Scrotal Irradiation in Primary Testicular Lymphoma: Review of the Literature and In Silico Planning Comparative Study
A partir d'une revue de la littérature publiée jusqu'en mai 2012 (14 études, 439 patients), d'une enquête téléphonique auprès de radio-oncologues et de physiciens médicaux de 21 instituts néerlandais de radiothérapie et d'une étude comparative in silico, cette étude analyse les recommandations en matière de radiothérapie adjuvante du scrotum pour traiter un lymphome primitif du testicule
We examined adjuvant irradiation of the scrotum in primary testicular lymphoma (PTL) by means of a literature review in MEDLINE, a telephone survey among Dutch institutes, and an in silico planning comparative study on scrotal irradiation in PTL. We did not find any uniform adjuvant irradiation technique assuring a safe planning target volume (PTV) coverage in published reports, and the definition of the clinical target volume is unclear. Histopathologic studies of PTL show a high invasion rate of the tunica albuginea, the epididymis, and the spermatic cord. In retrospective studies, a prescribed dose of at least 30 Gy involving the scrotum is associated with best survival. The majority of Dutch institutes irradiate the whole scrotum without using a planning computed tomography scan, with a single electron beam and a total dose of 30 Gy. The in silico planning comparative study showed that all evaluated approaches met a D95% scrotal dose of at least 85% of the prescription dose, without exceeding the dose limits of critical organs. Photon irradiation with 2 oblique beams using wedges resulted in the best PTV coverage, with a mean value of 95% of the prescribed dose, with lowest maximum dose. Adjuvant photon or electron irradiation of the whole scrotum including the contralateral testicle with a minimum dose of 30 Gy is recommended in PTL. Computed tomography-based radiation therapy treatment planning with proper patient positioning and position verification guarantees optimal dose coverage.
International Journal of Radiation Oncology, Biology, Physics 2012