Abstract
Objective To estimate the incidental radiation dose delivered to the testicles in three-dimensional
conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), and volumetric-modulated
arc therapy (VMAT) in rectal cancer patients and its impact on sexual activity using
a quality-of-life questionnaire.
Materials and Methods The present study included 40 male patients, aged between 25 and 50 years. with locally-advanced
rectal cancer, who would undergo neoadjuvant radiotherapy at a dose of 45 Gray (Gy)
in 25 fractions (fr) in the supine position. Planning was performed for three techniques:
3DCRT, IMRT, and VMAT. The testicular dose, testicular volume, planning target volume
(PTV), the distance of the tumor from the anal verge, and tumor thickness and length
in each plan were recorded. A quality-of-life questionnaire pertaining only to sexual
activity by the European Organization for Research and Treatment of Cancer–Quality
of Life in Colorectal (EORTC QLQ-CR29) and the Functional Assessment of Cancer Therapy–Colorectal
(FACT-C) were used to assess the posttreatment effect on sexual life.
Results The mean values for tumor length, thickness, and PTV were of 8.9 cm, 1.77 cm and
1,352 cm3 respectively. The mean dose to the right and left testicles (in centigray, cGy) were
as follows: 3DCRT – 336.23 and 206.65; IMRT – 165.15 and 140.25; and VMAT – 209.2
and 229.2 respectively. A significant correlation was observed involving the PTV and
testicular volume and the incidental testicular dose received. The questionnaire-based
analysis of sexual activity included 31 patients who were alive, of whom 27 had resumed
their normal sexual life 3 months after the treatment without difficulty (score 4).
Conclusion The IMRT showed a significant reduction in the testicular dose when compared to 3DCRT
and VMAT. The PTV and testicular volume presented a statistically significant impact
on the testicular dose, and the main reason for abstinence was nervousness about disease
recurrence.
Keywords
quality of life - toxicity - testis - rectal Neoplasms - radiotherapy - conformal
Bibliographical Record
Poornachandra Tejaswi-Siddappa, Shamsundar Sunkappa, Jagannath Kunigal-Puttaswamy,
Aradhana Katke, Nanda Ramanand, Thejaswini Boraiah. Impact of Treatment Technique
on Testicular Dose and Sexual Activity in Rectal Cancer Patients. Brazilian Journal
of Oncology 2024; 20: s00441791981.
DOI: 10.1055/s-0044-1791981
