Resting on a hospital bed after a session of chemotherapy, Sudanese banker Mohamed Hasan vividly recalls the day when doctors told him he had blood cancer.

It is a shock in any country but in Sudan, where access to drugs and treatment is impaired by 20-year-old US sanctions, it can be more life-threatening.  

"It was the first week of my honeymoon when I fell sick and was admitted to hospital," Hasan, 30, told AFP as a nurse prepared him for a sponge bath.

"I never imagined it would be cancer ... it was a real tragedy."

For a year now, Hasan has been receiving treatment at the Radiation and Isotopes Centre Khartoum, the biggest state-run cancer hospital in Sudan. 

Life-saving drugs and medical equipment supplied to Sudan are theoretically exempt from Washington's complex set of trade embargoes.

But restrictions on banking transactions, exchange of technology and spare parts, and other cumbersome trade regulations have hampered treatment of patients.

The Khartoum cancer hospital is no exception. Two of its four radiation therapy machines have been broken for months and repairing them has become a nightmare, general manager Khatir Al-Alla said.

"Their spare parts have to be brought from America or Europe," Alla told AFP.

"But because of diplomatic issues we are facing problems."

Importing equipment or components directly from manufacturers is cumbersome given the restrictions on transferring funds overseas.

- Long waiting lists -Washington imposed sanctions on Khartoum in 1997 for its alleged support of Islamist militant groups. 

Al-Qaeda founder Osama bin Laden lived in Khartoum between 1992 and 1996.

Over the years, successive US administrations have tightened the sanctions, accusing Khartoum of human rights violations, particularly in the 14-year-old conflict with ethnic minority rebels in the western region of Darfur.

Relations between Washington and Khartoum have improved in recent months, officials say, and on October 12 President Donald Trump is to decide whether to lift the sanctions permanently.

But doctors say the situation remains difficult.

The Khartoum cancer hospital receives about 1,000 new patients a month, and another 500 visit daily for follow-ups.

"The waiting period is between three to four weeks... which is too long for cancer patients," Alla said. 

Frustrated with the long waiting period, Hasan now plans to seek further treatment in India.

The situation is no different at the Khartoum Breast Care Centre (KBCC), the only specialised facility in Sudan to treat breast cancer.

The clinic's mammography machine has been broken for weeks, said British-trained radiologist Dr Hania Fadl, the founder of the not-for-profit hospital.

"The problem is with the service... we don’t have proper agents to service the equipment," Fadl said.

The technicians have to come from Egypt or Kenya to fix the mammography machine, the main equipment in detecting breast cancer.

It becomes a major concern when a new patient comes to the clinic.

She might have an easily detectable lump in one breast, Fadl said, but in the absence of a mammography machine, it becomes difficult to detect if she has a small lump in the other.

"You have to have a mammogram done on the other breast ... it is mandatory," Fadl said.

"If we go blindly and do the surgery, maybe after two or three months we might find she got another one."

If the sanctions are fully lifted, repairing the machines will take less time, she said.

"If anything goes wrong ... the engineer will come and they will have spare parts locally."

Fadl's patient Ghada Mohammed Ali, 47, who underwent surgery for breast cancer, said it was a big concern.

"When we come for check-ups we find the machine broken," she said.

"I am worried because the cancer might have spread."