Arc Therapy (VMAT)

Meier, Teresa; Mascia, Anthony; Wolf, Eric; Kharofa, Jordan

doi:10.1016/j.ijrobp.2016.06.955

Cited by 4 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Early data show promising reductions to small bowel and bone marrow, suggesting that GI and hematologic toxicity may improve (58,59,61,62). Modeling by Meier et al shows reduction in grade 3+ hematologic toxicity with IMPT, as implied by other treatment-planning studies (62,63). Long-term clinical studies will be needed to discern the incremental benefit offered by these advanced techniques relative to passive scatter PBT.…”

Section: Future Directionsmentioning

confidence: 78%

“…Long-term studies of PBT for prostate and breast cancer predict minimal late toxicity and excellent disease control (67,68). In the case of anorectal cancer, PBT may reduce hematologic toxicity compared to IMRT, as suggested by Meier et al (63). With 30-40% of patients recurring in 10 years and potentially requiring salvage chemotherapy, minimizing bone marrow exposure with PBT may be of substantial benefit (4,69).…”

Section: Future Directionsmentioning

confidence: 98%

See 1 more Smart Citation

Proton beam radiotherapy for anal and rectal cancers

Vaios¹,

Wo²

2020

J Gastrointest Oncol

View full text Add to dashboard Cite

This review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (1). Eligibility criteria included published work evaluating treatment plans and clinical outcomes of proton radiation therapy for anal or rectal cancer. Sources of information for this review included PubMed and EMBASE, those found in references from the major articles identified, and articles known to the authors. The searches were conducted to identify any and all articles addressing clinical outcomes of proton radiotherapy for anal or rectal neoplasms in adults with the following headings: protons, proton radiation therapy, proton beam therapy (PBT), pencil-beam, intensitymodulated PBT (IMPT), anal, anal cancer, rectal, or rectal cancer. Due to the limited amount of overall data, search terms were not restricted by publication year or number of patients. Searches were completed by October 4th, 2018.Based on the initial searches, a total of 575 articles and abstracts were identified. Care was taken to ensure that the inclusion criteria were sufficiently broad. To avoid missing potentially relevant publications, sources were excluded by individual screening rather than the initial database search. After duplicates were removed and the papers were independently screened for the described criteria, a further 528 studies were excluded. Articles without specific assessment of dosimetry or clinically relevant outcomes (e.g., survival, toxicity) of proton radiation therapy (RT) for anorectal cancers in adults were excluded. Of the 47 publications remaining, 17 review articles and 30 original investigations (15 published articles, 11 abstracts, and 4 case

show abstract

Section: Future Directionsmentioning

confidence: 78%

Section: Future Directionsmentioning

confidence: 98%

Proton beam radiotherapy for anal and rectal cancers

Vaios¹,

Wo²

2020

J Gastrointest Oncol

View full text Add to dashboard Cite

show abstract

“…With equivalent target coverage, PBS proved to spare the bowels, bladder, femoral heads, and iliac crests to a greater degree across different dose ranges. Other studies confirmed better OAR sparing with PBS, when compared to IMRT [ 79 , 80 ] or VMAT [ 81 , 82 , 83 ]. For example, Meier et al demonstrated that IMPT significantly decreased the mean dose to the bone marrow when compared to VMAT (17.42 Gy vs. 30.76 Gy, p < 0.0001), and this translated into a predicted decrease in Grade 3+ hematologic events from 40% to <5% as per the NTCP model for bone marrow toxicity [ 81 ].…”

Section: Anorectal Cancermentioning

confidence: 81%

Proton Therapy in the Management of Luminal Gastrointestinal Cancers: Esophagus, Stomach, and Anorectum

Kobeissi

Simone

Hilal

et al. 2022

Cancers

View full text Add to dashboard Cite

While the role of proton therapy in gastric cancer is marginal, its role in esophageal and anorectal cancers is expanding. In esophageal cancer, protons are superior in sparing the organs at risk, as shown by multiple dosimetric studies. Literature is conflicting regarding clinical significance, but the preponderance of evidence suggests that protons yield similar or improved oncologic outcomes to photons at a decreased toxicity cost. Similarly, protons have improved sparing of the organs at risk in anorectal cancers, but clinical data is much more limited to date, and toxicity benefits have not yet been shown clinically. Large, randomized trials are currently underway for both disease sites.

show abstract

“…There was no intention to show a dose escalation effect, since data supporting the potential benefit of dose escalation are not available. Contrastingly, there are insufficient theoretical and dosimetric data supporting less toxicity when utilising PBT [ 6 , 7 , 8 , 9 , 10 ]. A significant dose reduction was documented in the pelvic organs—bowel; bladder; and genitalia, including the penile bulb.…”

Section: Discussionmentioning

confidence: 99%

“…In addition to expectable dose reduction to the bladder, small intestine, and genitalia, there was a significant reduction in pelvic bone marrow. Other comparative studies have proved a dose distribution benefit, including that observed in bone marrow, compared to volumetric arc therapy (VMAT), IMRT, and 3D conformal radiotherapy techniques [ 8 , 9 , 10 ]. The results are important, since haematological toxicity may frequently result in treatment breaks and reduced efficacy [ 3 , 11 ].…”

Section: Introductionmentioning

confidence: 99%

Pencil Beam Scanning (PBS) Intensity-Modulated Proton Therapy (IMPT) Chemoradiotherapy for Anal Canal Cancer—Single Institution Experience

Vítek

Kubeš

Vondráček

et al. 2021

Cancers

View full text Add to dashboard Cite

Background: A favourable dose distribution has been described for proton beam therapy (PBT) of anal cancer in dosimetric studies. The relationship between dosimetric parameters in bone marrow and haematologic toxicity, treatment interruptions, and treatment efficacy has also been documented. There are only few references on clinical results of PBT for anal cancer. The primary objective of the retrospective study was to assess the efficacy of pencil beam scanning intensity-modulated proton therapy (PBS IMPT) in the definitive chemoradiotherapy of anal cancer. Secondary objectives were established to identify the risks of acute chronic toxicity risks and to assess colostomy rates. Materials and methods: Patients were treated for biopsy-proven squamous cell cancer (SCC) of the anus at initial or advanced stages. Eligible patients received PBS IMPT at a single institution. Treatment was administered in two volumes: 1—tumour with margins plus involved lymph nodes; 2—regional lymph node groups: perirectal (mesorectal), obturatory, inguinal, internal, external, and common iliac. The total doses of 57.5 GyE and 45 GyE, respectively, were administered in volumes 1 and 2 in 25 fractions, 5 fractions per week, respectively (a simultaneous integrated boost). Concomitant chemotherapy cisplatinum (CDDP) plus 5-FU or CDDP plus capecitabine was administered as per protocol. The treatment effect was assessed using DRE (digital rectal examination) and MRI (magnetic resonance imaging) within the follow-up period. Toxicity was scaled using CTCAE version 4.0 criteria. Results: 39 of 41 patients treated during the period of February 2014–August 2021 were eligible for analysis. All patients completed treatment, 76.9% without interruption. The median treatment time was 35 days (32–35). The median follow-up period was 30 months, 34 patients are alive to-date, 5 patients died prior to the date of analysis, and 2 deaths were unrelated to the primary disease. The 2-year overall survival, relapse-free survival, and colostomy-free survival were 94.2%, 93.8%, and 91.0%, respectively. Complete regression was achieved in 36 patients (92.3%), partial regression was achieved in 2 (5.1%), and immediate progression at end of treatment occurred in 1 patient (2.6%). Salvage resection was indicated for two patients in partial regression and due to severe chronic dermatologic toxicity. The grade 3 and 4 haematological toxicity rates were 7.7% and 5.1%, respectively. The most frequent non-haematological acute toxicities of grade 3–4 observed were dermatitis (23.1%), diarrhoea (7.7%), and dehydration (7.7%). Chronic toxicity emerged predominantly as skin atrophy/ulceration grade 2 (26.5%) and grade 3–4 (5.8%), and radiation proctitis grade 2 (38.2%) and grade 3 (2.9%). Discussion, conclusions: This single-institution study showed the high efficacy of PBS IMPT, achieving a high rate of complete regression. The haematological acute toxicity of grade 3–4 remained low; however, the impact of altered chemotherapy (CDDP instead of mitomycin C) remains unclear. The incidence of other acute toxicities shares similarity with photon therapy investigated in large studies. The acute toxicity completely resolved in all patients, had no lethal outcomes, and never resulted in the necessity for colostomy. By contrast, it was chronic toxicity, skin ulceration, perirectal fistulation, and fibrosis that resulted in salvage surgery and/or the need for a colostomy. A challenging question remains: to what extent can PBT prevent chronic toxicity? Longer follow-up remains necessary.

show abstract

Modeling of High-Grade Hematologic Toxicity in Anal Cancer Patients Treated With Intensity Modulated Proton Therapy (IMPT) and Volumetric Modulated Arc Therapy (VMAT)

Cited by 4 publications

References 0 publications

Proton beam radiotherapy for anal and rectal cancers

Proton beam radiotherapy for anal and rectal cancers

Proton Therapy in the Management of Luminal Gastrointestinal Cancers: Esophagus, Stomach, and Anorectum

Pencil Beam Scanning (PBS) Intensity-Modulated Proton Therapy (IMPT) Chemoradiotherapy for Anal Canal Cancer—Single Institution Experience

Contact Info

Product

Resources

About