Patients with early and advanced seminoma have at least a 95% and an 80% chance of cure, respectively. Since the mid-1970s, radiation therapy for early seminoma and chemotherapy for advanced seminoma have usually achieved cure. The confidence engendered by this success has led to the exploration of less intensive strategies of treatment for stage I seminoma (see Chapter 18). However, the relatively standard treatment approaches mentioned above remain the most widely used strategies for the treatment of most patients with this disease.
A radiobiologic doctrine is that oxygenation and active cell division are prerequisites for radiosensi-tivity. Although seminoma of the testicle is neither very vascular nor rapidly growing, it is most radiosensitive and radiocurable at a relatively low dose of 25 to 30 Gy in fractions of 160 to 180 cGy, using 5 fractions per week.
Many tumors are staged by the size of the primary or the extent of histopathologic invasion. However, the size of seminomas has not been a strong predictor for survival. A unique characteristic of seminoma is its ability to reach sizes greater than 2 cm without metastasizing. It is often not a locally invasive cancer as it may grow to a large size without extending through the tunica albuginea. Spread occurs along lymphatics that follow the spermatic cord to end in the aortocaval lymph nodes alongside of lumbar vertebrae 1 to 3 for the right testicle and lumbar vertebrae 1 to 2 for the left testicle (see Chapter 3). Bipedal lymphography has been definitive in showing these nodes, but the primary drainage from seminoma of the left testicle, located at the level of the left renal vein, near the renal hilus, is often not opacified (unless the testicle has been injected with dye). However, the discomfort of this technique and the difficulties of reproducing high-quality films after each procedure have led to its replacement by less invasive strategies. Computerized tomography (CT) of this region has solved this disparity and may even show lateral deviation of the left ureter when this left "renal vein" node is enlarged (Figures 19-1 and 19-2).
Before the advent of curative chemotherapy, radiation was used to treat all patients with semino-mas. Palpable abdominal masses were given abdominal irradiation, and the portal size was reduced after tumor shrinkage. The goal was to limit the dose to
the kidneys to 20 Gy and to deliver 30 Gy to the para-aortic nodes (Figure 19-3). Modifications of this "shrinking-field" technique were also used to treat para-aortic nodes larger than 5 cm, which often overlay one-half of the kidney or kidneys (Figures 19-4 and 19-5). In addition, mediastinal and left supraclavicular ports were added. Clinicians knew that extensive infradiaphragmatic disease meant a higher probability of undetectable supradiaphragmatic disease (Table 19-1). Although the cisterna chyli drains mainly to the left supraclavicular nodes, the right supraclavicular node may be a drainage site in 10% of patients.1
Currently, most advanced presentations (nodes > 5 cm) are often referred for treatment with chemotherapy. The practice of irradiating the bilateral iliac lymph node regions (common plus external iliac) and/or the homolateral hemiscrotum has decreased.2 The iliac nodes are rarely involved unless large para-aortic nodes are present. The 2-3% risk of local recurrence in the hemiscrotum that housed the primary tumor has been exaggerated.3,4 The practice of irradiating the iliac nodes after a herniorrhaphy or orchiopexy is justified although the probability of these nodes having disease is low (10-13%), despite the altered lymphatics5 (Figure 19-6). The stratagem of irradiating the contralateral testicle (to 20 Gy) to prevent a second primary seminoma has been successful at the Christie Hospital in Manchester, England, but has not been a common practice,6 predominantly because of the relatively low rate (4-5%) of second testicular malignancies without added therapy.
Was this article helpful?
Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.