The Impact of a Rectal Spacer in VMAT Dosimetry in the Treatment of Prostate Cancer
Source abstract
Abstract
Although the dosimetric advantages of rectal spacers in prostate cancer radiotherapy have been demonstrated in selected clinical trials, real-world data from routine clinical practice remain limited—particularly within the Portuguese healthcare system. This study offers a detailed dosimetric comparison of Volumetric Modulated Arc Therapy (VMAT), with and without rectal spacer use, in a real-world patient cohort, aiming to assess the clinical relevance of spacer insertion under standard treatment protocols. A retrospective dosimetric evaluation was performed on 80 prostate cancer patients treated at a radiotherapy centre in southern Portugal. Patients were equally divided into two matched groups (n = 40): one receiving VMAT alone, the other receiving VMAT with hydrogel rectal spacer placement. Dose-volume histograms (DVHs) were analysed for the planning target volume (PTV) and key organs at risk (OARs). Standard dosimetric metrics, such as V50–V75 for the rectum and bladder, V50 for femoral heads, and mean dose for the penile bulb, were assessed. PTV coverage was evaluated using conformity and homogeneity indices. Spacer use significantly decreased rectal dose exposure across all evaluated parameters without compromising PTV coverage or increasing dose to other OARs. These findings support routine rectal spacer applications to enhance treatment safety and patient outcomes.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Prostate Cancer Diagnosis and Treatment · Advanced Radiotherapy Techniques · Prostate Cancer Treatment and Research
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
PhD Programme in Nanoscience and Biomedicine, University of Vigo, Circunvalación ao Campus Universitario, 36310 Vigo, Pontevedra, Spain
Escola Superior de Saúde, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida 400, 4200-072 Porto, Portugal
Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Center, Portuguese Oncology Institute of Porto, Rua Dr. António Bernardino de Almeida, 4200-072 Porto, Portugal
FCS-UFP, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Rua Carlos da Maia, 296, 4200-150 Porto, Portugal
FP-I3ID, FP-BHS, Universidade Fernando Pessoa, Praça de 9 de Abril 349, 4249-004 Porto, Portugal
RISE-Health, Escola de Medicina e Ciências Biomédicas, Universidade Fernando Pessoa, Fundação Ensino e Cultura Fernando Pessoa, Avenida Fernando Pessoa, 150, 4420-096 Gondomar, Portugal
Medical Physics Service, Portuguese Oncology Institute of Porto, Rua Dr. António Bernardino de Almeida, 4200-072 Porto, Portugal
Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
Joaquim Chaves Saúde | Clínica de Radioncologia do Algarve, Rua da Associação Oncológica do Algarve do, 8000-316 Faro, Portugal
Psychology Service, Instituto Português Oncologia do Porto (IPO PORTO), Rua Dr. António Bernardino de Almeida 400, 4200-072 Porto, Portugal
NeuroCog-Centro de Reabilitação da Lesão Cerebral, Rua das Atividades Económicas, 2625-387 Lisboa, Portugal
Centre of Linguistics of the University of Lisbon (CLUL), Universidade de Lisboa, 1600-214 Lisboa, Portugal
RISE-HEALTH—Polo de Gestão, Escola Superior de Saúde, Instituto Politécnico do Porto, 4200-072 Porto, Portugal
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